# HG changeset patch
# User trims
# Date 1272579507 25200
# Node ID 7b03170e1fcbbeb8aa4a56858062394b0571e8eb
# Parent  e0a1a502e402dbe7bf2d9102b4084a7e79a99a9b# Parent  90acda19b80f7374e90c3ac6a8ccd8d7a4199486
Merge

diff -r e0a1a502e402 -r 7b03170e1fcb agent/src/os/linux/ps_core.c
--- a/agent/src/os/linux/ps_core.c	Thu Apr 22 16:54:23 2010 -0700
+++ b/agent/src/os/linux/ps_core.c	Thu Apr 29 15:18:27 2010 -0700
@@ -884,9 +884,12 @@
       }
 
       // read name of the shared object
-      if (read_string(ph, (uintptr_t) lib_name_addr, lib_name, sizeof(lib_name)) != true) {
+      lib_name[0] = '\0';
+      if (lib_name_addr != 0 &&
+          read_string(ph, (uintptr_t) lib_name_addr, lib_name, sizeof(lib_name)) != true) {
          print_debug("can't read shared object name\n");
-         return false;
+         // don't let failure to read the name stop opening the file.  If something is really wrong
+         // it will fail later.
       }
 
       if (lib_name[0] != '\0') {
diff -r e0a1a502e402 -r 7b03170e1fcb agent/src/share/classes/sun/jvm/hotspot/CommandProcessor.java
--- a/agent/src/share/classes/sun/jvm/hotspot/CommandProcessor.java	Thu Apr 22 16:54:23 2010 -0700
+++ b/agent/src/share/classes/sun/jvm/hotspot/CommandProcessor.java	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2005-2008 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2005-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -494,6 +494,68 @@
                 }
             }
         },
+        new Command("revptrs", "revptrs address", false) {
+            public void doit(Tokens t) {
+                int tokens = t.countTokens();
+                if (tokens != 1 && (tokens != 2 || !t.nextToken().equals("-c"))) {
+                    usage();
+                    return;
+                }
+                boolean chase = tokens == 2;
+                ReversePtrs revptrs = VM.getVM().getRevPtrs();
+                if (revptrs == null) {
+                    out.println("Computing reverse pointers...");
+                    ReversePtrsAnalysis analysis = new ReversePtrsAnalysis();
+                    final boolean[] complete = new boolean[1];
+                    HeapProgressThunk thunk = new HeapProgressThunk() {
+                            public void heapIterationFractionUpdate(double d) {}
+                            public synchronized void heapIterationComplete() {
+                                complete[0] = true;
+                                notify();
+                            }
+                        };
+                    analysis.setHeapProgressThunk(thunk);
+                    analysis.run();
+                    while (!complete[0]) {
+                        synchronized (thunk) {
+                            try {
+                                thunk.wait();
+                            } catch (Exception e) {
+                            }
+                        }
+                    }
+                    revptrs = VM.getVM().getRevPtrs();
+                    out.println("Done.");
+                }
+                Address a = VM.getVM().getDebugger().parseAddress(t.nextToken());
+                if (VM.getVM().getUniverse().heap().isInReserved(a)) {
+                    OopHandle handle = a.addOffsetToAsOopHandle(0);
+                    Oop oop = VM.getVM().getObjectHeap().newOop(handle);
+                    ArrayList ptrs = revptrs.get(oop);
+                    if (ptrs == null) {
+                        out.println("no live references to " + a);
+                    } else {
+                        if (chase) {
+                            while (ptrs.size() == 1) {
+                                LivenessPathElement e = (LivenessPathElement)ptrs.get(0);
+                                ByteArrayOutputStream bos = new ByteArrayOutputStream();
+                                Oop.printOopValueOn(e.getObj(), new PrintStream(bos));
+                                out.println(bos.toString());
+                                ptrs = revptrs.get(e.getObj());
+                            }
+                        } else {
+                            for (int i = 0; i < ptrs.size(); i++) {
+                                LivenessPathElement e = (LivenessPathElement)ptrs.get(i);
+                                ByteArrayOutputStream bos = new ByteArrayOutputStream();
+                                Oop.printOopValueOn(e.getObj(), new PrintStream(bos));
+                                out.println(bos.toString());
+                                oop = e.getObj();
+                            }
+                        }
+                    }
+                }
+            }
+        },
         new Command("inspect", "inspect expression", false) {
             public void doit(Tokens t) {
                 if (t.countTokens() != 1) {
@@ -816,8 +878,24 @@
                     dumpType(type);
                 } else {
                     Iterator i = agent.getTypeDataBase().getTypes();
+                    // Make sure the types are emitted in an order than can be read back in
+                    HashSet emitted = new HashSet();
+                    Stack pending = new Stack();
                     while (i.hasNext()) {
-                        dumpType((Type)i.next());
+                        Type n = (Type)i.next();
+                        if (emitted.contains(n.getName())) {
+                            continue;
+                        }
+
+                        while (n != null && !emitted.contains(n.getName())) {
+                            pending.push(n);
+                            n = n.getSuperclass();
+                        }
+                        while (!pending.empty()) {
+                            n = (Type)pending.pop();
+                            dumpType(n);
+                            emitted.add(n.getName());
+                        }
                     }
                 }
             }
@@ -846,83 +924,105 @@
 
             }
         },
-        new Command("search", "search [ heap | codecache | threads ] value", false) {
+        new Command("search", "search [ heap | perm | rawheap | codecache | threads ] value", false) {
             public void doit(Tokens t) {
                 if (t.countTokens() != 2) {
                     usage();
-                } else {
-                    String type = t.nextToken();
-                    final Address value = VM.getVM().getDebugger().parseAddress(t.nextToken());
-                    final long stride = VM.getVM().getAddressSize();
-                    if (type.equals("threads")) {
-                        Threads threads = VM.getVM().getThreads();
-                        for (JavaThread thread = threads.first(); thread != null; thread = thread.next()) {
-                            Address base = thread.getBaseOfStackPointer();
-                            Address end = thread.getLastJavaSP();
-                            if (end == null) continue;
-                            if (end.lessThan(base)) {
-                                Address tmp = base;
-                                base = end;
-                                end = tmp;
+                    return;
+                }
+                String type = t.nextToken();
+                final Address value = VM.getVM().getDebugger().parseAddress(t.nextToken());
+                final long stride = VM.getVM().getAddressSize();
+                if (type.equals("threads")) {
+                    Threads threads = VM.getVM().getThreads();
+                    for (JavaThread thread = threads.first(); thread != null; thread = thread.next()) {
+                        Address base = thread.getBaseOfStackPointer();
+                        Address end = thread.getLastJavaSP();
+                        if (end == null) continue;
+                        if (end.lessThan(base)) {
+                            Address tmp = base;
+                            base = end;
+                            end = tmp;
+                        }
+                        out.println("Searching " + base + " " + end);
+                        while (base != null && base.lessThan(end)) {
+                            Address val = base.getAddressAt(0);
+                            if (AddressOps.equal(val, value)) {
+                                out.println(base);
+                            }
+                            base = base.addOffsetTo(stride);
+                        }
+                    }
+                } else if (type.equals("rawheap")) {
+                    RawHeapVisitor iterator = new RawHeapVisitor() {
+                            public void prologue(long used) {
                             }
-                            out.println("Searching " + base + " " + end);
-                            while (base != null && base.lessThan(end)) {
-                                Address val = base.getAddressAt(0);
+
+                            public void visitAddress(Address addr) {
+                                Address val = addr.getAddressAt(0);
                                 if (AddressOps.equal(val, value)) {
-                                    out.println(base);
+                                        out.println("found at " + addr);
                                 }
-                                base = base.addOffsetTo(stride);
+                            }
+                            public void visitCompOopAddress(Address addr) {
+                                Address val = addr.getCompOopAddressAt(0);
+                                if (AddressOps.equal(val, value)) {
+                                    out.println("found at " + addr);
+                                }
                             }
-                        }
-                    } else if (type.equals("heap")) {
-                        RawHeapVisitor iterator = new RawHeapVisitor() {
-                                public void prologue(long used) {
-                                }
-
-                                public void visitAddress(Address addr) {
-                                    Address val = addr.getAddressAt(0);
+                            public void epilogue() {
+                            }
+                        };
+                    VM.getVM().getObjectHeap().iterateRaw(iterator);
+                } else if (type.equals("heap") || type.equals("perm")) {
+                    HeapVisitor iterator = new DefaultHeapVisitor() {
+                            public boolean doObj(Oop obj) {
+                                int index = 0;
+                                Address start = obj.getHandle();
+                                long end = obj.getObjectSize();
+                                while (index < end) {
+                                    Address val = start.getAddressAt(index);
                                     if (AddressOps.equal(val, value)) {
-                                        out.println("found at " + addr);
+                                        out.println("found in " + obj.getHandle());
+                                        break;
                                     }
-                                }
-                                public void visitCompOopAddress(Address addr) {
-                                    Address val = addr.getCompOopAddressAt(0);
-                                    if (AddressOps.equal(val, value)) {
-                                        out.println("found at " + addr);
-                                    }
-                                }
-                                public void epilogue() {
-                                }
-                            };
-                        VM.getVM().getObjectHeap().iterateRaw(iterator);
-                    } else if (type.equals("codecache")) {
-                        CodeCacheVisitor v = new CodeCacheVisitor() {
-                                public void prologue(Address start, Address end) {
+                                    index += 4;
                                 }
-                                public void visit(CodeBlob blob) {
-                                    boolean printed = false;
-                                    Address base = blob.getAddress();
-                                    Address end = base.addOffsetTo(blob.getSize());
-                                    while (base != null && base.lessThan(end)) {
-                                        Address val = base.getAddressAt(0);
-                                        if (AddressOps.equal(val, value)) {
-                                            if (!printed) {
-                                                printed = true;
-                                                blob.printOn(out);
-                                            }
-                                            out.println("found at " + base + "\n");
+                                return false;
+                            }
+                        };
+                    if (type.equals("heap")) {
+                        VM.getVM().getObjectHeap().iterate(iterator);
+                    } else {
+                        VM.getVM().getObjectHeap().iteratePerm(iterator);
+                    }
+                } else if (type.equals("codecache")) {
+                    CodeCacheVisitor v = new CodeCacheVisitor() {
+                            public void prologue(Address start, Address end) {
+                            }
+                            public void visit(CodeBlob blob) {
+                                boolean printed = false;
+                                Address base = blob.getAddress();
+                                Address end = base.addOffsetTo(blob.getSize());
+                                while (base != null && base.lessThan(end)) {
+                                    Address val = base.getAddressAt(0);
+                                    if (AddressOps.equal(val, value)) {
+                                        if (!printed) {
+                                            printed = true;
+                                            blob.printOn(out);
                                         }
-                                        base = base.addOffsetTo(stride);
+                                        out.println("found at " + base + "\n");
                                     }
+                                    base = base.addOffsetTo(stride);
                                 }
-                                public void epilogue() {
-                                }
+                            }
+                            public void epilogue() {
+                            }
 
 
-                            };
-                        VM.getVM().getCodeCache().iterate(v);
+                        };
+                    VM.getVM().getCodeCache().iterate(v);
 
-                    }
                 }
             }
         },
@@ -957,12 +1057,19 @@
                     Threads threads = VM.getVM().getThreads();
                     boolean all = name.equals("-a");
                     for (JavaThread thread = threads.first(); thread != null; thread = thread.next()) {
-                        StringWriter sw = new StringWriter();
                         ByteArrayOutputStream bos = new ByteArrayOutputStream();
                         thread.printThreadIDOn(new PrintStream(bos));
                         if (all || bos.toString().equals(name)) {
+                            out.println(bos.toString() + " = " + thread.getAddress());
                             HTMLGenerator gen = new HTMLGenerator(false);
-                            out.println(gen.genHTMLForJavaStackTrace(thread));
+                            try {
+                                out.println(gen.genHTMLForJavaStackTrace(thread));
+                            } catch (Exception e) {
+                                err.println("Error: " + e);
+                                if (verboseExceptions) {
+                                    e.printStackTrace(err);
+                                }
+                            }
                             if (!all) return;
                         }
                     }
@@ -970,6 +1077,26 @@
                 }
             }
         },
+        new Command("thread", "thread { -a | id }", false) {
+            public void doit(Tokens t) {
+                if (t.countTokens() != 1) {
+                    usage();
+                } else {
+                    String name = t.nextToken();
+                    Threads threads = VM.getVM().getThreads();
+                    boolean all = name.equals("-a");
+                    for (JavaThread thread = threads.first(); thread != null; thread = thread.next()) {
+                        ByteArrayOutputStream bos = new ByteArrayOutputStream();
+                        thread.printThreadIDOn(new PrintStream(bos));
+                        if (all || bos.toString().equals(name)) {
+                            out.println(bos.toString() + " = " + thread.getAddress());
+                            if (!all) return;
+                        }
+                    }
+                    out.println("Couldn't find thread " + name);
+                }
+            }
+        },
 
         new Command("threads", false) {
             public void doit(Tokens t) {
@@ -1161,7 +1288,7 @@
         }
     }
 
-    static Pattern historyPattern = Pattern.compile("((!\\*)|(!\\$)|(!!-?)|(!-?[0-9][0-9]*))");
+    static Pattern historyPattern = Pattern.compile("((!\\*)|(!\\$)|(!!-?)|(!-?[0-9][0-9]*)|(![a-zA-Z][^ ]*))");
 
     public void executeCommand(String ln) {
         if (ln.indexOf('!') != -1) {
@@ -1195,14 +1322,37 @@
                         result.append(item.at(item.countTokens() - 1));
                     } else {
                         String tail = cmd.substring(1);
-                        int index = Integer.parseInt(tail);
-                        if (index < 0) {
-                            index = history.size() + index;
+                        switch (tail.charAt(0)) {
+                        case '0':
+                        case '1':
+                        case '2':
+                        case '3':
+                        case '4':
+                        case '5':
+                        case '6':
+                        case '7':
+                        case '8':
+                        case '9':
+                        case '-': {
+                            int index = Integer.parseInt(tail);
+                            if (index < 0) {
+                                index = history.size() + index;
+                            }
+                            if (index > size) {
+                                err.println("No such history item");
+                            } else {
+                                result.append((String)history.get(index));
+                            }
+                            break;
                         }
-                        if (index > size) {
-                            err.println("No such history item");
-                        } else {
-                            result.append((String)history.get(index));
+                        default: {
+                            for (int i = history.size() - 1; i >= 0; i--) {
+                                String s = (String)history.get(i);
+                                if (s.startsWith(tail)) {
+                                    result.append(s);
+                                }
+                            }
+                        }
                         }
                     }
                 }
diff -r e0a1a502e402 -r 7b03170e1fcb agent/src/share/classes/sun/jvm/hotspot/HSDB.java
--- a/agent/src/share/classes/sun/jvm/hotspot/HSDB.java	Thu Apr 22 16:54:23 2010 -0700
+++ b/agent/src/share/classes/sun/jvm/hotspot/HSDB.java	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2008 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2000-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -985,6 +985,12 @@
               annoPanel.addAnnotation(new Annotation(curFrame.addressOfInterpreterFrameExpressionStack(),
                                                      curFrame.addressOfInterpreterFrameTOS(),
                                                      "Interpreter expression stack"));
+              Address monBegin = curFrame.interpreterFrameMonitorBegin().address();
+              Address monEnd = curFrame.interpreterFrameMonitorEnd().address();
+              if (!monBegin.equals(monEnd)) {
+                  annoPanel.addAnnotation(new Annotation(monBegin, monEnd,
+                                                         "BasicObjectLocks"));
+              }
               if (interpreterFrameMethod != null) {
                 // The offset is just to get the right stack slots highlighted in the output
                 int offset = 1;
diff -r e0a1a502e402 -r 7b03170e1fcb agent/src/share/classes/sun/jvm/hotspot/bugspot/BugSpot.java
--- a/agent/src/share/classes/sun/jvm/hotspot/bugspot/BugSpot.java	Thu Apr 22 16:54:23 2010 -0700
+++ b/agent/src/share/classes/sun/jvm/hotspot/bugspot/BugSpot.java	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2003 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -294,7 +294,7 @@
     attachDialog.setSize(400, 300);
     GraphicsUtilities.centerInContainer(attachDialog.getComponent(),
                                         getParentDimension(attachDialog.getComponent()));
-    attachDialog.show();
+    attachDialog.setVisible(true);
   }
 
   public void showThreadsDialog() {
@@ -321,7 +321,7 @@
                                            getParentDimension(threadsDialog.getComponent()));
     GraphicsUtilities.centerInContainer(threadsDialog.getComponent(),
                                         getParentDimension(threadsDialog.getComponent()));
-    threadsDialog.show();
+    threadsDialog.setVisible(true);
   }
 
   public void showMemoryDialog() {
@@ -341,7 +341,7 @@
                                            getParentDimension(memoryDialog.getComponent()));
     GraphicsUtilities.centerInContainer(memoryDialog.getComponent(),
                                         getParentDimension(memoryDialog.getComponent()));
-    memoryDialog.show();
+    memoryDialog.setVisible(true);
   }
 
   /** Changes the editor factory this debugger uses to display source
@@ -530,7 +530,7 @@
       addFrame(stackFrame);
       stackFrame.setSize(400, 200);
       GraphicsUtilities.moveToInContainer(stackFrame.getComponent(), 0.0f, 1.0f, 0, 20);
-      stackFrame.show();
+      stackFrame.setVisible(true);
 
       // Create register panel
       registerPanel = new RegisterPanel();
@@ -544,7 +544,7 @@
       registerFrame.setSize(225, 200);
       GraphicsUtilities.moveToInContainer(registerFrame.getComponent(),
                                           1.0f, 0.0f, 0, 0);
-      registerFrame.show();
+      registerFrame.setVisible(true);
 
       resetCurrentThread();
     } catch (DebuggerException e) {
@@ -979,7 +979,7 @@
                                                1.0f,
                                                0.85f,
                                                getParentDimension(editorFrame.getComponent()));
-        editorFrame.show();
+        editorFrame.setVisible(true);
         shown = true;
       }
       code.showLineNumber(lineNo);
diff -r e0a1a502e402 -r 7b03170e1fcb agent/src/share/classes/sun/jvm/hotspot/interpreter/BytecodeDisassembler.java
--- a/agent/src/share/classes/sun/jvm/hotspot/interpreter/BytecodeDisassembler.java	Thu Apr 22 16:54:23 2010 -0700
+++ b/agent/src/share/classes/sun/jvm/hotspot/interpreter/BytecodeDisassembler.java	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2002-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -96,10 +96,6 @@
       addBytecodeClass(Bytecodes._dstore, BytecodeStore.class);
       addBytecodeClass(Bytecodes._astore, BytecodeStore.class);
       addBytecodeClass(Bytecodes._tableswitch, BytecodeTableswitch.class);
-
-      // only special fast_xxx cases. others are handled differently.
-      addBytecodeClass(Bytecodes._fast_iaccess_0, BytecodeFastAAccess0.class);
-      addBytecodeClass(Bytecodes._fast_aaccess_0, BytecodeFastIAccess0.class);
    }
 
    public BytecodeDisassembler(Method method) {
diff -r e0a1a502e402 -r 7b03170e1fcb agent/src/share/classes/sun/jvm/hotspot/oops/ConstantPool.java
--- a/agent/src/share/classes/sun/jvm/hotspot/oops/ConstantPool.java	Thu Apr 22 16:54:23 2010 -0700
+++ b/agent/src/share/classes/sun/jvm/hotspot/oops/ConstantPool.java	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2008 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2000-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -263,11 +263,12 @@
     case JVM_CONSTANT_NameAndType:        return "JVM_CONSTANT_NameAndType";
     case JVM_CONSTANT_Invalid:            return "JVM_CONSTANT_Invalid";
     case JVM_CONSTANT_UnresolvedClass:    return "JVM_CONSTANT_UnresolvedClass";
+    case JVM_CONSTANT_UnresolvedClassInError:    return "JVM_CONSTANT_UnresolvedClassInError";
     case JVM_CONSTANT_ClassIndex:         return "JVM_CONSTANT_ClassIndex";
     case JVM_CONSTANT_UnresolvedString:   return "JVM_CONSTANT_UnresolvedString";
     case JVM_CONSTANT_StringIndex:        return "JVM_CONSTANT_StringIndex";
     }
-    throw new InternalError("unknown tag");
+    throw new InternalError("Unknown tag: " + tag);
   }
 
   public void iterateFields(OopVisitor visitor, boolean doVMFields) {
@@ -304,6 +305,7 @@
           index++;
           break;
 
+        case JVM_CONSTANT_UnresolvedClassInError:
         case JVM_CONSTANT_UnresolvedClass:
         case JVM_CONSTANT_Class:
         case JVM_CONSTANT_UnresolvedString:
@@ -409,6 +411,7 @@
               }
 
               // case JVM_CONSTANT_ClassIndex:
+              case JVM_CONSTANT_UnresolvedClassInError:
               case JVM_CONSTANT_UnresolvedClass: {
                   dos.writeByte(JVM_CONSTANT_Class);
                   String klassName = getSymbolAt(ci).asString();
@@ -464,6 +467,8 @@
                                           + ", type = " + signatureIndex);
                   break;
               }
+              default:
+                  throw new InternalError("unknown tag: " + cpConstType);
           } // switch
       }
       dos.flush();
diff -r e0a1a502e402 -r 7b03170e1fcb agent/src/share/classes/sun/jvm/hotspot/runtime/ClassConstants.java
--- a/agent/src/share/classes/sun/jvm/hotspot/runtime/ClassConstants.java	Thu Apr 22 16:54:23 2010 -0700
+++ b/agent/src/share/classes/sun/jvm/hotspot/runtime/ClassConstants.java	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2002-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -58,6 +58,9 @@
     // Temporary tag while constructing constant pool
     public static final int JVM_CONSTANT_StringIndex        = 103;
 
+    // Temporary tag while constructing constant pool
+    public static final int JVM_CONSTANT_UnresolvedClassInError = 104;
+
     // 1.5 major/minor version numbers from JVM spec. 3rd edition
     public static final short MAJOR_VERSION = 49;
     public static final short MINOR_VERSION = 0;
diff -r e0a1a502e402 -r 7b03170e1fcb agent/src/share/classes/sun/jvm/hotspot/runtime/SignatureIterator.java
--- a/agent/src/share/classes/sun/jvm/hotspot/runtime/SignatureIterator.java	Thu Apr 22 16:54:23 2010 -0700
+++ b/agent/src/share/classes/sun/jvm/hotspot/runtime/SignatureIterator.java	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2001 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -108,7 +108,7 @@
         return BasicTypeSize.getTArraySize();
       }
     }
-    throw new RuntimeException("Should not reach here");
+    throw new RuntimeException("Should not reach here: char " + (char)_signature.getByteAt(_index) + " @ " + _index + " in " + _signature.asString());
   }
   protected void checkSignatureEnd() {
     if (_index < _signature.getLength()) {
diff -r e0a1a502e402 -r 7b03170e1fcb agent/src/share/classes/sun/jvm/hotspot/tools/jcore/ClassWriter.java
--- a/agent/src/share/classes/sun/jvm/hotspot/tools/jcore/ClassWriter.java	Thu Apr 22 16:54:23 2010 -0700
+++ b/agent/src/share/classes/sun/jvm/hotspot/tools/jcore/ClassWriter.java	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2002-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -238,6 +238,7 @@
                 }
 
                 // case JVM_CONSTANT_ClassIndex:
+                case JVM_CONSTANT_UnresolvedClassInError:
                 case JVM_CONSTANT_UnresolvedClass: {
                      dos.writeByte(JVM_CONSTANT_Class);
                      String klassName = cpool.getSymbolAt(ci).asString();
@@ -296,6 +297,8 @@
                                         + ", type = " + signatureIndex);
                      break;
                 }
+                default:
+                  throw new InternalError("Unknown tag: " + cpConstType);
             } // switch
         }
     }
diff -r e0a1a502e402 -r 7b03170e1fcb agent/src/share/classes/sun/jvm/hotspot/ui/FrameWrapper.java
--- a/agent/src/share/classes/sun/jvm/hotspot/ui/FrameWrapper.java	Thu Apr 22 16:54:23 2010 -0700
+++ b/agent/src/share/classes/sun/jvm/hotspot/ui/FrameWrapper.java	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2001 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -39,7 +39,6 @@
   public void       setVisible(boolean visible);
   public void       setSize(int x, int y);
   public void       pack();
-  public void       show();
   public void       dispose();
   public void       setBackground(Color color);
   public void       setResizable(boolean resizable);
diff -r e0a1a502e402 -r 7b03170e1fcb agent/src/share/classes/sun/jvm/hotspot/ui/classbrowser/HTMLGenerator.java
--- a/agent/src/share/classes/sun/jvm/hotspot/ui/classbrowser/HTMLGenerator.java	Thu Apr 22 16:54:23 2010 -0700
+++ b/agent/src/share/classes/sun/jvm/hotspot/ui/classbrowser/HTMLGenerator.java	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2008 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2002-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -95,8 +95,10 @@
 
         // list tags
         void beginList()  { beginTag("ul"); nl(); }
+        void endList()    { endTag("ul"); nl();   }
+        void beginListItem() { beginTag("li"); }
+        void endListItem()   { endTag("li"); nl();   }
         void li(String s) { wrap("li", s); nl();  }
-        void endList()    { endTag("ul"); nl();   }
 
         // table tags
         void beginTable(int border) {
@@ -505,6 +507,11 @@
                buf.cell(cpool.getSymbolAt(index).asString());
                break;
 
+            case JVM_CONSTANT_UnresolvedClassInError:
+               buf.cell("JVM_CONSTANT_UnresolvedClassInError");
+               buf.cell(cpool.getSymbolAt(index).asString());
+               break;
+
             case JVM_CONSTANT_Class:
                buf.cell("JVM_CONSTANT_Class");
                Klass klass = (Klass) cpool.getObjAt(index);
@@ -564,6 +571,9 @@
                buf.cell("JVM_CONSTANT_StringIndex");
                buf.cell(Integer.toString(cpool.getIntAt(index)));
                break;
+
+            default:
+               throw new InternalError("unknown tag: " + ctag);
          }
 
          buf.endTag("tr");
@@ -671,7 +681,16 @@
                              buf.cell(Integer.toString(curBci) + spaces);
 
                              buf.beginTag("td");
-                             String instrStr = escapeHTMLSpecialChars(instr.toString());
+                             String instrStr = null;
+                             try {
+                                 instrStr = escapeHTMLSpecialChars(instr.toString());
+                             } catch (RuntimeException re) {
+                                 buf.append("exception during bytecode processing");
+                                 buf.endTag("td");
+                                 buf.endTag("tr");
+                                 re.printStackTrace();
+                                 return;
+                             }
 
                              if (instr instanceof BytecodeNew) {
                                 BytecodeNew newBytecode = (BytecodeNew) instr;
@@ -1396,9 +1415,7 @@
          final SymbolFinder symFinder = createSymbolFinder();
          final Disassembler disasm = createDisassembler(startPc, code);
          class NMethodVisitor implements InstructionVisitor {
-            boolean prevWasCall;
             public void prologue() {
-               prevWasCall = false;
             }
 
             public void visit(long currentPc, Instruction instr) {
@@ -1418,8 +1435,7 @@
 
                PCDesc pcDesc = (PCDesc) safepoints.get(longToAddress(currentPc));
 
-               boolean isSafepoint = (pcDesc != null);
-               if (isSafepoint && prevWasCall) {
+               if (pcDesc != null) {
                   buf.append(genSafepointInfo(nmethod, pcDesc));
                }
 
@@ -1435,11 +1451,6 @@
                }
 
                buf.br();
-               if (isSafepoint && !prevWasCall) {
-                 buf.append(genSafepointInfo(nmethod, pcDesc));
-               }
-
-               prevWasCall = instr.isCall();
             }
 
             public void epilogue() {
@@ -1783,22 +1794,20 @@
          buf.h3("Fields");
          buf.beginList();
          for (int f = 0; f < numFields; f += InstanceKlass.NEXT_OFFSET) {
-           int nameIndex = fields.getShortAt(f + InstanceKlass.NAME_INDEX_OFFSET);
-           int sigIndex  = fields.getShortAt(f + InstanceKlass.SIGNATURE_INDEX_OFFSET);
-           int genSigIndex = fields.getShortAt(f + InstanceKlass.GENERIC_SIGNATURE_INDEX_OFFSET);
-           Symbol f_name = cp.getSymbolAt(nameIndex);
-           Symbol f_sig  = cp.getSymbolAt(sigIndex);
-           Symbol f_genSig = (genSigIndex != 0)? cp.getSymbolAt(genSigIndex) : null;
-           AccessFlags acc = new AccessFlags(fields.getShortAt(f + InstanceKlass.ACCESS_FLAGS_OFFSET));
+           sun.jvm.hotspot.oops.Field field = klass.getFieldByIndex(f);
+           String f_name = ((NamedFieldIdentifier)field.getID()).getName();
+           Symbol f_sig  = field.getSignature();
+           Symbol f_genSig = field.getGenericSignature();
+           AccessFlags acc = field.getAccessFlagsObj();
 
-           buf.beginTag("li");
+           buf.beginListItem();
            buf.append(genFieldModifierString(acc));
            buf.append(' ');
            Formatter sigBuf = new Formatter(genHTML);
            new SignatureConverter(f_sig, sigBuf.getBuffer()).dispatchField();
            buf.append(sigBuf.toString().replace('/', '.'));
            buf.append(' ');
-           buf.append(f_name.asString());
+           buf.append(f_name);
            buf.append(';');
            // is it generic?
            if (f_genSig != null) {
@@ -1806,7 +1815,8 @@
               buf.append(escapeHTMLSpecialChars(f_genSig.asString()));
               buf.append("] ");
            }
-           buf.endTag("li");
+           buf.append(" (offset = " + field.getOffset() + ")");
+           buf.endListItem();
          }
          buf.endList();
       }
diff -r e0a1a502e402 -r 7b03170e1fcb agent/src/share/classes/sun/jvm/hotspot/utilities/Assert.java
--- a/agent/src/share/classes/sun/jvm/hotspot/utilities/Assert.java	Thu Apr 22 16:54:23 2010 -0700
+++ b/agent/src/share/classes/sun/jvm/hotspot/utilities/Assert.java	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2005 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2000-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -28,7 +28,7 @@
   public static boolean ASSERTS_ENABLED = true;
 
   public static void that(boolean test, String message) {
-    if (!test) {
+    if (ASSERTS_ENABLED && !test) {
       throw new AssertionFailure(message);
     }
   }
diff -r e0a1a502e402 -r 7b03170e1fcb make/linux/makefiles/adlc.make
--- a/make/linux/makefiles/adlc.make	Thu Apr 22 16:54:23 2010 -0700
+++ b/make/linux/makefiles/adlc.make	Thu Apr 29 15:18:27 2010 -0700
@@ -127,6 +127,9 @@
 # Note that product files are updated via "mv", which is atomic.
 TEMPDIR := $(OUTDIR)/mktmp$(shell echo $$$$)
 
+# Debuggable by default
+CFLAGS += -g
+
 # Pass -D flags into ADLC.
 ADLCFLAGS += $(SYSDEFS)
 
@@ -135,7 +138,7 @@
 
 # Normally, debugging is done directly on the ad_<arch>*.cpp files.
 # But -g will put #line directives in those files pointing back to <arch>.ad.
-#ADLCFLAGS += -g
+ADLCFLAGS += -g
 
 ifdef LP64
 ADLCFLAGS += -D_LP64
diff -r e0a1a502e402 -r 7b03170e1fcb make/solaris/makefiles/adlc.make
--- a/make/solaris/makefiles/adlc.make	Thu Apr 22 16:54:23 2010 -0700
+++ b/make/solaris/makefiles/adlc.make	Thu Apr 29 15:18:27 2010 -0700
@@ -147,6 +147,9 @@
 # Note that product files are updated via "mv", which is atomic.
 TEMPDIR := $(OUTDIR)/mktmp$(shell echo $$$$)
 
+# Debuggable by default
+CFLAGS += -g
+
 # Pass -D flags into ADLC.
 ADLCFLAGS += $(SYSDEFS)
 
@@ -155,7 +158,7 @@
 
 # Normally, debugging is done directly on the ad_<arch>*.cpp files.
 # But -g will put #line directives in those files pointing back to <arch>.ad.
-#ADLCFLAGS += -g
+ADLCFLAGS += -g
 
 ifdef LP64
 ADLCFLAGS += -D_LP64
diff -r e0a1a502e402 -r 7b03170e1fcb src/cpu/sparc/vm/assembler_sparc.hpp
--- a/src/cpu/sparc/vm/assembler_sparc.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/cpu/sparc/vm/assembler_sparc.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -661,9 +661,6 @@
     stx_op3      = 0x0e,
     swap_op3     = 0x0f,
 
-    lduwa_op3    = 0x10,
-    ldxa_op3     = 0x1b,
-
     stwa_op3     = 0x14,
     stxa_op3     = 0x1e,
 
diff -r e0a1a502e402 -r 7b03170e1fcb src/cpu/sparc/vm/c1_LIRAssembler_sparc.cpp
--- a/src/cpu/sparc/vm/c1_LIRAssembler_sparc.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/cpu/sparc/vm/c1_LIRAssembler_sparc.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -388,6 +388,60 @@
 }
 
 
+// Emit the code to remove the frame from the stack in the exception
+// unwind path.
+int LIR_Assembler::emit_unwind_handler() {
+#ifndef PRODUCT
+  if (CommentedAssembly) {
+    _masm->block_comment("Unwind handler");
+  }
+#endif
+
+  int offset = code_offset();
+
+  // Fetch the exception from TLS and clear out exception related thread state
+  __ ld_ptr(G2_thread, in_bytes(JavaThread::exception_oop_offset()), O0);
+  __ st_ptr(G0, G2_thread, in_bytes(JavaThread::exception_oop_offset()));
+  __ st_ptr(G0, G2_thread, in_bytes(JavaThread::exception_pc_offset()));
+
+  __ bind(_unwind_handler_entry);
+  __ verify_not_null_oop(O0);
+  if (method()->is_synchronized() || compilation()->env()->dtrace_method_probes()) {
+    __ mov(O0, I0);  // Preserve the exception
+  }
+
+  // Preform needed unlocking
+  MonitorExitStub* stub = NULL;
+  if (method()->is_synchronized()) {
+    monitor_address(0, FrameMap::I1_opr);
+    stub = new MonitorExitStub(FrameMap::I1_opr, true, 0);
+    __ unlock_object(I3, I2, I1, *stub->entry());
+    __ bind(*stub->continuation());
+  }
+
+  if (compilation()->env()->dtrace_method_probes()) {
+    jobject2reg(method()->constant_encoding(), O0);
+    __ call(CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_method_exit), relocInfo::runtime_call_type);
+    __ delayed()->nop();
+  }
+
+  if (method()->is_synchronized() || compilation()->env()->dtrace_method_probes()) {
+    __ mov(I0, O0);  // Restore the exception
+  }
+
+  // dispatch to the unwind logic
+  __ call(Runtime1::entry_for(Runtime1::unwind_exception_id), relocInfo::runtime_call_type);
+  __ delayed()->nop();
+
+  // Emit the slow path assembly
+  if (stub != NULL) {
+    stub->emit_code(this);
+  }
+
+  return offset;
+}
+
+
 int LIR_Assembler::emit_deopt_handler() {
   // if the last instruction is a call (typically to do a throw which
   // is coming at the end after block reordering) the return address
@@ -2050,26 +2104,29 @@
 }
 
 
-void LIR_Assembler::throw_op(LIR_Opr exceptionPC, LIR_Opr exceptionOop, CodeEmitInfo* info, bool unwind) {
+void LIR_Assembler::throw_op(LIR_Opr exceptionPC, LIR_Opr exceptionOop, CodeEmitInfo* info) {
   assert(exceptionOop->as_register() == Oexception, "should match");
-  assert(unwind || exceptionPC->as_register() == Oissuing_pc, "should match");
+  assert(exceptionPC->as_register() == Oissuing_pc, "should match");
 
   info->add_register_oop(exceptionOop);
 
-  if (unwind) {
-    __ call(Runtime1::entry_for(Runtime1::unwind_exception_id), relocInfo::runtime_call_type);
-    __ delayed()->nop();
-  } else {
-    // reuse the debug info from the safepoint poll for the throw op itself
-    address pc_for_athrow  = __ pc();
-    int pc_for_athrow_offset = __ offset();
-    RelocationHolder rspec = internal_word_Relocation::spec(pc_for_athrow);
-    __ set(pc_for_athrow, Oissuing_pc, rspec);
-    add_call_info(pc_for_athrow_offset, info); // for exception handler
-
-    __ call(Runtime1::entry_for(Runtime1::handle_exception_id), relocInfo::runtime_call_type);
-    __ delayed()->nop();
-  }
+  // reuse the debug info from the safepoint poll for the throw op itself
+  address pc_for_athrow  = __ pc();
+  int pc_for_athrow_offset = __ offset();
+  RelocationHolder rspec = internal_word_Relocation::spec(pc_for_athrow);
+  __ set(pc_for_athrow, Oissuing_pc, rspec);
+  add_call_info(pc_for_athrow_offset, info); // for exception handler
+
+  __ call(Runtime1::entry_for(Runtime1::handle_exception_id), relocInfo::runtime_call_type);
+  __ delayed()->nop();
+}
+
+
+void LIR_Assembler::unwind_op(LIR_Opr exceptionOop) {
+  assert(exceptionOop->as_register() == Oexception, "should match");
+
+  __ br(Assembler::always, false, Assembler::pt, _unwind_handler_entry);
+  __ delayed()->nop();
 }
 
 
@@ -2358,7 +2415,7 @@
   if (UseSlowPath ||
       (!UseFastNewObjectArray && (op->type() == T_OBJECT || op->type() == T_ARRAY)) ||
       (!UseFastNewTypeArray   && (op->type() != T_OBJECT && op->type() != T_ARRAY))) {
-    __ br(Assembler::always, false, Assembler::pn, *op->stub()->entry());
+    __ br(Assembler::always, false, Assembler::pt, *op->stub()->entry());
     __ delayed()->nop();
   } else {
     __ allocate_array(op->obj()->as_register(),
diff -r e0a1a502e402 -r 7b03170e1fcb src/cpu/sparc/vm/sparc.ad
--- a/src/cpu/sparc/vm/sparc.ad	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/cpu/sparc/vm/sparc.ad	Thu Apr 29 15:18:27 2010 -0700
@@ -923,38 +923,6 @@
 #endif
 }
 
-void emit_form3_mem_reg_asi(CodeBuffer &cbuf, const MachNode* n, int primary, int tertiary,
-                        int src1_enc, int disp32, int src2_enc, int dst_enc, int asi) {
-
-  uint instr;
-  instr = (Assembler::ldst_op << 30)
-        | (dst_enc        << 25)
-        | (primary        << 19)
-        | (src1_enc       << 14);
-
-  int disp = disp32;
-  int index    = src2_enc;
-
-  if (src1_enc == R_SP_enc || src1_enc == R_FP_enc)
-    disp += STACK_BIAS;
-
-  // We should have a compiler bailout here rather than a guarantee.
-  // Better yet would be some mechanism to handle variable-size matches correctly.
-  guarantee(Assembler::is_simm13(disp), "Do not match large constant offsets" );
-
-  if( disp != 0 ) {
-    // use reg-reg form
-    // set src2=R_O7 contains offset
-    index = R_O7_enc;
-    emit3_simm13( cbuf, Assembler::arith_op, index, Assembler::or_op3, 0, disp);
-  }
-  instr |= (asi << 5);
-  instr |= index;
-  uint *code = (uint*)cbuf.code_end();
-  *code = instr;
-  cbuf.set_code_end(cbuf.code_end() + BytesPerInstWord);
-}
-
 void emit_call_reloc(CodeBuffer &cbuf, intptr_t entry_point, relocInfo::relocType rtype, bool preserve_g2 = false, bool force_far_call = false) {
   // The method which records debug information at every safepoint
   // expects the call to be the first instruction in the snippet as
@@ -1954,11 +1922,6 @@
                        $mem$$base, $mem$$disp, $mem$$index, $dst$$reg);
   %}
 
-  enc_class form3_mem_reg_little( memory mem, iRegI dst) %{
-    emit_form3_mem_reg_asi(cbuf, this, $primary, -1,
-                     $mem$$base, $mem$$disp, $mem$$index, $dst$$reg, Assembler::ASI_PRIMARY_LITTLE);
-  %}
-
   enc_class form3_mem_prefetch_read( memory mem ) %{
     emit_form3_mem_reg(cbuf, this, $primary, -1,
                        $mem$$base, $mem$$disp, $mem$$index, 0/*prefetch function many-reads*/);
@@ -4311,8 +4274,8 @@
 // instructions for every form of operand when the instruction accepts
 // multiple operand types with the same basic encoding and format.  The classic
 // case of this is memory operands.
-// Indirect is not included since its use is limited to Compare & Swap
 opclass memory( indirect, indOffset13, indIndex );
+opclass indIndexMemory( indIndex );
 
 //----------PIPELINE-----------------------------------------------------------
 pipeline %{
@@ -9666,84 +9629,179 @@
 
 instruct bytes_reverse_int(iRegI dst, stackSlotI src) %{
   match(Set dst (ReverseBytesI src));
-  effect(DEF dst, USE src);
+
+  // Op cost is artificially doubled to make sure that load or store
+  // instructions are preferred over this one which requires a spill
+  // onto a stack slot.
+  ins_cost(2*DEFAULT_COST + MEMORY_REF_COST);
+  format %{ "LDUWA  $src, $dst\t!asi=primary_little" %}
+
+  ins_encode %{
+    __ set($src$$disp + STACK_BIAS, O7);
+    __ lduwa($src$$base$$Register, O7, Assembler::ASI_PRIMARY_LITTLE, $dst$$Register);
+  %}
+  ins_pipe( iload_mem );
+%}
+
+instruct bytes_reverse_long(iRegL dst, stackSlotL src) %{
+  match(Set dst (ReverseBytesL src));
 
   // Op cost is artificially doubled to make sure that load or store
   // instructions are preferred over this one which requires a spill
   // onto a stack slot.
   ins_cost(2*DEFAULT_COST + MEMORY_REF_COST);
-  size(8);
-  format %{ "LDUWA  $src, $dst\t!asi=primary_little" %}
-  opcode(Assembler::lduwa_op3);
-  ins_encode( form3_mem_reg_little(src, dst) );
+  format %{ "LDXA   $src, $dst\t!asi=primary_little" %}
+
+  ins_encode %{
+    __ set($src$$disp + STACK_BIAS, O7);
+    __ ldxa($src$$base$$Register, O7, Assembler::ASI_PRIMARY_LITTLE, $dst$$Register);
+  %}
   ins_pipe( iload_mem );
 %}
 
-instruct bytes_reverse_long(iRegL dst, stackSlotL src) %{
-  match(Set dst (ReverseBytesL src));
-  effect(DEF dst, USE src);
+instruct bytes_reverse_unsigned_short(iRegI dst, stackSlotI src) %{
+  match(Set dst (ReverseBytesUS src));
+
+  // Op cost is artificially doubled to make sure that load or store
+  // instructions are preferred over this one which requires a spill
+  // onto a stack slot.
+  ins_cost(2*DEFAULT_COST + MEMORY_REF_COST);
+  format %{ "LDUHA  $src, $dst\t!asi=primary_little\n\t" %}
+
+  ins_encode %{
+    // the value was spilled as an int so bias the load
+    __ set($src$$disp + STACK_BIAS + 2, O7);
+    __ lduha($src$$base$$Register, O7, Assembler::ASI_PRIMARY_LITTLE, $dst$$Register);
+  %}
+  ins_pipe( iload_mem );
+%}
+
+instruct bytes_reverse_short(iRegI dst, stackSlotI src) %{
+  match(Set dst (ReverseBytesS src));
 
   // Op cost is artificially doubled to make sure that load or store
   // instructions are preferred over this one which requires a spill
   // onto a stack slot.
   ins_cost(2*DEFAULT_COST + MEMORY_REF_COST);
-  size(8);
-  format %{ "LDXA   $src, $dst\t!asi=primary_little" %}
-
-  opcode(Assembler::ldxa_op3);
-  ins_encode( form3_mem_reg_little(src, dst) );
+  format %{ "LDSHA  $src, $dst\t!asi=primary_little\n\t" %}
+
+  ins_encode %{
+    // the value was spilled as an int so bias the load
+    __ set($src$$disp + STACK_BIAS + 2, O7);
+    __ ldsha($src$$base$$Register, O7, Assembler::ASI_PRIMARY_LITTLE, $dst$$Register);
+  %}
   ins_pipe( iload_mem );
 %}
 
 // Load Integer reversed byte order
-instruct loadI_reversed(iRegI dst, memory src) %{
+instruct loadI_reversed(iRegI dst, indIndexMemory src) %{
   match(Set dst (ReverseBytesI (LoadI src)));
 
   ins_cost(DEFAULT_COST + MEMORY_REF_COST);
-  size(8);
+  size(4);
   format %{ "LDUWA  $src, $dst\t!asi=primary_little" %}
 
-  opcode(Assembler::lduwa_op3);
-  ins_encode( form3_mem_reg_little( src, dst) );
+  ins_encode %{
+    __ lduwa($src$$base$$Register, $src$$index$$Register, Assembler::ASI_PRIMARY_LITTLE, $dst$$Register);
+  %}
   ins_pipe(iload_mem);
 %}
 
 // Load Long - aligned and reversed
-instruct loadL_reversed(iRegL dst, memory src) %{
+instruct loadL_reversed(iRegL dst, indIndexMemory src) %{
   match(Set dst (ReverseBytesL (LoadL src)));
 
-  ins_cost(DEFAULT_COST + MEMORY_REF_COST);
-  size(8);
+  ins_cost(MEMORY_REF_COST);
+  size(4);
   format %{ "LDXA   $src, $dst\t!asi=primary_little" %}
 
-  opcode(Assembler::ldxa_op3);
-  ins_encode( form3_mem_reg_little( src, dst ) );
+  ins_encode %{
+    __ ldxa($src$$base$$Register, $src$$index$$Register, Assembler::ASI_PRIMARY_LITTLE, $dst$$Register);
+  %}
+  ins_pipe(iload_mem);
+%}
+
+// Load unsigned short / char reversed byte order
+instruct loadUS_reversed(iRegI dst, indIndexMemory src) %{
+  match(Set dst (ReverseBytesUS (LoadUS src)));
+
+  ins_cost(MEMORY_REF_COST);
+  size(4);
+  format %{ "LDUHA  $src, $dst\t!asi=primary_little" %}
+
+  ins_encode %{
+    __ lduha($src$$base$$Register, $src$$index$$Register, Assembler::ASI_PRIMARY_LITTLE, $dst$$Register);
+  %}
+  ins_pipe(iload_mem);
+%}
+
+// Load short reversed byte order
+instruct loadS_reversed(iRegI dst, indIndexMemory src) %{
+  match(Set dst (ReverseBytesS (LoadS src)));
+
+  ins_cost(MEMORY_REF_COST);
+  size(4);
+  format %{ "LDSHA  $src, $dst\t!asi=primary_little" %}
+
+  ins_encode %{
+    __ ldsha($src$$base$$Register, $src$$index$$Register, Assembler::ASI_PRIMARY_LITTLE, $dst$$Register);
+  %}
   ins_pipe(iload_mem);
 %}
 
 // Store Integer reversed byte order
-instruct storeI_reversed(memory dst, iRegI src) %{
+instruct storeI_reversed(indIndexMemory dst, iRegI src) %{
   match(Set dst (StoreI dst (ReverseBytesI src)));
 
   ins_cost(MEMORY_REF_COST);
-  size(8);
+  size(4);
   format %{ "STWA   $src, $dst\t!asi=primary_little" %}
 
-  opcode(Assembler::stwa_op3);
-  ins_encode( form3_mem_reg_little( dst, src) );
+  ins_encode %{
+    __ stwa($src$$Register, $dst$$base$$Register, $dst$$index$$Register, Assembler::ASI_PRIMARY_LITTLE);
+  %}
   ins_pipe(istore_mem_reg);
 %}
 
 // Store Long reversed byte order
-instruct storeL_reversed(memory dst, iRegL src) %{
+instruct storeL_reversed(indIndexMemory dst, iRegL src) %{
   match(Set dst (StoreL dst (ReverseBytesL src)));
 
   ins_cost(MEMORY_REF_COST);
-  size(8);
+  size(4);
   format %{ "STXA   $src, $dst\t!asi=primary_little" %}
 
-  opcode(Assembler::stxa_op3);
-  ins_encode( form3_mem_reg_little( dst, src) );
+  ins_encode %{
+    __ stxa($src$$Register, $dst$$base$$Register, $dst$$index$$Register, Assembler::ASI_PRIMARY_LITTLE);
+  %}
+  ins_pipe(istore_mem_reg);
+%}
+
+// Store unsighed short/char reversed byte order
+instruct storeUS_reversed(indIndexMemory dst, iRegI src) %{
+  match(Set dst (StoreC dst (ReverseBytesUS src)));
+
+  ins_cost(MEMORY_REF_COST);
+  size(4);
+  format %{ "STHA   $src, $dst\t!asi=primary_little" %}
+
+  ins_encode %{
+    __ stha($src$$Register, $dst$$base$$Register, $dst$$index$$Register, Assembler::ASI_PRIMARY_LITTLE);
+  %}
+  ins_pipe(istore_mem_reg);
+%}
+
+// Store short reversed byte order
+instruct storeS_reversed(indIndexMemory dst, iRegI src) %{
+  match(Set dst (StoreC dst (ReverseBytesS src)));
+
+  ins_cost(MEMORY_REF_COST);
+  size(4);
+  format %{ "STHA   $src, $dst\t!asi=primary_little" %}
+
+  ins_encode %{
+    __ stha($src$$Register, $dst$$base$$Register, $dst$$index$$Register, Assembler::ASI_PRIMARY_LITTLE);
+  %}
   ins_pipe(istore_mem_reg);
 %}
 
diff -r e0a1a502e402 -r 7b03170e1fcb src/cpu/x86/vm/c1_LIRAssembler_x86.cpp
--- a/src/cpu/x86/vm/c1_LIRAssembler_x86.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/cpu/x86/vm/c1_LIRAssembler_x86.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -455,6 +455,60 @@
 }
 
 
+// Emit the code to remove the frame from the stack in the exception
+// unwind path.
+int LIR_Assembler::emit_unwind_handler() {
+#ifndef PRODUCT
+  if (CommentedAssembly) {
+    _masm->block_comment("Unwind handler");
+  }
+#endif
+
+  int offset = code_offset();
+
+  // Fetch the exception from TLS and clear out exception related thread state
+  __ get_thread(rsi);
+  __ movptr(rax, Address(rsi, JavaThread::exception_oop_offset()));
+  __ movptr(Address(rsi, JavaThread::exception_oop_offset()), (int32_t)NULL_WORD);
+  __ movptr(Address(rsi, JavaThread::exception_pc_offset()), (int32_t)NULL_WORD);
+
+  __ bind(_unwind_handler_entry);
+  __ verify_not_null_oop(rax);
+  if (method()->is_synchronized() || compilation()->env()->dtrace_method_probes()) {
+    __ mov(rsi, rax);  // Preserve the exception
+  }
+
+  // Preform needed unlocking
+  MonitorExitStub* stub = NULL;
+  if (method()->is_synchronized()) {
+    monitor_address(0, FrameMap::rax_opr);
+    stub = new MonitorExitStub(FrameMap::rax_opr, true, 0);
+    __ unlock_object(rdi, rbx, rax, *stub->entry());
+    __ bind(*stub->continuation());
+  }
+
+  if (compilation()->env()->dtrace_method_probes()) {
+    __ movoop(Address(rsp, 0), method()->constant_encoding());
+    __ call(RuntimeAddress(CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_method_exit)));
+  }
+
+  if (method()->is_synchronized() || compilation()->env()->dtrace_method_probes()) {
+    __ mov(rax, rsi);  // Restore the exception
+  }
+
+  // remove the activation and dispatch to the unwind handler
+  __ remove_frame(initial_frame_size_in_bytes());
+  __ jump(RuntimeAddress(Runtime1::entry_for(Runtime1::unwind_exception_id)));
+
+  // Emit the slow path assembly
+  if (stub != NULL) {
+    stub->emit_code(this);
+  }
+
+  return offset;
+}
+
+
 int LIR_Assembler::emit_deopt_handler() {
   // if the last instruction is a call (typically to do a throw which
   // is coming at the end after block reordering) the return address
@@ -1190,8 +1244,7 @@
       break;
 #endif // _L64
     case T_INT:
-      // %%% could this be a movl? this is safer but longer instruction
-      __ movl2ptr(dest->as_register(), from_addr);
+      __ movl(dest->as_register(), from_addr);
       break;
 
     case T_LONG: {
@@ -1249,7 +1302,6 @@
         __ shll(dest_reg, 24);
         __ sarl(dest_reg, 24);
       }
-      // These are unsigned so the zero extension on 64bit is just what we need
       break;
     }
 
@@ -1261,8 +1313,6 @@
       } else {
         __ movw(dest_reg, from_addr);
       }
-      // This is unsigned so the zero extension on 64bit is just what we need
-      // __ movl2ptr(dest_reg, dest_reg);
       break;
     }
 
@@ -1275,8 +1325,6 @@
         __ shll(dest_reg, 16);
         __ sarl(dest_reg, 16);
       }
-      // Might not be needed in 64bit but certainly doesn't hurt (except for code size)
-      __ movl2ptr(dest_reg, dest_reg);
       break;
     }
 
@@ -2795,42 +2843,43 @@
 }
 
 
-void LIR_Assembler::throw_op(LIR_Opr exceptionPC, LIR_Opr exceptionOop, CodeEmitInfo* info, bool unwind) {
+void LIR_Assembler::throw_op(LIR_Opr exceptionPC, LIR_Opr exceptionOop, CodeEmitInfo* info) {
   assert(exceptionOop->as_register() == rax, "must match");
-  assert(unwind || exceptionPC->as_register() == rdx, "must match");
+  assert(exceptionPC->as_register() == rdx, "must match");
 
   // exception object is not added to oop map by LinearScan
   // (LinearScan assumes that no oops are in fixed registers)
   info->add_register_oop(exceptionOop);
   Runtime1::StubID unwind_id;
 
-  if (!unwind) {
-    // get current pc information
-    // pc is only needed if the method has an exception handler, the unwind code does not need it.
-    int pc_for_athrow_offset = __ offset();
-    InternalAddress pc_for_athrow(__ pc());
-    __ lea(exceptionPC->as_register(), pc_for_athrow);
-    add_call_info(pc_for_athrow_offset, info); // for exception handler
-
-    __ verify_not_null_oop(rax);
-    // search an exception handler (rax: exception oop, rdx: throwing pc)
-    if (compilation()->has_fpu_code()) {
-      unwind_id = Runtime1::handle_exception_id;
-    } else {
-      unwind_id = Runtime1::handle_exception_nofpu_id;
-    }
-    __ call(RuntimeAddress(Runtime1::entry_for(unwind_id)));
+  // get current pc information
+  // pc is only needed if the method has an exception handler, the unwind code does not need it.
+  int pc_for_athrow_offset = __ offset();
+  InternalAddress pc_for_athrow(__ pc());
+  __ lea(exceptionPC->as_register(), pc_for_athrow);
+  add_call_info(pc_for_athrow_offset, info); // for exception handler
+
+  __ verify_not_null_oop(rax);
+  // search an exception handler (rax: exception oop, rdx: throwing pc)
+  if (compilation()->has_fpu_code()) {
+    unwind_id = Runtime1::handle_exception_id;
   } else {
-    // remove the activation
-    __ remove_frame(initial_frame_size_in_bytes());
-    __ jump(RuntimeAddress(Runtime1::entry_for(Runtime1::unwind_exception_id)));
+    unwind_id = Runtime1::handle_exception_nofpu_id;
   }
+  __ call(RuntimeAddress(Runtime1::entry_for(unwind_id)));
 
   // enough room for two byte trap
   __ nop();
 }
 
 
+void LIR_Assembler::unwind_op(LIR_Opr exceptionOop) {
+  assert(exceptionOop->as_register() == rax, "must match");
+
+  __ jmp(_unwind_handler_entry);
+}
+
+
 void LIR_Assembler::shift_op(LIR_Code code, LIR_Opr left, LIR_Opr count, LIR_Opr dest, LIR_Opr tmp) {
 
   // optimized version for linear scan:
diff -r e0a1a502e402 -r 7b03170e1fcb src/cpu/x86/vm/x86_32.ad
--- a/src/cpu/x86/vm/x86_32.ad	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/cpu/x86/vm/x86_32.ad	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 //
-// Copyright 1997-2009 Sun Microsystems, Inc.  All Rights Reserved.
+// Copyright 1997-2010 Sun Microsystems, Inc.  All Rights Reserved.
 // DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 //
 // This code is free software; you can redistribute it and/or modify it
@@ -6272,6 +6272,30 @@
   ins_pipe( ialu_reg_reg);
 %}
 
+instruct bytes_reverse_unsigned_short(eRegI dst) %{
+  match(Set dst (ReverseBytesUS dst));
+
+  format %{ "BSWAP  $dst\n\t" 
+            "SHR    $dst,16\n\t" %}
+  ins_encode %{
+    __ bswapl($dst$$Register);
+    __ shrl($dst$$Register, 16); 
+  %}
+  ins_pipe( ialu_reg );
+%}
+
+instruct bytes_reverse_short(eRegI dst) %{
+  match(Set dst (ReverseBytesS dst));
+
+  format %{ "BSWAP  $dst\n\t" 
+            "SAR    $dst,16\n\t" %}
+  ins_encode %{
+    __ bswapl($dst$$Register);
+    __ sarl($dst$$Register, 16); 
+  %}
+  ins_pipe( ialu_reg );
+%}
+
 
 //---------- Zeros Count Instructions ------------------------------------------
 
diff -r e0a1a502e402 -r 7b03170e1fcb src/cpu/x86/vm/x86_64.ad
--- a/src/cpu/x86/vm/x86_64.ad	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/cpu/x86/vm/x86_64.ad	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 //
-// Copyright 2003-2009 Sun Microsystems, Inc.  All Rights Reserved.
+// Copyright 2003-2010 Sun Microsystems, Inc.  All Rights Reserved.
 // DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 //
 // This code is free software; you can redistribute it and/or modify it
@@ -7371,6 +7371,30 @@
   ins_pipe( ialu_reg);
 %}
 
+instruct bytes_reverse_unsigned_short(rRegI dst) %{
+  match(Set dst (ReverseBytesUS dst));
+
+  format %{ "bswapl  $dst\n\t" 
+            "shrl    $dst,16\n\t" %}
+  ins_encode %{
+    __ bswapl($dst$$Register);
+    __ shrl($dst$$Register, 16); 
+  %}
+  ins_pipe( ialu_reg );
+%}
+
+instruct bytes_reverse_short(rRegI dst) %{
+  match(Set dst (ReverseBytesS dst));
+
+  format %{ "bswapl  $dst\n\t" 
+            "sar     $dst,16\n\t" %}
+  ins_encode %{
+    __ bswapl($dst$$Register);
+    __ sarl($dst$$Register, 16); 
+  %}
+  ins_pipe( ialu_reg );
+%}
+
 instruct loadI_reversed(rRegI dst, memory src) %{
   match(Set dst (ReverseBytesI (LoadI src)));
 
diff -r e0a1a502e402 -r 7b03170e1fcb src/cpu/zero/vm/cppInterpreter_zero.cpp
--- a/src/cpu/zero/vm/cppInterpreter_zero.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/cpu/zero/vm/cppInterpreter_zero.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -39,21 +39,9 @@
 
 void CppInterpreter::normal_entry(methodOop method, intptr_t UNUSED, TRAPS) {
   JavaThread *thread = (JavaThread *) THREAD;
-  ZeroStack *stack = thread->zero_stack();
-
-  // Adjust the caller's stack frame to accomodate any additional
-  // local variables we have contiguously with our parameters.
-  int extra_locals = method->max_locals() - method->size_of_parameters();
-  if (extra_locals > 0) {
-    if (extra_locals > stack->available_words()) {
-      Unimplemented();
-    }
-    for (int i = 0; i < extra_locals; i++)
-      stack->push(0);
-  }
 
   // Allocate and initialize our frame.
-  InterpreterFrame *frame = InterpreterFrame::build(stack, method, thread);
+  InterpreterFrame *frame = InterpreterFrame::build(method, CHECK);
   thread->push_zero_frame(frame);
 
   // Execute those bytecodes!
@@ -76,12 +64,6 @@
   intptr_t *result = NULL;
   int result_slots = 0;
 
-  // Check we're not about to run out of stack
-  if (stack_overflow_imminent(thread)) {
-    CALL_VM_NOCHECK(InterpreterRuntime::throw_StackOverflowError(thread));
-    goto unwind_and_return;
-  }
-
   while (true) {
     // We can set up the frame anchor with everything we want at
     // this point as we are thread_in_Java and no safepoints can
@@ -123,9 +105,9 @@
       int monitor_words = frame::interpreter_frame_monitor_size();
 
       // Allocate the space
-      if (monitor_words > stack->available_words()) {
-        Unimplemented();
-      }
+      stack->overflow_check(monitor_words, THREAD);
+      if (HAS_PENDING_EXCEPTION)
+        break;
       stack->alloc(monitor_words * wordSize);
 
       // Move the expression stack contents
@@ -172,8 +154,6 @@
     }
   }
 
- unwind_and_return:
-
   // Unwind the current frame
   thread->pop_zero_frame();
 
@@ -193,17 +173,11 @@
   ZeroStack *stack = thread->zero_stack();
 
   // Allocate and initialize our frame
-  InterpreterFrame *frame = InterpreterFrame::build(stack, method, thread);
+  InterpreterFrame *frame = InterpreterFrame::build(method, CHECK);
   thread->push_zero_frame(frame);
   interpreterState istate = frame->interpreter_state();
   intptr_t *locals = istate->locals();
 
-  // Check we're not about to run out of stack
-  if (stack_overflow_imminent(thread)) {
-    CALL_VM_NOCHECK(InterpreterRuntime::throw_StackOverflowError(thread));
-    goto unwind_and_return;
-  }
-
   // Update the invocation counter
   if ((UseCompiler || CountCompiledCalls) && !method->is_synchronized()) {
     InvocationCounter *counter = method->invocation_counter();
@@ -264,9 +238,10 @@
   assert(function != NULL, "should be set if signature handler is");
 
   // Build the argument list
-  if (handler->argument_count() * 2 > stack->available_words()) {
-    Unimplemented();
-  }
+  stack->overflow_check(handler->argument_count() * 2, THREAD);
+  if (HAS_PENDING_EXCEPTION)
+    goto unlock_unwind_and_return;
+
   void **arguments;
   void *mirror; {
     arguments =
@@ -503,9 +478,7 @@
   switch (entry->flag_state()) {
   case ltos:
   case dtos:
-    if (stack->available_words() < 1) {
-      Unimplemented();
-    }
+    stack->overflow_check(1, CHECK);
     stack->alloc(wordSize);
     break;
   }
@@ -601,39 +574,30 @@
   stack->set_sp(stack->sp() + method->size_of_parameters());
 }
 
-bool CppInterpreter::stack_overflow_imminent(JavaThread *thread) {
-  // How is the ABI stack?
-  address stack_top = thread->stack_base() - thread->stack_size();
-  int free_stack = os::current_stack_pointer() - stack_top;
-  if (free_stack < StackShadowPages * os::vm_page_size()) {
-    return true;
-  }
+InterpreterFrame *InterpreterFrame::build(const methodOop method, TRAPS) {
+  JavaThread *thread = (JavaThread *) THREAD;
+  ZeroStack *stack = thread->zero_stack();
+
+  // Calculate the size of the frame we'll build, including
+  // any adjustments to the caller's frame that we'll make.
+  int extra_locals  = 0;
+  int monitor_words = 0;
+  int stack_words   = 0;
 
-  // How is the Zero stack?
-  // Throwing a StackOverflowError involves a VM call, which means
-  // we need a frame on the stack.  We should be checking here to
-  // ensure that methods we call have enough room to install the
-  // largest possible frame, but that's more than twice the size
-  // of the entire Zero stack we get by default, so we just check
-  // we have *some* space instead...
-  free_stack = thread->zero_stack()->available_words() * wordSize;
-  if (free_stack < StackShadowPages * os::vm_page_size()) {
-    return true;
+  if (!method->is_native()) {
+    extra_locals = method->max_locals() - method->size_of_parameters();
+    stack_words  = method->max_stack();
   }
+  if (method->is_synchronized()) {
+    monitor_words = frame::interpreter_frame_monitor_size();
+  }
+  stack->overflow_check(
+    extra_locals + header_words + monitor_words + stack_words, CHECK_NULL);
 
-  return false;
-}
-
-InterpreterFrame *InterpreterFrame::build(ZeroStack*       stack,
-                                          const methodOop  method,
-                                          JavaThread*      thread) {
-  int monitor_words =
-    method->is_synchronized() ? frame::interpreter_frame_monitor_size() : 0;
-  int stack_words = method->is_native() ? 0 : method->max_stack();
-
-  if (header_words + monitor_words + stack_words > stack->available_words()) {
-    Unimplemented();
-  }
+  // Adjust the caller's stack frame to accomodate any additional
+  // local variables we have contiguously with our parameters.
+  for (int i = 0; i < extra_locals; i++)
+    stack->push(0);
 
   intptr_t *locals;
   if (method->is_native())
@@ -812,14 +776,13 @@
 
 // Deoptimization helpers
 
-InterpreterFrame *InterpreterFrame::build(ZeroStack* stack, int size) {
+InterpreterFrame *InterpreterFrame::build(int size, TRAPS) {
+  ZeroStack *stack = ((JavaThread *) THREAD)->zero_stack();
+
   int size_in_words = size >> LogBytesPerWord;
   assert(size_in_words * wordSize == size, "unaligned");
   assert(size_in_words >= header_words, "too small");
-
-  if (size_in_words > stack->available_words()) {
-    Unimplemented();
-  }
+  stack->overflow_check(size_in_words, CHECK_NULL);
 
   stack->push(0); // next_frame, filled in later
   intptr_t *fp = stack->sp();
diff -r e0a1a502e402 -r 7b03170e1fcb src/cpu/zero/vm/cppInterpreter_zero.hpp
--- a/src/cpu/zero/vm/cppInterpreter_zero.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/cpu/zero/vm/cppInterpreter_zero.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -39,9 +39,5 @@
   static void main_loop(int recurse, TRAPS);
 
  private:
-  // Stack overflow checks
-  static bool stack_overflow_imminent(JavaThread *thread);
-
- private:
   // Fast result type determination
   static BasicType result_type_of(methodOop method);
diff -r e0a1a502e402 -r 7b03170e1fcb src/cpu/zero/vm/entryFrame_zero.hpp
--- a/src/cpu/zero/vm/entryFrame_zero.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/cpu/zero/vm/entryFrame_zero.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,6 +1,6 @@
 /*
  * Copyright 2003-2007 Sun Microsystems, Inc.  All Rights Reserved.
- * Copyright 2008 Red Hat, Inc.
+ * Copyright 2008, 2010 Red Hat, Inc.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -47,10 +47,10 @@
   };
 
  public:
-  static EntryFrame *build(ZeroStack*       stack,
-                           const intptr_t*  parameters,
+  static EntryFrame *build(const intptr_t*  parameters,
                            int              parameter_words,
-                           JavaCallWrapper* call_wrapper);
+                           JavaCallWrapper* call_wrapper,
+                           TRAPS);
  public:
   JavaCallWrapper *call_wrapper() const {
     return (JavaCallWrapper *) value_of_word(call_wrapper_off);
diff -r e0a1a502e402 -r 7b03170e1fcb src/cpu/zero/vm/fakeStubFrame_zero.hpp
--- a/src/cpu/zero/vm/fakeStubFrame_zero.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/cpu/zero/vm/fakeStubFrame_zero.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,6 +1,6 @@
 /*
  * Copyright 2003-2007 Sun Microsystems, Inc.  All Rights Reserved.
- * Copyright 2008 Red Hat, Inc.
+ * Copyright 2008, 2010 Red Hat, Inc.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -42,7 +42,7 @@
   };
 
  public:
-  static FakeStubFrame *build(ZeroStack* stack);
+  static FakeStubFrame *build(TRAPS);
 
  public:
   void identify_word(int   frame_index,
diff -r e0a1a502e402 -r 7b03170e1fcb src/cpu/zero/vm/globals_zero.hpp
--- a/src/cpu/zero/vm/globals_zero.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/cpu/zero/vm/globals_zero.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -35,6 +35,7 @@
 define_pd_global(bool,  UncommonNullCast,     true);
 
 define_pd_global(intx,  CodeEntryAlignment,   32);
+define_pd_global(intx,  OptoLoopAlignment,    16);
 define_pd_global(intx,  InlineFrequencyCount, 100);
 define_pd_global(intx,  PreInflateSpin,       10);
 
diff -r e0a1a502e402 -r 7b03170e1fcb src/cpu/zero/vm/interpreterFrame_zero.hpp
--- a/src/cpu/zero/vm/interpreterFrame_zero.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/cpu/zero/vm/interpreterFrame_zero.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,6 +1,6 @@
 /*
  * Copyright 2003-2007 Sun Microsystems, Inc.  All Rights Reserved.
- * Copyright 2008 Red Hat, Inc.
+ * Copyright 2008, 2010 Red Hat, Inc.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -55,10 +55,8 @@
   };
 
  public:
-  static InterpreterFrame *build(ZeroStack*      stack,
-                                 const methodOop method,
-                                 JavaThread*     thread);
-  static InterpreterFrame *build(ZeroStack* stack, int size);
+  static InterpreterFrame *build(const methodOop method, TRAPS);
+  static InterpreterFrame *build(int size, TRAPS);
 
  public:
   interpreterState interpreter_state() const {
diff -r e0a1a502e402 -r 7b03170e1fcb src/cpu/zero/vm/interpreterRT_zero.cpp
--- a/src/cpu/zero/vm/interpreterRT_zero.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/cpu/zero/vm/interpreterRT_zero.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,6 +1,6 @@
 /*
  * Copyright 2003-2005 Sun Microsystems, Inc.  All Rights Reserved.
- * Copyright 2007, 2008 Red Hat, Inc.
+ * Copyright 2007, 2008, 2010 Red Hat, Inc.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -140,9 +140,8 @@
   int required_words =
     (align_size_up(sizeof(ffi_cif), wordSize) >> LogBytesPerWord) +
     (method->is_static() ? 2 : 1) + method->size_of_parameters() + 1;
-  if (required_words > stack->available_words()) {
-    Unimplemented();
-  }
+
+  stack->overflow_check(required_words, CHECK_NULL);
 
   intptr_t *buf = (intptr_t *) stack->alloc(required_words * wordSize);
   SlowSignatureHandlerGenerator sshg(methodHandle(thread, method), buf);
diff -r e0a1a502e402 -r 7b03170e1fcb src/cpu/zero/vm/stack_zero.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/cpu/zero/vm/stack_zero.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -0,0 +1,73 @@
+/*
+ * Copyright 2003-2007 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2010 Red Hat, Inc.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+#include "incls/_precompiled.incl"
+#include "incls/_stack_zero.cpp.incl"
+
+void ZeroStack::handle_overflow(TRAPS) {
+  JavaThread *thread = (JavaThread *) THREAD;
+
+  // Set up the frame anchor if it isn't already
+  bool has_last_Java_frame = thread->has_last_Java_frame();
+  if (!has_last_Java_frame) {
+    ZeroFrame *frame = thread->top_zero_frame();
+    while (frame) {
+      if (frame->is_shark_frame())
+        break;
+
+      if (frame->is_interpreter_frame()) {
+        interpreterState istate =
+          frame->as_interpreter_frame()->interpreter_state();
+        if (istate->self_link() == istate)
+          break;
+      }
+
+      frame = frame->next();
+    }
+
+    if (frame == NULL)
+      fatal("unrecoverable stack overflow");
+
+    thread->set_last_Java_frame(frame);
+  }
+
+  // Throw the exception
+  switch (thread->thread_state()) {
+  case _thread_in_Java:
+    InterpreterRuntime::throw_StackOverflowError(thread);
+    break;
+
+  case _thread_in_vm:
+    Exceptions::throw_stack_overflow_exception(thread, __FILE__, __LINE__);
+    break;
+
+  default:
+    ShouldNotReachHere();
+  }
+
+  // Reset the frame anchor if necessary
+  if (!has_last_Java_frame)
+    thread->reset_last_Java_frame();
+}
diff -r e0a1a502e402 -r 7b03170e1fcb src/cpu/zero/vm/stack_zero.hpp
--- a/src/cpu/zero/vm/stack_zero.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/cpu/zero/vm/stack_zero.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,6 +1,6 @@
 /*
  * Copyright 2003-2007 Sun Microsystems, Inc.  All Rights Reserved.
- * Copyright 2008, 2009 Red Hat, Inc.
+ * Copyright 2008, 2009, 2010 Red Hat, Inc.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -29,9 +29,14 @@
   intptr_t *_top;  // the word past the end of the stack
   intptr_t *_sp;   // the top word on the stack
 
+ private:
+  int _shadow_pages_size; // how much ABI stack must we keep free?
+
  public:
   ZeroStack()
-    : _base(NULL), _top(NULL), _sp(NULL) {}
+    : _base(NULL), _top(NULL), _sp(NULL) {
+    _shadow_pages_size = StackShadowPages * os::vm_page_size();
+  }
 
   bool needs_setup() const {
     return _base == NULL;
@@ -81,6 +86,14 @@
     return _sp -= count;
   }
 
+  int shadow_pages_size() const {
+    return _shadow_pages_size;
+  }
+
+ public:
+  void overflow_check(int required_words, TRAPS);
+  static void handle_overflow(TRAPS);
+
  public:
   static ByteSize base_offset() {
     return byte_offset_of(ZeroStack, _base);
diff -r e0a1a502e402 -r 7b03170e1fcb src/cpu/zero/vm/stack_zero.inline.hpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/cpu/zero/vm/stack_zero.inline.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -0,0 +1,43 @@
+/*
+ * Copyright 2003-2007 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2010 Red Hat, Inc.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+// This function should match SharkStack::CreateStackOverflowCheck
+inline void ZeroStack::overflow_check(int required_words, TRAPS) {
+  JavaThread *thread = (JavaThread *) THREAD;
+
+  // Check the Zero stack
+  if (required_words > available_words()) {
+    handle_overflow(THREAD);
+    return;
+  }
+
+  // Check the ABI stack
+  address stack_top = thread->stack_base() - thread->stack_size();
+  int free_stack = ((address) &stack_top) - stack_top;
+  if (free_stack < shadow_pages_size()) {
+    handle_overflow(THREAD);
+    return;
+  }
+}
diff -r e0a1a502e402 -r 7b03170e1fcb src/cpu/zero/vm/stubGenerator_zero.cpp
--- a/src/cpu/zero/vm/stubGenerator_zero.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/cpu/zero/vm/stubGenerator_zero.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,6 +1,6 @@
 /*
  * Copyright 2003-2007 Sun Microsystems, Inc.  All Rights Reserved.
- * Copyright 2007, 2008 Red Hat, Inc.
+ * Copyright 2007, 2008, 2010 Red Hat, Inc.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -60,38 +60,43 @@
     }
 
     // Allocate and initialize our frame
-    thread->push_zero_frame(
-      EntryFrame::build(stack, parameters, parameter_words, call_wrapper));
+    EntryFrame *frame =
+      EntryFrame::build(parameters, parameter_words, call_wrapper, THREAD);
 
-    // Make the call
-    Interpreter::invoke_method(method, entry_point, THREAD);
-
-    // Store result depending on type
     if (!HAS_PENDING_EXCEPTION) {
-      switch (result_type) {
-      case T_INT:
-        *(jint *) result = *(jint *) stack->sp();
-        break;
-      case T_LONG:
-        *(jlong *) result = *(jlong *) stack->sp();
-        break;
-      case T_FLOAT:
-        *(jfloat *) result = *(jfloat *) stack->sp();
-        break;
-      case T_DOUBLE:
-        *(jdouble *) result = *(jdouble *) stack->sp();
-        break;
-      case T_OBJECT:
-        *(oop *) result = *(oop *) stack->sp();
-        break;
-      default:
-        ShouldNotReachHere();
+      // Push the frame
+      thread->push_zero_frame(frame);
+
+      // Make the call
+      Interpreter::invoke_method(method, entry_point, THREAD);
+
+      // Store the result
+      if (!HAS_PENDING_EXCEPTION) {
+        switch (result_type) {
+        case T_INT:
+          *(jint *) result = *(jint *) stack->sp();
+          break;
+        case T_LONG:
+          *(jlong *) result = *(jlong *) stack->sp();
+          break;
+        case T_FLOAT:
+          *(jfloat *) result = *(jfloat *) stack->sp();
+          break;
+        case T_DOUBLE:
+          *(jdouble *) result = *(jdouble *) stack->sp();
+          break;
+        case T_OBJECT:
+          *(oop *) result = *(oop *) stack->sp();
+          break;
+        default:
+          ShouldNotReachHere();
+        }
       }
+
+      // Unwind the frame
+      thread->pop_zero_frame();
     }
 
-    // Unwind our frame
-    thread->pop_zero_frame();
-
     // Tear down the stack if necessary
     if (stack_needs_teardown)
       stack->teardown();
@@ -226,13 +231,13 @@
   StubGenerator g(code, all);
 }
 
-EntryFrame *EntryFrame::build(ZeroStack*       stack,
-                              const intptr_t*  parameters,
+EntryFrame *EntryFrame::build(const intptr_t*  parameters,
                               int              parameter_words,
-                              JavaCallWrapper* call_wrapper) {
-  if (header_words + parameter_words > stack->available_words()) {
-    Unimplemented();
-  }
+                              JavaCallWrapper* call_wrapper,
+                              TRAPS) {
+
+  ZeroStack *stack = ((JavaThread *) THREAD)->zero_stack();
+  stack->overflow_check(header_words + parameter_words, CHECK_NULL);
 
   stack->push(0); // next_frame, filled in later
   intptr_t *fp = stack->sp();
diff -r e0a1a502e402 -r 7b03170e1fcb src/os_cpu/linux_zero/vm/thread_linux_zero.hpp
--- a/src/os_cpu/linux_zero/vm/thread_linux_zero.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/os_cpu/linux_zero/vm/thread_linux_zero.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,6 +1,6 @@
 /*
  * Copyright 2000-2007 Sun Microsystems, Inc.  All Rights Reserved.
- * Copyright 2007, 2008, 2009 Red Hat, Inc.
+ * Copyright 2007, 2008, 2009, 2010 Red Hat, Inc.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -68,12 +68,13 @@
 
  public:
   void set_last_Java_frame() {
-    JavaFrameAnchor *jfa = frame_anchor();
-    jfa->set_last_Java_sp((intptr_t *) top_zero_frame());
+    set_last_Java_frame(top_zero_frame());
   }
   void reset_last_Java_frame() {
-    JavaFrameAnchor *jfa = frame_anchor();
-    jfa->set_last_Java_sp(NULL);
+    set_last_Java_frame(NULL);
+  }
+  void set_last_Java_frame(ZeroFrame* frame) {
+    frame_anchor()->set_last_Java_sp((intptr_t *) frame);
   }
 
  private:
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/adlc/formssel.cpp
--- a/src/share/vm/adlc/formssel.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/adlc/formssel.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 1998-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 1998-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -3861,6 +3861,8 @@
         strcmp(opType,"RoundFloat")==0 ||
         strcmp(opType,"ReverseBytesI")==0 ||
         strcmp(opType,"ReverseBytesL")==0 ||
+        strcmp(opType,"ReverseBytesUS")==0 ||
+        strcmp(opType,"ReverseBytesS")==0 ||
         strcmp(opType,"Replicate16B")==0 ||
         strcmp(opType,"Replicate8B")==0 ||
         strcmp(opType,"Replicate4B")==0 ||
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/asm/codeBuffer.hpp
--- a/src/share/vm/asm/codeBuffer.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/asm/codeBuffer.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -40,6 +40,7 @@
                  Exceptions,     // Offset where exception handler lives
                  Deopt,          // Offset where deopt handler lives
                  DeoptMH,        // Offset where MethodHandle deopt handler lives
+                 UnwindHandler,  // Offset to default unwind handler
                  max_Entries };
 
   // special value to note codeBlobs where profile (forte) stack walking is
@@ -59,6 +60,7 @@
     _values[Exceptions    ] = -1;
     _values[Deopt         ] = -1;
     _values[DeoptMH       ] = -1;
+    _values[UnwindHandler ] = -1;
   }
 
   int value(Entries e) { return _values[e]; }
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/c1/c1_Compilation.cpp
--- a/src/share/vm/c1/c1_Compilation.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/c1/c1_Compilation.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -229,6 +229,10 @@
   code_offsets->set_value(CodeOffsets::DeoptMH, assembler->emit_deopt_handler());
   CHECK_BAILOUT();
 
+  // Emit the handler to remove the activation from the stack and
+  // dispatch to the caller.
+  offsets()->set_value(CodeOffsets::UnwindHandler, assembler->emit_unwind_handler());
+
   // done
   masm()->flush();
 }
@@ -312,7 +316,7 @@
     implicit_exception_table(),
     compiler(),
     _env->comp_level(),
-    needs_debug_information(),
+    true,
     has_unsafe_access()
   );
 }
@@ -445,8 +449,6 @@
   assert(_arena == NULL, "shouldn't only one instance of Compilation in existence at a time");
   _arena = Thread::current()->resource_area();
   _compilation = this;
-  _needs_debug_information = _env->jvmti_can_examine_or_deopt_anywhere() ||
-                               JavaMonitorsInStackTrace || AlwaysEmitDebugInfo || DeoptimizeALot;
   _exception_info_list = new ExceptionInfoList();
   _implicit_exception_table.set_size(0);
   compile_method();
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/c1/c1_Compilation.hpp
--- a/src/share/vm/c1/c1_Compilation.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/c1/c1_Compilation.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 1999-2007 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 1999-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -70,7 +70,6 @@
   int                _max_spills;
   FrameMap*          _frame_map;
   C1_MacroAssembler* _masm;
-  bool               _needs_debug_information;
   bool               _has_exception_handlers;
   bool               _has_fpu_code;
   bool               _has_unsafe_access;
@@ -117,7 +116,6 @@
   // accessors
   ciEnv* env() const                             { return _env; }
   AbstractCompiler* compiler() const             { return _compiler; }
-  bool needs_debug_information() const           { return _needs_debug_information; }
   bool has_exception_handlers() const            { return _has_exception_handlers; }
   bool has_fpu_code() const                      { return _has_fpu_code; }
   bool has_unsafe_access() const                 { return _has_unsafe_access; }
@@ -132,7 +130,6 @@
   CodeOffsets* offsets()                         { return &_offsets; }
 
   // setters
-  void set_needs_debug_information(bool f)       { _needs_debug_information = f; }
   void set_has_exception_handlers(bool f)        { _has_exception_handlers = f; }
   void set_has_fpu_code(bool f)                  { _has_fpu_code = f; }
   void set_has_unsafe_access(bool f)             { _has_unsafe_access = f; }
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/c1/c1_GraphBuilder.cpp
--- a/src/share/vm/c1/c1_GraphBuilder.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/c1/c1_GraphBuilder.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -829,12 +829,8 @@
     // should be left alone since there can be only one and all code
     // should dispatch to the same one.
     XHandler* h = handlers->handler_at(i);
-    if (h->handler_bci() != SynchronizationEntryBCI) {
-      h->set_entry_block(block_at(h->handler_bci()));
-    } else {
-      assert(h->entry_block()->is_set(BlockBegin::default_exception_handler_flag),
-             "should be the synthetic unlock block");
-    }
+    assert(h->handler_bci() != SynchronizationEntryBCI, "must be real");
+    h->set_entry_block(block_at(h->handler_bci()));
   }
   _jsr_xhandlers = handlers;
 }
@@ -1497,7 +1493,6 @@
 
 Dependencies* GraphBuilder::dependency_recorder() const {
   assert(DeoptC1, "need debug information");
-  compilation()->set_needs_debug_information(true);
   return compilation()->dependency_recorder();
 }
 
@@ -2867,19 +2862,6 @@
   _initial_state = state_at_entry();
   start_block->merge(_initial_state);
 
-  // setup an exception handler to do the unlocking and/or
-  // notification and unwind the frame.
-  BlockBegin* sync_handler = new BlockBegin(-1);
-  sync_handler->set(BlockBegin::exception_entry_flag);
-  sync_handler->set(BlockBegin::is_on_work_list_flag);
-  sync_handler->set(BlockBegin::default_exception_handler_flag);
-
-  ciExceptionHandler* desc = new ciExceptionHandler(method()->holder(), 0, method()->code_size(), -1, 0);
-  XHandler* h = new XHandler(desc);
-  h->set_entry_block(sync_handler);
-  scope_data()->xhandlers()->append(h);
-  scope_data()->set_has_handler();
-
   // complete graph
   _vmap        = new ValueMap();
   scope->compute_lock_stack_size();
@@ -2930,19 +2912,6 @@
   }
   CHECK_BAILOUT();
 
-  if (sync_handler && sync_handler->state() != NULL) {
-    Value lock = NULL;
-    if (method()->is_synchronized()) {
-      lock = method()->is_static() ? new Constant(new InstanceConstant(method()->holder()->java_mirror())) :
-                                     _initial_state->local_at(0);
-
-      sync_handler->state()->unlock();
-      sync_handler->state()->lock(scope, lock);
-
-    }
-    fill_sync_handler(lock, sync_handler, true);
-  }
-
   _start = setup_start_block(osr_bci, start_block, _osr_entry, _initial_state);
 
   eliminate_redundant_phis(_start);
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/c1/c1_Instruction.hpp
--- a/src/share/vm/c1/c1_Instruction.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/c1/c1_Instruction.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1628,11 +1628,10 @@
     backward_branch_target_flag   = 1 << 4,
     is_on_work_list_flag          = 1 << 5,
     was_visited_flag              = 1 << 6,
-    default_exception_handler_flag = 1 << 8, // identify block which represents the default exception handler
-    parser_loop_header_flag       = 1 << 9,  // set by parser to identify blocks where phi functions can not be created on demand
-    critical_edge_split_flag      = 1 << 10, // set for all blocks that are introduced when critical edges are split
-    linear_scan_loop_header_flag  = 1 << 11, // set during loop-detection for LinearScan
-    linear_scan_loop_end_flag     = 1 << 12  // set during loop-detection for LinearScan
+    parser_loop_header_flag       = 1 << 7,  // set by parser to identify blocks where phi functions can not be created on demand
+    critical_edge_split_flag      = 1 << 8, // set for all blocks that are introduced when critical edges are split
+    linear_scan_loop_header_flag  = 1 << 9, // set during loop-detection for LinearScan
+    linear_scan_loop_end_flag     = 1 << 10  // set during loop-detection for LinearScan
   };
 
   void set(Flag f)                               { _flags |= f; }
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/c1/c1_LIR.cpp
--- a/src/share/vm/c1/c1_LIR.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/c1/c1_LIR.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -626,8 +626,7 @@
       break;
     }
 
-    case lir_throw:
-    case lir_unwind: {
+    case lir_throw: {
       assert(op->as_Op2() != NULL, "must be");
       LIR_Op2* op2 = (LIR_Op2*)op;
 
@@ -639,6 +638,17 @@
       break;
     }
 
+    case lir_unwind: {
+      assert(op->as_Op1() != NULL, "must be");
+      LIR_Op1* op1 = (LIR_Op1*)op;
+
+      assert(op1->_info == NULL, "no info");
+      assert(op1->_opr->is_valid(), "exception oop");         do_input(op1->_opr);
+      assert(op1->_result->is_illegal(), "no result");
+
+      break;
+    }
+
 
     case lir_tan:
     case lir_sin:
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/c1/c1_LIR.hpp
--- a/src/share/vm/c1/c1_LIR.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/c1/c1_LIR.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -801,6 +801,7 @@
       , lir_monaddr
       , lir_roundfp
       , lir_safepoint
+      , lir_unwind
   , end_op1
   , begin_op2
       , lir_cmp
@@ -830,7 +831,6 @@
       , lir_ushr
       , lir_alloc_array
       , lir_throw
-      , lir_unwind
       , lir_compare_to
   , end_op2
   , begin_op3
@@ -1827,8 +1827,12 @@
   void logical_xor (LIR_Opr left, LIR_Opr right, LIR_Opr dst) { append(new LIR_Op2(lir_logic_xor,  left, right, dst)); }
 
   void null_check(LIR_Opr opr, CodeEmitInfo* info)         { append(new LIR_Op1(lir_null_check, opr, info)); }
-  void throw_exception(LIR_Opr exceptionPC, LIR_Opr exceptionOop, CodeEmitInfo* info) { append(new LIR_Op2(lir_throw, exceptionPC, exceptionOop, LIR_OprFact::illegalOpr, info)); }
-  void unwind_exception(LIR_Opr exceptionPC, LIR_Opr exceptionOop, CodeEmitInfo* info) { append(new LIR_Op2(lir_unwind, exceptionPC, exceptionOop, LIR_OprFact::illegalOpr, info)); }
+  void throw_exception(LIR_Opr exceptionPC, LIR_Opr exceptionOop, CodeEmitInfo* info) {
+    append(new LIR_Op2(lir_throw, exceptionPC, exceptionOop, LIR_OprFact::illegalOpr, info));
+  }
+  void unwind_exception(LIR_Opr exceptionOop) {
+    append(new LIR_Op1(lir_unwind, exceptionOop));
+  }
 
   void compare_to (LIR_Opr left, LIR_Opr right, LIR_Opr dst) {
     append(new LIR_Op2(lir_compare_to,  left, right, dst));
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/c1/c1_LIRAssembler.cpp
--- a/src/share/vm/c1/c1_LIRAssembler.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/c1/c1_LIRAssembler.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -552,6 +552,10 @@
       monitor_address(op->in_opr()->as_constant_ptr()->as_jint(), op->result_opr());
       break;
 
+    case lir_unwind:
+      unwind_op(op->in_opr());
+      break;
+
     default:
       Unimplemented();
       break;
@@ -707,8 +711,7 @@
       break;
 
     case lir_throw:
-    case lir_unwind:
-      throw_op(op->in_opr1(), op->in_opr2(), op->info(), op->code() == lir_unwind);
+      throw_op(op->in_opr1(), op->in_opr2(), op->info());
       break;
 
     default:
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/c1/c1_LIRAssembler.hpp
--- a/src/share/vm/c1/c1_LIRAssembler.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/c1/c1_LIRAssembler.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -39,6 +39,8 @@
   Instruction*       _pending_non_safepoint;
   int                _pending_non_safepoint_offset;
 
+  Label              _unwind_handler_entry;
+
 #ifdef ASSERT
   BlockList          _branch_target_blocks;
   void check_no_unbound_labels();
@@ -134,6 +136,7 @@
 
   // code patterns
   int  emit_exception_handler();
+  int  emit_unwind_handler();
   void emit_exception_entries(ExceptionInfoList* info_list);
   int  emit_deopt_handler();
 
@@ -217,7 +220,8 @@
 
   void build_frame();
 
-  void throw_op(LIR_Opr exceptionPC, LIR_Opr exceptionOop, CodeEmitInfo* info, bool unwind);
+  void throw_op(LIR_Opr exceptionPC, LIR_Opr exceptionOop, CodeEmitInfo* info);
+  void unwind_op(LIR_Opr exceptionOop);
   void monitor_address(int monitor_ix, LIR_Opr dst);
 
   void align_backward_branch_target();
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/c1/c1_LIRGenerator.cpp
--- a/src/share/vm/c1/c1_LIRGenerator.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/c1/c1_LIRGenerator.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1765,35 +1765,17 @@
     __ null_check(exception_opr, new CodeEmitInfo(info, true));
   }
 
-  if (compilation()->env()->jvmti_can_post_on_exceptions() &&
-      !block()->is_set(BlockBegin::default_exception_handler_flag)) {
+  if (compilation()->env()->jvmti_can_post_on_exceptions()) {
     // we need to go through the exception lookup path to get JVMTI
     // notification done
     unwind = false;
   }
 
-  assert(!block()->is_set(BlockBegin::default_exception_handler_flag) || unwind,
-         "should be no more handlers to dispatch to");
-
-  if (compilation()->env()->dtrace_method_probes() &&
-      block()->is_set(BlockBegin::default_exception_handler_flag)) {
-    // notify that this frame is unwinding
-    BasicTypeList signature;
-    signature.append(T_INT);    // thread
-    signature.append(T_OBJECT); // methodOop
-    LIR_OprList* args = new LIR_OprList();
-    args->append(getThreadPointer());
-    LIR_Opr meth = new_register(T_OBJECT);
-    __ oop2reg(method()->constant_encoding(), meth);
-    args->append(meth);
-    call_runtime(&signature, args, CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_method_exit), voidType, NULL);
-  }
-
   // move exception oop into fixed register
   __ move(exception_opr, exceptionOopOpr());
 
   if (unwind) {
-    __ unwind_exception(LIR_OprFact::illegalOpr, exceptionOopOpr(), info);
+    __ unwind_exception(exceptionOopOpr());
   } else {
     __ throw_exception(exceptionPcOpr(), exceptionOopOpr(), info);
   }
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/c1/c1_LinearScan.cpp
--- a/src/share/vm/c1/c1_LinearScan.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/c1/c1_LinearScan.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2005-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2005-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -2814,9 +2814,6 @@
 
 
 void LinearScan::compute_debug_info(CodeEmitInfo* info, int op_id) {
-  if (!compilation()->needs_debug_information()) {
-    return;
-  }
   TRACE_LINEAR_SCAN(3, tty->print_cr("creating debug information at op_id %d", op_id));
 
   IRScope* innermost_scope = info->scope();
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/c1/c1_globals.hpp
--- a/src/share/vm/c1/c1_globals.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/c1/c1_globals.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2007 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2000-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -252,9 +252,6 @@
   develop(bool, BailoutOnExceptionHandlers, false,                          \
           "bailout of compilation for methods with exception handlers")     \
                                                                             \
-  develop(bool, AlwaysEmitDebugInfo, false,                                 \
-          "always emit debug info")                                         \
-                                                                            \
   develop(bool, InstallMethods, true,                                       \
           "Install methods at the end of successful compilations")          \
                                                                             \
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/ci/bcEscapeAnalyzer.cpp
--- a/src/share/vm/ci/bcEscapeAnalyzer.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/ci/bcEscapeAnalyzer.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1408,8 +1408,11 @@
 }
 
 void BCEscapeAnalyzer::copy_dependencies(Dependencies *deps) {
-  if(!has_dependencies())
-    return;
+  if (ciEnv::current()->jvmti_can_hotswap_or_post_breakpoint()) {
+    // Also record evol dependencies so redefinition of the
+    // callee will trigger recompilation.
+    deps->assert_evol_method(method());
+  }
   for (int i = 0; i < _dependencies.length(); i+=2) {
     ciKlass *k = _dependencies[i]->as_klass();
     ciMethod *m = _dependencies[i+1]->as_method();
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/ci/ciEnv.cpp
--- a/src/share/vm/ci/ciEnv.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/ci/ciEnv.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -176,7 +176,6 @@
   // Get Jvmti capabilities under lock to get consistant values.
   MutexLocker mu(JvmtiThreadState_lock);
   _jvmti_can_hotswap_or_post_breakpoint = JvmtiExport::can_hotswap_or_post_breakpoint();
-  _jvmti_can_examine_or_deopt_anywhere  = JvmtiExport::can_examine_or_deopt_anywhere();
   _jvmti_can_access_local_variables     = JvmtiExport::can_access_local_variables();
   _jvmti_can_post_on_exceptions         = JvmtiExport::can_post_on_exceptions();
 }
@@ -887,8 +886,6 @@
     if (!failing() &&
         ( (!jvmti_can_hotswap_or_post_breakpoint() &&
            JvmtiExport::can_hotswap_or_post_breakpoint()) ||
-          (!jvmti_can_examine_or_deopt_anywhere() &&
-           JvmtiExport::can_examine_or_deopt_anywhere()) ||
           (!jvmti_can_access_local_variables() &&
            JvmtiExport::can_access_local_variables()) ||
           (!jvmti_can_post_on_exceptions() &&
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/ci/ciEnv.hpp
--- a/src/share/vm/ci/ciEnv.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/ci/ciEnv.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -55,7 +55,6 @@
 
   // Cache Jvmti state
   bool  _jvmti_can_hotswap_or_post_breakpoint;
-  bool  _jvmti_can_examine_or_deopt_anywhere;
   bool  _jvmti_can_access_local_variables;
   bool  _jvmti_can_post_on_exceptions;
 
@@ -257,7 +256,6 @@
   // Cache Jvmti state
   void  cache_jvmti_state();
   bool  jvmti_can_hotswap_or_post_breakpoint() const { return _jvmti_can_hotswap_or_post_breakpoint; }
-  bool  jvmti_can_examine_or_deopt_anywhere()  const { return _jvmti_can_examine_or_deopt_anywhere; }
   bool  jvmti_can_access_local_variables()     const { return _jvmti_can_access_local_variables; }
   bool  jvmti_can_post_on_exceptions()         const { return _jvmti_can_post_on_exceptions; }
 
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/classfile/vmSymbols.hpp
--- a/src/share/vm/classfile/vmSymbols.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/classfile/vmSymbols.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 1997-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 1997-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -357,6 +357,8 @@
   template(void_double_signature,                     "()D")                                      \
   template(int_void_signature,                        "(I)V")                                     \
   template(int_int_signature,                         "(I)I")                                     \
+  template(char_char_signature,                       "(C)C")                                     \
+  template(short_short_signature,                     "(S)S")                                     \
   template(int_bool_signature,                        "(I)Z")                                     \
   template(float_int_signature,                       "(F)I")                                     \
   template(double_long_signature,                     "(D)J")                                     \
@@ -585,6 +587,10 @@
    do_name(     reverseBytes_name,                               "reverseBytes")                                        \
   do_intrinsic(_reverseBytes_l,           java_lang_Long,         reverseBytes_name,        long_long_signature, F_S)   \
     /*  (symbol reverseBytes_name defined above) */                                                                     \
+  do_intrinsic(_reverseBytes_c,           java_lang_Character,    reverseBytes_name,        char_char_signature, F_S)   \
+    /*  (symbol reverseBytes_name defined above) */                                                                     \
+  do_intrinsic(_reverseBytes_s,           java_lang_Short,        reverseBytes_name,        short_short_signature, F_S) \
+    /*  (symbol reverseBytes_name defined above) */                                                                     \
                                                                                                                         \
   do_intrinsic(_identityHashCode,         java_lang_System,       identityHashCode_name, object_int_signature,   F_S)   \
    do_name(     identityHashCode_name,                           "identityHashCode")                                    \
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/code/nmethod.cpp
--- a/src/share/vm/code/nmethod.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/code/nmethod.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -685,6 +685,7 @@
     _exception_offset        = 0;
     _deoptimize_offset       = 0;
     _deoptimize_mh_offset    = 0;
+    _unwind_handler_offset   = -1;
     _trap_offset             = offsets->value(CodeOffsets::Dtrace_trap);
     _orig_pc_offset          = 0;
     _stub_offset             = data_offset();
@@ -798,6 +799,11 @@
     _exception_offset        = _stub_offset + offsets->value(CodeOffsets::Exceptions);
     _deoptimize_offset       = _stub_offset + offsets->value(CodeOffsets::Deopt);
     _deoptimize_mh_offset    = _stub_offset + offsets->value(CodeOffsets::DeoptMH);
+    if (offsets->value(CodeOffsets::UnwindHandler) != -1) {
+      _unwind_handler_offset   = instructions_offset() + offsets->value(CodeOffsets::UnwindHandler);
+    } else {
+      _unwind_handler_offset   = -1;
+    }
     _consts_offset           = instructions_offset() + code_buffer->total_offset_of(code_buffer->consts()->start());
     _scopes_data_offset      = data_offset();
     _scopes_pcs_offset       = _scopes_data_offset   + round_to(debug_info->data_size         (), oopSize);
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/code/nmethod.hpp
--- a/src/share/vm/code/nmethod.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/code/nmethod.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -154,6 +154,9 @@
   // All deoptee's at a MethodHandle call site will resume execution
   // at this location described by this offset.
   int _deoptimize_mh_offset;
+  // Offset of the unwind handler if it exists
+  int _unwind_handler_offset;
+
 #ifdef HAVE_DTRACE_H
   int _trap_offset;
 #endif // def HAVE_DTRACE_H
@@ -341,6 +344,7 @@
   address exception_begin       () const          { return           header_begin() + _exception_offset     ; }
   address deopt_handler_begin   () const          { return           header_begin() + _deoptimize_offset    ; }
   address deopt_mh_handler_begin() const          { return           header_begin() + _deoptimize_mh_offset ; }
+  address unwind_handler_begin  () const          { return _unwind_handler_offset != -1 ? (header_begin() + _unwind_handler_offset) : NULL; }
   address stub_begin            () const          { return           header_begin() + _stub_offset          ; }
   address stub_end              () const          { return           header_begin() + _consts_offset        ; }
   address consts_begin          () const          { return           header_begin() + _consts_offset        ; }
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/concurrentMarkSweep/cmsCollectorPolicy.hpp
--- a/src/share/vm/gc_implementation/concurrentMarkSweep/cmsCollectorPolicy.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/concurrentMarkSweep/cmsCollectorPolicy.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2007 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2007-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -32,11 +32,10 @@
   ConcurrentMarkSweepPolicy* as_concurrent_mark_sweep_policy() { return this; }
 
   void initialize_gc_policy_counters();
-#if 1
+
   virtual void initialize_size_policy(size_t init_eden_size,
                                       size_t init_promo_size,
                                       size_t init_survivor_size);
-#endif
 
   // Returns true if the incremental mode is enabled.
   virtual bool has_soft_ended_eden();
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp
--- a/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -1815,8 +1815,19 @@
     do_compaction_work(clear_all_soft_refs);
 
     // Has the GC time limit been exceeded?
-    check_gc_time_limit();
-
+    DefNewGeneration* young_gen = _young_gen->as_DefNewGeneration();
+    size_t max_eden_size = young_gen->max_capacity() -
+                           young_gen->to()->capacity() -
+                           young_gen->from()->capacity();
+    GenCollectedHeap* gch = GenCollectedHeap::heap();
+    GCCause::Cause gc_cause = gch->gc_cause();
+    size_policy()->check_gc_overhead_limit(_young_gen->used(),
+                                           young_gen->eden()->used(),
+                                           _cmsGen->max_capacity(),
+                                           max_eden_size,
+                                           full,
+                                           gc_cause,
+                                           gch->collector_policy());
   } else {
     do_mark_sweep_work(clear_all_soft_refs, first_state,
       should_start_over);
@@ -1828,55 +1839,6 @@
   return;
 }
 
-void CMSCollector::check_gc_time_limit() {
-
-  // Ignore explicit GC's.  Exiting here does not set the flag and
-  // does not reset the count.  Updating of the averages for system
-  // GC's is still controlled by UseAdaptiveSizePolicyWithSystemGC.
-  GCCause::Cause gc_cause = GenCollectedHeap::heap()->gc_cause();
-  if (GCCause::is_user_requested_gc(gc_cause) ||
-      GCCause::is_serviceability_requested_gc(gc_cause)) {
-    return;
-  }
-
-  // Calculate the fraction of the CMS generation was freed during
-  // the last collection.
-  // Only consider the STW compacting cost for now.
-  //
-  // Note that the gc time limit test only works for the collections
-  // of the young gen + tenured gen and not for collections of the
-  // permanent gen.  That is because the calculation of the space
-  // freed by the collection is the free space in the young gen +
-  // tenured gen.
-
-  double fraction_free =
-    ((double)_cmsGen->free())/((double)_cmsGen->max_capacity());
-  if ((100.0 * size_policy()->compacting_gc_cost()) >
-         ((double) GCTimeLimit) &&
-        ((fraction_free * 100) < GCHeapFreeLimit)) {
-    size_policy()->inc_gc_time_limit_count();
-    if (UseGCOverheadLimit &&
-        (size_policy()->gc_time_limit_count() >
-         AdaptiveSizePolicyGCTimeLimitThreshold)) {
-      size_policy()->set_gc_time_limit_exceeded(true);
-      // Avoid consecutive OOM due to the gc time limit by resetting
-      // the counter.
-      size_policy()->reset_gc_time_limit_count();
-      if (PrintGCDetails) {
-        gclog_or_tty->print_cr("      GC is exceeding overhead limit "
-          "of %d%%", GCTimeLimit);
-      }
-    } else {
-      if (PrintGCDetails) {
-        gclog_or_tty->print_cr("      GC would exceed overhead limit "
-          "of %d%%", GCTimeLimit);
-      }
-    }
-  } else {
-    size_policy()->reset_gc_time_limit_count();
-  }
-}
-
 // Resize the perm generation and the tenured generation
 // after obtaining the free list locks for the
 // two generations.
@@ -6182,6 +6144,11 @@
       }
       curAddr = chunk.end();
     }
+    // A successful mostly concurrent collection has been done.
+    // Because only the full (i.e., concurrent mode failure) collections
+    // are being measured for gc overhead limits, clean the "near" flag
+    // and count.
+    sp->reset_gc_overhead_limit_count();
     _collectorState = Idling;
   } else {
     // already have the lock
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.hpp
--- a/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -570,10 +570,6 @@
   ConcurrentMarkSweepPolicy* _collector_policy;
   ConcurrentMarkSweepPolicy* collector_policy() { return _collector_policy; }
 
-  // Check whether the gc time limit has been
-  // exceeded and set the size policy flag
-  // appropriately.
-  void check_gc_time_limit();
   // XXX Move these to CMSStats ??? FIX ME !!!
   elapsedTimer _inter_sweep_timer;   // time between sweeps
   elapsedTimer _intra_sweep_timer;   // time _in_ sweeps
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/g1/concurrentG1RefineThread.cpp
--- a/src/share/vm/gc_implementation/g1/concurrentG1RefineThread.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/g1/concurrentG1RefineThread.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -69,9 +69,9 @@
   G1CollectorPolicy* g1p = g1h->g1_policy();
   if (g1p->adaptive_young_list_length()) {
     int regions_visited = 0;
-    g1h->young_list_rs_length_sampling_init();
-    while (g1h->young_list_rs_length_sampling_more()) {
-      g1h->young_list_rs_length_sampling_next();
+    g1h->young_list()->rs_length_sampling_init();
+    while (g1h->young_list()->rs_length_sampling_more()) {
+      g1h->young_list()->rs_length_sampling_next();
       ++regions_visited;
 
       // we try to yield every time we visit 10 regions
@@ -162,6 +162,7 @@
   if (_worker_id >= cg1r()->worker_thread_num()) {
     run_young_rs_sampling();
     terminate();
+    return;
   }
 
   _vtime_start = os::elapsedVTime();
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/g1/concurrentMark.cpp
--- a/src/share/vm/gc_implementation/g1/concurrentMark.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/g1/concurrentMark.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -767,7 +767,8 @@
   _has_aborted = false;
 
   if (G1PrintReachableAtInitialMark) {
-    print_reachable(true, "before");
+    print_reachable("at-cycle-start",
+                    true /* use_prev_marking */, true /* all */);
   }
 
   // Initialise marking structures. This has to be done in a STW phase.
@@ -1979,19 +1980,21 @@
 
 #ifndef PRODUCT
 
-class ReachablePrinterOopClosure: public OopClosure {
+class PrintReachableOopClosure: public OopClosure {
 private:
   G1CollectedHeap* _g1h;
   CMBitMapRO*      _bitmap;
   outputStream*    _out;
   bool             _use_prev_marking;
+  bool             _all;
 
 public:
-  ReachablePrinterOopClosure(CMBitMapRO*   bitmap,
-                             outputStream* out,
-                             bool          use_prev_marking) :
+  PrintReachableOopClosure(CMBitMapRO*   bitmap,
+                           outputStream* out,
+                           bool          use_prev_marking,
+                           bool          all) :
     _g1h(G1CollectedHeap::heap()),
-    _bitmap(bitmap), _out(out), _use_prev_marking(use_prev_marking) { }
+    _bitmap(bitmap), _out(out), _use_prev_marking(use_prev_marking), _all(all) { }
 
   void do_oop(narrowOop* p) { do_oop_work(p); }
   void do_oop(      oop* p) { do_oop_work(p); }
@@ -2001,9 +2004,11 @@
     const char* str = NULL;
     const char* str2 = "";
 
-    if (!_g1h->is_in_g1_reserved(obj))
-      str = "outside G1 reserved";
-    else {
+    if (obj == NULL) {
+      str = "";
+    } else if (!_g1h->is_in_g1_reserved(obj)) {
+      str = " O";
+    } else {
       HeapRegion* hr  = _g1h->heap_region_containing(obj);
       guarantee(hr != NULL, "invariant");
       bool over_tams = false;
@@ -2012,74 +2017,67 @@
       } else {
         over_tams = hr->obj_allocated_since_next_marking(obj);
       }
+      bool marked = _bitmap->isMarked((HeapWord*) obj);
 
       if (over_tams) {
-        str = "over TAMS";
-        if (_bitmap->isMarked((HeapWord*) obj)) {
+        str = " >";
+        if (marked) {
           str2 = " AND MARKED";
         }
-      } else if (_bitmap->isMarked((HeapWord*) obj)) {
-        str = "marked";
+      } else if (marked) {
+        str = " M";
       } else {
-        str = "#### NOT MARKED ####";
+        str = " NOT";
       }
     }
 
-    _out->print_cr("    "PTR_FORMAT" contains "PTR_FORMAT" %s%s",
+    _out->print_cr("  "PTR_FORMAT": "PTR_FORMAT"%s%s",
                    p, (void*) obj, str, str2);
   }
 };
 
-class ReachablePrinterClosure: public BitMapClosure {
+class PrintReachableObjectClosure : public ObjectClosure {
 private:
   CMBitMapRO*   _bitmap;
   outputStream* _out;
   bool          _use_prev_marking;
+  bool          _all;
+  HeapRegion*   _hr;
 
 public:
-  ReachablePrinterClosure(CMBitMapRO*   bitmap,
-                          outputStream* out,
-                          bool          use_prev_marking) :
-    _bitmap(bitmap), _out(out), _use_prev_marking(use_prev_marking) { }
-
-  bool do_bit(size_t offset) {
-    HeapWord* addr = _bitmap->offsetToHeapWord(offset);
-    ReachablePrinterOopClosure oopCl(_bitmap, _out, _use_prev_marking);
-
-    _out->print_cr("  obj "PTR_FORMAT", offset %10d (marked)", addr, offset);
-    oop(addr)->oop_iterate(&oopCl);
-    _out->print_cr("");
-
-    return true;
+  PrintReachableObjectClosure(CMBitMapRO*   bitmap,
+                              outputStream* out,
+                              bool          use_prev_marking,
+                              bool          all,
+                              HeapRegion*   hr) :
+    _bitmap(bitmap), _out(out),
+    _use_prev_marking(use_prev_marking), _all(all), _hr(hr) { }
+
+  void do_object(oop o) {
+    bool over_tams;
+    if (_use_prev_marking) {
+      over_tams = _hr->obj_allocated_since_prev_marking(o);
+    } else {
+      over_tams = _hr->obj_allocated_since_next_marking(o);
+    }
+    bool marked = _bitmap->isMarked((HeapWord*) o);
+    bool print_it = _all || over_tams || marked;
+
+    if (print_it) {
+      _out->print_cr(" "PTR_FORMAT"%s",
+                     o, (over_tams) ? " >" : (marked) ? " M" : "");
+      PrintReachableOopClosure oopCl(_bitmap, _out, _use_prev_marking, _all);
+      o->oop_iterate(&oopCl);
+    }
   }
 };
 
-class ObjInRegionReachablePrinterClosure : public ObjectClosure {
+class PrintReachableRegionClosure : public HeapRegionClosure {
 private:
   CMBitMapRO*   _bitmap;
   outputStream* _out;
   bool          _use_prev_marking;
-
-public:
-  ObjInRegionReachablePrinterClosure(CMBitMapRO*   bitmap,
-                                     outputStream* out,
-                                     bool          use_prev_marking) :
-    _bitmap(bitmap), _out(out), _use_prev_marking(use_prev_marking) { }
-
-  void do_object(oop o) {
-    ReachablePrinterOopClosure oopCl(_bitmap, _out, _use_prev_marking);
-
-    _out->print_cr("  obj "PTR_FORMAT" (over TAMS)", (void*) o);
-    o->oop_iterate(&oopCl);
-    _out->print_cr("");
-  }
-};
-
-class RegionReachablePrinterClosure : public HeapRegionClosure {
-private:
-  CMBitMapRO*   _bitmap;
-  outputStream* _out;
-  bool          _use_prev_marking;
+  bool          _all;
 
 public:
   bool doHeapRegion(HeapRegion* hr) {
@@ -2094,22 +2092,35 @@
     }
     _out->print_cr("** ["PTR_FORMAT", "PTR_FORMAT"] top: "PTR_FORMAT" "
                    "TAMS: "PTR_FORMAT, b, e, t, p);
-    _out->print_cr("");
-
-    ObjInRegionReachablePrinterClosure ocl(_bitmap, _out, _use_prev_marking);
-    hr->object_iterate_mem_careful(MemRegion(p, t), &ocl);
+    _out->cr();
+
+    HeapWord* from = b;
+    HeapWord* to   = t;
+
+    if (to > from) {
+      _out->print_cr("Objects in ["PTR_FORMAT", "PTR_FORMAT"]", from, to);
+      _out->cr();
+      PrintReachableObjectClosure ocl(_bitmap, _out,
+                                      _use_prev_marking, _all, hr);
+      hr->object_iterate_mem_careful(MemRegion(from, to), &ocl);
+      _out->cr();
+    }
 
     return false;
   }
 
-  RegionReachablePrinterClosure(CMBitMapRO*   bitmap,
-                                outputStream* out,
-                                bool          use_prev_marking) :
-    _bitmap(bitmap), _out(out), _use_prev_marking(use_prev_marking) { }
+  PrintReachableRegionClosure(CMBitMapRO*   bitmap,
+                              outputStream* out,
+                              bool          use_prev_marking,
+                              bool          all) :
+    _bitmap(bitmap), _out(out), _use_prev_marking(use_prev_marking), _all(all) { }
 };
 
-void ConcurrentMark::print_reachable(bool use_prev_marking, const char* str) {
-  gclog_or_tty->print_cr("== Doing reachable object dump... ");
+void ConcurrentMark::print_reachable(const char* str,
+                                     bool use_prev_marking,
+                                     bool all) {
+  gclog_or_tty->cr();
+  gclog_or_tty->print_cr("== Doing heap dump... ");
 
   if (G1PrintReachableBaseFile == NULL) {
     gclog_or_tty->print_cr("  #### error: no base file defined");
@@ -2144,19 +2155,14 @@
   out->print_cr("-- USING %s", (use_prev_marking) ? "PTAMS" : "NTAMS");
   out->cr();
 
-  RegionReachablePrinterClosure rcl(bitmap, out, use_prev_marking);
-  out->print_cr("--- ITERATING OVER REGIONS WITH TAMS < TOP");
-  out->cr();
-  _g1h->heap_region_iterate(&rcl);
+  out->print_cr("--- ITERATING OVER REGIONS");
   out->cr();
-
-  ReachablePrinterClosure cl(bitmap, out, use_prev_marking);
-  out->print_cr("--- ITERATING OVER MARKED OBJECTS ON THE BITMAP");
-  out->cr();
-  bitmap->iterate(&cl);
+  PrintReachableRegionClosure rcl(bitmap, out, use_prev_marking, all);
+  _g1h->heap_region_iterate(&rcl);
   out->cr();
 
   gclog_or_tty->print_cr("  done");
+  gclog_or_tty->flush();
 }
 
 #endif // PRODUCT
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/g1/concurrentMark.hpp
--- a/src/share/vm/gc_implementation/g1/concurrentMark.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/g1/concurrentMark.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -652,11 +652,24 @@
   // we do nothing.
   void markAndGrayObjectIfNecessary(oop p);
 
-  // This iterates over the marking bitmap (either prev or next) and
-  // prints out all objects that are marked on the bitmap and indicates
-  // whether what they point to is also marked or not. It also iterates
-  // the objects over TAMS (either prev or next).
-  void print_reachable(bool use_prev_marking, const char* str);
+  // It iterates over the heap and for each object it comes across it
+  // will dump the contents of its reference fields, as well as
+  // liveness information for the object and its referents. The dump
+  // will be written to a file with the following name:
+  // G1PrintReachableBaseFile + "." + str. use_prev_marking decides
+  // whether the prev (use_prev_marking == true) or next
+  // (use_prev_marking == false) marking information will be used to
+  // determine the liveness of each object / referent. If all is true,
+  // all objects in the heap will be dumped, otherwise only the live
+  // ones. In the dump the following symbols / abbreviations are used:
+  //   M : an explicitly live object (its bitmap bit is set)
+  //   > : an implicitly live object (over tams)
+  //   O : an object outside the G1 heap (typically: in the perm gen)
+  //   NOT : a reference field whose referent is not live
+  //   AND MARKED : indicates that an object is both explicitly and
+  //   implicitly live (it should be one or the other, not both)
+  void print_reachable(const char* str,
+                       bool use_prev_marking, bool all) PRODUCT_RETURN;
 
   // Clear the next marking bitmap (will be called concurrently).
   void clearNextBitmap();
@@ -720,6 +733,19 @@
   // to determine whether any heap regions are located above the finger.
   void registerCSetRegion(HeapRegion* hr);
 
+  // Registers the maximum region-end associated with a set of
+  // regions with CM. Again this is used to determine whether any
+  // heap regions are located above the finger.
+  void register_collection_set_finger(HeapWord* max_finger) {
+    // max_finger is the highest heap region end of the regions currently
+    // contained in the collection set. If this value is larger than
+    // _min_finger then we need to gray objects.
+    // This routine is like registerCSetRegion but for an entire
+    // collection of regions.
+    if (max_finger > _min_finger)
+      _should_gray_objects = true;
+  }
+
   // Returns "true" if at least one mark has been completed.
   bool at_least_one_mark_complete() { return _at_least_one_mark_complete; }
 
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp
--- a/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -30,7 +30,7 @@
 // turn it on so that the contents of the young list (scan-only /
 // to-be-collected) are printed at "strategic" points before / during
 // / after the collection --- this is useful for debugging
-#define SCAN_ONLY_VERBOSE 0
+#define YOUNG_LIST_VERBOSE 0
 // CURRENT STATUS
 // This file is under construction.  Search for "FIXME".
 
@@ -133,8 +133,7 @@
 
 YoungList::YoungList(G1CollectedHeap* g1h)
   : _g1h(g1h), _head(NULL),
-    _scan_only_head(NULL), _scan_only_tail(NULL), _curr_scan_only(NULL),
-    _length(0), _scan_only_length(0),
+    _length(0),
     _last_sampled_rs_lengths(0),
     _survivor_head(NULL), _survivor_tail(NULL), _survivor_length(0)
 {
@@ -166,48 +165,6 @@
   ++_survivor_length;
 }
 
-HeapRegion* YoungList::pop_region() {
-  while (_head != NULL) {
-    assert( length() > 0, "list should not be empty" );
-    HeapRegion* ret = _head;
-    _head = ret->get_next_young_region();
-    ret->set_next_young_region(NULL);
-    --_length;
-    assert(ret->is_young(), "region should be very young");
-
-    // Replace 'Survivor' region type with 'Young'. So the region will
-    // be treated as a young region and will not be 'confused' with
-    // newly created survivor regions.
-    if (ret->is_survivor()) {
-      ret->set_young();
-    }
-
-    if (!ret->is_scan_only()) {
-      return ret;
-    }
-
-    // scan-only, we'll add it to the scan-only list
-    if (_scan_only_tail == NULL) {
-      guarantee( _scan_only_head == NULL, "invariant" );
-
-      _scan_only_head = ret;
-      _curr_scan_only = ret;
-    } else {
-      guarantee( _scan_only_head != NULL, "invariant" );
-      _scan_only_tail->set_next_young_region(ret);
-    }
-    guarantee( ret->get_next_young_region() == NULL, "invariant" );
-    _scan_only_tail = ret;
-
-    // no need to be tagged as scan-only any more
-    ret->set_young();
-
-    ++_scan_only_length;
-  }
-  assert( length() == 0, "list should be empty" );
-  return NULL;
-}
-
 void YoungList::empty_list(HeapRegion* list) {
   while (list != NULL) {
     HeapRegion* next = list->get_next_young_region();
@@ -225,12 +182,6 @@
   _head = NULL;
   _length = 0;
 
-  empty_list(_scan_only_head);
-  _scan_only_head = NULL;
-  _scan_only_tail = NULL;
-  _scan_only_length = 0;
-  _curr_scan_only = NULL;
-
   empty_list(_survivor_head);
   _survivor_head = NULL;
   _survivor_tail = NULL;
@@ -248,11 +199,11 @@
   HeapRegion* curr = _head;
   HeapRegion* last = NULL;
   while (curr != NULL) {
-    if (!curr->is_young() || curr->is_scan_only()) {
+    if (!curr->is_young()) {
       gclog_or_tty->print_cr("### YOUNG REGION "PTR_FORMAT"-"PTR_FORMAT" "
-                             "incorrectly tagged (%d, %d)",
+                             "incorrectly tagged (y: %d, surv: %d)",
                              curr->bottom(), curr->end(),
-                             curr->is_young(), curr->is_scan_only());
+                             curr->is_young(), curr->is_survivor());
       ret = false;
     }
     ++length;
@@ -267,47 +218,10 @@
                            length, _length);
   }
 
-  bool scan_only_ret = true;
-  length = 0;
-  curr = _scan_only_head;
-  last = NULL;
-  while (curr != NULL) {
-    if (!curr->is_young() || curr->is_scan_only()) {
-      gclog_or_tty->print_cr("### SCAN-ONLY REGION "PTR_FORMAT"-"PTR_FORMAT" "
-                             "incorrectly tagged (%d, %d)",
-                             curr->bottom(), curr->end(),
-                             curr->is_young(), curr->is_scan_only());
-      scan_only_ret = false;
-    }
-    ++length;
-    last = curr;
-    curr = curr->get_next_young_region();
-  }
-  scan_only_ret = scan_only_ret && (length == _scan_only_length);
-
-  if ( (last != _scan_only_tail) ||
-       (_scan_only_head == NULL && _scan_only_tail != NULL) ||
-       (_scan_only_head != NULL && _scan_only_tail == NULL) ) {
-     gclog_or_tty->print_cr("## _scan_only_tail is set incorrectly");
-     scan_only_ret = false;
-  }
-
-  if (_curr_scan_only != NULL && _curr_scan_only != _scan_only_head) {
-    gclog_or_tty->print_cr("### _curr_scan_only is set incorrectly");
-    scan_only_ret = false;
-   }
-
-  if (!scan_only_ret) {
-    gclog_or_tty->print_cr("### SCAN-ONLY LIST seems not well formed!");
-    gclog_or_tty->print_cr("###   list has %d entries, _scan_only_length is %d",
-                  length, _scan_only_length);
-  }
-
-  return ret && scan_only_ret;
+  return ret;
 }
 
-bool YoungList::check_list_empty(bool ignore_scan_only_list,
-                                 bool check_sample) {
+bool YoungList::check_list_empty(bool check_sample) {
   bool ret = true;
 
   if (_length != 0) {
@@ -327,28 +241,7 @@
     gclog_or_tty->print_cr("### YOUNG LIST does not seem empty");
   }
 
-  if (ignore_scan_only_list)
-    return ret;
-
-  bool scan_only_ret = true;
-  if (_scan_only_length != 0) {
-    gclog_or_tty->print_cr("### SCAN-ONLY LIST should have 0 length, not %d",
-                  _scan_only_length);
-    scan_only_ret = false;
-  }
-  if (_scan_only_head != NULL) {
-    gclog_or_tty->print_cr("### SCAN-ONLY LIST does not have a NULL head");
-     scan_only_ret = false;
-  }
-  if (_scan_only_tail != NULL) {
-    gclog_or_tty->print_cr("### SCAN-ONLY LIST does not have a NULL tail");
-    scan_only_ret = false;
-  }
-  if (!scan_only_ret) {
-    gclog_or_tty->print_cr("### SCAN-ONLY LIST does not seem empty");
-  }
-
-  return ret && scan_only_ret;
+  return ret;
 }
 
 void
@@ -365,7 +258,18 @@
 void
 YoungList::rs_length_sampling_next() {
   assert( _curr != NULL, "invariant" );
-  _sampled_rs_lengths += _curr->rem_set()->occupied();
+  size_t rs_length = _curr->rem_set()->occupied();
+
+  _sampled_rs_lengths += rs_length;
+
+  // The current region may not yet have been added to the
+  // incremental collection set (it gets added when it is
+  // retired as the current allocation region).
+  if (_curr->in_collection_set()) {
+    // Update the collection set policy information for this region
+    _g1h->g1_policy()->update_incremental_cset_info(_curr, rs_length);
+  }
+
   _curr = _curr->get_next_young_region();
   if (_curr == NULL) {
     _last_sampled_rs_lengths = _sampled_rs_lengths;
@@ -375,54 +279,46 @@
 
 void
 YoungList::reset_auxilary_lists() {
-  // We could have just "moved" the scan-only list to the young list.
-  // However, the scan-only list is ordered according to the region
-  // age in descending order, so, by moving one entry at a time, we
-  // ensure that it is recreated in ascending order.
-
   guarantee( is_empty(), "young list should be empty" );
   assert(check_list_well_formed(), "young list should be well formed");
 
   // Add survivor regions to SurvRateGroup.
   _g1h->g1_policy()->note_start_adding_survivor_regions();
   _g1h->g1_policy()->finished_recalculating_age_indexes(true /* is_survivors */);
+
   for (HeapRegion* curr = _survivor_head;
        curr != NULL;
        curr = curr->get_next_young_region()) {
     _g1h->g1_policy()->set_region_survivors(curr);
+
+    // The region is a non-empty survivor so let's add it to
+    // the incremental collection set for the next evacuation
+    // pause.
+    _g1h->g1_policy()->add_region_to_incremental_cset_rhs(curr);
   }
   _g1h->g1_policy()->note_stop_adding_survivor_regions();
 
+  _head   = _survivor_head;
+  _length = _survivor_length;
   if (_survivor_head != NULL) {
-    _head           = _survivor_head;
-    _length         = _survivor_length + _scan_only_length;
-    _survivor_tail->set_next_young_region(_scan_only_head);
-  } else {
-    _head           = _scan_only_head;
-    _length         = _scan_only_length;
-  }
-
-  for (HeapRegion* curr = _scan_only_head;
-       curr != NULL;
-       curr = curr->get_next_young_region()) {
-    curr->recalculate_age_in_surv_rate_group();
-  }
-  _scan_only_head   = NULL;
-  _scan_only_tail   = NULL;
-  _scan_only_length = 0;
-  _curr_scan_only   = NULL;
-
-  _survivor_head    = NULL;
-  _survivor_tail   = NULL;
-  _survivor_length  = 0;
+    assert(_survivor_tail != NULL, "cause it shouldn't be");
+    assert(_survivor_length > 0, "invariant");
+    _survivor_tail->set_next_young_region(NULL);
+  }
+
+  // Don't clear the survivor list handles until the start of
+  // the next evacuation pause - we need it in order to re-tag
+  // the survivor regions from this evacuation pause as 'young'
+  // at the start of the next.
+
   _g1h->g1_policy()->finished_recalculating_age_indexes(false /* is_survivors */);
 
   assert(check_list_well_formed(), "young list should be well formed");
 }
 
 void YoungList::print() {
-  HeapRegion* lists[] = {_head,   _scan_only_head, _survivor_head};
-  const char* names[] = {"YOUNG", "SCAN-ONLY",     "SURVIVOR"};
+  HeapRegion* lists[] = {_head,   _survivor_head};
+  const char* names[] = {"YOUNG", "SURVIVOR"};
 
   for (unsigned int list = 0; list < ARRAY_SIZE(lists); ++list) {
     gclog_or_tty->print_cr("%s LIST CONTENTS", names[list]);
@@ -431,7 +327,7 @@
       gclog_or_tty->print_cr("  empty");
     while (curr != NULL) {
       gclog_or_tty->print_cr("  [%08x-%08x], t: %08x, P: %08x, N: %08x, C: %08x, "
-                             "age: %4d, y: %d, s-o: %d, surv: %d",
+                             "age: %4d, y: %d, surv: %d",
                              curr->bottom(), curr->end(),
                              curr->top(),
                              curr->prev_top_at_mark_start(),
@@ -439,7 +335,6 @@
                              curr->top_at_conc_mark_count(),
                              curr->age_in_surv_rate_group_cond(),
                              curr->is_young(),
-                             curr->is_scan_only(),
                              curr->is_survivor());
       curr = curr->get_next_young_region();
     }
@@ -707,6 +602,12 @@
     // region below.
     if (_cur_alloc_region != NULL) {
       // We're finished with the _cur_alloc_region.
+      // As we're builing (at least the young portion) of the collection
+      // set incrementally we'll add the current allocation region to
+      // the collection set here.
+      if (_cur_alloc_region->is_young()) {
+        g1_policy()->add_region_to_incremental_cset_lhs(_cur_alloc_region);
+      }
       _summary_bytes_used += _cur_alloc_region->used();
       _cur_alloc_region = NULL;
     }
@@ -820,6 +721,12 @@
       _free_regions++;
       free_region(_cur_alloc_region);
     } else {
+      // As we're builing (at least the young portion) of the collection
+      // set incrementally we'll add the current allocation region to
+      // the collection set here.
+      if (_cur_alloc_region->is_young()) {
+        g1_policy()->add_region_to_incremental_cset_lhs(_cur_alloc_region);
+      }
       _summary_bytes_used += _cur_alloc_region->used();
     }
     _cur_alloc_region = NULL;
@@ -913,20 +820,25 @@
   }
 
   if (full && DisableExplicitGC) {
-    gclog_or_tty->print("\n\n\nDisabling Explicit GC\n\n\n");
     return;
   }
 
   assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
   assert(Thread::current() == VMThread::vm_thread(), "should be in vm thread");
 
+  const bool do_clear_all_soft_refs = clear_all_soft_refs ||
+                           collector_policy()->should_clear_all_soft_refs();
+
+  ClearedAllSoftRefs casr(do_clear_all_soft_refs, collector_policy());
+
   {
     IsGCActiveMark x;
 
     // Timing
     gclog_or_tty->date_stamp(PrintGC && PrintGCDateStamps);
     TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty);
-    TraceTime t(full ? "Full GC (System.gc())" : "Full GC", PrintGC, true, gclog_or_tty);
+    TraceTime t(full ? "Full GC (System.gc())" : "Full GC",
+                PrintGC, true, gclog_or_tty);
 
     TraceMemoryManagerStats tms(true /* fullGC */);
 
@@ -970,6 +882,15 @@
     g1_rem_set()->as_HRInto_G1RemSet()->cleanupHRRS();
     tear_down_region_lists();
     set_used_regions_to_need_zero_fill();
+
+    // We may have added regions to the current incremental collection
+    // set between the last GC or pause and now. We need to clear the
+    // incremental collection set and then start rebuilding it afresh
+    // after this full GC.
+    abandon_collection_set(g1_policy()->inc_cset_head());
+    g1_policy()->clear_incremental_cset();
+    g1_policy()->stop_incremental_cset_building();
+
     if (g1_policy()->in_young_gc_mode()) {
       empty_young_list();
       g1_policy()->set_full_young_gcs(true);
@@ -985,12 +906,12 @@
     ReferenceProcessorIsAliveMutator rp_is_alive_null(ref_processor(), NULL);
 
     ref_processor()->enable_discovery();
-    ref_processor()->setup_policy(clear_all_soft_refs);
+    ref_processor()->setup_policy(do_clear_all_soft_refs);
 
     // Do collection work
     {
       HandleMark hm;  // Discard invalid handles created during gc
-      G1MarkSweep::invoke_at_safepoint(ref_processor(), clear_all_soft_refs);
+      G1MarkSweep::invoke_at_safepoint(ref_processor(), do_clear_all_soft_refs);
     }
     // Because freeing humongous regions may have added some unclean
     // regions, it is necessary to tear down again before rebuilding.
@@ -1053,6 +974,15 @@
       perm()->compute_new_size();
     }
 
+    // Start a new incremental collection set for the next pause
+    assert(g1_policy()->collection_set() == NULL, "must be");
+    g1_policy()->start_incremental_cset_building();
+
+    // Clear the _cset_fast_test bitmap in anticipation of adding
+    // regions to the incremental collection set for the next
+    // evacuation pause.
+    clear_cset_fast_test();
+
     double end = os::elapsedTime();
     g1_policy()->record_full_collection_end();
 
@@ -1071,7 +1001,9 @@
 
   if (g1_policy()->in_young_gc_mode()) {
     _young_list->reset_sampled_info();
-    assert( check_young_list_empty(false, false),
+    // At this point there should be no regions in the
+    // entire heap tagged as young.
+    assert( check_young_list_empty(true /* check_heap */),
             "young list should be empty at this point");
   }
 
@@ -1208,6 +1140,9 @@
     return result;
   }
 
+  assert(!collector_policy()->should_clear_all_soft_refs(),
+    "Flag should have been handled and cleared prior to this point");
+
   // What else?  We might try synchronous finalization later.  If the total
   // space available is large enough for the allocation, then a more
   // complete compaction phase than we've tried so far might be
@@ -1565,6 +1500,20 @@
 
   _g1h = this;
 
+   _in_cset_fast_test_length = max_regions();
+   _in_cset_fast_test_base = NEW_C_HEAP_ARRAY(bool, _in_cset_fast_test_length);
+
+   // We're biasing _in_cset_fast_test to avoid subtracting the
+   // beginning of the heap every time we want to index; basically
+   // it's the same with what we do with the card table.
+   _in_cset_fast_test = _in_cset_fast_test_base -
+                ((size_t) _g1_reserved.start() >> HeapRegion::LogOfHRGrainBytes);
+
+   // Clear the _cset_fast_test bitmap in anticipation of adding
+   // regions to the incremental collection set for the first
+   // evacuation pause.
+   clear_cset_fast_test();
+
   // Create the ConcurrentMark data structure and thread.
   // (Must do this late, so that "max_regions" is defined.)
   _cm       = new ConcurrentMark(heap_rs, (int) max_regions());
@@ -2185,8 +2134,10 @@
     assert(o != NULL, "Huh?");
     if (!_g1h->is_obj_dead_cond(o, _use_prev_marking)) {
       o->oop_iterate(&isLive);
-      if (!_hr->obj_allocated_since_prev_marking(o))
-        _live_bytes += (o->size() * HeapWordSize);
+      if (!_hr->obj_allocated_since_prev_marking(o)) {
+        size_t obj_size = o->size();    // Make sure we don't overflow
+        _live_bytes += (obj_size * HeapWordSize);
+      }
     }
   }
   size_t live_bytes() { return _live_bytes; }
@@ -2388,8 +2339,8 @@
       print_on(gclog_or_tty, true /* extended */);
       gclog_or_tty->print_cr("");
       if (VerifyDuringGC && G1VerifyDuringGCPrintReachable) {
-        concurrent_mark()->print_reachable(use_prev_marking,
-                                           "failed-verification");
+        concurrent_mark()->print_reachable("at-verification-failure",
+                                           use_prev_marking, false /* all */);
       }
       gclog_or_tty->flush();
     }
@@ -2741,25 +2692,19 @@
       double start_time_sec = os::elapsedTime();
       size_t start_used_bytes = used();
 
+#if YOUNG_LIST_VERBOSE
+      gclog_or_tty->print_cr("\nBefore recording pause start.\nYoung_list:");
+      _young_list->print();
+      g1_policy()->print_collection_set(g1_policy()->inc_cset_head(), gclog_or_tty);
+#endif // YOUNG_LIST_VERBOSE
+
       g1_policy()->record_collection_pause_start(start_time_sec,
                                                  start_used_bytes);
 
-      guarantee(_in_cset_fast_test == NULL, "invariant");
-      guarantee(_in_cset_fast_test_base == NULL, "invariant");
-      _in_cset_fast_test_length = max_regions();
-      _in_cset_fast_test_base =
-                             NEW_C_HEAP_ARRAY(bool, _in_cset_fast_test_length);
-      memset(_in_cset_fast_test_base, false,
-                                     _in_cset_fast_test_length * sizeof(bool));
-      // We're biasing _in_cset_fast_test to avoid subtracting the
-      // beginning of the heap every time we want to index; basically
-      // it's the same with what we do with the card table.
-      _in_cset_fast_test = _in_cset_fast_test_base -
-              ((size_t) _g1_reserved.start() >> HeapRegion::LogOfHRGrainBytes);
-
-#if SCAN_ONLY_VERBOSE
+#if YOUNG_LIST_VERBOSE
+      gclog_or_tty->print_cr("\nAfter recording pause start.\nYoung_list:");
       _young_list->print();
-#endif // SCAN_ONLY_VERBOSE
+#endif // YOUNG_LIST_VERBOSE
 
       if (g1_policy()->during_initial_mark_pause()) {
         concurrent_mark()->checkpointRootsInitialPre();
@@ -2786,12 +2731,15 @@
       if (mark_in_progress())
         concurrent_mark()->newCSet();
 
-      // Now choose the CS.
-      g1_policy()->choose_collection_set();
-
-      // We may abandon a pause if we find no region that will fit in the MMU
-      // pause.
-      bool abandoned = (g1_policy()->collection_set() == NULL);
+#if YOUNG_LIST_VERBOSE
+      gclog_or_tty->print_cr("\nBefore choosing collection set.\nYoung_list:");
+      _young_list->print();
+      g1_policy()->print_collection_set(g1_policy()->inc_cset_head(), gclog_or_tty);
+#endif // YOUNG_LIST_VERBOSE
+
+      // Now choose the CS. We may abandon a pause if we find no
+      // region that will fit in the MMU pause.
+      bool abandoned = g1_policy()->choose_collection_set();
 
       // Nothing to do if we were unable to choose a collection set.
       if (!abandoned) {
@@ -2809,40 +2757,64 @@
 
         // Actually do the work...
         evacuate_collection_set();
+
         free_collection_set(g1_policy()->collection_set());
         g1_policy()->clear_collection_set();
 
-        FREE_C_HEAP_ARRAY(bool, _in_cset_fast_test_base);
-        // this is more for peace of mind; we're nulling them here and
-        // we're expecting them to be null at the beginning of the next GC
-        _in_cset_fast_test = NULL;
-        _in_cset_fast_test_base = NULL;
-
         cleanup_surviving_young_words();
 
+        // Start a new incremental collection set for the next pause.
+        g1_policy()->start_incremental_cset_building();
+
+        // Clear the _cset_fast_test bitmap in anticipation of adding
+        // regions to the incremental collection set for the next
+        // evacuation pause.
+        clear_cset_fast_test();
+
         if (g1_policy()->in_young_gc_mode()) {
           _young_list->reset_sampled_info();
-          assert(check_young_list_empty(true),
-                 "young list should be empty");
-
-#if SCAN_ONLY_VERBOSE
+
+          // Don't check the whole heap at this point as the
+          // GC alloc regions from this pause have been tagged
+          // as survivors and moved on to the survivor list.
+          // Survivor regions will fail the !is_young() check.
+          assert(check_young_list_empty(false /* check_heap */),
+              "young list should be empty");
+
+#if YOUNG_LIST_VERBOSE
+          gclog_or_tty->print_cr("Before recording survivors.\nYoung List:");
           _young_list->print();
-#endif // SCAN_ONLY_VERBOSE
+#endif // YOUNG_LIST_VERBOSE
 
           g1_policy()->record_survivor_regions(_young_list->survivor_length(),
                                           _young_list->first_survivor_region(),
                                           _young_list->last_survivor_region());
+
           _young_list->reset_auxilary_lists();
         }
       } else {
-        if (_in_cset_fast_test != NULL) {
-          assert(_in_cset_fast_test_base != NULL, "Since _in_cset_fast_test isn't");
-          FREE_C_HEAP_ARRAY(bool, _in_cset_fast_test_base);
-          //  this is more for peace of mind; we're nulling them here and
-          // we're expecting them to be null at the beginning of the next GC
-          _in_cset_fast_test = NULL;
-          _in_cset_fast_test_base = NULL;
-        }
+        // We have abandoned the current collection. This can only happen
+        // if we're not doing young or partially young collections, and
+        // we didn't find an old region that we're able to collect within
+        // the allowed time.
+
+        assert(g1_policy()->collection_set() == NULL, "should be");
+        assert(_young_list->length() == 0, "because it should be");
+
+        // This should be a no-op.
+        abandon_collection_set(g1_policy()->inc_cset_head());
+
+        g1_policy()->clear_incremental_cset();
+        g1_policy()->stop_incremental_cset_building();
+
+        // Start a new incremental collection set for the next pause.
+        g1_policy()->start_incremental_cset_building();
+
+        // Clear the _cset_fast_test bitmap in anticipation of adding
+        // regions to the incremental collection set for the next
+        // evacuation pause.
+        clear_cset_fast_test();
+
         // This looks confusing, because the DPT should really be empty
         // at this point -- since we have not done any collection work,
         // there should not be any derived pointers in the table to update;
@@ -2876,9 +2848,11 @@
         doConcurrentMark();
       }
 
-#if SCAN_ONLY_VERBOSE
+#if YOUNG_LIST_VERBOSE
+      gclog_or_tty->print_cr("\nEnd of the pause.\nYoung_list:");
       _young_list->print();
-#endif // SCAN_ONLY_VERBOSE
+      g1_policy()->print_collection_set(g1_policy()->inc_cset_head(), gclog_or_tty);
+#endif // YOUNG_LIST_VERBOSE
 
       double end_time_sec = os::elapsedTime();
       double pause_time_ms = (end_time_sec - start_time_sec) * MILLIUNITS;
@@ -2936,6 +2910,25 @@
   }
 }
 
+size_t G1CollectedHeap::desired_plab_sz(GCAllocPurpose purpose)
+{
+  size_t gclab_word_size;
+  switch (purpose) {
+    case GCAllocForSurvived:
+      gclab_word_size = YoungPLABSize;
+      break;
+    case GCAllocForTenured:
+      gclab_word_size = OldPLABSize;
+      break;
+    default:
+      assert(false, "unknown GCAllocPurpose");
+      gclab_word_size = OldPLABSize;
+      break;
+  }
+  return gclab_word_size;
+}
+
+
 void G1CollectedHeap::set_gc_alloc_region(int purpose, HeapRegion* r) {
   assert(purpose >= 0 && purpose < GCAllocPurposeCount, "invalid purpose");
   // make sure we don't call set_gc_alloc_region() multiple times on
@@ -3109,6 +3102,11 @@
     } else {
       // the region was retained from the last collection
       ++_gc_alloc_region_counts[ap];
+      if (G1PrintHeapRegions) {
+        gclog_or_tty->print_cr("new alloc region %d:["PTR_FORMAT", "PTR_FORMAT"], "
+                               "top "PTR_FORMAT,
+                               alloc_region->hrs_index(), alloc_region->bottom(), alloc_region->end(), alloc_region->top());
+      }
     }
 
     if (alloc_region != NULL) {
@@ -3665,6 +3663,8 @@
     _g1_rem(g1h->g1_rem_set()),
     _hash_seed(17), _queue_num(queue_num),
     _term_attempts(0),
+    _surviving_alloc_buffer(g1h->desired_plab_sz(GCAllocForSurvived)),
+    _tenured_alloc_buffer(g1h->desired_plab_sz(GCAllocForTenured)),
     _age_table(false),
 #if G1_DETAILED_STATS
     _pushes(0), _pops(0), _steals(0),
@@ -3691,6 +3691,9 @@
 
   _overflowed_refs = new OverflowQueue(10);
 
+  _alloc_buffers[GCAllocForSurvived] = &_surviving_alloc_buffer;
+  _alloc_buffers[GCAllocForTenured]  = &_tenured_alloc_buffer;
+
   _start = os::elapsedTime();
 }
 
@@ -3988,16 +3991,13 @@
 
     OopsInHeapRegionClosure        *scan_root_cl;
     OopsInHeapRegionClosure        *scan_perm_cl;
-    OopsInHeapRegionClosure        *scan_so_cl;
 
     if (_g1h->g1_policy()->during_initial_mark_pause()) {
       scan_root_cl = &scan_mark_root_cl;
       scan_perm_cl = &scan_mark_perm_cl;
-      scan_so_cl   = &scan_mark_heap_rs_cl;
     } else {
       scan_root_cl = &only_scan_root_cl;
       scan_perm_cl = &only_scan_perm_cl;
-      scan_so_cl   = &only_scan_heap_rs_cl;
     }
 
     pss.start_strong_roots();
@@ -4005,7 +4005,6 @@
                                   SharedHeap::SO_AllClasses,
                                   scan_root_cl,
                                   &push_heap_rs_cl,
-                                  scan_so_cl,
                                   scan_perm_cl,
                                   i);
     pss.end_strong_roots();
@@ -4067,7 +4066,6 @@
                         SharedHeap::ScanningOption so,
                         OopClosure* scan_non_heap_roots,
                         OopsInHeapRegionClosure* scan_rs,
-                        OopsInHeapRegionClosure* scan_so,
                         OopsInGenClosure* scan_perm,
                         int worker_i) {
   // First scan the strong roots, including the perm gen.
@@ -4087,6 +4085,7 @@
                        &buf_scan_non_heap_roots,
                        &eager_scan_code_roots,
                        &buf_scan_perm);
+
   // Finish up any enqueued closure apps.
   buf_scan_non_heap_roots.done();
   buf_scan_perm.done();
@@ -4109,9 +4108,6 @@
 
   // XXX What should this be doing in the parallel case?
   g1_policy()->record_collection_pause_end_CH_strong_roots();
-  if (scan_so != NULL) {
-    scan_scan_only_set(scan_so, worker_i);
-  }
   // Now scan the complement of the collection set.
   if (scan_rs != NULL) {
     g1_rem_set()->oops_into_collection_set_do(scan_rs, worker_i);
@@ -4125,54 +4121,6 @@
 }
 
 void
-G1CollectedHeap::scan_scan_only_region(HeapRegion* r,
-                                       OopsInHeapRegionClosure* oc,
-                                       int worker_i) {
-  HeapWord* startAddr = r->bottom();
-  HeapWord* endAddr = r->used_region().end();
-
-  oc->set_region(r);
-
-  HeapWord* p = r->bottom();
-  HeapWord* t = r->top();
-  guarantee( p == r->next_top_at_mark_start(), "invariant" );
-  while (p < t) {
-    oop obj = oop(p);
-    p += obj->oop_iterate(oc);
-  }
-}
-
-void
-G1CollectedHeap::scan_scan_only_set(OopsInHeapRegionClosure* oc,
-                                    int worker_i) {
-  double start = os::elapsedTime();
-
-  BufferingOopsInHeapRegionClosure boc(oc);
-
-  FilterInHeapRegionAndIntoCSClosure scan_only(this, &boc);
-  FilterAndMarkInHeapRegionAndIntoCSClosure scan_and_mark(this, &boc, concurrent_mark());
-
-  OopsInHeapRegionClosure *foc;
-  if (g1_policy()->during_initial_mark_pause())
-    foc = &scan_and_mark;
-  else
-    foc = &scan_only;
-
-  HeapRegion* hr;
-  int n = 0;
-  while ((hr = _young_list->par_get_next_scan_only_region()) != NULL) {
-    scan_scan_only_region(hr, foc, worker_i);
-    ++n;
-  }
-  boc.done();
-
-  double closure_app_s = boc.closure_app_seconds();
-  g1_policy()->record_obj_copy_time(worker_i, closure_app_s * 1000.0);
-  double ms = (os::elapsedTime() - start - closure_app_s)*1000.0;
-  g1_policy()->record_scan_only_time(worker_i, ms, n);
-}
-
-void
 G1CollectedHeap::g1_process_weak_roots(OopClosure* root_closure,
                                        OopClosure* non_root_closure) {
   CodeBlobToOopClosure roots_in_blobs(root_closure, /*do_marking=*/ false);
@@ -4370,17 +4318,14 @@
 class G1ParCleanupCTTask : public AbstractGangTask {
   CardTableModRefBS* _ct_bs;
   G1CollectedHeap* _g1h;
-  HeapRegion* volatile _so_head;
   HeapRegion* volatile _su_head;
 public:
   G1ParCleanupCTTask(CardTableModRefBS* ct_bs,
                      G1CollectedHeap* g1h,
-                     HeapRegion* scan_only_list,
                      HeapRegion* survivor_list) :
     AbstractGangTask("G1 Par Cleanup CT Task"),
     _ct_bs(ct_bs),
     _g1h(g1h),
-    _so_head(scan_only_list),
     _su_head(survivor_list)
   { }
 
@@ -4389,14 +4334,13 @@
     while (r = _g1h->pop_dirty_cards_region()) {
       clear_cards(r);
     }
-    // Redirty the cards of the scan-only and survivor regions.
-    dirty_list(&this->_so_head);
+    // Redirty the cards of the survivor regions.
     dirty_list(&this->_su_head);
   }
 
   void clear_cards(HeapRegion* r) {
-    // Cards for Survivor and Scan-Only regions will be dirtied later.
-    if (!r->is_scan_only() && !r->is_survivor()) {
+    // Cards for Survivor regions will be dirtied later.
+    if (!r->is_survivor()) {
       _ct_bs->clear(MemRegion(r->bottom(), r->end()));
     }
   }
@@ -4429,7 +4373,7 @@
   virtual bool doHeapRegion(HeapRegion* r)
   {
     MemRegion mr(r->bottom(), r->end());
-    if (r->is_scan_only() || r->is_survivor()) {
+    if (r->is_survivor()) {
       _ct_bs->verify_dirty_region(mr);
     } else {
       _ct_bs->verify_clean_region(mr);
@@ -4445,8 +4389,8 @@
 
   // Iterate over the dirty cards region list.
   G1ParCleanupCTTask cleanup_task(ct_bs, this,
-                                  _young_list->first_scan_only_region(),
                                   _young_list->first_survivor_region());
+
   if (ParallelGCThreads > 0) {
     set_par_threads(workers()->total_workers());
     workers()->run_task(&cleanup_task);
@@ -4462,12 +4406,12 @@
       }
       r->set_next_dirty_cards_region(NULL);
     }
-    // now, redirty the cards of the scan-only and survivor regions
+    // now, redirty the cards of the survivor regions
     // (it seemed faster to do it this way, instead of iterating over
     // all regions and then clearing / dirtying as appropriate)
-    dirtyCardsForYoungRegions(ct_bs, _young_list->first_scan_only_region());
     dirtyCardsForYoungRegions(ct_bs, _young_list->first_survivor_region());
   }
+
   double elapsed = os::elapsedTime() - start;
   g1_policy()->record_clear_ct_time( elapsed * 1000.0);
 #ifndef PRODUCT
@@ -4488,6 +4432,11 @@
   double young_time_ms     = 0.0;
   double non_young_time_ms = 0.0;
 
+  // Since the collection set is a superset of the the young list,
+  // all we need to do to clear the young list is clear its
+  // head and length, and unlink any young regions in the code below
+  _young_list->clear();
+
   G1CollectorPolicy* policy = g1_policy();
 
   double start_sec = os::elapsedTime();
@@ -4531,6 +4480,12 @@
       guarantee( (size_t)index < policy->young_cset_length(), "invariant" );
       size_t words_survived = _surviving_young_words[index];
       cur->record_surv_words_in_group(words_survived);
+
+      // At this point the we have 'popped' cur from the collection set
+      // (linked via next_in_collection_set()) but it is still in the
+      // young list (linked via next_young_region()). Clear the
+      // _next_young_region field.
+      cur->set_next_young_region(NULL);
     } else {
       int index = cur->young_index_in_cset();
       guarantee( index == -1, "invariant" );
@@ -4546,7 +4501,6 @@
              "Should not have empty regions in a CS.");
       free_region(cur);
     } else {
-      guarantee( !cur->is_scan_only(), "should not be scan only" );
       cur->uninstall_surv_rate_group();
       if (cur->is_young())
         cur->set_young_index_in_cset(-1);
@@ -4570,6 +4524,27 @@
   policy->record_non_young_free_cset_time_ms(non_young_time_ms);
 }
 
+// This routine is similar to the above but does not record
+// any policy statistics or update free lists; we are abandoning
+// the current incremental collection set in preparation of a
+// full collection. After the full GC we will start to build up
+// the incremental collection set again.
+// This is only called when we're doing a full collection
+// and is immediately followed by the tearing down of the young list.
+
+void G1CollectedHeap::abandon_collection_set(HeapRegion* cs_head) {
+  HeapRegion* cur = cs_head;
+
+  while (cur != NULL) {
+    HeapRegion* next = cur->next_in_collection_set();
+    assert(cur->in_collection_set(), "bad CS");
+    cur->set_next_in_collection_set(NULL);
+    cur->set_in_collection_set(false);
+    cur->set_young_index_in_cset(-1);
+    cur = next;
+  }
+}
+
 HeapRegion*
 G1CollectedHeap::alloc_region_from_unclean_list_locked(bool zero_filled) {
   assert(ZF_mon->owned_by_self(), "Precondition");
@@ -4936,12 +4911,10 @@
   bool success() { return _success; }
 };
 
-bool G1CollectedHeap::check_young_list_empty(bool ignore_scan_only_list,
-                                             bool check_sample) {
-  bool ret = true;
-
-  ret = _young_list->check_list_empty(ignore_scan_only_list, check_sample);
-  if (!ignore_scan_only_list) {
+bool G1CollectedHeap::check_young_list_empty(bool check_heap, bool check_sample) {
+  bool ret = _young_list->check_list_empty(check_sample);
+
+  if (check_heap) {
     NoYoungRegionsClosure closure;
     heap_region_iterate(&closure);
     ret = ret && closure.success();
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp
--- a/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -81,33 +81,29 @@
 
   HeapRegion* _head;
 
-  HeapRegion* _scan_only_head;
-  HeapRegion* _scan_only_tail;
+  HeapRegion* _survivor_head;
+  HeapRegion* _survivor_tail;
+
+  HeapRegion* _curr;
+
   size_t      _length;
-  size_t      _scan_only_length;
+  size_t      _survivor_length;
 
   size_t      _last_sampled_rs_lengths;
   size_t      _sampled_rs_lengths;
-  HeapRegion* _curr;
-  HeapRegion* _curr_scan_only;
 
-  HeapRegion* _survivor_head;
-  HeapRegion* _survivor_tail;
-  size_t      _survivor_length;
-
-  void          empty_list(HeapRegion* list);
+  void         empty_list(HeapRegion* list);
 
 public:
   YoungList(G1CollectedHeap* g1h);
 
-  void          push_region(HeapRegion* hr);
-  void          add_survivor_region(HeapRegion* hr);
-  HeapRegion*   pop_region();
-  void          empty_list();
-  bool          is_empty() { return _length == 0; }
-  size_t        length() { return _length; }
-  size_t        scan_only_length() { return _scan_only_length; }
-  size_t        survivor_length() { return _survivor_length; }
+  void         push_region(HeapRegion* hr);
+  void         add_survivor_region(HeapRegion* hr);
+
+  void         empty_list();
+  bool         is_empty() { return _length == 0; }
+  size_t       length() { return _length; }
+  size_t       survivor_length() { return _survivor_length; }
 
   void rs_length_sampling_init();
   bool rs_length_sampling_more();
@@ -120,22 +116,21 @@
 
   // for development purposes
   void reset_auxilary_lists();
+  void clear() { _head = NULL; _length = 0; }
+
+  void clear_survivors() {
+    _survivor_head    = NULL;
+    _survivor_tail    = NULL;
+    _survivor_length  = 0;
+  }
+
   HeapRegion* first_region() { return _head; }
-  HeapRegion* first_scan_only_region() { return _scan_only_head; }
   HeapRegion* first_survivor_region() { return _survivor_head; }
   HeapRegion* last_survivor_region() { return _survivor_tail; }
-  HeapRegion* par_get_next_scan_only_region() {
-    MutexLockerEx x(ParGCRareEvent_lock, Mutex::_no_safepoint_check_flag);
-    HeapRegion* ret = _curr_scan_only;
-    if (ret != NULL)
-      _curr_scan_only = ret->get_next_young_region();
-    return ret;
-  }
 
   // debugging
   bool          check_list_well_formed();
-  bool          check_list_empty(bool ignore_scan_only_list,
-                                 bool check_sample = true);
+  bool          check_list_empty(bool check_sample = true);
   void          print();
 };
 
@@ -232,6 +227,9 @@
   // current collection.
   HeapRegion* _gc_alloc_region_list;
 
+  // Determines PLAB size for a particular allocation purpose.
+  static size_t desired_plab_sz(GCAllocPurpose purpose);
+
   // When called by par thread, require par_alloc_during_gc_lock() to be held.
   void push_gc_alloc_region(HeapRegion* hr);
 
@@ -402,8 +400,7 @@
     assert(_in_cset_fast_test_base != NULL, "sanity");
     assert(r->in_collection_set(), "invariant");
     int index = r->hrs_index();
-    assert(0 <= (size_t) index && (size_t) index < _in_cset_fast_test_length,
-           "invariant");
+    assert(0 <= index && (size_t) index < _in_cset_fast_test_length, "invariant");
     assert(!_in_cset_fast_test_base[index], "invariant");
     _in_cset_fast_test_base[index] = true;
   }
@@ -428,6 +425,12 @@
     }
   }
 
+  void clear_cset_fast_test() {
+    assert(_in_cset_fast_test_base != NULL, "sanity");
+    memset(_in_cset_fast_test_base, false,
+        _in_cset_fast_test_length * sizeof(bool));
+  }
+
 protected:
 
   // Shrink the garbage-first heap by at most the given size (in bytes!).
@@ -473,6 +476,10 @@
   // regions.
   void free_collection_set(HeapRegion* cs_head);
 
+  // Abandon the current collection set without recording policy
+  // statistics or updating free lists.
+  void abandon_collection_set(HeapRegion* cs_head);
+
   // Applies "scan_non_heap_roots" to roots outside the heap,
   // "scan_rs" to roots inside the heap (having done "set_region" to
   // indicate the region in which the root resides), and does "scan_perm"
@@ -485,16 +492,9 @@
                                SharedHeap::ScanningOption so,
                                OopClosure* scan_non_heap_roots,
                                OopsInHeapRegionClosure* scan_rs,
-                               OopsInHeapRegionClosure* scan_so,
                                OopsInGenClosure* scan_perm,
                                int worker_i);
 
-  void scan_scan_only_set(OopsInHeapRegionClosure* oc,
-                          int worker_i);
-  void scan_scan_only_region(HeapRegion* hr,
-                             OopsInHeapRegionClosure* oc,
-                             int worker_i);
-
   // Apply "blk" to all the weak roots of the system.  These include
   // JNI weak roots, the code cache, system dictionary, symbol table,
   // string table, and referents of reachable weak refs.
@@ -1133,36 +1133,14 @@
   void set_region_short_lived_locked(HeapRegion* hr);
   // add appropriate methods for any other surv rate groups
 
-  void young_list_rs_length_sampling_init() {
-    _young_list->rs_length_sampling_init();
-  }
-  bool young_list_rs_length_sampling_more() {
-    return _young_list->rs_length_sampling_more();
-  }
-  void young_list_rs_length_sampling_next() {
-    _young_list->rs_length_sampling_next();
-  }
-  size_t young_list_sampled_rs_lengths() {
-    return _young_list->sampled_rs_lengths();
-  }
-
-  size_t young_list_length()   { return _young_list->length(); }
-  size_t young_list_scan_only_length() {
-                                      return _young_list->scan_only_length(); }
-
-  HeapRegion* pop_region_from_young_list() {
-    return _young_list->pop_region();
-  }
-
-  HeapRegion* young_list_first_region() {
-    return _young_list->first_region();
-  }
+  YoungList* young_list() { return _young_list; }
 
   // debugging
   bool check_young_list_well_formed() {
     return _young_list->check_list_well_formed();
   }
-  bool check_young_list_empty(bool ignore_scan_only_list,
+
+  bool check_young_list_empty(bool check_heap,
                               bool check_sample = true);
 
   // *** Stuff related to concurrent marking.  It's not clear to me that so
@@ -1367,12 +1345,18 @@
     return BitsPerWord << shifter();
   }
 
-  static size_t gclab_word_size() {
-    return G1ParallelGCAllocBufferSize / HeapWordSize;
+  size_t gclab_word_size() const {
+    return _gclab_word_size;
   }
 
-  static size_t bitmap_size_in_bits() {
-    size_t bits_in_bitmap = gclab_word_size() >> shifter();
+  // Calculates actual GCLab size in words
+  size_t gclab_real_word_size() const {
+    return bitmap_size_in_bits(pointer_delta(_real_end_word, _start_word))
+           / BitsPerWord;
+  }
+
+  static size_t bitmap_size_in_bits(size_t gclab_word_size) {
+    size_t bits_in_bitmap = gclab_word_size >> shifter();
     // We are going to ensure that the beginning of a word in this
     // bitmap also corresponds to the beginning of a word in the
     // global marking bitmap. To handle the case where a GCLab
@@ -1382,13 +1366,13 @@
     return bits_in_bitmap + BitsPerWord - 1;
   }
 public:
-  GCLabBitMap(HeapWord* heap_start)
-    : BitMap(bitmap_size_in_bits()),
+  GCLabBitMap(HeapWord* heap_start, size_t gclab_word_size)
+    : BitMap(bitmap_size_in_bits(gclab_word_size)),
       _cm(G1CollectedHeap::heap()->concurrent_mark()),
       _shifter(shifter()),
       _bitmap_word_covers_words(bitmap_word_covers_words()),
       _heap_start(heap_start),
-      _gclab_word_size(gclab_word_size()),
+      _gclab_word_size(gclab_word_size),
       _real_start_word(NULL),
       _real_end_word(NULL),
       _start_word(NULL)
@@ -1483,7 +1467,7 @@
       mark_bitmap->mostly_disjoint_range_union(this,
                                 0, // always start from the start of the bitmap
                                 _start_word,
-                                size_in_words());
+                                gclab_real_word_size());
       _cm->grayRegionIfNecessary(MemRegion(_real_start_word, _real_end_word));
 
 #ifndef PRODUCT
@@ -1495,9 +1479,10 @@
     }
   }
 
-  static size_t bitmap_size_in_words() {
-    return (bitmap_size_in_bits() + BitsPerWord - 1) / BitsPerWord;
+  size_t bitmap_size_in_words() const {
+    return (bitmap_size_in_bits(gclab_word_size()) + BitsPerWord - 1) / BitsPerWord;
   }
+
 };
 
 class G1ParGCAllocBuffer: public ParGCAllocBuffer {
@@ -1507,10 +1492,10 @@
   GCLabBitMap _bitmap;
 
 public:
-  G1ParGCAllocBuffer() :
-    ParGCAllocBuffer(G1ParallelGCAllocBufferSize / HeapWordSize),
+  G1ParGCAllocBuffer(size_t gclab_word_size) :
+    ParGCAllocBuffer(gclab_word_size),
     _during_marking(G1CollectedHeap::heap()->mark_in_progress()),
-    _bitmap(G1CollectedHeap::heap()->reserved_region().start()),
+    _bitmap(G1CollectedHeap::heap()->reserved_region().start(), gclab_word_size),
     _retired(false)
   { }
 
@@ -1549,8 +1534,10 @@
   typedef GrowableArray<StarTask> OverflowQueue;
   OverflowQueue* _overflowed_refs;
 
-  G1ParGCAllocBuffer _alloc_buffers[GCAllocPurposeCount];
-  ageTable           _age_table;
+  G1ParGCAllocBuffer  _surviving_alloc_buffer;
+  G1ParGCAllocBuffer  _tenured_alloc_buffer;
+  G1ParGCAllocBuffer* _alloc_buffers[GCAllocPurposeCount];
+  ageTable            _age_table;
 
   size_t           _alloc_buffer_waste;
   size_t           _undo_waste;
@@ -1619,7 +1606,7 @@
   ageTable*         age_table()       { return &_age_table;       }
 
   G1ParGCAllocBuffer* alloc_buffer(GCAllocPurpose purpose) {
-    return &_alloc_buffers[purpose];
+    return _alloc_buffers[purpose];
   }
 
   size_t alloc_buffer_waste()                    { return _alloc_buffer_waste; }
@@ -1684,15 +1671,15 @@
   HeapWord* allocate_slow(GCAllocPurpose purpose, size_t word_sz) {
 
     HeapWord* obj = NULL;
-    if (word_sz * 100 <
-        (size_t)(G1ParallelGCAllocBufferSize / HeapWordSize) *
-                                                  ParallelGCBufferWastePct) {
+    size_t gclab_word_size = _g1h->desired_plab_sz(purpose);
+    if (word_sz * 100 < gclab_word_size * ParallelGCBufferWastePct) {
       G1ParGCAllocBuffer* alloc_buf = alloc_buffer(purpose);
+      assert(gclab_word_size == alloc_buf->word_sz(),
+             "dynamic resizing is not supported");
       add_to_alloc_buffer_waste(alloc_buf->words_remaining());
       alloc_buf->retire(false, false);
 
-      HeapWord* buf =
-        _g1h->par_allocate_during_gc(purpose, G1ParallelGCAllocBufferSize / HeapWordSize);
+      HeapWord* buf = _g1h->par_allocate_during_gc(purpose, gclab_word_size);
       if (buf == NULL) return NULL; // Let caller handle allocation failure.
       // Otherwise.
       alloc_buf->set_buf(buf);
@@ -1786,9 +1773,9 @@
 
   void retire_alloc_buffers() {
     for (int ap = 0; ap < GCAllocPurposeCount; ++ap) {
-      size_t waste = _alloc_buffers[ap].words_remaining();
+      size_t waste = _alloc_buffers[ap]->words_remaining();
       add_to_alloc_buffer_waste(waste);
-      _alloc_buffers[ap].retire(true, false);
+      _alloc_buffers[ap]->retire(true, false);
     }
   }
 
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp
--- a/src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/g1/g1CollectorPolicy.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -42,10 +42,6 @@
   0.01, 0.005, 0.005, 0.003, 0.003, 0.002, 0.002, 0.0015
 };
 
-static double cost_per_scan_only_region_ms_defaults[] = {
-  1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
-};
-
 // all the same
 static double fully_young_cards_per_entry_ratio_defaults[] = {
   1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0
@@ -125,7 +121,6 @@
   _pending_card_diff_seq(new TruncatedSeq(TruncatedSeqLength)),
   _rs_length_diff_seq(new TruncatedSeq(TruncatedSeqLength)),
   _cost_per_card_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
-  _cost_per_scan_only_region_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
   _fully_young_cards_per_entry_ratio_seq(new TruncatedSeq(TruncatedSeqLength)),
   _partially_young_cards_per_entry_ratio_seq(
                                          new TruncatedSeq(TruncatedSeqLength)),
@@ -133,7 +128,6 @@
   _partially_young_cost_per_entry_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
   _cost_per_byte_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
   _cost_per_byte_ms_during_cm_seq(new TruncatedSeq(TruncatedSeqLength)),
-  _cost_per_scan_only_region_ms_during_cm_seq(new TruncatedSeq(TruncatedSeqLength)),
   _constant_other_time_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
   _young_other_cost_per_region_ms_seq(new TruncatedSeq(TruncatedSeqLength)),
   _non_young_other_cost_per_region_ms_seq(
@@ -186,6 +180,22 @@
   _prev_collection_pause_used_at_end_bytes(0),
 
   _collection_set(NULL),
+  _collection_set_size(0),
+  _collection_set_bytes_used_before(0),
+
+  // Incremental CSet attributes
+  _inc_cset_build_state(Inactive),
+  _inc_cset_head(NULL),
+  _inc_cset_tail(NULL),
+  _inc_cset_size(0),
+  _inc_cset_young_index(0),
+  _inc_cset_bytes_used_before(0),
+  _inc_cset_max_finger(NULL),
+  _inc_cset_recorded_young_bytes(0),
+  _inc_cset_recorded_rs_lengths(0),
+  _inc_cset_predicted_elapsed_time_ms(0.0),
+  _inc_cset_predicted_bytes_to_copy(0),
+
 #ifdef _MSC_VER // the use of 'this' below gets a warning, make it go away
 #pragma warning( disable:4355 ) // 'this' : used in base member initializer list
 #endif // _MSC_VER
@@ -209,13 +219,20 @@
   HeapRegion::setup_heap_region_size(Arguments::min_heap_size());
   HeapRegionRemSet::setup_remset_size();
 
+  // Verify PLAB sizes
+  const uint region_size = HeapRegion::GrainWords;
+  if (YoungPLABSize > region_size || OldPLABSize > region_size) {
+    char buffer[128];
+    jio_snprintf(buffer, sizeof(buffer), "%sPLABSize should be at most %u",
+                 OldPLABSize > region_size ? "Old" : "Young", region_size);
+    vm_exit_during_initialization(buffer);
+  }
+
   _recent_prev_end_times_for_all_gcs_sec->add(os::elapsedTime());
   _prev_collection_pause_end_ms = os::elapsedTime() * 1000.0;
 
   _par_last_ext_root_scan_times_ms = new double[_parallel_gc_threads];
   _par_last_mark_stack_scan_times_ms = new double[_parallel_gc_threads];
-  _par_last_scan_only_times_ms = new double[_parallel_gc_threads];
-  _par_last_scan_only_regions_scanned = new double[_parallel_gc_threads];
 
   _par_last_update_rs_start_times_ms = new double[_parallel_gc_threads];
   _par_last_update_rs_times_ms = new double[_parallel_gc_threads];
@@ -245,8 +262,6 @@
   _pending_card_diff_seq->add(0.0);
   _rs_length_diff_seq->add(rs_length_diff_defaults[index]);
   _cost_per_card_ms_seq->add(cost_per_card_ms_defaults[index]);
-  _cost_per_scan_only_region_ms_seq->add(
-                                 cost_per_scan_only_region_ms_defaults[index]);
   _fully_young_cards_per_entry_ratio_seq->add(
                             fully_young_cards_per_entry_ratio_defaults[index]);
   _cost_per_entry_ms_seq->add(cost_per_entry_ms_defaults[index]);
@@ -274,7 +289,7 @@
 
   // if G1FixedSurvivorSpaceSize is 0 which means the size is not
   // fixed, then _max_survivor_regions will be calculated at
-  // calculate_young_list_target_config during initialization
+  // calculate_young_list_target_length during initialization
   _max_survivor_regions = G1FixedSurvivorSpaceSize / HeapRegion::GrainBytes;
 
   assert(GCTimeRatio > 0,
@@ -348,15 +363,18 @@
       set_adaptive_young_list_length(false);
       _young_list_fixed_length = initial_region_num;
     }
-     _free_regions_at_end_of_collection = _g1->free_regions();
-     _scan_only_regions_at_end_of_collection = 0;
-     calculate_young_list_min_length();
-     guarantee( _young_list_min_length == 0, "invariant, not enough info" );
-     calculate_young_list_target_config();
-   } else {
+    _free_regions_at_end_of_collection = _g1->free_regions();
+    calculate_young_list_min_length();
+    guarantee( _young_list_min_length == 0, "invariant, not enough info" );
+    calculate_young_list_target_length();
+  } else {
      _young_list_fixed_length = 0;
     _in_young_gc_mode = false;
   }
+
+  // We may immediately start allocating regions and placing them on the
+  // collection set list. Initialize the per-collection set info
+  start_incremental_cset_building();
 }
 
 // Create the jstat counters for the policy.
@@ -376,112 +394,29 @@
     double when_ms = _mmu_tracker->when_max_gc_sec(now_sec) * 1000.0;
     double alloc_rate_ms = predict_alloc_rate_ms();
     int min_regions = (int) ceil(alloc_rate_ms * when_ms);
-    int current_region_num = (int) _g1->young_list_length();
+    int current_region_num = (int) _g1->young_list()->length();
     _young_list_min_length = min_regions + current_region_num;
   }
 }
 
-void G1CollectorPolicy::calculate_young_list_target_config() {
+void G1CollectorPolicy::calculate_young_list_target_length() {
   if (adaptive_young_list_length()) {
     size_t rs_lengths = (size_t) get_new_prediction(_rs_lengths_seq);
-    calculate_young_list_target_config(rs_lengths);
+    calculate_young_list_target_length(rs_lengths);
   } else {
     if (full_young_gcs())
       _young_list_target_length = _young_list_fixed_length;
     else
       _young_list_target_length = _young_list_fixed_length / 2;
+
     _young_list_target_length = MAX2(_young_list_target_length, (size_t)1);
-    size_t so_length = calculate_optimal_so_length(_young_list_target_length);
-    guarantee( so_length < _young_list_target_length, "invariant" );
-    _young_list_so_prefix_length = so_length;
   }
   calculate_survivors_policy();
 }
 
-// This method calculate the optimal scan-only set for a fixed young
-// gen size. I couldn't work out how to reuse the more elaborate one,
-// i.e. calculate_young_list_target_config(rs_length), as the loops are
-// fundamentally different (the other one finds a config for different
-// S-O lengths, whereas here we need to do the opposite).
-size_t G1CollectorPolicy::calculate_optimal_so_length(
-                                                    size_t young_list_length) {
-  if (!G1UseScanOnlyPrefix)
-    return 0;
-
-  if (_all_pause_times_ms->num() < 3) {
-    // we won't use a scan-only set at the beginning to allow the rest
-    // of the predictors to warm up
-    return 0;
-  }
-
-  if (_cost_per_scan_only_region_ms_seq->num() < 3) {
-    // then, we'll only set the S-O set to 1 for a little bit of time,
-    // to get enough information on the scanning cost
-    return 1;
-  }
-
-  size_t pending_cards = (size_t) get_new_prediction(_pending_cards_seq);
-  size_t rs_lengths = (size_t) get_new_prediction(_rs_lengths_seq);
-  size_t adj_rs_lengths = rs_lengths + predict_rs_length_diff();
-  size_t scanned_cards;
-  if (full_young_gcs())
-    scanned_cards = predict_young_card_num(adj_rs_lengths);
-  else
-    scanned_cards = predict_non_young_card_num(adj_rs_lengths);
-  double base_time_ms = predict_base_elapsed_time_ms(pending_cards,
-                                                     scanned_cards);
-
-  size_t so_length = 0;
-  double max_gc_eff = 0.0;
-  for (size_t i = 0; i < young_list_length; ++i) {
-    double gc_eff = 0.0;
-    double pause_time_ms = 0.0;
-    predict_gc_eff(young_list_length, i, base_time_ms,
-                   &gc_eff, &pause_time_ms);
-    if (gc_eff > max_gc_eff) {
-      max_gc_eff = gc_eff;
-      so_length = i;
-    }
-  }
-
-  // set it to 95% of the optimal to make sure we sample the "area"
-  // around the optimal length to get up-to-date survival rate data
-  return so_length * 950 / 1000;
-}
-
-// This is a really cool piece of code! It finds the best
-// target configuration (young length / scan-only prefix length) so
-// that GC efficiency is maximized and that we also meet a pause
-// time. It's a triple nested loop. These loops are explained below
-// from the inside-out :-)
-//
-// (a) The innermost loop will try to find the optimal young length
-// for a fixed S-O length. It uses a binary search to speed up the
-// process. We assume that, for a fixed S-O length, as we add more
-// young regions to the CSet, the GC efficiency will only go up (I'll
-// skip the proof). So, using a binary search to optimize this process
-// makes perfect sense.
-//
-// (b) The middle loop will fix the S-O length before calling the
-// innermost one. It will vary it between two parameters, increasing
-// it by a given increment.
-//
-// (c) The outermost loop will call the middle loop three times.
-//   (1) The first time it will explore all possible S-O length values
-//   from 0 to as large as it can get, using a coarse increment (to
-//   quickly "home in" to where the optimal seems to be).
-//   (2) The second time it will explore the values around the optimal
-//   that was found by the first iteration using a fine increment.
-//   (3) Once the optimal config has been determined by the second
-//   iteration, we'll redo the calculation, but setting the S-O length
-//   to 95% of the optimal to make sure we sample the "area"
-//   around the optimal length to get up-to-date survival rate data
-//
-// Termination conditions for the iterations are several: the pause
-// time is over the limit, we do not have enough to-space, etc.
-
-void G1CollectorPolicy::calculate_young_list_target_config(size_t rs_lengths) {
+void G1CollectorPolicy::calculate_young_list_target_length(size_t rs_lengths) {
   guarantee( adaptive_young_list_length(), "pre-condition" );
+  guarantee( !_in_marking_window || !_last_full_young_gc, "invariant" );
 
   double start_time_sec = os::elapsedTime();
   size_t min_reserve_perc = MAX2((size_t)2, (size_t)G1ReservePercent);
@@ -495,285 +430,80 @@
     double survivor_regions_evac_time =
         predict_survivor_regions_evac_time();
 
-    size_t min_so_length = 0;
-    size_t max_so_length = 0;
-
-    if (G1UseScanOnlyPrefix) {
-      if (_all_pause_times_ms->num() < 3) {
-        // we won't use a scan-only set at the beginning to allow the rest
-        // of the predictors to warm up
-        min_so_length = 0;
-        max_so_length = 0;
-      } else if (_cost_per_scan_only_region_ms_seq->num() < 3) {
-        // then, we'll only set the S-O set to 1 for a little bit of time,
-        // to get enough information on the scanning cost
-        min_so_length = 1;
-        max_so_length = 1;
-      } else if (_in_marking_window || _last_full_young_gc) {
-        // no S-O prefix during a marking phase either, as at the end
-        // of the marking phase we'll have to use a very small young
-        // length target to fill up the rest of the CSet with
-        // non-young regions and, if we have lots of scan-only regions
-        // left-over, we will not be able to add any more non-young
-        // regions.
-        min_so_length = 0;
-        max_so_length = 0;
-      } else {
-        // this is the common case; we'll never reach the maximum, we
-        // one of the end conditions will fire well before that
-        // (hopefully!)
-        min_so_length = 0;
-        max_so_length = _free_regions_at_end_of_collection - 1;
-      }
-    } else {
-      // no S-O prefix, as the switch is not set, but we still need to
-      // do one iteration to calculate the best young target that
-      // meets the pause time; this way we reuse the same code instead
-      // of replicating it
-      min_so_length = 0;
-      max_so_length = 0;
-    }
-
     double target_pause_time_ms = _mmu_tracker->max_gc_time() * 1000.0;
     size_t pending_cards = (size_t) get_new_prediction(_pending_cards_seq);
     size_t adj_rs_lengths = rs_lengths + predict_rs_length_diff();
-    size_t scanned_cards;
-    if (full_young_gcs())
-      scanned_cards = predict_young_card_num(adj_rs_lengths);
-    else
-      scanned_cards = predict_non_young_card_num(adj_rs_lengths);
-    // calculate this once, so that we don't have to recalculate it in
-    // the innermost loop
+    size_t scanned_cards = predict_young_card_num(adj_rs_lengths);
     double base_time_ms = predict_base_elapsed_time_ms(pending_cards, scanned_cards)
                           + survivor_regions_evac_time;
+
     // the result
     size_t final_young_length = 0;
-    size_t final_so_length = 0;
-    double final_gc_eff = 0.0;
-    // we'll also keep track of how many times we go into the inner loop
-    // this is for profiling reasons
-    size_t calculations = 0;
-
-    // this determines which of the three iterations the outer loop is in
-    typedef enum {
-      pass_type_coarse,
-      pass_type_fine,
-      pass_type_final
-    } pass_type_t;
-
-    // range of the outer loop's iteration
-    size_t from_so_length   = min_so_length;
-    size_t to_so_length     = max_so_length;
-    guarantee( from_so_length <= to_so_length, "invariant" );
-
-    // this will keep the S-O length that's found by the second
-    // iteration of the outer loop; we'll keep it just in case the third
-    // iteration fails to find something
-    size_t fine_so_length   = 0;
-
-    // the increment step for the coarse (first) iteration
-    size_t so_coarse_increments = 5;
-
-    // the common case, we'll start with the coarse iteration
-    pass_type_t pass = pass_type_coarse;
-    size_t so_length_incr = so_coarse_increments;
-
-    if (from_so_length == to_so_length) {
-      // not point in doing the coarse iteration, we'll go directly into
-      // the fine one (we essentially trying to find the optimal young
-      // length for a fixed S-O length).
-      so_length_incr = 1;
-      pass = pass_type_final;
-    } else if (to_so_length - from_so_length < 3 * so_coarse_increments) {
-      // again, the range is too short so no point in foind the coarse
-      // iteration either
-      so_length_incr = 1;
-      pass = pass_type_fine;
-    }
-
-    bool done = false;
-    // this is the outermost loop
-    while (!done) {
-#ifdef TRACE_CALC_YOUNG_CONFIG
-      // leave this in for debugging, just in case
-      gclog_or_tty->print_cr("searching between " SIZE_FORMAT " and " SIZE_FORMAT
-                             ", incr " SIZE_FORMAT ", pass %s",
-                             from_so_length, to_so_length, so_length_incr,
-                             (pass == pass_type_coarse) ? "coarse" :
-                             (pass == pass_type_fine) ? "fine" : "final");
-#endif // TRACE_CALC_YOUNG_CONFIG
-
-      size_t so_length = from_so_length;
-      size_t init_free_regions =
-        MAX2((size_t)0,
-             _free_regions_at_end_of_collection +
-             _scan_only_regions_at_end_of_collection - reserve_regions);
-
-      // this determines whether a configuration was found
-      bool gc_eff_set = false;
-      // this is the middle loop
-      while (so_length <= to_so_length) {
-        // base time, which excludes region-related time; again we
-        // calculate it once to avoid recalculating it in the
-        // innermost loop
-        double base_time_with_so_ms =
-                           base_time_ms + predict_scan_only_time_ms(so_length);
-        // it's already over the pause target, go around
-        if (base_time_with_so_ms > target_pause_time_ms)
-          break;
-
-        size_t starting_young_length = so_length+1;
-
-        // we make sure that the short young length that makes sense
-        // (one more than the S-O length) is feasible
-        size_t min_young_length = starting_young_length;
-        double min_gc_eff;
-        bool min_ok;
-        ++calculations;
-        min_ok = predict_gc_eff(min_young_length, so_length,
-                                base_time_with_so_ms,
-                                init_free_regions, target_pause_time_ms,
-                                &min_gc_eff);
-
-        if (min_ok) {
-          // the shortest young length is indeed feasible; we'll know
-          // set up the max young length and we'll do a binary search
-          // between min_young_length and max_young_length
-          size_t max_young_length = _free_regions_at_end_of_collection - 1;
-          double max_gc_eff = 0.0;
-          bool max_ok = false;
-
-          // the innermost loop! (finally!)
-          while (max_young_length > min_young_length) {
-            // we'll make sure that min_young_length is always at a
-            // feasible config
-            guarantee( min_ok, "invariant" );
-
-            ++calculations;
-            max_ok = predict_gc_eff(max_young_length, so_length,
-                                    base_time_with_so_ms,
-                                    init_free_regions, target_pause_time_ms,
-                                    &max_gc_eff);
+
+    size_t init_free_regions =
+      MAX2((size_t)0, _free_regions_at_end_of_collection - reserve_regions);
+
+    // if we're still under the pause target...
+    if (base_time_ms <= target_pause_time_ms) {
+      // We make sure that the shortest young length that makes sense
+      // fits within the target pause time.
+      size_t min_young_length = 1;
+
+      if (predict_will_fit(min_young_length, base_time_ms,
+                                     init_free_regions, target_pause_time_ms)) {
+        // The shortest young length will fit within the target pause time;
+        // we'll now check whether the absolute maximum number of young
+        // regions will fit in the target pause time. If not, we'll do
+        // a binary search between min_young_length and max_young_length
+        size_t abs_max_young_length = _free_regions_at_end_of_collection - 1;
+        size_t max_young_length = abs_max_young_length;
+
+        if (max_young_length > min_young_length) {
+          // Let's check if the initial max young length will fit within the
+          // target pause. If so then there is no need to search for a maximal
+          // young length - we'll return the initial maximum
+
+          if (predict_will_fit(max_young_length, base_time_ms,
+                                init_free_regions, target_pause_time_ms)) {
+            // The maximum young length will satisfy the target pause time.
+            // We are done so set min young length to this maximum length.
+            // The code after the loop will then set final_young_length using
+            // the value cached in the minimum length.
+            min_young_length = max_young_length;
+          } else {
+            // The maximum possible number of young regions will not fit within
+            // the target pause time so let's search....
 
             size_t diff = (max_young_length - min_young_length) / 2;
-            if (max_ok) {
-              min_young_length = max_young_length;
-              min_gc_eff = max_gc_eff;
-              min_ok = true;
+            max_young_length = min_young_length + diff;
+
+            while (max_young_length > min_young_length) {
+              if (predict_will_fit(max_young_length, base_time_ms,
+                                        init_free_regions, target_pause_time_ms)) {
+
+                // The current max young length will fit within the target
+                // pause time. Note we do not exit the loop here. By setting
+                // min = max, and then increasing the max below means that
+                // we will continue searching for an upper bound in the
+                // range [max..max+diff]
+                min_young_length = max_young_length;
+              }
+              diff = (max_young_length - min_young_length) / 2;
+              max_young_length = min_young_length + diff;
             }
-            max_young_length = min_young_length + diff;
+            // the above loop found a maximal young length that will fit
+            // within the target pause time.
           }
-
-          // the innermost loop found a config
-          guarantee( min_ok, "invariant" );
-          if (min_gc_eff > final_gc_eff) {
-            // it's the best config so far, so we'll keep it
-            final_gc_eff = min_gc_eff;
-            final_young_length = min_young_length;
-            final_so_length = so_length;
-            gc_eff_set = true;
-          }
+          assert(min_young_length <= abs_max_young_length, "just checking");
         }
-
-        // incremental the fixed S-O length and go around
-        so_length += so_length_incr;
+        final_young_length = min_young_length;
       }
-
-      // this is the end of the outermost loop and we need to decide
-      // what to do during the next iteration
-      if (pass == pass_type_coarse) {
-        // we just did the coarse pass (first iteration)
-
-        if (!gc_eff_set)
-          // we didn't find a feasible config so we'll just bail out; of
-          // course, it might be the case that we missed it; but I'd say
-          // it's a bit unlikely
-          done = true;
-        else {
-          // We did find a feasible config with optimal GC eff during
-          // the first pass. So the second pass we'll only consider the
-          // S-O lengths around that config with a fine increment.
-
-          guarantee( so_length_incr == so_coarse_increments, "invariant" );
-          guarantee( final_so_length >= min_so_length, "invariant" );
-
-#ifdef TRACE_CALC_YOUNG_CONFIG
-          // leave this in for debugging, just in case
-          gclog_or_tty->print_cr("  coarse pass: SO length " SIZE_FORMAT,
-                                 final_so_length);
-#endif // TRACE_CALC_YOUNG_CONFIG
-
-          from_so_length =
-            (final_so_length - min_so_length > so_coarse_increments) ?
-            final_so_length - so_coarse_increments + 1 : min_so_length;
-          to_so_length =
-            (max_so_length - final_so_length > so_coarse_increments) ?
-            final_so_length + so_coarse_increments - 1 : max_so_length;
-
-          pass = pass_type_fine;
-          so_length_incr = 1;
-        }
-      } else if (pass == pass_type_fine) {
-        // we just finished the second pass
-
-        if (!gc_eff_set) {
-          // we didn't find a feasible config (yes, it's possible;
-          // notice that, sometimes, we go directly into the fine
-          // iteration and skip the coarse one) so we bail out
-          done = true;
-        } else {
-          // We did find a feasible config with optimal GC eff
-          guarantee( so_length_incr == 1, "invariant" );
-
-          if (final_so_length == 0) {
-            // The config is of an empty S-O set, so we'll just bail out
-            done = true;
-          } else {
-            // we'll go around once more, setting the S-O length to 95%
-            // of the optimal
-            size_t new_so_length = 950 * final_so_length / 1000;
-
-#ifdef TRACE_CALC_YOUNG_CONFIG
-            // leave this in for debugging, just in case
-            gclog_or_tty->print_cr("  fine pass: SO length " SIZE_FORMAT
-                                   ", setting it to " SIZE_FORMAT,
-                                    final_so_length, new_so_length);
-#endif // TRACE_CALC_YOUNG_CONFIG
-
-            from_so_length = new_so_length;
-            to_so_length = new_so_length;
-            fine_so_length = final_so_length;
-
-            pass = pass_type_final;
-          }
-        }
-      } else if (pass == pass_type_final) {
-        // we just finished the final (third) pass
-
-        if (!gc_eff_set)
-          // we didn't find a feasible config, so we'll just use the one
-          // we found during the second pass, which we saved
-          final_so_length = fine_so_length;
-
-        // and we're done!
-        done = true;
-      } else {
-        guarantee( false, "should never reach here" );
-      }
-
-      // we now go around the outermost loop
     }
+    // and we're done!
 
     // we should have at least one region in the target young length
     _young_list_target_length =
         MAX2((size_t) 1, final_young_length + _recorded_survivor_regions);
-    if (final_so_length >= final_young_length)
-      // and we need to ensure that the S-O length is not greater than
-      // the target young length (this is being a bit careful)
-      final_so_length = 0;
-    _young_list_so_prefix_length = final_so_length;
-    guarantee( !_in_marking_window || !_last_full_young_gc ||
-               _young_list_so_prefix_length == 0, "invariant" );
 
     // let's keep an eye of how long we spend on this calculation
     // right now, I assume that we'll print it when we need it; we
@@ -781,142 +511,91 @@
     double end_time_sec = os::elapsedTime();
     double elapsed_time_ms = (end_time_sec - start_time_sec) * 1000.0;
 
-#ifdef TRACE_CALC_YOUNG_CONFIG
+#ifdef TRACE_CALC_YOUNG_LENGTH
     // leave this in for debugging, just in case
-    gclog_or_tty->print_cr("target = %1.1lf ms, young = " SIZE_FORMAT
-                           ", SO = " SIZE_FORMAT ", "
-                           "elapsed %1.2lf ms, calcs: " SIZE_FORMAT " (%s%s) "
-                           SIZE_FORMAT SIZE_FORMAT,
+    gclog_or_tty->print_cr("target = %1.1lf ms, young = " SIZE_FORMAT ", "
+                           "elapsed %1.2lf ms, (%s%s) " SIZE_FORMAT SIZE_FORMAT,
                            target_pause_time_ms,
-                           _young_list_target_length - _young_list_so_prefix_length,
-                           _young_list_so_prefix_length,
+                           _young_list_target_length
                            elapsed_time_ms,
-                           calculations,
                            full_young_gcs() ? "full" : "partial",
                            during_initial_mark_pause() ? " i-m" : "",
                            _in_marking_window,
                            _in_marking_window_im);
-#endif // TRACE_CALC_YOUNG_CONFIG
+#endif // TRACE_CALC_YOUNG_LENGTH
 
     if (_young_list_target_length < _young_list_min_length) {
-      // bummer; this means that, if we do a pause when the optimal
-      // config dictates, we'll violate the pause spacing target (the
+      // bummer; this means that, if we do a pause when the maximal
+      // length dictates, we'll violate the pause spacing target (the
       // min length was calculate based on the application's current
       // alloc rate);
 
       // so, we have to bite the bullet, and allocate the minimum
       // number. We'll violate our target, but we just can't meet it.
 
-      size_t so_length = 0;
-      // a note further up explains why we do not want an S-O length
-      // during marking
-      if (!_in_marking_window && !_last_full_young_gc)
-        // but we can still try to see whether we can find an optimal
-        // S-O length
-        so_length = calculate_optimal_so_length(_young_list_min_length);
-
-#ifdef TRACE_CALC_YOUNG_CONFIG
+#ifdef TRACE_CALC_YOUNG_LENGTH
       // leave this in for debugging, just in case
       gclog_or_tty->print_cr("adjusted target length from "
-                             SIZE_FORMAT " to " SIZE_FORMAT
-                             ", SO " SIZE_FORMAT,
-                             _young_list_target_length, _young_list_min_length,
-                             so_length);
-#endif // TRACE_CALC_YOUNG_CONFIG
-
-      _young_list_target_length =
-        MAX2(_young_list_min_length, (size_t)1);
-      _young_list_so_prefix_length = so_length;
+                             SIZE_FORMAT " to " SIZE_FORMAT,
+                             _young_list_target_length, _young_list_min_length);
+#endif // TRACE_CALC_YOUNG_LENGTH
+
+      _young_list_target_length = _young_list_min_length;
     }
   } else {
     // we are in a partially-young mode or we've run out of regions (due
     // to evacuation failure)
 
-#ifdef TRACE_CALC_YOUNG_CONFIG
+#ifdef TRACE_CALC_YOUNG_LENGTH
     // leave this in for debugging, just in case
     gclog_or_tty->print_cr("(partial) setting target to " SIZE_FORMAT
-                           ", SO " SIZE_FORMAT,
-                           _young_list_min_length, 0);
-#endif // TRACE_CALC_YOUNG_CONFIG
-
-    // we'll do the pause as soon as possible and with no S-O prefix
-    // (see above for the reasons behind the latter)
+                           _young_list_min_length);
+#endif // TRACE_CALC_YOUNG_LENGTH
+    // we'll do the pause as soon as possible by choosing the minimum
     _young_list_target_length =
       MAX2(_young_list_min_length, (size_t) 1);
-    _young_list_so_prefix_length = 0;
   }
 
   _rs_lengths_prediction = rs_lengths;
 }
 
-// This is used by: calculate_optimal_so_length(length). It returns
-// the GC eff and predicted pause time for a particular config
-void
-G1CollectorPolicy::predict_gc_eff(size_t young_length,
-                                  size_t so_length,
-                                  double base_time_ms,
-                                  double* ret_gc_eff,
-                                  double* ret_pause_time_ms) {
-  double so_time_ms = predict_scan_only_time_ms(so_length);
-  double accum_surv_rate_adj = 0.0;
-  if (so_length > 0)
-    accum_surv_rate_adj = accum_yg_surv_rate_pred((int)(so_length - 1));
-  double accum_surv_rate =
-    accum_yg_surv_rate_pred((int)(young_length - 1)) - accum_surv_rate_adj;
-  size_t bytes_to_copy =
-    (size_t) (accum_surv_rate * (double) HeapRegion::GrainBytes);
-  double copy_time_ms = predict_object_copy_time_ms(bytes_to_copy);
-  double young_other_time_ms =
-                       predict_young_other_time_ms(young_length - so_length);
-  double pause_time_ms =
-                base_time_ms + so_time_ms + copy_time_ms + young_other_time_ms;
-  size_t reclaimed_bytes =
-    (young_length - so_length) * HeapRegion::GrainBytes - bytes_to_copy;
-  double gc_eff = (double) reclaimed_bytes / pause_time_ms;
-
-  *ret_gc_eff = gc_eff;
-  *ret_pause_time_ms = pause_time_ms;
-}
-
-// This is used by: calculate_young_list_target_config(rs_length). It
-// returns the GC eff of a particular config. It returns false if that
-// config violates any of the end conditions of the search in the
-// calling method, or true upon success. The end conditions were put
-// here since it's called twice and it was best not to replicate them
-// in the caller. Also, passing the parameteres avoids having to
-// recalculate them in the innermost loop.
+// This is used by: calculate_young_list_target_length(rs_length). It
+// returns true iff:
+//   the predicted pause time for the given young list will not overflow
+//   the target pause time
+// and:
+//   the predicted amount of surviving data will not overflow the
+//   the amount of free space available for survivor regions.
+//
 bool
-G1CollectorPolicy::predict_gc_eff(size_t young_length,
-                                  size_t so_length,
-                                  double base_time_with_so_ms,
-                                  size_t init_free_regions,
-                                  double target_pause_time_ms,
-                                  double* ret_gc_eff) {
-  *ret_gc_eff = 0.0;
+G1CollectorPolicy::predict_will_fit(size_t young_length,
+                                    double base_time_ms,
+                                    size_t init_free_regions,
+                                    double target_pause_time_ms) {
 
   if (young_length >= init_free_regions)
     // end condition 1: not enough space for the young regions
     return false;
 
   double accum_surv_rate_adj = 0.0;
-  if (so_length > 0)
-    accum_surv_rate_adj = accum_yg_surv_rate_pred((int)(so_length - 1));
   double accum_surv_rate =
     accum_yg_surv_rate_pred((int)(young_length - 1)) - accum_surv_rate_adj;
+
   size_t bytes_to_copy =
     (size_t) (accum_surv_rate * (double) HeapRegion::GrainBytes);
+
   double copy_time_ms = predict_object_copy_time_ms(bytes_to_copy);
+
   double young_other_time_ms =
-                       predict_young_other_time_ms(young_length - so_length);
+                       predict_young_other_time_ms(young_length);
+
   double pause_time_ms =
-                   base_time_with_so_ms + copy_time_ms + young_other_time_ms;
+                   base_time_ms + copy_time_ms + young_other_time_ms;
 
   if (pause_time_ms > target_pause_time_ms)
     // end condition 2: over the target pause time
     return false;
 
-  size_t reclaimed_bytes =
-    (young_length - so_length) * HeapRegion::GrainBytes - bytes_to_copy;
   size_t free_bytes =
                  (init_free_regions - young_length) * HeapRegion::GrainBytes;
 
@@ -925,9 +604,6 @@
     return false;
 
   // success!
-  double gc_eff = (double) reclaimed_bytes / pause_time_ms;
-  *ret_gc_eff = gc_eff;
-
   return true;
 }
 
@@ -944,11 +620,11 @@
 void G1CollectorPolicy::check_prediction_validity() {
   guarantee( adaptive_young_list_length(), "should not call this otherwise" );
 
-  size_t rs_lengths = _g1->young_list_sampled_rs_lengths();
+  size_t rs_lengths = _g1->young_list()->sampled_rs_lengths();
   if (rs_lengths > _rs_lengths_prediction) {
     // add 10% to avoid having to recalculate often
     size_t rs_lengths_prediction = rs_lengths * 1100 / 1000;
-    calculate_young_list_target_config(rs_lengths_prediction);
+    calculate_young_list_target_length(rs_lengths_prediction);
   }
 }
 
@@ -970,7 +646,7 @@
 
 #ifndef PRODUCT
 bool G1CollectorPolicy::verify_young_ages() {
-  HeapRegion* head = _g1->young_list_first_region();
+  HeapRegion* head = _g1->young_list()->first_region();
   return
     verify_young_ages(head, _short_lived_surv_rate_group);
   // also call verify_young_ages on any additional surv rate groups
@@ -1047,7 +723,6 @@
   _in_marking_window = false;
   _in_marking_window_im = false;
 
-  _short_lived_surv_rate_group->record_scan_only_prefix(0);
   _short_lived_surv_rate_group->start_adding_regions();
   // also call this on any additional surv rate groups
 
@@ -1057,11 +732,10 @@
   _prev_region_num_tenured = _region_num_tenured;
 
   _free_regions_at_end_of_collection = _g1->free_regions();
-  _scan_only_regions_at_end_of_collection = 0;
   // Reset survivors SurvRateGroup.
   _survivor_surv_rate_group->reset();
   calculate_young_list_min_length();
-  calculate_young_list_target_config();
+  calculate_young_list_target_length();
  }
 
 void G1CollectorPolicy::record_before_bytes(size_t bytes) {
@@ -1110,8 +784,6 @@
   for (int i = 0; i < _parallel_gc_threads; ++i) {
     _par_last_ext_root_scan_times_ms[i] = -666.0;
     _par_last_mark_stack_scan_times_ms[i] = -666.0;
-    _par_last_scan_only_times_ms[i] = -666.0;
-    _par_last_scan_only_regions_scanned[i] = -666.0;
     _par_last_update_rs_start_times_ms[i] = -666.0;
     _par_last_update_rs_times_ms[i] = -666.0;
     _par_last_update_rs_processed_buffers[i] = -666.0;
@@ -1134,47 +806,13 @@
   if (in_young_gc_mode())
     _last_young_gc_full = false;
 
-
   // do that for any other surv rate groups
   _short_lived_surv_rate_group->stop_adding_regions();
-  size_t short_lived_so_length = _young_list_so_prefix_length;
-  _short_lived_surv_rate_group->record_scan_only_prefix(short_lived_so_length);
-  tag_scan_only(short_lived_so_length);
   _survivors_age_table.clear();
 
   assert( verify_young_ages(), "region age verification" );
 }
 
-void G1CollectorPolicy::tag_scan_only(size_t short_lived_scan_only_length) {
-  // done in a way that it can be extended for other surv rate groups too...
-
-  HeapRegion* head = _g1->young_list_first_region();
-  bool finished_short_lived = (short_lived_scan_only_length == 0);
-
-  if (finished_short_lived)
-    return;
-
-  for (HeapRegion* curr = head;
-       curr != NULL;
-       curr = curr->get_next_young_region()) {
-    SurvRateGroup* surv_rate_group = curr->surv_rate_group();
-    int age = curr->age_in_surv_rate_group();
-
-    if (surv_rate_group == _short_lived_surv_rate_group) {
-      if ((size_t)age < short_lived_scan_only_length)
-        curr->set_scan_only();
-      else
-        finished_short_lived = true;
-    }
-
-
-    if (finished_short_lived)
-      return;
-  }
-
-  guarantee( false, "we should never reach here" );
-}
-
 void G1CollectorPolicy::record_mark_closure_time(double mark_closure_time_ms) {
   _mark_closure_time_ms = mark_closure_time_ms;
 }
@@ -1268,7 +906,7 @@
     _last_full_young_gc = true;
     _in_marking_window = false;
     if (adaptive_young_list_length())
-      calculate_young_list_target_config();
+      calculate_young_list_target_length();
   }
 }
 
@@ -1503,6 +1141,7 @@
   size_t freed_bytes =
     _cur_collection_pause_used_at_start_bytes - cur_used_bytes;
   size_t surviving_bytes = _collection_set_bytes_used_before - freed_bytes;
+
   double survival_fraction =
     (double)surviving_bytes/
     (double)_collection_set_bytes_used_before;
@@ -1590,9 +1229,6 @@
 
   double ext_root_scan_time = avg_value(_par_last_ext_root_scan_times_ms);
   double mark_stack_scan_time = avg_value(_par_last_mark_stack_scan_times_ms);
-  double scan_only_time = avg_value(_par_last_scan_only_times_ms);
-  double scan_only_regions_scanned =
-    sum_of_values(_par_last_scan_only_regions_scanned);
   double update_rs_time = avg_value(_par_last_update_rs_times_ms);
   double update_rs_processed_buffers =
     sum_of_values(_par_last_update_rs_processed_buffers);
@@ -1602,7 +1238,7 @@
 
   double parallel_other_time = _cur_collection_par_time_ms -
     (update_rs_time + ext_root_scan_time + mark_stack_scan_time +
-     scan_only_time + scan_rs_time + obj_copy_time + termination_time);
+     scan_rs_time + obj_copy_time + termination_time);
   if (update_stats) {
     MainBodySummary* body_summary = summary->main_body_summary();
     guarantee(body_summary != NULL, "should not be null!");
@@ -1613,7 +1249,6 @@
       body_summary->record_satb_drain_time_ms(0.0);
     body_summary->record_ext_root_scan_time_ms(ext_root_scan_time);
     body_summary->record_mark_stack_scan_time_ms(mark_stack_scan_time);
-    body_summary->record_scan_only_time_ms(scan_only_time);
     body_summary->record_update_rs_time_ms(update_rs_time);
     body_summary->record_scan_rs_time_ms(scan_rs_time);
     body_summary->record_obj_copy_time_ms(obj_copy_time);
@@ -1667,7 +1302,7 @@
     else
       other_time_ms -=
         update_rs_time +
-        ext_root_scan_time + mark_stack_scan_time + scan_only_time +
+        ext_root_scan_time + mark_stack_scan_time +
         scan_rs_time + obj_copy_time;
   }
 
@@ -1692,9 +1327,6 @@
                           _par_last_update_rs_processed_buffers, true);
         print_par_stats(2, "Ext Root Scanning", _par_last_ext_root_scan_times_ms);
         print_par_stats(2, "Mark Stack Scanning", _par_last_mark_stack_scan_times_ms);
-        print_par_stats(2, "Scan-Only Scanning", _par_last_scan_only_times_ms);
-        print_par_buffers(3, "Scan-Only Regions",
-                          _par_last_scan_only_regions_scanned, true);
         print_par_stats(2, "Scan RS", _par_last_scan_rs_times_ms);
         print_par_stats(2, "Object Copy", _par_last_obj_copy_times_ms);
         print_par_stats(2, "Termination", _par_last_termination_times_ms);
@@ -1706,7 +1338,6 @@
                     (int)update_rs_processed_buffers);
         print_stats(1, "Ext Root Scanning", ext_root_scan_time);
         print_stats(1, "Mark Stack Scanning", mark_stack_scan_time);
-        print_stats(1, "Scan-Only Scanning", scan_only_time);
         print_stats(1, "Scan RS", scan_rs_time);
         print_stats(1, "Object Copying", obj_copy_time);
       }
@@ -1721,6 +1352,8 @@
     }
 #endif
     print_stats(1, "Other", other_time_ms);
+    print_stats(2, "Choose CSet", _recorded_young_cset_choice_time_ms);
+
     for (int i = 0; i < _aux_num; ++i) {
       if (_cur_aux_times_set[i]) {
         char buffer[96];
@@ -1806,16 +1439,6 @@
       _cost_per_card_ms_seq->add(cost_per_card_ms);
     }
 
-    double cost_per_scan_only_region_ms = 0.0;
-    if (scan_only_regions_scanned > 0.0) {
-      cost_per_scan_only_region_ms =
-        scan_only_time / scan_only_regions_scanned;
-      if (_in_marking_window_im)
-        _cost_per_scan_only_region_ms_during_cm_seq->add(cost_per_scan_only_region_ms);
-      else
-        _cost_per_scan_only_region_ms_seq->add(cost_per_scan_only_region_ms);
-    }
-
     size_t cards_scanned = _g1->cards_scanned();
 
     double cost_per_entry_ms = 0.0;
@@ -1851,7 +1474,7 @@
     }
 
     double all_other_time_ms = pause_time_ms -
-      (update_rs_time + scan_only_time + scan_rs_time + obj_copy_time +
+      (update_rs_time + scan_rs_time + obj_copy_time +
        _mark_closure_time_ms + termination_time);
 
     double young_other_time_ms = 0.0;
@@ -1898,11 +1521,10 @@
     if (PREDICTIONS_VERBOSE) {
       gclog_or_tty->print_cr("");
       gclog_or_tty->print_cr("PREDICTIONS %1.4lf %d "
-                    "REGIONS %d %d %d %d "
+                    "REGIONS %d %d %d "
                     "PENDING_CARDS %d %d "
                     "CARDS_SCANNED %d %d "
                     "RS_LENGTHS %d %d "
-                    "SCAN_ONLY_SCAN %1.6lf %1.6lf "
                     "RS_UPDATE %1.6lf %1.6lf RS_SCAN %1.6lf %1.6lf "
                     "SURVIVAL_RATIO %1.6lf %1.6lf "
                     "OBJECT_COPY %1.6lf %1.6lf OTHER_CONSTANT %1.6lf %1.6lf "
@@ -1915,12 +1537,10 @@
                     (last_pause_included_initial_mark) ? 1 : 0,
                     _recorded_region_num,
                     _recorded_young_regions,
-                    _recorded_scan_only_regions,
                     _recorded_non_young_regions,
                     _predicted_pending_cards, _pending_cards,
                     _predicted_cards_scanned, cards_scanned,
                     _predicted_rs_lengths, _max_rs_lengths,
-                    _predicted_scan_only_scan_time_ms, scan_only_time,
                     _predicted_rs_update_time_ms, update_rs_time,
                     _predicted_rs_scan_time_ms, scan_rs_time,
                     _predicted_survival_ratio, survival_ratio,
@@ -1945,14 +1565,12 @@
   _in_marking_window = new_in_marking_window;
   _in_marking_window_im = new_in_marking_window_im;
   _free_regions_at_end_of_collection = _g1->free_regions();
-  _scan_only_regions_at_end_of_collection = _g1->young_list_length();
   calculate_young_list_min_length();
-  calculate_young_list_target_config();
+  calculate_young_list_target_length();
 
   // Note that _mmu_tracker->max_gc_time() returns the time in seconds.
   double update_rs_time_goal_ms = _mmu_tracker->max_gc_time() * MILLIUNITS * G1RSetUpdatingPauseTimePercent / 100.0;
   adjust_concurrent_refinement(update_rs_time, update_rs_processed_buffers, update_rs_time_goal_ms);
-
   // </NEW PREDICTION>
 
   _target_pause_time_ms = -1.0;
@@ -2007,13 +1625,13 @@
   guarantee( adjustment == 0 || adjustment == 1, "invariant" );
 
   G1CollectedHeap* g1h = G1CollectedHeap::heap();
-  size_t young_num = g1h->young_list_length();
+  size_t young_num = g1h->young_list()->length();
   if (young_num == 0)
     return 0.0;
 
   young_num += adjustment;
   size_t pending_cards = predict_pending_cards();
-  size_t rs_lengths = g1h->young_list_sampled_rs_lengths() +
+  size_t rs_lengths = g1h->young_list()->sampled_rs_lengths() +
                       predict_rs_length_diff();
   size_t card_num;
   if (full_young_gcs())
@@ -2097,31 +1715,22 @@
 void
 G1CollectorPolicy::start_recording_regions() {
   _recorded_rs_lengths            = 0;
-  _recorded_scan_only_regions     = 0;
   _recorded_young_regions         = 0;
   _recorded_non_young_regions     = 0;
 
 #if PREDICTIONS_VERBOSE
-  _predicted_rs_lengths           = 0;
-  _predicted_cards_scanned        = 0;
-
   _recorded_marked_bytes          = 0;
   _recorded_young_bytes           = 0;
   _predicted_bytes_to_copy        = 0;
+  _predicted_rs_lengths           = 0;
+  _predicted_cards_scanned        = 0;
 #endif // PREDICTIONS_VERBOSE
 }
 
 void
-G1CollectorPolicy::record_cset_region(HeapRegion* hr, bool young) {
-  if (young) {
-    ++_recorded_young_regions;
-  } else {
-    ++_recorded_non_young_regions;
-  }
+G1CollectorPolicy::record_cset_region_info(HeapRegion* hr, bool young) {
 #if PREDICTIONS_VERBOSE
-  if (young) {
-    _recorded_young_bytes += hr->used();
-  } else {
+  if (!young) {
     _recorded_marked_bytes += hr->max_live_bytes();
   }
   _predicted_bytes_to_copy += predict_bytes_to_copy(hr);
@@ -2132,12 +1741,37 @@
 }
 
 void
-G1CollectorPolicy::record_scan_only_regions(size_t scan_only_length) {
-  _recorded_scan_only_regions = scan_only_length;
+G1CollectorPolicy::record_non_young_cset_region(HeapRegion* hr) {
+  assert(!hr->is_young(), "should not call this");
+  ++_recorded_non_young_regions;
+  record_cset_region_info(hr, false);
+}
+
+void
+G1CollectorPolicy::set_recorded_young_regions(size_t n_regions) {
+  _recorded_young_regions = n_regions;
+}
+
+void G1CollectorPolicy::set_recorded_young_bytes(size_t bytes) {
+#if PREDICTIONS_VERBOSE
+  _recorded_young_bytes = bytes;
+#endif // PREDICTIONS_VERBOSE
+}
+
+void G1CollectorPolicy::set_recorded_rs_lengths(size_t rs_lengths) {
+  _recorded_rs_lengths = rs_lengths;
+}
+
+void G1CollectorPolicy::set_predicted_bytes_to_copy(size_t bytes) {
+  _predicted_bytes_to_copy = bytes;
 }
 
 void
 G1CollectorPolicy::end_recording_regions() {
+  // The _predicted_pause_time_ms field is referenced in code
+  // not under PREDICTIONS_VERBOSE. Let's initialize it.
+  _predicted_pause_time_ms = -1.0;
+
 #if PREDICTIONS_VERBOSE
   _predicted_pending_cards = predict_pending_cards();
   _predicted_rs_lengths = _recorded_rs_lengths + predict_rs_length_diff();
@@ -2148,8 +1782,6 @@
       predict_non_young_card_num(_predicted_rs_lengths);
   _recorded_region_num = _recorded_young_regions + _recorded_non_young_regions;
 
-  _predicted_scan_only_scan_time_ms =
-    predict_scan_only_time_ms(_recorded_scan_only_regions);
   _predicted_rs_update_time_ms =
     predict_rs_update_time_ms(_g1->pending_card_num());
   _predicted_rs_scan_time_ms =
@@ -2164,7 +1796,6 @@
     predict_non_young_other_time_ms(_recorded_non_young_regions);
 
   _predicted_pause_time_ms =
-    _predicted_scan_only_scan_time_ms +
     _predicted_rs_update_time_ms +
     _predicted_rs_scan_time_ms +
     _predicted_object_copy_time_ms +
@@ -2454,8 +2085,6 @@
                       body_summary->get_ext_root_scan_seq());
         print_summary(2, "Mark Stack Scanning",
                       body_summary->get_mark_stack_scan_seq());
-        print_summary(2, "Scan-Only Scanning",
-                      body_summary->get_scan_only_seq());
         print_summary(2, "Scan RS", body_summary->get_scan_rs_seq());
         print_summary(2, "Object Copy", body_summary->get_obj_copy_seq());
         print_summary(2, "Termination", body_summary->get_termination_seq());
@@ -2465,7 +2094,6 @@
             body_summary->get_update_rs_seq(),
             body_summary->get_ext_root_scan_seq(),
             body_summary->get_mark_stack_scan_seq(),
-            body_summary->get_scan_only_seq(),
             body_summary->get_scan_rs_seq(),
             body_summary->get_obj_copy_seq(),
             body_summary->get_termination_seq()
@@ -2483,8 +2111,6 @@
                       body_summary->get_ext_root_scan_seq());
         print_summary(1, "Mark Stack Scanning",
                       body_summary->get_mark_stack_scan_seq());
-        print_summary(1, "Scan-Only Scanning",
-                      body_summary->get_scan_only_seq());
         print_summary(1, "Scan RS", body_summary->get_scan_rs_seq());
         print_summary(1, "Object Copy", body_summary->get_obj_copy_seq());
       }
@@ -2510,7 +2136,6 @@
             body_summary->get_update_rs_seq(),
             body_summary->get_ext_root_scan_seq(),
             body_summary->get_mark_stack_scan_seq(),
-            body_summary->get_scan_only_seq(),
             body_summary->get_scan_rs_seq(),
             body_summary->get_obj_copy_seq()
           };
@@ -2604,7 +2229,7 @@
 G1CollectorPolicy::should_add_next_region_to_young_list() {
   assert(in_young_gc_mode(), "should be in young GC mode");
   bool ret;
-  size_t young_list_length = _g1->young_list_length();
+  size_t young_list_length = _g1->young_list()->length();
   size_t young_list_max_length = _young_list_target_length;
   if (G1FixedEdenSize) {
     young_list_max_length -= _max_survivor_regions;
@@ -2667,7 +2292,7 @@
   assert(_g1->regions_accounted_for(), "Region leakage!");
   double max_pause_time_ms = _mmu_tracker->max_gc_time() * 1000.0;
 
-  size_t young_list_length = _g1->young_list_length();
+  size_t young_list_length = _g1->young_list()->length();
   size_t young_list_max_length = _young_list_target_length;
   if (G1FixedEdenSize) {
     young_list_max_length -= _max_survivor_regions;
@@ -2676,7 +2301,7 @@
 
   if (in_young_gc_mode()) {
     if (reached_target_length) {
-      assert( young_list_length > 0 && _g1->young_list_length() > 0,
+      assert( young_list_length > 0 && _g1->young_list()->length() > 0,
               "invariant" );
       _target_pause_time_ms = max_pause_time_ms;
       return true;
@@ -2937,22 +2562,24 @@
   }
 }
 
-// Add the heap region to the collection set and return the conservative
-// estimate of the number of live bytes.
+// Add the heap region at the head of the non-incremental collection set
 void G1CollectorPolicy::
 add_to_collection_set(HeapRegion* hr) {
+  assert(_inc_cset_build_state == Active, "Precondition");
+  assert(!hr->is_young(), "non-incremental add of young region");
+
   if (G1PrintHeapRegions) {
-    gclog_or_tty->print_cr("added region to cset %d:["PTR_FORMAT", "PTR_FORMAT"], "
-                  "top "PTR_FORMAT", young %s",
-                  hr->hrs_index(), hr->bottom(), hr->end(),
-                  hr->top(), (hr->is_young()) ? "YES" : "NO");
+    gclog_or_tty->print_cr("added region to cset "
+                           "%d:["PTR_FORMAT", "PTR_FORMAT"], "
+                           "top "PTR_FORMAT", %s",
+                           hr->hrs_index(), hr->bottom(), hr->end(),
+                           hr->top(), hr->is_young() ? "YOUNG" : "NOT_YOUNG");
   }
 
   if (_g1->mark_in_progress())
     _g1->concurrent_mark()->registerCSetRegion(hr);
 
-  assert(!hr->in_collection_set(),
-              "should not already be in the CSet");
+  assert(!hr->in_collection_set(), "should not already be in the CSet");
   hr->set_in_collection_set(true);
   hr->set_next_in_collection_set(_collection_set);
   _collection_set = hr;
@@ -2961,10 +2588,230 @@
   _g1->register_region_with_in_cset_fast_test(hr);
 }
 
-void
-G1CollectorPolicy_BestRegionsFirst::
-choose_collection_set() {
-  double non_young_start_time_sec;
+// Initialize the per-collection-set information
+void G1CollectorPolicy::start_incremental_cset_building() {
+  assert(_inc_cset_build_state == Inactive, "Precondition");
+
+  _inc_cset_head = NULL;
+  _inc_cset_tail = NULL;
+  _inc_cset_size = 0;
+  _inc_cset_bytes_used_before = 0;
+
+  if (in_young_gc_mode()) {
+    _inc_cset_young_index = 0;
+  }
+
+  _inc_cset_max_finger = 0;
+  _inc_cset_recorded_young_bytes = 0;
+  _inc_cset_recorded_rs_lengths = 0;
+  _inc_cset_predicted_elapsed_time_ms = 0;
+  _inc_cset_predicted_bytes_to_copy = 0;
+  _inc_cset_build_state = Active;
+}
+
+void G1CollectorPolicy::add_to_incremental_cset_info(HeapRegion* hr, size_t rs_length) {
+  // This routine is used when:
+  // * adding survivor regions to the incremental cset at the end of an
+  //   evacuation pause,
+  // * adding the current allocation region to the incremental cset
+  //   when it is retired, and
+  // * updating existing policy information for a region in the
+  //   incremental cset via young list RSet sampling.
+  // Therefore this routine may be called at a safepoint by the
+  // VM thread, or in-between safepoints by mutator threads (when
+  // retiring the current allocation region) or a concurrent
+  // refine thread (RSet sampling).
+
+  double region_elapsed_time_ms = predict_region_elapsed_time_ms(hr, true);
+  size_t used_bytes = hr->used();
+
+  _inc_cset_recorded_rs_lengths += rs_length;
+  _inc_cset_predicted_elapsed_time_ms += region_elapsed_time_ms;
+
+  _inc_cset_bytes_used_before += used_bytes;
+
+  // Cache the values we have added to the aggregated informtion
+  // in the heap region in case we have to remove this region from
+  // the incremental collection set, or it is updated by the
+  // rset sampling code
+  hr->set_recorded_rs_length(rs_length);
+  hr->set_predicted_elapsed_time_ms(region_elapsed_time_ms);
+
+#if PREDICTIONS_VERBOSE
+  size_t bytes_to_copy = predict_bytes_to_copy(hr);
+  _inc_cset_predicted_bytes_to_copy += bytes_to_copy;
+
+  // Record the number of bytes used in this region
+  _inc_cset_recorded_young_bytes += used_bytes;
+
+  // Cache the values we have added to the aggregated informtion
+  // in the heap region in case we have to remove this region from
+  // the incremental collection set, or it is updated by the
+  // rset sampling code
+  hr->set_predicted_bytes_to_copy(bytes_to_copy);
+#endif // PREDICTIONS_VERBOSE
+}
+
+void G1CollectorPolicy::remove_from_incremental_cset_info(HeapRegion* hr) {
+  // This routine is currently only called as part of the updating of
+  // existing policy information for regions in the incremental cset that
+  // is performed by the concurrent refine thread(s) as part of young list
+  // RSet sampling. Therefore we should not be at a safepoint.
+
+  assert(!SafepointSynchronize::is_at_safepoint(), "should not be at safepoint");
+  assert(hr->is_young(), "it should be");
+
+  size_t used_bytes = hr->used();
+  size_t old_rs_length = hr->recorded_rs_length();
+  double old_elapsed_time_ms = hr->predicted_elapsed_time_ms();
+
+  // Subtract the old recorded/predicted policy information for
+  // the given heap region from the collection set info.
+  _inc_cset_recorded_rs_lengths -= old_rs_length;
+  _inc_cset_predicted_elapsed_time_ms -= old_elapsed_time_ms;
+
+  _inc_cset_bytes_used_before -= used_bytes;
+
+  // Clear the values cached in the heap region
+  hr->set_recorded_rs_length(0);
+  hr->set_predicted_elapsed_time_ms(0);
+
+#if PREDICTIONS_VERBOSE
+  size_t old_predicted_bytes_to_copy = hr->predicted_bytes_to_copy();
+  _inc_cset_predicted_bytes_to_copy -= old_predicted_bytes_to_copy;
+
+  // Subtract the number of bytes used in this region
+  _inc_cset_recorded_young_bytes -= used_bytes;
+
+  // Clear the values cached in the heap region
+  hr->set_predicted_bytes_to_copy(0);
+#endif // PREDICTIONS_VERBOSE
+}
+
+void G1CollectorPolicy::update_incremental_cset_info(HeapRegion* hr, size_t new_rs_length) {
+  // Update the collection set information that is dependent on the new RS length
+  assert(hr->is_young(), "Precondition");
+
+  remove_from_incremental_cset_info(hr);
+  add_to_incremental_cset_info(hr, new_rs_length);
+}
+
+void G1CollectorPolicy::add_region_to_incremental_cset_common(HeapRegion* hr) {
+  assert( hr->is_young(), "invariant");
+  assert( hr->young_index_in_cset() == -1, "invariant" );
+  assert(_inc_cset_build_state == Active, "Precondition");
+
+  // We need to clear and set the cached recorded/cached collection set
+  // information in the heap region here (before the region gets added
+  // to the collection set). An individual heap region's cached values
+  // are calculated, aggregated with the policy collection set info,
+  // and cached in the heap region here (initially) and (subsequently)
+  // by the Young List sampling code.
+
+  size_t rs_length = hr->rem_set()->occupied();
+  add_to_incremental_cset_info(hr, rs_length);
+
+  HeapWord* hr_end = hr->end();
+  _inc_cset_max_finger = MAX2(_inc_cset_max_finger, hr_end);
+
+  assert(!hr->in_collection_set(), "invariant");
+  hr->set_in_collection_set(true);
+  assert( hr->next_in_collection_set() == NULL, "invariant");
+
+  _inc_cset_size++;
+  _g1->register_region_with_in_cset_fast_test(hr);
+
+  hr->set_young_index_in_cset((int) _inc_cset_young_index);
+  ++_inc_cset_young_index;
+}
+
+// Add the region at the RHS of the incremental cset
+void G1CollectorPolicy::add_region_to_incremental_cset_rhs(HeapRegion* hr) {
+  // We should only ever be appending survivors at the end of a pause
+  assert( hr->is_survivor(), "Logic");
+
+  // Do the 'common' stuff
+  add_region_to_incremental_cset_common(hr);
+
+  // Now add the region at the right hand side
+  if (_inc_cset_tail == NULL) {
+    assert(_inc_cset_head == NULL, "invariant");
+    _inc_cset_head = hr;
+  } else {
+    _inc_cset_tail->set_next_in_collection_set(hr);
+  }
+  _inc_cset_tail = hr;
+
+  if (G1PrintHeapRegions) {
+    gclog_or_tty->print_cr(" added region to incremental cset (RHS) "
+                  "%d:["PTR_FORMAT", "PTR_FORMAT"], "
+                  "top "PTR_FORMAT", young %s",
+                  hr->hrs_index(), hr->bottom(), hr->end(),
+                  hr->top(), (hr->is_young()) ? "YES" : "NO");
+  }
+}
+
+// Add the region to the LHS of the incremental cset
+void G1CollectorPolicy::add_region_to_incremental_cset_lhs(HeapRegion* hr) {
+  // Survivors should be added to the RHS at the end of a pause
+  assert(!hr->is_survivor(), "Logic");
+
+  // Do the 'common' stuff
+  add_region_to_incremental_cset_common(hr);
+
+  // Add the region at the left hand side
+  hr->set_next_in_collection_set(_inc_cset_head);
+  if (_inc_cset_head == NULL) {
+    assert(_inc_cset_tail == NULL, "Invariant");
+    _inc_cset_tail = hr;
+  }
+  _inc_cset_head = hr;
+
+  if (G1PrintHeapRegions) {
+    gclog_or_tty->print_cr(" added region to incremental cset (LHS) "
+                  "%d:["PTR_FORMAT", "PTR_FORMAT"], "
+                  "top "PTR_FORMAT", young %s",
+                  hr->hrs_index(), hr->bottom(), hr->end(),
+                  hr->top(), (hr->is_young()) ? "YES" : "NO");
+  }
+}
+
+#ifndef PRODUCT
+void G1CollectorPolicy::print_collection_set(HeapRegion* list_head, outputStream* st) {
+  assert(list_head == inc_cset_head() || list_head == collection_set(), "must be");
+
+  st->print_cr("\nCollection_set:");
+  HeapRegion* csr = list_head;
+  while (csr != NULL) {
+    HeapRegion* next = csr->next_in_collection_set();
+    assert(csr->in_collection_set(), "bad CS");
+    st->print_cr("  [%08x-%08x], t: %08x, P: %08x, N: %08x, C: %08x, "
+                 "age: %4d, y: %d, surv: %d",
+                        csr->bottom(), csr->end(),
+                        csr->top(),
+                        csr->prev_top_at_mark_start(),
+                        csr->next_top_at_mark_start(),
+                        csr->top_at_conc_mark_count(),
+                        csr->age_in_surv_rate_group_cond(),
+                        csr->is_young(),
+                        csr->is_survivor());
+    csr = next;
+  }
+}
+#endif // !PRODUCT
+
+bool
+G1CollectorPolicy_BestRegionsFirst::choose_collection_set() {
+  // Set this here - in case we're not doing young collections.
+  double non_young_start_time_sec = os::elapsedTime();
+
+  // The result that this routine will return. This will be set to
+  // false if:
+  // * we're doing a young or partially young collection and we
+  //   have added the youg regions to collection set, or
+  // * we add old regions to the collection set.
+  bool abandon_collection = true;
+
   start_recording_regions();
 
   guarantee(_target_pause_time_ms > -1.0
@@ -3017,47 +2864,79 @@
 
     if (G1PolicyVerbose > 0) {
       gclog_or_tty->print_cr("Adding %d young regions to the CSet",
-                    _g1->young_list_length());
+                    _g1->young_list()->length());
     }
+
     _young_cset_length  = 0;
     _last_young_gc_full = full_young_gcs() ? true : false;
+
     if (_last_young_gc_full)
       ++_full_young_pause_num;
     else
       ++_partial_young_pause_num;
-    hr = _g1->pop_region_from_young_list();
+
+    // The young list is laid with the survivor regions from the previous
+    // pause are appended to the RHS of the young list, i.e.
+    //   [Newly Young Regions ++ Survivors from last pause].
+
+    hr = _g1->young_list()->first_survivor_region();
     while (hr != NULL) {
-
-      assert( hr->young_index_in_cset() == -1, "invariant" );
-      assert( hr->age_in_surv_rate_group() != -1, "invariant" );
-      hr->set_young_index_in_cset((int) _young_cset_length);
-
-      ++_young_cset_length;
-      double predicted_time_ms = predict_region_elapsed_time_ms(hr, true);
-      time_remaining_ms -= predicted_time_ms;
-      predicted_pause_time_ms += predicted_time_ms;
-      assert(!hr->in_collection_set(), "invariant");
-      add_to_collection_set(hr);
-      record_cset_region(hr, true);
-      max_live_bytes -= MIN2(hr->max_live_bytes(), max_live_bytes);
-      if (G1PolicyVerbose > 0) {
-        gclog_or_tty->print_cr("  Added [" PTR_FORMAT ", " PTR_FORMAT") to CS.",
-                      hr->bottom(), hr->end());
-        gclog_or_tty->print_cr("    (" SIZE_FORMAT " KB left in heap.)",
-                      max_live_bytes/K);
-      }
-      hr = _g1->pop_region_from_young_list();
+      assert(hr->is_survivor(), "badly formed young list");
+      hr->set_young();
+      hr = hr->get_next_young_region();
     }
 
-    record_scan_only_regions(_g1->young_list_scan_only_length());
+    // Clear the fields that point to the survivor list - they are
+    // all young now.
+    _g1->young_list()->clear_survivors();
+
+    if (_g1->mark_in_progress())
+      _g1->concurrent_mark()->register_collection_set_finger(_inc_cset_max_finger);
+
+    _young_cset_length = _inc_cset_young_index;
+    _collection_set = _inc_cset_head;
+    _collection_set_size = _inc_cset_size;
+    _collection_set_bytes_used_before = _inc_cset_bytes_used_before;
+
+    // For young regions in the collection set, we assume the worst
+    // case of complete survival
+    max_live_bytes -= _inc_cset_size * HeapRegion::GrainBytes;
+
+    time_remaining_ms -= _inc_cset_predicted_elapsed_time_ms;
+    predicted_pause_time_ms += _inc_cset_predicted_elapsed_time_ms;
+
+    // The number of recorded young regions is the incremental
+    // collection set's current size
+    set_recorded_young_regions(_inc_cset_size);
+    set_recorded_rs_lengths(_inc_cset_recorded_rs_lengths);
+    set_recorded_young_bytes(_inc_cset_recorded_young_bytes);
+#if PREDICTIONS_VERBOSE
+    set_predicted_bytes_to_copy(_inc_cset_predicted_bytes_to_copy);
+#endif // PREDICTIONS_VERBOSE
+
+    if (G1PolicyVerbose > 0) {
+      gclog_or_tty->print_cr("  Added " PTR_FORMAT " Young Regions to CS.",
+                             _inc_cset_size);
+      gclog_or_tty->print_cr("    (" SIZE_FORMAT " KB left in heap.)",
+                            max_live_bytes/K);
+    }
+
+    assert(_inc_cset_size == _g1->young_list()->length(), "Invariant");
+    if (_inc_cset_size > 0) {
+      assert(_collection_set != NULL, "Invariant");
+      abandon_collection = false;
+    }
 
     double young_end_time_sec = os::elapsedTime();
     _recorded_young_cset_choice_time_ms =
       (young_end_time_sec - young_start_time_sec) * 1000.0;
 
-    non_young_start_time_sec = os::elapsedTime();
-
-    if (_young_cset_length > 0 && _last_young_gc_full) {
+    // We are doing young collections so reset this.
+    non_young_start_time_sec = young_end_time_sec;
+
+    // Note we can use either _collection_set_size or
+    // _young_cset_length here
+    if (_collection_set_size > 0 && _last_young_gc_full) {
       // don't bother adding more regions...
       goto choose_collection_set_end;
     }
@@ -3067,6 +2946,11 @@
     bool should_continue = true;
     NumberSeq seq;
     double avg_prediction = 100000000000000000.0; // something very large
+
+    // Save the current size of the collection set to detect
+    // if we actually added any old regions.
+    size_t n_young_regions = _collection_set_size;
+
     do {
       hr = _collectionSetChooser->getNextMarkedRegion(time_remaining_ms,
                                                       avg_prediction);
@@ -3075,7 +2959,7 @@
         time_remaining_ms -= predicted_time_ms;
         predicted_pause_time_ms += predicted_time_ms;
         add_to_collection_set(hr);
-        record_cset_region(hr, false);
+        record_non_young_cset_region(hr);
         max_live_bytes -= MIN2(hr->max_live_bytes(), max_live_bytes);
         if (G1PolicyVerbose > 0) {
           gclog_or_tty->print_cr("    (" SIZE_FORMAT " KB left in heap.)",
@@ -3093,9 +2977,17 @@
     if (!adaptive_young_list_length() &&
         _collection_set_size < _young_list_fixed_length)
       _should_revert_to_full_young_gcs  = true;
+
+    if (_collection_set_size > n_young_regions) {
+      // We actually added old regions to the collection set
+      // so we are not abandoning this collection.
+      abandon_collection = false;
+    }
   }
 
 choose_collection_set_end:
+  stop_incremental_cset_building();
+
   count_CS_bytes_used();
 
   end_recording_regions();
@@ -3103,6 +2995,8 @@
   double non_young_end_time_sec = os::elapsedTime();
   _recorded_non_young_cset_choice_time_ms =
     (non_young_end_time_sec - non_young_start_time_sec) * 1000.0;
+
+  return abandon_collection;
 }
 
 void G1CollectorPolicy_BestRegionsFirst::record_full_collection_end() {
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/g1/g1CollectorPolicy.hpp
--- a/src/share/vm/gc_implementation/g1/g1CollectorPolicy.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/g1/g1CollectorPolicy.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -61,7 +61,6 @@
   define_num_seq(parallel) // parallel only
     define_num_seq(ext_root_scan)
     define_num_seq(mark_stack_scan)
-    define_num_seq(scan_only)
     define_num_seq(update_rs)
     define_num_seq(scan_rs)
     define_num_seq(scan_new_refs) // Only for temp use; added to
@@ -174,8 +173,6 @@
 
   double* _par_last_ext_root_scan_times_ms;
   double* _par_last_mark_stack_scan_times_ms;
-  double* _par_last_scan_only_times_ms;
-  double* _par_last_scan_only_regions_scanned;
   double* _par_last_update_rs_start_times_ms;
   double* _par_last_update_rs_times_ms;
   double* _par_last_update_rs_processed_buffers;
@@ -196,7 +193,6 @@
   bool _adaptive_young_list_length;
   size_t _young_list_min_length;
   size_t _young_list_target_length;
-  size_t _young_list_so_prefix_length;
   size_t _young_list_fixed_length;
 
   size_t _young_cset_length;
@@ -234,7 +230,6 @@
   TruncatedSeq* _pending_card_diff_seq;
   TruncatedSeq* _rs_length_diff_seq;
   TruncatedSeq* _cost_per_card_ms_seq;
-  TruncatedSeq* _cost_per_scan_only_region_ms_seq;
   TruncatedSeq* _fully_young_cards_per_entry_ratio_seq;
   TruncatedSeq* _partially_young_cards_per_entry_ratio_seq;
   TruncatedSeq* _cost_per_entry_ms_seq;
@@ -249,19 +244,16 @@
   TruncatedSeq* _rs_lengths_seq;
 
   TruncatedSeq* _cost_per_byte_ms_during_cm_seq;
-  TruncatedSeq* _cost_per_scan_only_region_ms_during_cm_seq;
 
   TruncatedSeq* _young_gc_eff_seq;
 
   TruncatedSeq* _max_conc_overhead_seq;
 
   size_t _recorded_young_regions;
-  size_t _recorded_scan_only_regions;
   size_t _recorded_non_young_regions;
   size_t _recorded_region_num;
 
   size_t _free_regions_at_end_of_collection;
-  size_t _scan_only_regions_at_end_of_collection;
 
   size_t _recorded_rs_lengths;
   size_t _max_rs_lengths;
@@ -277,7 +269,6 @@
   double _predicted_survival_ratio;
   double _predicted_rs_update_time_ms;
   double _predicted_rs_scan_time_ms;
-  double _predicted_scan_only_scan_time_ms;
   double _predicted_object_copy_time_ms;
   double _predicted_constant_other_time_ms;
   double _predicted_young_other_time_ms;
@@ -344,8 +335,6 @@
   bool verify_young_ages();
 #endif // PRODUCT
 
-  void tag_scan_only(size_t short_lived_scan_only_length);
-
   double get_new_prediction(TruncatedSeq* seq) {
     return MAX2(seq->davg() + sigma() * seq->dsd(),
                 seq->davg() * confidence_factor(seq->num()));
@@ -431,23 +420,6 @@
         get_new_prediction(_partially_young_cost_per_entry_ms_seq);
   }
 
-  double predict_scan_only_time_ms_during_cm(size_t scan_only_region_num) {
-    if (_cost_per_scan_only_region_ms_during_cm_seq->num() < 3)
-      return 1.5 * (double) scan_only_region_num *
-        get_new_prediction(_cost_per_scan_only_region_ms_seq);
-    else
-      return (double) scan_only_region_num *
-        get_new_prediction(_cost_per_scan_only_region_ms_during_cm_seq);
-  }
-
-  double predict_scan_only_time_ms(size_t scan_only_region_num) {
-    if (_in_marking_window_im)
-      return predict_scan_only_time_ms_during_cm(scan_only_region_num);
-    else
-      return (double) scan_only_region_num *
-        get_new_prediction(_cost_per_scan_only_region_ms_seq);
-  }
-
   double predict_object_copy_time_ms_during_cm(size_t bytes_to_copy) {
     if (_cost_per_byte_ms_during_cm_seq->num() < 3)
       return 1.1 * (double) bytes_to_copy *
@@ -490,24 +462,21 @@
   size_t predict_bytes_to_copy(HeapRegion* hr);
   double predict_region_elapsed_time_ms(HeapRegion* hr, bool young);
 
-  // for use by: calculate_optimal_so_length(length)
-  void predict_gc_eff(size_t young_region_num,
-                      size_t so_length,
-                      double base_time_ms,
-                      double *gc_eff,
-                      double *pause_time_ms);
-
-  // for use by: calculate_young_list_target_config(rs_length)
-  bool predict_gc_eff(size_t young_region_num,
-                      size_t so_length,
-                      double base_time_with_so_ms,
-                      size_t init_free_regions,
-                      double target_pause_time_ms,
-                      double* gc_eff);
+    // for use by: calculate_young_list_target_length(rs_length)
+  bool predict_will_fit(size_t young_region_num,
+                        double base_time_ms,
+                        size_t init_free_regions,
+                        double target_pause_time_ms);
 
   void start_recording_regions();
-  void record_cset_region(HeapRegion* hr, bool young);
-  void record_scan_only_regions(size_t scan_only_length);
+  void record_cset_region_info(HeapRegion* hr, bool young);
+  void record_non_young_cset_region(HeapRegion* hr);
+
+  void set_recorded_young_regions(size_t n_regions);
+  void set_recorded_young_bytes(size_t bytes);
+  void set_recorded_rs_lengths(size_t rs_lengths);
+  void set_predicted_bytes_to_copy(size_t bytes);
+
   void end_recording_regions();
 
   void record_vtime_diff_ms(double vtime_diff_ms) {
@@ -638,11 +607,74 @@
   void update_recent_gc_times(double end_time_sec, double elapsed_ms);
 
   // The head of the list (via "next_in_collection_set()") representing the
-  // current collection set.
+  // current collection set. Set from the incrementally built collection
+  // set at the start of the pause.
   HeapRegion* _collection_set;
+
+  // The number of regions in the collection set. Set from the incrementally
+  // built collection set at the start of an evacuation pause.
   size_t _collection_set_size;
+
+  // The number of bytes in the collection set before the pause. Set from
+  // the incrementally built collection set at the start of an evacuation
+  // pause.
   size_t _collection_set_bytes_used_before;
 
+  // The associated information that is maintained while the incremental
+  // collection set is being built with young regions. Used to populate
+  // the recorded info for the evacuation pause.
+
+  enum CSetBuildType {
+    Active,             // We are actively building the collection set
+    Inactive            // We are not actively building the collection set
+  };
+
+  CSetBuildType _inc_cset_build_state;
+
+  // The head of the incrementally built collection set.
+  HeapRegion* _inc_cset_head;
+
+  // The tail of the incrementally built collection set.
+  HeapRegion* _inc_cset_tail;
+
+  // The number of regions in the incrementally built collection set.
+  // Used to set _collection_set_size at the start of an evacuation
+  // pause.
+  size_t _inc_cset_size;
+
+  // Used as the index in the surving young words structure
+  // which tracks the amount of space, for each young region,
+  // that survives the pause.
+  size_t _inc_cset_young_index;
+
+  // The number of bytes in the incrementally built collection set.
+  // Used to set _collection_set_bytes_used_before at the start of
+  // an evacuation pause.
+  size_t _inc_cset_bytes_used_before;
+
+  // Used to record the highest end of heap region in collection set
+  HeapWord* _inc_cset_max_finger;
+
+  // The number of recorded used bytes in the young regions
+  // of the collection set. This is the sum of the used() bytes
+  // of retired young regions in the collection set.
+  size_t _inc_cset_recorded_young_bytes;
+
+  // The RSet lengths recorded for regions in the collection set
+  // (updated by the periodic sampling of the regions in the
+  // young list/collection set).
+  size_t _inc_cset_recorded_rs_lengths;
+
+  // The predicted elapsed time it will take to collect the regions
+  // in the collection set (updated by the periodic sampling of the
+  // regions in the young list/collection set).
+  double _inc_cset_predicted_elapsed_time_ms;
+
+  // The predicted bytes to copy for the regions in the collection
+  // set (updated by the periodic sampling of the regions in the
+  // young list/collection set).
+  size_t _inc_cset_predicted_bytes_to_copy;
+
   // Info about marking.
   int _n_marks; // Sticky at 2, so we know when we've done at least 2.
 
@@ -761,9 +793,8 @@
   double _mark_closure_time_ms;
 
   void   calculate_young_list_min_length();
-  void   calculate_young_list_target_config();
-  void   calculate_young_list_target_config(size_t rs_lengths);
-  size_t calculate_optimal_so_length(size_t young_list_length);
+  void   calculate_young_list_target_length();
+  void   calculate_young_list_target_length(size_t rs_lengths);
 
 public:
 
@@ -868,11 +899,6 @@
     _par_last_mark_stack_scan_times_ms[worker_i] = ms;
   }
 
-  void record_scan_only_time(int worker_i, double ms, int n) {
-    _par_last_scan_only_times_ms[worker_i] = ms;
-    _par_last_scan_only_regions_scanned[worker_i] = (double) n;
-  }
-
   void record_satb_drain_time(double ms) {
     _cur_satb_drain_time_ms = ms;
     _satb_drain_time_set    = true;
@@ -987,20 +1013,67 @@
   // Choose a new collection set.  Marks the chosen regions as being
   // "in_collection_set", and links them together.  The head and number of
   // the collection set are available via access methods.
-  virtual void choose_collection_set() = 0;
-
-  void clear_collection_set() { _collection_set = NULL; }
+  virtual bool choose_collection_set() = 0;
 
   // The head of the list (via "next_in_collection_set()") representing the
   // current collection set.
   HeapRegion* collection_set() { return _collection_set; }
 
+  void clear_collection_set() { _collection_set = NULL; }
+
   // The number of elements in the current collection set.
   size_t collection_set_size() { return _collection_set_size; }
 
   // Add "hr" to the CS.
   void add_to_collection_set(HeapRegion* hr);
 
+  // Incremental CSet Support
+
+  // The head of the incrementally built collection set.
+  HeapRegion* inc_cset_head() { return _inc_cset_head; }
+
+  // The tail of the incrementally built collection set.
+  HeapRegion* inc_set_tail() { return _inc_cset_tail; }
+
+  // The number of elements in the incrementally built collection set.
+  size_t inc_cset_size() { return _inc_cset_size; }
+
+  // Initialize incremental collection set info.
+  void start_incremental_cset_building();
+
+  void clear_incremental_cset() {
+    _inc_cset_head = NULL;
+    _inc_cset_tail = NULL;
+  }
+
+  // Stop adding regions to the incremental collection set
+  void stop_incremental_cset_building() { _inc_cset_build_state = Inactive; }
+
+  // Add/remove information about hr to the aggregated information
+  // for the incrementally built collection set.
+  void add_to_incremental_cset_info(HeapRegion* hr, size_t rs_length);
+  void remove_from_incremental_cset_info(HeapRegion* hr);
+
+  // Update information about hr in the aggregated information for
+  // the incrementally built collection set.
+  void update_incremental_cset_info(HeapRegion* hr, size_t new_rs_length);
+
+private:
+  // Update the incremental cset information when adding a region
+  // (should not be called directly).
+  void add_region_to_incremental_cset_common(HeapRegion* hr);
+
+public:
+  // Add hr to the LHS of the incremental collection set.
+  void add_region_to_incremental_cset_lhs(HeapRegion* hr);
+
+  // Add hr to the RHS of the incremental collection set.
+  void add_region_to_incremental_cset_rhs(HeapRegion* hr);
+
+#ifndef PRODUCT
+  void print_collection_set(HeapRegion* list_head, outputStream* st);
+#endif // !PRODUCT
+
   bool initiate_conc_mark_if_possible()       { return _initiate_conc_mark_if_possible;  }
   void set_initiate_conc_mark_if_possible()   { _initiate_conc_mark_if_possible = true;  }
   void clear_initiate_conc_mark_if_possible() { _initiate_conc_mark_if_possible = false; }
@@ -1191,7 +1264,7 @@
   // If the estimated is less then desirable, resize if possible.
   void expand_if_possible(size_t numRegions);
 
-  virtual void choose_collection_set();
+  virtual bool choose_collection_set();
   virtual void record_collection_pause_start(double start_time_sec,
                                              size_t start_used);
   virtual void record_concurrent_mark_cleanup_end(size_t freed_bytes,
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/g1/g1MarkSweep.cpp
--- a/src/share/vm/gc_implementation/g1/g1MarkSweep.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/g1/g1MarkSweep.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -31,6 +31,12 @@
                                       bool clear_all_softrefs) {
   assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint");
 
+  SharedHeap* sh = SharedHeap::heap();
+#ifdef ASSERT
+  if (sh->collector_policy()->should_clear_all_soft_refs()) {
+    assert(clear_all_softrefs, "Policy should have been checked earler");
+  }
+#endif
   // hook up weak ref data so it can be used during Mark-Sweep
   assert(GenMarkSweep::ref_processor() == NULL, "no stomping");
   assert(rp != NULL, "should be non-NULL");
@@ -44,7 +50,6 @@
 
   // Increment the invocation count for the permanent generation, since it is
   // implicitly collected whenever we do a full mark sweep collection.
-  SharedHeap* sh = SharedHeap::heap();
   sh->perm_gen()->stat_record()->invocations++;
 
   bool marked_for_unloading = false;
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/g1/g1_globals.hpp
--- a/src/share/vm/gc_implementation/g1/g1_globals.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/g1/g1_globals.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -28,9 +28,6 @@
 
 #define G1_FLAGS(develop, develop_pd, product, product_pd, diagnostic, experimental, notproduct, manageable, product_rw) \
                                                                             \
-  product(intx, G1ParallelGCAllocBufferSize, 8*K,                           \
-          "Size of parallel G1 allocation buffers in to-space.")            \
-                                                                            \
   product(intx, G1ConfidencePercent, 50,                                    \
           "Confidence level for MMU/pause predictions")                     \
                                                                             \
@@ -229,10 +226,6 @@
           "the number of regions for which we'll print a surv rate "        \
           "summary.")                                                       \
                                                                             \
-  develop(bool, G1UseScanOnlyPrefix, false,                                 \
-          "It determines whether the system will calculate an optimum "     \
-          "scan-only set.")                                                 \
-                                                                            \
   product(intx, G1ReservePercent, 10,                                       \
           "It determines the minimum reserve we should have in the heap "   \
           "to minimize the probability of promotion failure.")              \
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/g1/heapRegion.cpp
--- a/src/share/vm/gc_implementation/g1/heapRegion.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/g1/heapRegion.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -75,6 +75,16 @@
   virtual void do_oop(narrowOop* p) { do_oop_work(p); }
   virtual void do_oop(      oop* p) { do_oop_work(p); }
 
+  void print_object(outputStream* out, oop obj) {
+#ifdef PRODUCT
+    klassOop k = obj->klass();
+    const char* class_name = instanceKlass::cast(k)->external_name();
+    out->print_cr("class name %s", class_name);
+#else // PRODUCT
+    obj->print_on(out);
+#endif // PRODUCT
+  }
+
   template <class T> void do_oop_work(T* p) {
     assert(_containing_obj != NULL, "Precondition");
     assert(!_g1h->is_obj_dead_cond(_containing_obj, _use_prev_marking),
@@ -90,21 +100,29 @@
           gclog_or_tty->print_cr("----------");
         }
         if (!_g1h->is_in_closed_subset(obj)) {
-          gclog_or_tty->print_cr("Field "PTR_FORMAT
-                        " of live obj "PTR_FORMAT
-                        " points to obj "PTR_FORMAT
-                        " not in the heap.",
-                        p, (void*) _containing_obj, (void*) obj);
-        } else {
+          HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p);
           gclog_or_tty->print_cr("Field "PTR_FORMAT
-                        " of live obj "PTR_FORMAT
-                        " points to dead obj "PTR_FORMAT".",
-                        p, (void*) _containing_obj, (void*) obj);
+                                 " of live obj "PTR_FORMAT" in region "
+                                 "["PTR_FORMAT", "PTR_FORMAT")",
+                                 p, (void*) _containing_obj,
+                                 from->bottom(), from->end());
+          print_object(gclog_or_tty, _containing_obj);
+          gclog_or_tty->print_cr("points to obj "PTR_FORMAT" not in the heap",
+                                 (void*) obj);
+        } else {
+          HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p);
+          HeapRegion* to   = _g1h->heap_region_containing((HeapWord*)obj);
+          gclog_or_tty->print_cr("Field "PTR_FORMAT
+                                 " of live obj "PTR_FORMAT" in region "
+                                 "["PTR_FORMAT", "PTR_FORMAT")",
+                                 p, (void*) _containing_obj,
+                                 from->bottom(), from->end());
+          print_object(gclog_or_tty, _containing_obj);
+          gclog_or_tty->print_cr("points to dead obj "PTR_FORMAT" in region "
+                                 "["PTR_FORMAT", "PTR_FORMAT")",
+                                 (void*) obj, to->bottom(), to->end());
+          print_object(gclog_or_tty, obj);
         }
-        gclog_or_tty->print_cr("Live obj:");
-        _containing_obj->print_on(gclog_or_tty);
-        gclog_or_tty->print_cr("Bad referent:");
-        obj->print_on(gclog_or_tty);
         gclog_or_tty->print_cr("----------");
         _failures = true;
         failed = true;
@@ -432,7 +450,9 @@
     _young_type(NotYoung), _next_young_region(NULL),
     _next_dirty_cards_region(NULL),
     _young_index_in_cset(-1), _surv_rate_group(NULL), _age_index(-1),
-    _rem_set(NULL), _zfs(NotZeroFilled)
+    _rem_set(NULL), _zfs(NotZeroFilled),
+    _recorded_rs_length(0), _predicted_elapsed_time_ms(0),
+    _predicted_bytes_to_copy(0)
 {
   _orig_end = mr.end();
   // Note that initialize() will set the start of the unmarked area of the
@@ -715,7 +735,7 @@
   else
     st->print("   ");
   if (is_young())
-    st->print(is_scan_only() ? " SO" : (is_survivor() ? " SU" : " Y "));
+    st->print(is_survivor() ? " SU" : " Y ");
   else
     st->print("   ");
   if (is_empty())
@@ -723,6 +743,8 @@
   else
     st->print("  ");
   st->print(" %5d", _gc_time_stamp);
+  st->print(" PTAMS "PTR_FORMAT" NTAMS "PTR_FORMAT,
+            prev_top_at_mark_start(), next_top_at_mark_start());
   G1OffsetTableContigSpace::print_on(st);
 }
 
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/g1/heapRegion.hpp
--- a/src/share/vm/gc_implementation/g1/heapRegion.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/g1/heapRegion.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -247,7 +247,6 @@
 
   enum YoungType {
     NotYoung,                   // a region is not young
-    ScanOnly,                   // a region is young and scan-only
     Young,                      // a region is young
     Survivor                    // a region is young and it contains
                                 // survivor
@@ -292,6 +291,20 @@
     _young_type = new_type;
   }
 
+  // Cached attributes used in the collection set policy information
+
+  // The RSet length that was added to the total value
+  // for the collection set.
+  size_t _recorded_rs_length;
+
+  // The predicted elapsed time that was added to total value
+  // for the collection set.
+  double _predicted_elapsed_time_ms;
+
+  // The predicted number of bytes to copy that was added to
+  // the total value for the collection set.
+  size_t _predicted_bytes_to_copy;
+
  public:
   // If "is_zeroed" is "true", the region "mr" can be assumed to contain zeros.
   HeapRegion(G1BlockOffsetSharedArray* sharedOffsetArray,
@@ -614,7 +627,6 @@
   // </PREDICTION>
 
   bool is_young() const     { return _young_type != NotYoung; }
-  bool is_scan_only() const { return _young_type == ScanOnly; }
   bool is_survivor() const  { return _young_type == Survivor; }
 
   int  young_index_in_cset() const { return _young_index_in_cset; }
@@ -629,12 +641,6 @@
     return _surv_rate_group->age_in_group(_age_index);
   }
 
-  void recalculate_age_in_surv_rate_group() {
-    assert( _surv_rate_group != NULL, "pre-condition" );
-    assert( _age_index > -1, "pre-condition" );
-    _age_index = _surv_rate_group->recalculate_age_index(_age_index);
-  }
-
   void record_surv_words_in_group(size_t words_survived) {
     assert( _surv_rate_group != NULL, "pre-condition" );
     assert( _age_index > -1, "pre-condition" );
@@ -676,8 +682,6 @@
 
   void set_young() { set_young_type(Young); }
 
-  void set_scan_only() { set_young_type(ScanOnly); }
-
   void set_survivor() { set_young_type(Survivor); }
 
   void set_not_young() { set_young_type(NotYoung); }
@@ -775,6 +779,22 @@
     _zero_filler = NULL;
   }
 
+  size_t recorded_rs_length() const        { return _recorded_rs_length; }
+  double predicted_elapsed_time_ms() const { return _predicted_elapsed_time_ms; }
+  size_t predicted_bytes_to_copy() const   { return _predicted_bytes_to_copy; }
+
+  void set_recorded_rs_length(size_t rs_length) {
+    _recorded_rs_length = rs_length;
+  }
+
+  void set_predicted_elapsed_time_ms(double ms) {
+    _predicted_elapsed_time_ms = ms;
+  }
+
+  void set_predicted_bytes_to_copy(size_t bytes) {
+    _predicted_bytes_to_copy = bytes;
+  }
+
 #define HeapRegion_OOP_SINCE_SAVE_MARKS_DECL(OopClosureType, nv_suffix)  \
   virtual void oop_since_save_marks_iterate##nv_suffix(OopClosureType* cl);
   SPECIALIZED_SINCE_SAVE_MARKS_CLOSURES(HeapRegion_OOP_SINCE_SAVE_MARKS_DECL)
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/g1/heapRegionRemSet.cpp
--- a/src/share/vm/gc_implementation/g1/heapRegionRemSet.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/g1/heapRegionRemSet.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -662,8 +662,6 @@
         prt = PosParPRT::alloc(from_hr);
       }
       prt->init(from_hr);
-      // Record the outgoing pointer in the from_region's outgoing bitmap.
-      from_hr->rem_set()->add_outgoing_reference(hr());
 
       PosParPRT* first_prt = _fine_grain_regions[ind];
       prt->set_next(first_prt);  // XXX Maybe move to init?
@@ -1073,11 +1071,7 @@
 
 HeapRegionRemSet::HeapRegionRemSet(G1BlockOffsetSharedArray* bosa,
                                    HeapRegion* hr)
-    : _bosa(bosa), _other_regions(hr),
-      _outgoing_region_map(G1CollectedHeap::heap()->max_regions(),
-                           false /* in-resource-area */),
-      _iter_state(Unclaimed)
-{}
+  : _bosa(bosa), _other_regions(hr), _iter_state(Unclaimed) { }
 
 
 void HeapRegionRemSet::setup_remset_size() {
@@ -1148,30 +1142,11 @@
   PosParPRT::par_contract_all();
 }
 
-void HeapRegionRemSet::add_outgoing_reference(HeapRegion* to_hr) {
-  _outgoing_region_map.par_at_put(to_hr->hrs_index(), 1);
-}
-
 void HeapRegionRemSet::clear() {
-  clear_outgoing_entries();
-  _outgoing_region_map.clear();
   _other_regions.clear();
   assert(occupied() == 0, "Should be clear.");
 }
 
-void HeapRegionRemSet::clear_outgoing_entries() {
-  G1CollectedHeap* g1h = G1CollectedHeap::heap();
-  size_t i = _outgoing_region_map.get_next_one_offset(0);
-  while (i < _outgoing_region_map.size()) {
-    HeapRegion* to_region = g1h->region_at(i);
-    if (!to_region->in_collection_set()) {
-      to_region->rem_set()->clear_incoming_entry(hr());
-    }
-    i = _outgoing_region_map.get_next_one_offset(i+1);
-  }
-}
-
-
 void HeapRegionRemSet::scrub(CardTableModRefBS* ctbs,
                              BitMap* region_bm, BitMap* card_bm) {
   _other_regions.scrub(ctbs, region_bm, card_bm);
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/g1/heapRegionRemSet.hpp
--- a/src/share/vm/gc_implementation/g1/heapRegionRemSet.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/g1/heapRegionRemSet.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -179,13 +179,6 @@
 
   OtherRegionsTable _other_regions;
 
-  // One set bit for every region that has an entry for this one.
-  BitMap _outgoing_region_map;
-
-  // Clear entries for the current region in any rem sets named in
-  // the _outgoing_region_map.
-  void clear_outgoing_entries();
-
   enum ParIterState { Unclaimed, Claimed, Complete };
   volatile ParIterState _iter_state;
   volatile jlong _iter_claimed;
@@ -243,10 +236,6 @@
     _other_regions.add_reference(from, tid);
   }
 
-  // Records the fact that the current region contains an outgoing
-  // reference into "to_hr".
-  void add_outgoing_reference(HeapRegion* to_hr);
-
   // Removes any entries shown by the given bitmaps to contain only dead
   // objects.
   void scrub(CardTableModRefBS* ctbs, BitMap* region_bm, BitMap* card_bm);
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/g1/survRateGroup.cpp
--- a/src/share/vm/gc_implementation/g1/survRateGroup.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/g1/survRateGroup.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -55,7 +55,6 @@
 void SurvRateGroup::reset()
 {
   _all_regions_allocated = 0;
-  _scan_only_prefix      = 0;
   _setup_seq_num         = 0;
   _stats_arrays_length   = 0;
   _accum_surv_rate       = 0.0;
@@ -74,7 +73,7 @@
 void
 SurvRateGroup::start_adding_regions() {
   _setup_seq_num   = _stats_arrays_length;
-  _region_num      = _scan_only_prefix;
+  _region_num      = 0;
   _accum_surv_rate = 0.0;
 
 #if 0
@@ -164,12 +163,6 @@
 }
 
 void
-SurvRateGroup::record_scan_only_prefix(size_t scan_only_prefix) {
-  guarantee( scan_only_prefix <= _region_num, "pre-condition" );
-  _scan_only_prefix = scan_only_prefix;
-}
-
-void
 SurvRateGroup::record_surviving_words(int age_in_group, size_t surv_words) {
   guarantee( 0 <= age_in_group && (size_t) age_in_group < _region_num,
              "pre-condition" );
@@ -218,13 +211,12 @@
 #ifndef PRODUCT
 void
 SurvRateGroup::print() {
-  gclog_or_tty->print_cr("Surv Rate Group: %s (%d entries, %d scan-only)",
-                _name, _region_num, _scan_only_prefix);
+  gclog_or_tty->print_cr("Surv Rate Group: %s (%d entries)",
+                _name, _region_num);
   for (size_t i = 0; i < _region_num; ++i) {
-    gclog_or_tty->print_cr("    age %4d   surv rate %6.2lf %%   pred %6.2lf %%%s",
+    gclog_or_tty->print_cr("    age %4d   surv rate %6.2lf %%   pred %6.2lf %%",
                   i, _surv_rate[i] * 100.0,
-                  _g1p->get_new_prediction(_surv_rate_pred[i]) * 100.0,
-                  (i < _scan_only_prefix) ? " S-O" : "    ");
+                  _g1p->get_new_prediction(_surv_rate_pred[i]) * 100.0);
   }
 }
 
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/g1/survRateGroup.hpp
--- a/src/share/vm/gc_implementation/g1/survRateGroup.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/g1/survRateGroup.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -41,7 +41,6 @@
 
   int _all_regions_allocated;
   size_t _region_num;
-  size_t _scan_only_prefix;
   size_t _setup_seq_num;
 
 public:
@@ -51,13 +50,11 @@
   void reset();
   void start_adding_regions();
   void stop_adding_regions();
-  void record_scan_only_prefix(size_t scan_only_prefix);
   void record_surviving_words(int age_in_group, size_t surv_words);
   void all_surviving_words_recorded(bool propagate);
   const char* name() { return _name; }
 
   size_t region_num() { return _region_num; }
-  size_t scan_only_length() { return _scan_only_prefix; }
   double accum_surv_rate_pred(int age) {
     assert(age >= 0, "must be");
     if ((size_t)age < _stats_arrays_length)
@@ -82,17 +79,12 @@
 
   int next_age_index();
   int age_in_group(int age_index) {
-    int ret = (int) (_all_regions_allocated -  age_index);
+    int ret = (int) (_all_regions_allocated - age_index);
     assert( ret >= 0, "invariant" );
     return ret;
   }
-  int recalculate_age_index(int age_index) {
-    int new_age_index = (int) _scan_only_prefix - age_in_group(age_index);
-    guarantee( new_age_index >= 0, "invariant" );
-    return new_age_index;
-  }
   void finished_recalculating_age_indexes() {
-    _all_regions_allocated = (int) _scan_only_prefix;
+    _all_regions_allocated = 0;
   }
 
 #ifndef PRODUCT
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/includeDB_gc_parallelScavenge
--- a/src/share/vm/gc_implementation/includeDB_gc_parallelScavenge	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/includeDB_gc_parallelScavenge	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 //
-// Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+// Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
 // DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 //
 // This code is free software; you can redistribute it and/or modify it
@@ -161,8 +161,10 @@
 parMarkBitMap.hpp			bitMap.inline.hpp
 parMarkBitMap.hpp			psVirtualspace.hpp
 
+psAdaptiveSizePolicy.cpp                collectorPolicy.hpp
 psAdaptiveSizePolicy.cpp                gcPolicyCounters.hpp
 psAdaptiveSizePolicy.cpp		gcCause.hpp
+psAdaptiveSizePolicy.cpp                generationSizer.hpp
 psAdaptiveSizePolicy.cpp                psAdaptiveSizePolicy.hpp
 psAdaptiveSizePolicy.cpp                psGCAdaptivePolicyCounters.hpp
 psAdaptiveSizePolicy.cpp                psScavenge.hpp
@@ -215,6 +217,7 @@
 psMarkSweep.cpp                         fprofiler.hpp
 psMarkSweep.cpp                         gcCause.hpp
 psMarkSweep.cpp                         gcLocker.inline.hpp
+psMarkSweep.cpp                         generationSizer.hpp
 psMarkSweep.cpp                         isGCActiveMark.hpp
 psMarkSweep.cpp                         oop.inline.hpp
 psMarkSweep.cpp                         memoryService.hpp
@@ -256,6 +259,7 @@
 psParallelCompact.cpp			gcCause.hpp
 psParallelCompact.cpp			gcLocker.inline.hpp
 psParallelCompact.cpp                   gcTaskManager.hpp
+psParallelCompact.cpp                   generationSizer.hpp
 psParallelCompact.cpp			isGCActiveMark.hpp
 psParallelCompact.cpp			management.hpp
 psParallelCompact.cpp			memoryService.hpp
@@ -344,10 +348,12 @@
 psScavenge.cpp                          psAdaptiveSizePolicy.hpp
 psScavenge.cpp                          biasedLocking.hpp
 psScavenge.cpp                          cardTableExtension.hpp
+psScavenge.cpp                          collectorPolicy.hpp
 psScavenge.cpp                          fprofiler.hpp
 psScavenge.cpp                          gcCause.hpp
 psScavenge.cpp                          gcLocker.inline.hpp
 psScavenge.cpp                          gcTaskManager.hpp
+psScavenge.cpp                          generationSizer.hpp
 psScavenge.cpp                          handles.inline.hpp
 psScavenge.cpp                          isGCActiveMark.hpp
 psScavenge.cpp                          oop.inline.hpp
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/includeDB_gc_serial
--- a/src/share/vm/gc_implementation/includeDB_gc_serial	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/includeDB_gc_serial	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 //
-// Copyright (c) 2007 Sun Microsystems, Inc.  All Rights Reserved.
+// Copyright 2007-2010 Sun Microsystems, Inc.  All Rights Reserved.
 // DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 //   
 // This code is free software; you can redistribute it and/or modify it
@@ -29,6 +29,7 @@
 adaptiveSizePolicy.hpp			universe.hpp
 
 adaptiveSizePolicy.cpp			adaptiveSizePolicy.hpp
+adaptiveSizePolicy.cpp			collectorPolicy.hpp
 adaptiveSizePolicy.cpp			gcCause.hpp
 adaptiveSizePolicy.cpp			ostream.hpp
 adaptiveSizePolicy.cpp			timer.hpp
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/parNew/parNewGeneration.cpp
--- a/src/share/vm/gc_implementation/parNew/parNewGeneration.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/parNew/parNewGeneration.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -892,6 +892,10 @@
     }
     swap_spaces();
 
+    // A successful scavenge should restart the GC time limit count which is
+    // for full GC's.
+    size_policy->reset_gc_overhead_limit_count();
+
     assert(to()->is_empty(), "to space should be empty now");
   } else {
     assert(HandlePromotionFailure,
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/parallelScavenge/parallelScavengeHeap.cpp
--- a/src/share/vm/gc_implementation/parallelScavenge/parallelScavengeHeap.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/parallelScavenge/parallelScavengeHeap.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -54,15 +54,16 @@
   CollectedHeap::pre_initialize();
 
   // Cannot be initialized until after the flags are parsed
-  GenerationSizer flag_parser;
+  // GenerationSizer flag_parser;
+  _collector_policy = new GenerationSizer();
 
-  size_t yg_min_size = flag_parser.min_young_gen_size();
-  size_t yg_max_size = flag_parser.max_young_gen_size();
-  size_t og_min_size = flag_parser.min_old_gen_size();
-  size_t og_max_size = flag_parser.max_old_gen_size();
+  size_t yg_min_size = _collector_policy->min_young_gen_size();
+  size_t yg_max_size = _collector_policy->max_young_gen_size();
+  size_t og_min_size = _collector_policy->min_old_gen_size();
+  size_t og_max_size = _collector_policy->max_old_gen_size();
   // Why isn't there a min_perm_gen_size()?
-  size_t pg_min_size = flag_parser.perm_gen_size();
-  size_t pg_max_size = flag_parser.max_perm_gen_size();
+  size_t pg_min_size = _collector_policy->perm_gen_size();
+  size_t pg_max_size = _collector_policy->max_perm_gen_size();
 
   trace_gen_sizes("ps heap raw",
                   pg_min_size, pg_max_size,
@@ -89,12 +90,14 @@
   // move to the common code.
   yg_min_size = align_size_up(yg_min_size, yg_align);
   yg_max_size = align_size_up(yg_max_size, yg_align);
-  size_t yg_cur_size = align_size_up(flag_parser.young_gen_size(), yg_align);
+  size_t yg_cur_size =
+    align_size_up(_collector_policy->young_gen_size(), yg_align);
   yg_cur_size = MAX2(yg_cur_size, yg_min_size);
 
   og_min_size = align_size_up(og_min_size, og_align);
   og_max_size = align_size_up(og_max_size, og_align);
-  size_t og_cur_size = align_size_up(flag_parser.old_gen_size(), og_align);
+  size_t og_cur_size =
+    align_size_up(_collector_policy->old_gen_size(), og_align);
   og_cur_size = MAX2(og_cur_size, og_min_size);
 
   pg_min_size = align_size_up(pg_min_size, pg_align);
@@ -355,6 +358,11 @@
   assert(Thread::current() != (Thread*)VMThread::vm_thread(), "should not be in vm thread");
   assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
 
+  // In general gc_overhead_limit_was_exceeded should be false so
+  // set it so here and reset it to true only if the gc time
+  // limit is being exceeded as checked below.
+  *gc_overhead_limit_was_exceeded = false;
+
   HeapWord* result = young_gen()->allocate(size, is_tlab);
 
   uint loop_count = 0;
@@ -428,24 +436,6 @@
 
     if (result == NULL) {
 
-      // Exit the loop if if the gc time limit has been exceeded.
-      // The allocation must have failed above (result must be NULL),
-      // and the most recent collection must have exceeded the
-      // gc time limit.  Exit the loop so that an out-of-memory
-      // will be thrown (returning a NULL will do that), but
-      // clear gc_time_limit_exceeded so that the next collection
-      // will succeeded if the applications decides to handle the
-      // out-of-memory and tries to go on.
-      *gc_overhead_limit_was_exceeded = size_policy()->gc_time_limit_exceeded();
-      if (size_policy()->gc_time_limit_exceeded()) {
-        size_policy()->set_gc_time_limit_exceeded(false);
-        if (PrintGCDetails && Verbose) {
-        gclog_or_tty->print_cr("ParallelScavengeHeap::mem_allocate: "
-          "return NULL because gc_time_limit_exceeded is set");
-        }
-        return NULL;
-      }
-
       // Generate a VM operation
       VM_ParallelGCFailedAllocation op(size, is_tlab, gc_count);
       VMThread::execute(&op);
@@ -463,16 +453,34 @@
           assert(op.result() == NULL, "must be NULL if gc_locked() is true");
           continue;  // retry and/or stall as necessary
         }
-        // If a NULL result is being returned, an out-of-memory
-        // will be thrown now.  Clear the gc_time_limit_exceeded
-        // flag to avoid the following situation.
-        //      gc_time_limit_exceeded is set during a collection
-        //      the collection fails to return enough space and an OOM is thrown
-        //      the next GC is skipped because the gc_time_limit_exceeded
-        //        flag is set and another OOM is thrown
-        if (op.result() == NULL) {
-          size_policy()->set_gc_time_limit_exceeded(false);
+
+        // Exit the loop if the gc time limit has been exceeded.
+        // The allocation must have failed above ("result" guarding
+        // this path is NULL) and the most recent collection has exceeded the
+        // gc overhead limit (although enough may have been collected to
+        // satisfy the allocation).  Exit the loop so that an out-of-memory
+        // will be thrown (return a NULL ignoring the contents of
+        // op.result()),
+        // but clear gc_overhead_limit_exceeded so that the next collection
+        // starts with a clean slate (i.e., forgets about previous overhead
+        // excesses).  Fill op.result() with a filler object so that the
+        // heap remains parsable.
+        const bool limit_exceeded = size_policy()->gc_overhead_limit_exceeded();
+        const bool softrefs_clear = collector_policy()->all_soft_refs_clear();
+        assert(!limit_exceeded || softrefs_clear, "Should have been cleared");
+        if (limit_exceeded && softrefs_clear) {
+          *gc_overhead_limit_was_exceeded = true;
+          size_policy()->set_gc_overhead_limit_exceeded(false);
+          if (PrintGCDetails && Verbose) {
+            gclog_or_tty->print_cr("ParallelScavengeHeap::mem_allocate: "
+              "return NULL because gc_overhead_limit_exceeded is set");
+          }
+          if (op.result() != NULL) {
+            CollectedHeap::fill_with_object(op.result(), size);
+          }
+          return NULL;
         }
+
         return op.result();
       }
     }
@@ -613,14 +621,15 @@
       // and the most recent collection must have exceeded the
       // gc time limit.  Exit the loop so that an out-of-memory
       // will be thrown (returning a NULL will do that), but
-      // clear gc_time_limit_exceeded so that the next collection
+      // clear gc_overhead_limit_exceeded so that the next collection
       // will succeeded if the applications decides to handle the
       // out-of-memory and tries to go on.
-      if (size_policy()->gc_time_limit_exceeded()) {
-        size_policy()->set_gc_time_limit_exceeded(false);
+      const bool limit_exceeded = size_policy()->gc_overhead_limit_exceeded();
+      if (limit_exceeded) {
+        size_policy()->set_gc_overhead_limit_exceeded(false);
         if (PrintGCDetails && Verbose) {
-        gclog_or_tty->print_cr("ParallelScavengeHeap::permanent_mem_allocate: "
-          "return NULL because gc_time_limit_exceeded is set");
+          gclog_or_tty->print_cr("ParallelScavengeHeap::permanent_mem_allocate:"
+            " return NULL because gc_overhead_limit_exceeded is set");
         }
         assert(result == NULL, "Allocation did not fail");
         return NULL;
@@ -643,14 +652,15 @@
           continue;  // retry and/or stall as necessary
         }
         // If a NULL results is being returned, an out-of-memory
-        // will be thrown now.  Clear the gc_time_limit_exceeded
+        // will be thrown now.  Clear the gc_overhead_limit_exceeded
         // flag to avoid the following situation.
-        //      gc_time_limit_exceeded is set during a collection
+        //      gc_overhead_limit_exceeded is set during a collection
         //      the collection fails to return enough space and an OOM is thrown
-        //      the next GC is skipped because the gc_time_limit_exceeded
-        //        flag is set and another OOM is thrown
+        //      a subsequent GC prematurely throws an out-of-memory because
+        //        the gc_overhead_limit_exceeded counts did not start
+        //        again from 0.
         if (op.result() == NULL) {
-          size_policy()->set_gc_time_limit_exceeded(false);
+          size_policy()->reset_gc_overhead_limit_count();
         }
         return op.result();
       }
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/parallelScavenge/parallelScavengeHeap.hpp
--- a/src/share/vm/gc_implementation/parallelScavenge/parallelScavengeHeap.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/parallelScavenge/parallelScavengeHeap.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -25,6 +25,8 @@
 class AdjoiningGenerations;
 class GCTaskManager;
 class PSAdaptiveSizePolicy;
+class GenerationSizer;
+class CollectorPolicy;
 
 class ParallelScavengeHeap : public CollectedHeap {
   friend class VMStructs;
@@ -43,6 +45,8 @@
   size_t _young_gen_alignment;
   size_t _old_gen_alignment;
 
+  GenerationSizer* _collector_policy;
+
   inline size_t set_alignment(size_t& var, size_t val);
 
   // Collection of generations that are adjacent in the
@@ -72,6 +76,9 @@
     return CollectedHeap::ParallelScavengeHeap;
   }
 
+CollectorPolicy* collector_policy() const { return (CollectorPolicy*) _collector_policy; }
+  // GenerationSizer* collector_policy() const { return _collector_policy; }
+
   static PSYoungGen* young_gen()     { return _young_gen; }
   static PSOldGen* old_gen()         { return _old_gen; }
   static PSPermGen* perm_gen()       { return _perm_gen; }
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/parallelScavenge/psAdaptiveSizePolicy.cpp
--- a/src/share/vm/gc_implementation/parallelScavenge/psAdaptiveSizePolicy.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/parallelScavenge/psAdaptiveSizePolicy.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2007 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2002-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -184,18 +184,19 @@
   set_change_young_gen_for_maj_pauses(0);
 }
 
-
 // If this is not a full GC, only test and modify the young generation.
 
-void PSAdaptiveSizePolicy::compute_generation_free_space(size_t young_live,
-                                               size_t eden_live,
-                                               size_t old_live,
-                                               size_t perm_live,
-                                               size_t cur_eden,
-                                               size_t max_old_gen_size,
-                                               size_t max_eden_size,
-                                               bool   is_full_gc,
-                                               GCCause::Cause gc_cause) {
+void PSAdaptiveSizePolicy::compute_generation_free_space(
+                                           size_t young_live,
+                                           size_t eden_live,
+                                           size_t old_live,
+                                           size_t perm_live,
+                                           size_t cur_eden,
+                                           size_t max_old_gen_size,
+                                           size_t max_eden_size,
+                                           bool   is_full_gc,
+                                           GCCause::Cause gc_cause,
+                                           CollectorPolicy* collector_policy) {
 
   // Update statistics
   // Time statistics are updated as we go, update footprint stats here
@@ -380,91 +381,16 @@
   // Is too much time being spent in GC?
   //   Is the heap trying to grow beyond it's limits?
 
-  const size_t free_in_old_gen = (size_t)(max_old_gen_size - avg_old_live()->average());
+  const size_t free_in_old_gen =
+    (size_t)(max_old_gen_size - avg_old_live()->average());
   if (desired_promo_size > free_in_old_gen && desired_eden_size > eden_limit) {
-
-    // eden_limit is the upper limit on the size of eden based on
-    // the maximum size of the young generation and the sizes
-    // of the survivor space.
-    // The question being asked is whether the gc costs are high
-    // and the space being recovered by a collection is low.
-    // free_in_young_gen is the free space in the young generation
-    // after a collection and promo_live is the free space in the old
-    // generation after a collection.
-    //
-    // Use the minimum of the current value of the live in the
-    // young gen or the average of the live in the young gen.
-    // If the current value drops quickly, that should be taken
-    // into account (i.e., don't trigger if the amount of free
-    // space has suddenly jumped up).  If the current is much
-    // higher than the average, use the average since it represents
-    // the longer term behavor.
-    const size_t live_in_eden = MIN2(eden_live, (size_t) avg_eden_live()->average());
-    const size_t free_in_eden = eden_limit > live_in_eden ?
-      eden_limit - live_in_eden : 0;
-    const size_t total_free_limit = free_in_old_gen + free_in_eden;
-    const size_t total_mem = max_old_gen_size + max_eden_size;
-    const double mem_free_limit = total_mem * (GCHeapFreeLimit/100.0);
-    if (PrintAdaptiveSizePolicy && (Verbose ||
-        (total_free_limit < (size_t) mem_free_limit))) {
-      gclog_or_tty->print_cr(
-            "PSAdaptiveSizePolicy::compute_generation_free_space limits:"
-            " promo_limit: " SIZE_FORMAT
-            " eden_limit: " SIZE_FORMAT
-            " total_free_limit: " SIZE_FORMAT
-            " max_old_gen_size: " SIZE_FORMAT
-            " max_eden_size: " SIZE_FORMAT
-            " mem_free_limit: " SIZE_FORMAT,
-            promo_limit, eden_limit, total_free_limit,
-            max_old_gen_size, max_eden_size,
-            (size_t) mem_free_limit);
-    }
-
-    if (is_full_gc) {
-      if (gc_cost() > gc_cost_limit &&
-        total_free_limit < (size_t) mem_free_limit) {
-        // Collections, on average, are taking too much time, and
-        //      gc_cost() > gc_cost_limit
-        // we have too little space available after a full gc.
-        //      total_free_limit < mem_free_limit
-        // where
-        //   total_free_limit is the free space available in
-        //     both generations
-        //   total_mem is the total space available for allocation
-        //     in both generations (survivor spaces are not included
-        //     just as they are not included in eden_limit).
-        //   mem_free_limit is a fraction of total_mem judged to be an
-        //     acceptable amount that is still unused.
-        // The heap can ask for the value of this variable when deciding
-        // whether to thrown an OutOfMemory error.
-        // Note that the gc time limit test only works for the collections
-        // of the young gen + tenured gen and not for collections of the
-        // permanent gen.  That is because the calculation of the space
-        // freed by the collection is the free space in the young gen +
-        // tenured gen.
-        // Ignore explicit GC's. Ignoring explicit GC's at this level
-        // is the equivalent of the GC did not happen as far as the
-        // overhead calculation is concerted (i.e., the flag is not set
-        // and the count is not affected).  Also the average will not
-        // have been updated unless UseAdaptiveSizePolicyWithSystemGC is on.
-        if (!GCCause::is_user_requested_gc(gc_cause) &&
-            !GCCause::is_serviceability_requested_gc(gc_cause)) {
-          inc_gc_time_limit_count();
-          if (UseGCOverheadLimit &&
-              (gc_time_limit_count() > AdaptiveSizePolicyGCTimeLimitThreshold)){
-            // All conditions have been met for throwing an out-of-memory
-            _gc_time_limit_exceeded = true;
-            // Avoid consecutive OOM due to the gc time limit by resetting
-            // the counter.
-            reset_gc_time_limit_count();
-          }
-          _print_gc_time_limit_would_be_exceeded = true;
-        }
-      } else {
-        // Did not exceed overhead limits
-        reset_gc_time_limit_count();
-      }
-    }
+    check_gc_overhead_limit(young_live,
+                            eden_live,
+                            max_old_gen_size,
+                            max_eden_size,
+                            is_full_gc,
+                            gc_cause,
+                            collector_policy);
   }
 
 
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/parallelScavenge/psAdaptiveSizePolicy.hpp
--- a/src/share/vm/gc_implementation/parallelScavenge/psAdaptiveSizePolicy.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/parallelScavenge/psAdaptiveSizePolicy.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2007 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2002-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -45,6 +45,7 @@
 
 // Forward decls
 class elapsedTimer;
+class GenerationSizer;
 
 class PSAdaptiveSizePolicy : public AdaptiveSizePolicy {
  friend class PSGCAdaptivePolicyCounters;
@@ -340,7 +341,8 @@
                                      size_t max_old_gen_size,
                                      size_t max_eden_size,
                                      bool   is_full_gc,
-                                     GCCause::Cause gc_cause);
+                                     GCCause::Cause gc_cause,
+                                     CollectorPolicy* collector_policy);
 
   // Calculates new survivor space size;  returns a new tenuring threshold
   // value. Stores new survivor size in _survivor_size.
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/parallelScavenge/psGCAdaptivePolicyCounters.cpp
--- a/src/share/vm/gc_implementation/parallelScavenge/psGCAdaptivePolicyCounters.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/parallelScavenge/psGCAdaptivePolicyCounters.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2003-2006 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2003-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -117,11 +117,13 @@
       PerfData::U_Bytes, (jlong) ps_size_policy()->avg_base_footprint()->average(), CHECK);
 
     cname = PerfDataManager::counter_name(name_space(), "gcTimeLimitExceeded");
-    _gc_time_limit_exceeded = PerfDataManager::create_variable(SUN_GC, cname,
-      PerfData::U_Events, ps_size_policy()->gc_time_limit_exceeded(), CHECK);
+    _gc_overhead_limit_exceeded_counter =
+      PerfDataManager::create_variable(SUN_GC, cname,
+      PerfData::U_Events, ps_size_policy()->gc_overhead_limit_exceeded(), CHECK);
 
     cname = PerfDataManager::counter_name(name_space(), "liveAtLastFullGc");
-    _live_at_last_full_gc = PerfDataManager::create_variable(SUN_GC, cname,
+    _live_at_last_full_gc_counter =
+      PerfDataManager::create_variable(SUN_GC, cname,
       PerfData::U_Bytes, ps_size_policy()->live_at_last_full_gc(), CHECK);
 
     cname = PerfDataManager::counter_name(name_space(), "majorPauseOldSlope");
@@ -189,6 +191,8 @@
     update_minor_pause_old_slope();
     update_major_pause_young_slope();
     update_minor_collection_slope_counter();
+    update_gc_overhead_limit_exceeded_counter();
+    update_live_at_last_full_gc_counter();
   }
 }
 
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/parallelScavenge/psGCAdaptivePolicyCounters.hpp
--- a/src/share/vm/gc_implementation/parallelScavenge/psGCAdaptivePolicyCounters.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/parallelScavenge/psGCAdaptivePolicyCounters.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2003-2005 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2003-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -44,8 +44,8 @@
   PerfVariable* _live_space;
   PerfVariable* _free_space;
   PerfVariable* _avg_base_footprint;
-  PerfVariable* _gc_time_limit_exceeded;
-  PerfVariable* _live_at_last_full_gc;
+  PerfVariable* _gc_overhead_limit_exceeded_counter;
+  PerfVariable* _live_at_last_full_gc_counter;
   PerfVariable* _old_capacity;
   PerfVariable* _boundary_moved;
 
@@ -169,6 +169,14 @@
       (jlong)(ps_size_policy()->major_pause_young_slope() * 1000)
     );
   }
+  inline void update_gc_overhead_limit_exceeded_counter() {
+    _gc_overhead_limit_exceeded_counter->set_value(
+      (jlong) ps_size_policy()->gc_overhead_limit_exceeded());
+  }
+  inline void update_live_at_last_full_gc_counter() {
+    _live_at_last_full_gc_counter->set_value(
+      (jlong)(ps_size_policy()->live_at_last_full_gc()));
+  }
 
   inline void update_scavenge_skipped(int cause) {
     _scavenge_skipped->set_value(cause);
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.cpp
--- a/src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -46,6 +46,12 @@
 //
 // Note that this method should only be called from the vm_thread while
 // at a safepoint!
+//
+// Note that the all_soft_refs_clear flag in the collector policy
+// may be true because this method can be called without intervening
+// activity.  For example when the heap space is tight and full measure
+// are being taken to free space.
+
 void PSMarkSweep::invoke(bool maximum_heap_compaction) {
   assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
   assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
@@ -54,24 +60,18 @@
   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
   GCCause::Cause gc_cause = heap->gc_cause();
   PSAdaptiveSizePolicy* policy = heap->size_policy();
+  IsGCActiveMark mark;
 
-  // Before each allocation/collection attempt, find out from the
-  // policy object if GCs are, on the whole, taking too long. If so,
-  // bail out without attempting a collection.  The exceptions are
-  // for explicitly requested GC's.
-  if (!policy->gc_time_limit_exceeded() ||
-      GCCause::is_user_requested_gc(gc_cause) ||
-      GCCause::is_serviceability_requested_gc(gc_cause)) {
-    IsGCActiveMark mark;
+  if (ScavengeBeforeFullGC) {
+    PSScavenge::invoke_no_policy();
+  }
 
-    if (ScavengeBeforeFullGC) {
-      PSScavenge::invoke_no_policy();
-    }
+  const bool clear_all_soft_refs =
+    heap->collector_policy()->should_clear_all_soft_refs();
 
-    int count = (maximum_heap_compaction)?1:MarkSweepAlwaysCompactCount;
-    IntFlagSetting flag_setting(MarkSweepAlwaysCompactCount, count);
-    PSMarkSweep::invoke_no_policy(maximum_heap_compaction);
-  }
+  int count = (maximum_heap_compaction)?1:MarkSweepAlwaysCompactCount;
+  IntFlagSetting flag_setting(MarkSweepAlwaysCompactCount, count);
+  PSMarkSweep::invoke_no_policy(clear_all_soft_refs || maximum_heap_compaction);
 }
 
 // This method contains no policy. You should probably
@@ -89,6 +89,10 @@
   assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
   PSAdaptiveSizePolicy* size_policy = heap->size_policy();
 
+  // The scope of casr should end after code that can change
+  // CollectorPolicy::_should_clear_all_soft_refs.
+  ClearedAllSoftRefs casr(clear_all_softrefs, heap->collector_policy());
+
   PSYoungGen* young_gen = heap->young_gen();
   PSOldGen* old_gen = heap->old_gen();
   PSPermGen* perm_gen = heap->perm_gen();
@@ -275,7 +279,8 @@
                                  old_gen->max_gen_size(),
                                  max_eden_size,
                                  true /* full gc*/,
-                                 gc_cause);
+                                 gc_cause,
+                                 heap->collector_policy());
 
         heap->resize_old_gen(size_policy->calculated_old_free_size_in_bytes());
 
@@ -326,19 +331,6 @@
     // Track memory usage and detect low memory
     MemoryService::track_memory_usage();
     heap->update_counters();
-
-    if (PrintGCDetails) {
-      if (size_policy->print_gc_time_limit_would_be_exceeded()) {
-        if (size_policy->gc_time_limit_exceeded()) {
-          gclog_or_tty->print_cr("      GC time is exceeding GCTimeLimit "
-            "of %d%%", GCTimeLimit);
-        } else {
-          gclog_or_tty->print_cr("      GC time would exceed GCTimeLimit "
-            "of %d%%", GCTimeLimit);
-        }
-      }
-      size_policy->set_print_gc_time_limit_would_be_exceeded(false);
-    }
   }
 
   if (VerifyAfterGC && heap->total_collections() >= VerifyGCStartAt) {
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.cpp
--- a/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2005-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2005-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -1923,31 +1923,32 @@
 //
 // Note that this method should only be called from the vm_thread while at a
 // safepoint.
+//
+// Note that the all_soft_refs_clear flag in the collector policy
+// may be true because this method can be called without intervening
+// activity.  For example when the heap space is tight and full measure
+// are being taken to free space.
 void PSParallelCompact::invoke(bool maximum_heap_compaction) {
   assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
   assert(Thread::current() == (Thread*)VMThread::vm_thread(),
          "should be in vm thread");
+
   ParallelScavengeHeap* heap = gc_heap();
   GCCause::Cause gc_cause = heap->gc_cause();
   assert(!heap->is_gc_active(), "not reentrant");
 
   PSAdaptiveSizePolicy* policy = heap->size_policy();
-
-  // Before each allocation/collection attempt, find out from the
-  // policy object if GCs are, on the whole, taking too long. If so,
-  // bail out without attempting a collection.  The exceptions are
-  // for explicitly requested GC's.
-  if (!policy->gc_time_limit_exceeded() ||
-      GCCause::is_user_requested_gc(gc_cause) ||
-      GCCause::is_serviceability_requested_gc(gc_cause)) {
-    IsGCActiveMark mark;
-
-    if (ScavengeBeforeFullGC) {
-      PSScavenge::invoke_no_policy();
-    }
-
-    PSParallelCompact::invoke_no_policy(maximum_heap_compaction);
+  IsGCActiveMark mark;
+
+  if (ScavengeBeforeFullGC) {
+    PSScavenge::invoke_no_policy();
   }
+
+  const bool clear_all_soft_refs =
+    heap->collector_policy()->should_clear_all_soft_refs();
+
+  PSParallelCompact::invoke_no_policy(clear_all_soft_refs ||
+                                      maximum_heap_compaction);
 }
 
 bool ParallelCompactData::region_contains(size_t region_index, HeapWord* addr) {
@@ -1976,6 +1977,11 @@
   PSPermGen* perm_gen = heap->perm_gen();
   PSAdaptiveSizePolicy* size_policy = heap->size_policy();
 
+  // The scope of casr should end after code that can change
+  // CollectorPolicy::_should_clear_all_soft_refs.
+  ClearedAllSoftRefs casr(maximum_heap_compaction,
+                          heap->collector_policy());
+
   if (ZapUnusedHeapArea) {
     // Save information needed to minimize mangling
     heap->record_gen_tops_before_GC();
@@ -2109,7 +2115,8 @@
                               old_gen->max_gen_size(),
                               max_eden_size,
                               true /* full gc*/,
-                              gc_cause);
+                              gc_cause,
+                              heap->collector_policy());
 
         heap->resize_old_gen(
           size_policy->calculated_old_free_size_in_bytes());
@@ -2157,19 +2164,6 @@
     // Track memory usage and detect low memory
     MemoryService::track_memory_usage();
     heap->update_counters();
-
-    if (PrintGCDetails) {
-      if (size_policy->print_gc_time_limit_would_be_exceeded()) {
-        if (size_policy->gc_time_limit_exceeded()) {
-          gclog_or_tty->print_cr("      GC time is exceeding GCTimeLimit "
-            "of %d%%", GCTimeLimit);
-        } else {
-          gclog_or_tty->print_cr("      GC time would exceed GCTimeLimit "
-            "of %d%%", GCTimeLimit);
-        }
-      }
-      size_policy->set_print_gc_time_limit_would_be_exceeded(false);
-    }
   }
 
   if (VerifyAfterGC && heap->total_collections() >= VerifyGCStartAt) {
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/parallelScavenge/psScavenge.cpp
--- a/src/share/vm/gc_implementation/parallelScavenge/psScavenge.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/parallelScavenge/psScavenge.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2002-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -187,8 +187,7 @@
 //
 // Note that this method should only be called from the vm_thread while
 // at a safepoint!
-void PSScavenge::invoke()
-{
+void PSScavenge::invoke() {
   assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
   assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
   assert(!Universe::heap()->is_gc_active(), "not reentrant");
@@ -197,29 +196,25 @@
   assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
 
   PSAdaptiveSizePolicy* policy = heap->size_policy();
+  IsGCActiveMark mark;
 
-  // Before each allocation/collection attempt, find out from the
-  // policy object if GCs are, on the whole, taking too long. If so,
-  // bail out without attempting a collection.
-  if (!policy->gc_time_limit_exceeded()) {
-    IsGCActiveMark mark;
+  bool scavenge_was_done = PSScavenge::invoke_no_policy();
 
-    bool scavenge_was_done = PSScavenge::invoke_no_policy();
-
-    PSGCAdaptivePolicyCounters* counters = heap->gc_policy_counters();
+  PSGCAdaptivePolicyCounters* counters = heap->gc_policy_counters();
+  if (UsePerfData)
+    counters->update_full_follows_scavenge(0);
+  if (!scavenge_was_done ||
+      policy->should_full_GC(heap->old_gen()->free_in_bytes())) {
     if (UsePerfData)
-      counters->update_full_follows_scavenge(0);
-    if (!scavenge_was_done ||
-        policy->should_full_GC(heap->old_gen()->free_in_bytes())) {
-      if (UsePerfData)
-        counters->update_full_follows_scavenge(full_follows_scavenge);
+      counters->update_full_follows_scavenge(full_follows_scavenge);
+    GCCauseSetter gccs(heap, GCCause::_adaptive_size_policy);
+    CollectorPolicy* cp = heap->collector_policy();
+    const bool clear_all_softrefs = cp->should_clear_all_soft_refs();
 
-      GCCauseSetter gccs(heap, GCCause::_adaptive_size_policy);
-      if (UseParallelOldGC) {
-        PSParallelCompact::invoke_no_policy(false);
-      } else {
-        PSMarkSweep::invoke_no_policy(false);
-      }
+    if (UseParallelOldGC) {
+      PSParallelCompact::invoke_no_policy(clear_all_softrefs);
+    } else {
+      PSMarkSweep::invoke_no_policy(clear_all_softrefs);
     }
   }
 }
@@ -447,6 +442,9 @@
       size_t promoted = old_gen->used_in_bytes() - old_gen_used_before;
       size_policy->update_averages(_survivor_overflow, survived, promoted);
 
+      // A successful scavenge should restart the GC time limit count which is
+      // for full GC's.
+      size_policy->reset_gc_overhead_limit_count();
       if (UseAdaptiveSizePolicy) {
         // Calculate the new survivor size and tenuring threshold
 
@@ -523,7 +521,8 @@
                                    old_gen->max_gen_size(),
                                    max_eden_size,
                                    false  /* full gc*/,
-                                   gc_cause);
+                                   gc_cause,
+                                   heap->collector_policy());
 
         }
         // Resize the young generation at every collection
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/shared/adaptiveSizePolicy.cpp
--- a/src/share/vm/gc_implementation/shared/adaptiveSizePolicy.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/shared/adaptiveSizePolicy.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2004-2006 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2004-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -44,13 +44,15 @@
     _survivor_size(init_survivor_size),
     _gc_pause_goal_sec(gc_pause_goal_sec),
     _throughput_goal(1.0 - double(1.0 / (1.0 + (double) gc_cost_ratio))),
-    _gc_time_limit_exceeded(false),
-    _print_gc_time_limit_would_be_exceeded(false),
-    _gc_time_limit_count(0),
+    _gc_overhead_limit_exceeded(false),
+    _print_gc_overhead_limit_would_be_exceeded(false),
+    _gc_overhead_limit_count(0),
     _latest_minor_mutator_interval_seconds(0),
     _threshold_tolerance_percent(1.0 + ThresholdTolerance/100.0),
     _young_gen_change_for_minor_throughput(0),
     _old_gen_change_for_major_throughput(0) {
+  assert(AdaptiveSizePolicyGCTimeLimitThreshold > 0,
+    "No opportunity to clear SoftReferences before GC overhead limit");
   _avg_minor_pause    =
     new AdaptivePaddedAverage(AdaptiveTimeWeight, PausePadding);
   _avg_minor_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
@@ -278,6 +280,147 @@
   set_decide_at_full_gc(0);
 }
 
+void AdaptiveSizePolicy::check_gc_overhead_limit(
+                                          size_t young_live,
+                                          size_t eden_live,
+                                          size_t max_old_gen_size,
+                                          size_t max_eden_size,
+                                          bool   is_full_gc,
+                                          GCCause::Cause gc_cause,
+                                          CollectorPolicy* collector_policy) {
+
+  // Ignore explicit GC's.  Exiting here does not set the flag and
+  // does not reset the count.  Updating of the averages for system
+  // GC's is still controlled by UseAdaptiveSizePolicyWithSystemGC.
+  if (GCCause::is_user_requested_gc(gc_cause) ||
+      GCCause::is_serviceability_requested_gc(gc_cause)) {
+    return;
+  }
+  // eden_limit is the upper limit on the size of eden based on
+  // the maximum size of the young generation and the sizes
+  // of the survivor space.
+  // The question being asked is whether the gc costs are high
+  // and the space being recovered by a collection is low.
+  // free_in_young_gen is the free space in the young generation
+  // after a collection and promo_live is the free space in the old
+  // generation after a collection.
+  //
+  // Use the minimum of the current value of the live in the
+  // young gen or the average of the live in the young gen.
+  // If the current value drops quickly, that should be taken
+  // into account (i.e., don't trigger if the amount of free
+  // space has suddenly jumped up).  If the current is much
+  // higher than the average, use the average since it represents
+  // the longer term behavor.
+  const size_t live_in_eden =
+    MIN2(eden_live, (size_t) avg_eden_live()->average());
+  const size_t free_in_eden = max_eden_size > live_in_eden ?
+    max_eden_size - live_in_eden : 0;
+  const size_t free_in_old_gen = (size_t)(max_old_gen_size - avg_old_live()->average());
+  const size_t total_free_limit = free_in_old_gen + free_in_eden;
+  const size_t total_mem = max_old_gen_size + max_eden_size;
+  const double mem_free_limit = total_mem * (GCHeapFreeLimit/100.0);
+  const double mem_free_old_limit = max_old_gen_size * (GCHeapFreeLimit/100.0);
+  const double mem_free_eden_limit = max_eden_size * (GCHeapFreeLimit/100.0);
+  const double gc_cost_limit = GCTimeLimit/100.0;
+  size_t promo_limit = (size_t)(max_old_gen_size - avg_old_live()->average());
+  // But don't force a promo size below the current promo size. Otherwise,
+  // the promo size will shrink for no good reason.
+  promo_limit = MAX2(promo_limit, _promo_size);
+
+
+  if (PrintAdaptiveSizePolicy && (Verbose ||
+      (free_in_old_gen < (size_t) mem_free_old_limit &&
+       free_in_eden < (size_t) mem_free_eden_limit))) {
+    gclog_or_tty->print_cr(
+          "PSAdaptiveSizePolicy::compute_generation_free_space limits:"
+          " promo_limit: " SIZE_FORMAT
+          " max_eden_size: " SIZE_FORMAT
+          " total_free_limit: " SIZE_FORMAT
+          " max_old_gen_size: " SIZE_FORMAT
+          " max_eden_size: " SIZE_FORMAT
+          " mem_free_limit: " SIZE_FORMAT,
+          promo_limit, max_eden_size, total_free_limit,
+          max_old_gen_size, max_eden_size,
+          (size_t) mem_free_limit);
+  }
+
+  bool print_gc_overhead_limit_would_be_exceeded = false;
+  if (is_full_gc) {
+    if (gc_cost() > gc_cost_limit &&
+      free_in_old_gen < (size_t) mem_free_old_limit &&
+      free_in_eden < (size_t) mem_free_eden_limit) {
+      // Collections, on average, are taking too much time, and
+      //      gc_cost() > gc_cost_limit
+      // we have too little space available after a full gc.
+      //      total_free_limit < mem_free_limit
+      // where
+      //   total_free_limit is the free space available in
+      //     both generations
+      //   total_mem is the total space available for allocation
+      //     in both generations (survivor spaces are not included
+      //     just as they are not included in eden_limit).
+      //   mem_free_limit is a fraction of total_mem judged to be an
+      //     acceptable amount that is still unused.
+      // The heap can ask for the value of this variable when deciding
+      // whether to thrown an OutOfMemory error.
+      // Note that the gc time limit test only works for the collections
+      // of the young gen + tenured gen and not for collections of the
+      // permanent gen.  That is because the calculation of the space
+      // freed by the collection is the free space in the young gen +
+      // tenured gen.
+      // At this point the GC overhead limit is being exceeded.
+      inc_gc_overhead_limit_count();
+      if (UseGCOverheadLimit) {
+        if (gc_overhead_limit_count() >=
+            AdaptiveSizePolicyGCTimeLimitThreshold){
+          // All conditions have been met for throwing an out-of-memory
+          set_gc_overhead_limit_exceeded(true);
+          // Avoid consecutive OOM due to the gc time limit by resetting
+          // the counter.
+          reset_gc_overhead_limit_count();
+        } else {
+          // The required consecutive collections which exceed the
+          // GC time limit may or may not have been reached. We
+          // are approaching that condition and so as not to
+          // throw an out-of-memory before all SoftRef's have been
+          // cleared, set _should_clear_all_soft_refs in CollectorPolicy.
+          // The clearing will be done on the next GC.
+          bool near_limit = gc_overhead_limit_near();
+          if (near_limit) {
+            collector_policy->set_should_clear_all_soft_refs(true);
+            if (PrintGCDetails && Verbose) {
+              gclog_or_tty->print_cr("  Nearing GC overhead limit, "
+                "will be clearing all SoftReference");
+            }
+          }
+        }
+      }
+      // Set this even when the overhead limit will not
+      // cause an out-of-memory.  Diagnostic message indicating
+      // that the overhead limit is being exceeded is sometimes
+      // printed.
+      print_gc_overhead_limit_would_be_exceeded = true;
+
+    } else {
+      // Did not exceed overhead limits
+      reset_gc_overhead_limit_count();
+    }
+  }
+
+  if (UseGCOverheadLimit && PrintGCDetails && Verbose) {
+    if (gc_overhead_limit_exceeded()) {
+      gclog_or_tty->print_cr("      GC is exceeding overhead limit "
+        "of %d%%", GCTimeLimit);
+      reset_gc_overhead_limit_count();
+    } else if (print_gc_overhead_limit_would_be_exceeded) {
+      assert(gc_overhead_limit_count() > 0, "Should not be printing");
+      gclog_or_tty->print_cr("      GC would exceed overhead limit "
+        "of %d%% %d consecutive time(s)",
+        GCTimeLimit, gc_overhead_limit_count());
+    }
+  }
+}
 // Printing
 
 bool AdaptiveSizePolicy::print_adaptive_size_policy_on(outputStream* st) const {
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/shared/adaptiveSizePolicy.hpp
--- a/src/share/vm/gc_implementation/shared/adaptiveSizePolicy.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/shared/adaptiveSizePolicy.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2004-2006 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2004-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -27,6 +27,7 @@
 
 // Forward decls
 class elapsedTimer;
+class CollectorPolicy;
 
 class AdaptiveSizePolicy : public CHeapObj {
  friend class GCAdaptivePolicyCounters;
@@ -75,13 +76,16 @@
 
   // This is a hint for the heap:  we've detected that gc times
   // are taking longer than GCTimeLimit allows.
-  bool _gc_time_limit_exceeded;
-  // Use for diagnostics only.  If UseGCTimeLimit is false,
+  bool _gc_overhead_limit_exceeded;
+  // Use for diagnostics only.  If UseGCOverheadLimit is false,
   // this variable is still set.
-  bool _print_gc_time_limit_would_be_exceeded;
+  bool _print_gc_overhead_limit_would_be_exceeded;
   // Count of consecutive GC that have exceeded the
   // GC time limit criterion.
-  uint _gc_time_limit_count;
+  uint _gc_overhead_limit_count;
+  // This flag signals that GCTimeLimit is being exceeded
+  // but may not have done so for the required number of consequetive
+  // collections.
 
   // Minor collection timers used to determine both
   // pause and interval times for collections.
@@ -406,22 +410,21 @@
   // Most heaps will choose to throw an OutOfMemoryError when
   // this occurs but it is up to the heap to request this information
   // of the policy
-  bool gc_time_limit_exceeded() {
-    return _gc_time_limit_exceeded;
-  }
-  void set_gc_time_limit_exceeded(bool v) {
-    _gc_time_limit_exceeded = v;
+  bool gc_overhead_limit_exceeded() {
+    return _gc_overhead_limit_exceeded;
   }
-  bool print_gc_time_limit_would_be_exceeded() {
-    return _print_gc_time_limit_would_be_exceeded;
-  }
-  void set_print_gc_time_limit_would_be_exceeded(bool v) {
-    _print_gc_time_limit_would_be_exceeded = v;
+  void set_gc_overhead_limit_exceeded(bool v) {
+    _gc_overhead_limit_exceeded = v;
   }
 
-  uint gc_time_limit_count() { return _gc_time_limit_count; }
-  void reset_gc_time_limit_count() { _gc_time_limit_count = 0; }
-  void inc_gc_time_limit_count() { _gc_time_limit_count++; }
+  // Tests conditions indicate the GC overhead limit is being approached.
+  bool gc_overhead_limit_near() {
+    return gc_overhead_limit_count() >=
+        (AdaptiveSizePolicyGCTimeLimitThreshold - 1);
+  }
+  uint gc_overhead_limit_count() { return _gc_overhead_limit_count; }
+  void reset_gc_overhead_limit_count() { _gc_overhead_limit_count = 0; }
+  void inc_gc_overhead_limit_count() { _gc_overhead_limit_count++; }
   // accessors for flags recording the decisions to resize the
   // generations to meet the pause goal.
 
@@ -436,6 +439,16 @@
   int decide_at_full_gc() { return _decide_at_full_gc; }
   void set_decide_at_full_gc(int v) { _decide_at_full_gc = v; }
 
+  // Check the conditions for an out-of-memory due to excessive GC time.
+  // Set _gc_overhead_limit_exceeded if all the conditions have been met.
+  void check_gc_overhead_limit(size_t young_live,
+                               size_t eden_live,
+                               size_t max_old_gen_size,
+                               size_t max_eden_size,
+                               bool   is_full_gc,
+                               GCCause::Cause gc_cause,
+                               CollectorPolicy* collector_policy);
+
   // Printing support
   virtual bool print_adaptive_size_policy_on(outputStream* st) const;
   bool print_adaptive_size_policy_on(outputStream* st, int
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/shared/vmGCOperations.cpp
--- a/src/share/vm/gc_implementation/shared/vmGCOperations.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/shared/vmGCOperations.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -115,11 +115,25 @@
 void VM_GC_HeapInspection::doit() {
   HandleMark hm;
   CollectedHeap* ch = Universe::heap();
+  ch->ensure_parsability(false); // must happen, even if collection does
+                                 // not happen (e.g. due to GC_locker)
   if (_full_gc) {
-    ch->collect_as_vm_thread(GCCause::_heap_inspection);
-  } else {
-    // make the heap parsable (no need to retire TLABs)
-    ch->ensure_parsability(false);
+    // The collection attempt below would be skipped anyway if
+    // the gc locker is held. The following dump may then be a tad
+    // misleading to someone expecting only live objects to show
+    // up in the dump (see CR 6944195). Just issue a suitable warning
+    // in that case and do not attempt to do a collection.
+    // The latter is a subtle point, because even a failed attempt
+    // to GC will, in fact, induce one in the future, which we
+    // probably want to avoid in this case because the GC that we may
+    // be about to attempt holds value for us only
+    // if it happens now and not if it happens in the eventual
+    // future.
+    if (GC_locker::is_active()) {
+      warning("GC locker is held; pre-dump GC was skipped");
+    } else {
+      ch->collect_as_vm_thread(GCCause::_heap_inspection);
+    }
   }
   HeapInspection::heap_inspection(_out, _need_prologue /* need_prologue */);
 }
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_implementation/shared/vmGCOperations.hpp
--- a/src/share/vm/gc_implementation/shared/vmGCOperations.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_implementation/shared/vmGCOperations.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2005-2008 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2005-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -89,8 +89,19 @@
     if (full) {
       _full_gc_count_before = full_gc_count_before;
     }
+    // In ParallelScavengeHeap::mem_allocate() collections can be
+    // executed within a loop and _all_soft_refs_clear can be set
+    // true after they have been cleared by a collection and another
+    // collection started so that _all_soft_refs_clear can be true
+    // when this collection is started.  Don't assert that
+    // _all_soft_refs_clear have to be false here even though
+    // mutators have run.  Soft refs will be cleared again in this
+    // collection.
   }
-  ~VM_GC_Operation() {}
+  ~VM_GC_Operation() {
+    CollectedHeap* ch = Universe::heap();
+    ch->collector_policy()->set_all_soft_refs_clear(false);
+  }
 
   // Acquire the reference synchronization lock
   virtual bool doit_prologue();
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/gc_interface/collectedHeap.hpp
--- a/src/share/vm/gc_interface/collectedHeap.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/gc_interface/collectedHeap.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -31,6 +31,7 @@
 class ThreadClosure;
 class AdaptiveSizePolicy;
 class Thread;
+class CollectorPolicy;
 
 //
 // CollectedHeap
@@ -506,6 +507,9 @@
   // Return the AdaptiveSizePolicy for the heap.
   virtual AdaptiveSizePolicy* size_policy() = 0;
 
+  // Return the CollectorPolicy for the heap
+  virtual CollectorPolicy* collector_policy() const = 0;
+
   // Iterate over all the ref-containing fields of all objects, calling
   // "cl.do_oop" on each. This includes objects in permanent memory.
   virtual void oop_iterate(OopClosure* cl) = 0;
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/includeDB_zero
--- a/src/share/vm/includeDB_zero	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/includeDB_zero	Thu Apr 29 15:18:27 2010 -0700
@@ -1,6 +1,6 @@
 //
 // Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
-// Copyright 2009 Red Hat, Inc.
+// Copyright 2009, 2010 Red Hat, Inc.
 // DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 //
 // This code is free software; you can redistribute it and/or modify it
@@ -25,6 +25,8 @@
 
 // NOTE: DO NOT CHANGE THIS COPYRIGHT TO NEW STYLE - IT WILL BREAK makeDeps!
 
+cppInterpreter_<arch>.cpp               stack_<arch>.inline.hpp
+
 entryFrame_<arch>.hpp                   javaCalls.hpp
 entryFrame_<arch>.hpp                   stack_<arch>.hpp
 
@@ -47,9 +49,19 @@
 interpreterFrame_<arch>.hpp             stack_<arch>.hpp
 interpreterFrame_<arch>.hpp             thread.hpp
 
+interpreterRT_<arch>.cpp                stack_<arch>.inline.hpp
+
 sharkFrame_<arch>.hpp                   methodOop.hpp
 sharkFrame_<arch>.hpp                   stack_<arch>.hpp
 
 stack_<arch>.hpp                        sizes.hpp
 
+stack_<arch>.inline.hpp                 stack_<arch>.hpp
+stack_<arch>.inline.hpp                 thread.hpp
+
+stack_<arch>.cpp                        interpreterRuntime.hpp
+stack_<arch>.cpp                        stack_<arch>.hpp
+
+stubGenerator_<arch>.cpp                stack_<arch>.inline.hpp
+
 thread.hpp                              stack_<arch>.hpp
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/memory/collectorPolicy.cpp
--- a/src/share/vm/memory/collectorPolicy.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/memory/collectorPolicy.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2008 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -112,6 +112,11 @@
   }
 }
 
+bool CollectorPolicy::use_should_clear_all_soft_refs(bool v) {
+  bool result = _should_clear_all_soft_refs;
+  set_should_clear_all_soft_refs(false);
+  return result;
+}
 
 GenRemSet* CollectorPolicy::create_rem_set(MemRegion whole_heap,
                                            int max_covered_regions) {
@@ -126,6 +131,17 @@
   }
 }
 
+void CollectorPolicy::cleared_all_soft_refs() {
+  // If near gc overhear limit, continue to clear SoftRefs.  SoftRefs may
+  // have been cleared in the last collection but if the gc overhear
+  // limit continues to be near, SoftRefs should still be cleared.
+  if (size_policy() != NULL) {
+    _should_clear_all_soft_refs = size_policy()->gc_overhead_limit_near();
+  }
+  _all_soft_refs_clear = true;
+}
+
+
 // GenCollectorPolicy methods.
 
 size_t GenCollectorPolicy::scale_by_NewRatio_aligned(size_t base_size) {
@@ -489,6 +505,12 @@
 
   debug_only(gch->check_for_valid_allocation_state());
   assert(gch->no_gc_in_progress(), "Allocation during gc not allowed");
+
+  // In general gc_overhead_limit_was_exceeded should be false so
+  // set it so here and reset it to true only if the gc time
+  // limit is being exceeded as checked below.
+  *gc_overhead_limit_was_exceeded = false;
+
   HeapWord* result = NULL;
 
   // Loop until the allocation is satisified,
@@ -524,12 +546,6 @@
         return result;
       }
 
-      // There are NULL's returned for different circumstances below.
-      // In general gc_overhead_limit_was_exceeded should be false so
-      // set it so here and reset it to true only if the gc time
-      // limit is being exceeded as checked below.
-      *gc_overhead_limit_was_exceeded = false;
-
       if (GC_locker::is_active_and_needs_gc()) {
         if (is_tlab) {
           return NULL;  // Caller will retry allocating individual object
@@ -568,18 +584,6 @@
       gc_count_before = Universe::heap()->total_collections();
     }
 
-    // Allocation has failed and a collection is about
-    // to be done.  If the gc time limit was exceeded the
-    // last time a collection was done, return NULL so
-    // that an out-of-memory will be thrown.  Clear
-    // gc_time_limit_exceeded so that subsequent attempts
-    // at a collection will be made.
-    if (size_policy()->gc_time_limit_exceeded()) {
-      *gc_overhead_limit_was_exceeded = true;
-      size_policy()->set_gc_time_limit_exceeded(false);
-      return NULL;
-    }
-
     VM_GenCollectForAllocation op(size,
                                   is_tlab,
                                   gc_count_before);
@@ -590,6 +594,24 @@
          assert(result == NULL, "must be NULL if gc_locked() is true");
          continue;  // retry and/or stall as necessary
       }
+
+      // Allocation has failed and a collection
+      // has been done.  If the gc time limit was exceeded the
+      // this time, return NULL so that an out-of-memory
+      // will be thrown.  Clear gc_overhead_limit_exceeded
+      // so that the overhead exceeded does not persist.
+
+      const bool limit_exceeded = size_policy()->gc_overhead_limit_exceeded();
+      const bool softrefs_clear = all_soft_refs_clear();
+      assert(!limit_exceeded || softrefs_clear, "Should have been cleared");
+      if (limit_exceeded && softrefs_clear) {
+        *gc_overhead_limit_was_exceeded = true;
+        size_policy()->set_gc_overhead_limit_exceeded(false);
+        if (op.result() != NULL) {
+          CollectedHeap::fill_with_object(op.result(), size);
+        }
+        return NULL;
+      }
       assert(result == NULL || gch->is_in_reserved(result),
              "result not in heap");
       return result;
@@ -688,6 +710,9 @@
     return result;
   }
 
+  assert(!should_clear_all_soft_refs(),
+    "Flag should have been handled and cleared prior to this point");
+
   // What else?  We might try synchronous finalization later.  If the total
   // space available is large enough for the allocation, then a more
   // complete compaction phase than we've tried so far might be
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/memory/collectorPolicy.hpp
--- a/src/share/vm/memory/collectorPolicy.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/memory/collectorPolicy.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2008 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -69,12 +69,28 @@
   size_t _min_alignment;
   size_t _max_alignment;
 
+  // The sizing of the heap are controlled by a sizing policy.
+  AdaptiveSizePolicy* _size_policy;
+
+  // Set to true when policy wants soft refs cleared.
+  // Reset to false by gc after it clears all soft refs.
+  bool _should_clear_all_soft_refs;
+  // Set to true by the GC if the just-completed gc cleared all
+  // softrefs.  This is set to true whenever a gc clears all softrefs, and
+  // set to false each time gc returns to the mutator.  For example, in the
+  // ParallelScavengeHeap case the latter would be done toward the end of
+  // mem_allocate() where it returns op.result()
+  bool _all_soft_refs_clear;
+
   CollectorPolicy() :
     _min_alignment(1),
     _max_alignment(1),
     _initial_heap_byte_size(0),
     _max_heap_byte_size(0),
-    _min_heap_byte_size(0)
+    _min_heap_byte_size(0),
+    _size_policy(NULL),
+    _should_clear_all_soft_refs(false),
+    _all_soft_refs_clear(false)
   {}
 
  public:
@@ -98,6 +114,19 @@
     G1CollectorPolicyKind
   };
 
+  AdaptiveSizePolicy* size_policy() { return _size_policy; }
+  bool should_clear_all_soft_refs() { return _should_clear_all_soft_refs; }
+  void set_should_clear_all_soft_refs(bool v) { _should_clear_all_soft_refs = v; }
+  // Returns the current value of _should_clear_all_soft_refs.
+  // _should_clear_all_soft_refs is set to false as a side effect.
+  bool use_should_clear_all_soft_refs(bool v);
+  bool all_soft_refs_clear() { return _all_soft_refs_clear; }
+  void set_all_soft_refs_clear(bool v) { _all_soft_refs_clear = v; }
+
+  // Called by the GC after Soft Refs have been cleared to indicate
+  // that the request in _should_clear_all_soft_refs has been fulfilled.
+  void cleared_all_soft_refs();
+
   // Identification methods.
   virtual GenCollectorPolicy*           as_generation_policy()            { return NULL; }
   virtual TwoGenerationCollectorPolicy* as_two_generation_policy()        { return NULL; }
@@ -165,6 +194,22 @@
 
 };
 
+class ClearedAllSoftRefs : public StackObj {
+  bool _clear_all_soft_refs;
+  CollectorPolicy* _collector_policy;
+ public:
+  ClearedAllSoftRefs(bool clear_all_soft_refs,
+                     CollectorPolicy* collector_policy) :
+    _clear_all_soft_refs(clear_all_soft_refs),
+    _collector_policy(collector_policy) {}
+
+  ~ClearedAllSoftRefs() {
+    if (_clear_all_soft_refs) {
+      _collector_policy->cleared_all_soft_refs();
+    }
+  }
+};
+
 class GenCollectorPolicy : public CollectorPolicy {
  protected:
   size_t _min_gen0_size;
@@ -173,10 +218,6 @@
 
   GenerationSpec **_generations;
 
-  // The sizing of the different generations in the heap are controlled
-  // by a sizing policy.
-  AdaptiveSizePolicy* _size_policy;
-
   // Return true if an allocation should be attempted in the older
   // generation if it fails in the younger generation.  Return
   // false, otherwise.
@@ -236,14 +277,11 @@
   virtual size_t large_typearray_limit();
 
   // Adaptive size policy
-  AdaptiveSizePolicy* size_policy() { return _size_policy; }
   virtual void initialize_size_policy(size_t init_eden_size,
                                       size_t init_promo_size,
                                       size_t init_survivor_size);
-
 };
 
-
 // All of hotspot's current collectors are subtypes of this
 // class. Currently, these collectors all use the same gen[0],
 // but have different gen[1] types. If we add another subtype
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/memory/defNewGeneration.cpp
--- a/src/share/vm/memory/defNewGeneration.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/memory/defNewGeneration.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2008 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -594,6 +594,10 @@
     _tenuring_threshold =
       age_table()->compute_tenuring_threshold(to()->capacity()/HeapWordSize);
 
+    // A successful scavenge should restart the GC time limit count which is
+    // for full GC's.
+    AdaptiveSizePolicy* size_policy = gch->gen_policy()->size_policy();
+    size_policy->reset_gc_overhead_limit_count();
     if (PrintGC && !PrintGCDetails) {
       gch->print_heap_change(gch_prev_used);
     }
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/memory/genCollectedHeap.cpp
--- a/src/share/vm/memory/genCollectedHeap.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/memory/genCollectedHeap.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2000-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -428,7 +428,8 @@
   assert(my_thread->is_VM_thread() ||
          my_thread->is_ConcurrentGC_thread(),
          "incorrect thread type capability");
-  assert(Heap_lock->is_locked(), "the requesting thread should have the Heap_lock");
+  assert(Heap_lock->is_locked(),
+         "the requesting thread should have the Heap_lock");
   guarantee(!is_gc_active(), "collection is not reentrant");
   assert(max_level < n_gens(), "sanity check");
 
@@ -436,6 +437,11 @@
     return; // GC is disabled (e.g. JNI GetXXXCritical operation)
   }
 
+  const bool do_clear_all_soft_refs = clear_all_soft_refs ||
+                          collector_policy()->should_clear_all_soft_refs();
+
+  ClearedAllSoftRefs casr(do_clear_all_soft_refs, collector_policy());
+
   const size_t perm_prev_used = perm_gen()->used();
 
   if (PrintHeapAtGC) {
@@ -560,11 +566,11 @@
           if (rp->discovery_is_atomic()) {
             rp->verify_no_references_recorded();
             rp->enable_discovery();
-            rp->setup_policy(clear_all_soft_refs);
+            rp->setup_policy(do_clear_all_soft_refs);
           } else {
             // collect() below will enable discovery as appropriate
           }
-          _gens[i]->collect(full, clear_all_soft_refs, size, is_tlab);
+          _gens[i]->collect(full, do_clear_all_soft_refs, size, is_tlab);
           if (!rp->enqueuing_is_done()) {
             rp->enqueue_discovered_references();
           } else {
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/memory/genMarkSweep.cpp
--- a/src/share/vm/memory/genMarkSweep.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/memory/genMarkSweep.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -29,6 +29,13 @@
   bool clear_all_softrefs) {
   assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint");
 
+  GenCollectedHeap* gch = GenCollectedHeap::heap();
+#ifdef ASSERT
+  if (gch->collector_policy()->should_clear_all_soft_refs()) {
+    assert(clear_all_softrefs, "Policy should have been checked earlier");
+  }
+#endif
+
   // hook up weak ref data so it can be used during Mark-Sweep
   assert(ref_processor() == NULL, "no stomping");
   assert(rp != NULL, "should be non-NULL");
@@ -44,7 +51,6 @@
 
   // Increment the invocation count for the permanent generation, since it is
   // implicitly collected whenever we do a full mark sweep collection.
-  GenCollectedHeap* gch = GenCollectedHeap::heap();
   gch->perm_gen()->stat_record()->invocations++;
 
   // Capture heap size before collection for printing.
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/opto/c2compiler.cpp
--- a/src/share/vm/opto/c2compiler.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/opto/c2compiler.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 1999-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 1999-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -105,8 +105,7 @@
   }
   bool subsume_loads = true;
   bool do_escape_analysis = DoEscapeAnalysis &&
-                            !(env->jvmti_can_hotswap_or_post_breakpoint() ||
-                              env->jvmti_can_examine_or_deopt_anywhere());
+    !env->jvmti_can_access_local_variables();
   while (!env->failing()) {
     // Attempt to compile while subsuming loads into machine instructions.
     Compile C(env, this, target, entry_bci, subsume_loads, do_escape_analysis);
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/opto/classes.hpp
--- a/src/share/vm/opto/classes.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/opto/classes.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 1997-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 1997-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -44,6 +44,8 @@
 macro(BoxLock)
 macro(ReverseBytesI)
 macro(ReverseBytesL)
+macro(ReverseBytesUS)
+macro(ReverseBytesS)
 macro(CProj)
 macro(CallDynamicJava)
 macro(CallJava)
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/opto/compile.cpp
--- a/src/share/vm/opto/compile.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/opto/compile.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -871,7 +871,6 @@
   set_has_split_ifs(false);
   set_has_loops(has_method() && method()->has_loops()); // first approximation
   set_has_stringbuilder(false);
-  _deopt_happens = true;  // start out assuming the worst
   _trap_can_recompile = false;  // no traps emitted yet
   _major_progress = true; // start out assuming good things will happen
   set_has_unsafe_access(false);
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/opto/compile.hpp
--- a/src/share/vm/opto/compile.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/opto/compile.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -146,7 +146,6 @@
   int                   _orig_pc_slot_offset_in_bytes;
 
   int                   _major_progress;        // Count of something big happening
-  bool                  _deopt_happens;         // TRUE if de-optimization CAN happen
   bool                  _has_loops;             // True if the method _may_ have some loops
   bool                  _has_split_ifs;         // True if the method _may_ have some split-if
   bool                  _has_unsafe_access;     // True if the method _may_ produce faults in unsafe loads or stores.
@@ -300,7 +299,6 @@
   void          set_freq_inline_size(int n)     { _freq_inline_size = n; }
   int               freq_inline_size() const    { return _freq_inline_size; }
   void          set_max_inline_size(int n)      { _max_inline_size = n; }
-  bool              deopt_happens() const       { return _deopt_happens; }
   bool              has_loops() const           { return _has_loops; }
   void          set_has_loops(bool z)           { _has_loops = z; }
   bool              has_split_ifs() const       { return _has_split_ifs; }
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/opto/graphKit.cpp
--- a/src/share/vm/opto/graphKit.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/opto/graphKit.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -812,10 +812,6 @@
 
   JVMState* youngest_jvms = sync_jvms();
 
-  // Do we need debug info here?  If it is a SafePoint and this method
-  // cannot de-opt, then we do NOT need any debug info.
-  bool full_info = (C->deopt_happens() || call->Opcode() != Op_SafePoint);
-
   // If we are guaranteed to throw, we can prune everything but the
   // input to the current bytecode.
   bool can_prune_locals = false;
@@ -829,10 +825,9 @@
     }
   }
 
-  if (env()->jvmti_can_examine_or_deopt_anywhere()) {
+  if (env()->jvmti_can_access_local_variables()) {
     // At any safepoint, this method can get breakpointed, which would
     // then require an immediate deoptimization.
-    full_info = true;
     can_prune_locals = false;  // do not prune locals
     stack_slots_not_pruned = 0;
   }
@@ -890,7 +885,7 @@
     k = in_jvms->locoff();
     l = in_jvms->loc_size();
     out_jvms->set_locoff(p);
-    if (full_info && !can_prune_locals) {
+    if (!can_prune_locals) {
       for (j = 0; j < l; j++)
         call->set_req(p++, in_map->in(k+j));
     } else {
@@ -901,7 +896,7 @@
     k = in_jvms->stkoff();
     l = in_jvms->sp();
     out_jvms->set_stkoff(p);
-    if (full_info && !can_prune_locals) {
+    if (!can_prune_locals) {
       for (j = 0; j < l; j++)
         call->set_req(p++, in_map->in(k+j));
     } else if (can_prune_locals && stack_slots_not_pruned != 0) {
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/opto/library_call.cpp
--- a/src/share/vm/opto/library_call.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/opto/library_call.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -636,6 +636,8 @@
 
   case vmIntrinsics::_reverseBytes_i:
   case vmIntrinsics::_reverseBytes_l:
+  case vmIntrinsics::_reverseBytes_s:
+  case vmIntrinsics::_reverseBytes_c:
     return inline_reverseBytes((vmIntrinsics::ID) intrinsic_id());
 
   case vmIntrinsics::_get_AtomicLong:
@@ -2010,13 +2012,19 @@
   return true;
 }
 
-//----------------------------inline_reverseBytes_int/long-------------------
+//----------------------------inline_reverseBytes_int/long/char/short-------------------
 // inline Integer.reverseBytes(int)
 // inline Long.reverseBytes(long)
+// inline Character.reverseBytes(char)
+// inline Short.reverseBytes(short)
 bool LibraryCallKit::inline_reverseBytes(vmIntrinsics::ID id) {
-  assert(id == vmIntrinsics::_reverseBytes_i || id == vmIntrinsics::_reverseBytes_l, "not reverse Bytes");
-  if (id == vmIntrinsics::_reverseBytes_i && !Matcher::has_match_rule(Op_ReverseBytesI)) return false;
-  if (id == vmIntrinsics::_reverseBytes_l && !Matcher::has_match_rule(Op_ReverseBytesL)) return false;
+  assert(id == vmIntrinsics::_reverseBytes_i || id == vmIntrinsics::_reverseBytes_l ||
+         id == vmIntrinsics::_reverseBytes_c || id == vmIntrinsics::_reverseBytes_s,
+         "not reverse Bytes");
+  if (id == vmIntrinsics::_reverseBytes_i && !Matcher::has_match_rule(Op_ReverseBytesI))  return false;
+  if (id == vmIntrinsics::_reverseBytes_l && !Matcher::has_match_rule(Op_ReverseBytesL))  return false;
+  if (id == vmIntrinsics::_reverseBytes_c && !Matcher::has_match_rule(Op_ReverseBytesUS)) return false;
+  if (id == vmIntrinsics::_reverseBytes_s && !Matcher::has_match_rule(Op_ReverseBytesS))  return false;
   _sp += arg_size();        // restore stack pointer
   switch (id) {
   case vmIntrinsics::_reverseBytes_i:
@@ -2025,6 +2033,12 @@
   case vmIntrinsics::_reverseBytes_l:
     push_pair(_gvn.transform(new (C, 2) ReverseBytesLNode(0, pop_pair())));
     break;
+  case vmIntrinsics::_reverseBytes_c:
+    push(_gvn.transform(new (C, 2) ReverseBytesUSNode(0, pop())));
+    break;
+  case vmIntrinsics::_reverseBytes_s:
+    push(_gvn.transform(new (C, 2) ReverseBytesSNode(0, pop())));
+    break;
   default:
     ;
   }
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/opto/parse1.cpp
--- a/src/share/vm/opto/parse1.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/opto/parse1.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -280,7 +280,13 @@
       continue;
     }
     // Construct code to access the appropriate local.
-    Node *value = fetch_interpreter_state(index, type->basic_type(), locals_addr, osr_buf);
+    BasicType bt = type->basic_type();
+    if (type == TypePtr::NULL_PTR) {
+      // Ptr types are mixed together with T_ADDRESS but NULL is
+      // really for T_OBJECT types so correct it.
+      bt = T_OBJECT;
+    }
+    Node *value = fetch_interpreter_state(index, bt, locals_addr, osr_buf);
     set_local(index, value);
   }
 
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/opto/subnode.hpp
--- a/src/share/vm/opto/subnode.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/opto/subnode.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 1997-2008 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 1997-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -509,3 +509,23 @@
   const Type *bottom_type() const { return TypeLong::LONG; }
   virtual uint ideal_reg() const { return Op_RegL; }
 };
+
+//-------------------------------ReverseBytesUSNode--------------------------------
+// reverse bytes of an unsigned short / char
+class ReverseBytesUSNode : public Node {
+public:
+  ReverseBytesUSNode(Node *c, Node *in1) : Node(c, in1) {}
+  virtual int Opcode() const;
+  const Type *bottom_type() const { return TypeInt::CHAR; }
+  virtual uint ideal_reg() const { return Op_RegI; }
+};
+
+//-------------------------------ReverseBytesSNode--------------------------------
+// reverse bytes of a short
+class ReverseBytesSNode : public Node {
+public:
+  ReverseBytesSNode(Node *c, Node *in1) : Node(c, in1) {}
+  virtual int Opcode() const;
+  const Type *bottom_type() const { return TypeInt::SHORT; }
+  virtual uint ideal_reg() const { return Op_RegI; }
+};
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/prims/jvmtiExport.cpp
--- a/src/share/vm/prims/jvmtiExport.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/prims/jvmtiExport.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -270,7 +270,6 @@
 int               JvmtiExport::_field_modification_count                  = 0;
 
 bool              JvmtiExport::_can_access_local_variables                = false;
-bool              JvmtiExport::_can_examine_or_deopt_anywhere             = false;
 bool              JvmtiExport::_can_hotswap_or_post_breakpoint            = false;
 bool              JvmtiExport::_can_modify_any_class                      = false;
 bool              JvmtiExport::_can_walk_any_space                        = false;
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/prims/jvmtiExport.hpp
--- a/src/share/vm/prims/jvmtiExport.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/prims/jvmtiExport.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -58,7 +58,6 @@
   static int         _field_modification_count;
 
   static bool        _can_access_local_variables;
-  static bool        _can_examine_or_deopt_anywhere;
   static bool        _can_hotswap_or_post_breakpoint;
   static bool        _can_modify_any_class;
   static bool        _can_walk_any_space;
@@ -112,7 +111,6 @@
 
   // these should only be called by the friend class
   friend class JvmtiManageCapabilities;
-  inline static void set_can_examine_or_deopt_anywhere(bool on)        { _can_examine_or_deopt_anywhere = (on != 0); }
   inline static void set_can_modify_any_class(bool on)                 { _can_modify_any_class = (on != 0); }
   inline static void set_can_access_local_variables(bool on)           { _can_access_local_variables = (on != 0); }
   inline static void set_can_hotswap_or_post_breakpoint(bool on)       { _can_hotswap_or_post_breakpoint = (on != 0); }
@@ -220,7 +218,6 @@
   static void enter_live_phase();
 
   // ------ can_* conditions (below) are set at OnLoad and never changed ------------
-  inline static bool can_examine_or_deopt_anywhere()              { return _can_examine_or_deopt_anywhere; }
   inline static bool can_modify_any_class()                       { return _can_modify_any_class; }
   inline static bool can_access_local_variables()                 { return _can_access_local_variables; }
   inline static bool can_hotswap_or_post_breakpoint()             { return _can_hotswap_or_post_breakpoint; }
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/prims/jvmtiManageCapabilities.cpp
--- a/src/share/vm/prims/jvmtiManageCapabilities.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/prims/jvmtiManageCapabilities.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -332,16 +332,6 @@
   }
 
   JvmtiExport::set_can_get_source_debug_extension(avail.can_get_source_debug_extension);
-  JvmtiExport::set_can_examine_or_deopt_anywhere(
-    avail.can_generate_breakpoint_events ||
-    interp_events ||
-    avail.can_redefine_classes ||
-    avail.can_retransform_classes ||
-    avail.can_access_local_variables ||
-    avail.can_get_owned_monitor_info ||
-    avail.can_get_current_contended_monitor ||
-    avail.can_get_monitor_info ||
-    avail.can_get_owned_monitor_stack_depth_info);
   JvmtiExport::set_can_maintain_original_method_order(avail.can_maintain_original_method_order);
   JvmtiExport::set_can_post_interpreter_events(interp_events);
   JvmtiExport::set_can_hotswap_or_post_breakpoint(
@@ -353,10 +343,13 @@
     avail.can_generate_all_class_hook_events);
   JvmtiExport::set_can_walk_any_space(
     avail.can_tag_objects);   // disable sharing in onload phase
+  // This controls whether the compilers keep extra locals live to
+  // improve the debugging experience so only set them if the selected
+  // capabilities look like a debugger.
   JvmtiExport::set_can_access_local_variables(
-    avail.can_access_local_variables  ||
-    avail.can_redefine_classes ||
-    avail.can_retransform_classes);
+    avail.can_access_local_variables ||
+    avail.can_generate_breakpoint_events ||
+    avail.can_generate_frame_pop_events);
   JvmtiExport::set_can_post_on_exceptions(
     avail.can_generate_exception_events ||
     avail.can_generate_frame_pop_events ||
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/runtime/sharedRuntime.cpp
--- a/src/share/vm/runtime/sharedRuntime.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/runtime/sharedRuntime.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -473,6 +473,13 @@
     t = table.entry_for(catch_pco, -1, 0);
   }
 
+#ifdef COMPILER1
+  if (t == NULL && nm->is_compiled_by_c1()) {
+    assert(nm->unwind_handler_begin() != NULL, "");
+    return nm->unwind_handler_begin();
+  }
+#endif
+
   if (t == NULL) {
     tty->print_cr("MISSING EXCEPTION HANDLER for pc " INTPTR_FORMAT " and handler bci %d", ret_pc, handler_bci);
     tty->print_cr("   Exception:");
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/services/g1MemoryPool.cpp
--- a/src/share/vm/services/g1MemoryPool.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/services/g1MemoryPool.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2007 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2007-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -45,7 +45,7 @@
 
 // See the comment at the top of g1MemoryPool.hpp
 size_t G1MemoryPoolSuper::eden_space_used(G1CollectedHeap* g1h) {
-  size_t young_list_length = g1h->young_list_length();
+  size_t young_list_length = g1h->young_list()->length();
   size_t eden_used = young_list_length * HeapRegion::GrainBytes;
   size_t survivor_used = survivor_space_used(g1h);
   eden_used = subtract_up_to_zero(eden_used, survivor_used);
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/utilities/vmError.cpp
--- a/src/share/vm/utilities/vmError.cpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/utilities/vmError.cpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2003-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2003-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -212,6 +212,51 @@
   return buf;
 }
 
+void VMError::print_stack_trace(outputStream* st, JavaThread* jt,
+                                char* buf, int buflen, bool verbose) {
+#ifdef ZERO
+  if (jt->zero_stack()->sp() && jt->top_zero_frame()) {
+    // StackFrameStream uses the frame anchor, which may not have
+    // been set up.  This can be done at any time in Zero, however,
+    // so if it hasn't been set up then we just set it up now and
+    // clear it again when we're done.
+    bool has_last_Java_frame = jt->has_last_Java_frame();
+    if (!has_last_Java_frame)
+      jt->set_last_Java_frame();
+    st->print("Java frames:");
+
+    // If the top frame is a Shark frame and the frame anchor isn't
+    // set up then it's possible that the information in the frame
+    // is garbage: it could be from a previous decache, or it could
+    // simply have never been written.  So we print a warning...
+    StackFrameStream sfs(jt);
+    if (!has_last_Java_frame && !sfs.is_done()) {
+      if (sfs.current()->zeroframe()->is_shark_frame()) {
+        st->print(" (TOP FRAME MAY BE JUNK)");
+      }
+    }
+    st->cr();
+
+    // Print the frames
+    for(int i = 0; !sfs.is_done(); sfs.next(), i++) {
+      sfs.current()->zero_print_on_error(i, st, buf, buflen);
+      st->cr();
+    }
+
+    // Reset the frame anchor if necessary
+    if (!has_last_Java_frame)
+      jt->reset_last_Java_frame();
+  }
+#else
+  if (jt->has_last_Java_frame()) {
+    st->print_cr("Java frames: (J=compiled Java code, j=interpreted, Vv=VM code)");
+    for(StackFrameStream sfs(jt); !sfs.is_done(); sfs.next()) {
+      sfs.current()->print_on_error(st, buf, buflen, verbose);
+      st->cr();
+    }
+  }
+#endif // ZERO
+}
 
 // This is the main function to report a fatal error. Only one thread can
 // call this function, so we don't need to worry about MT-safety. But it's
@@ -457,49 +502,7 @@
   STEP(130, "(printing Java stack)" )
 
      if (_verbose && _thread && _thread->is_Java_thread()) {
-       JavaThread* jt = (JavaThread*)_thread;
-#ifdef ZERO
-       if (jt->zero_stack()->sp() && jt->top_zero_frame()) {
-         // StackFrameStream uses the frame anchor, which may not have
-         // been set up.  This can be done at any time in Zero, however,
-         // so if it hasn't been set up then we just set it up now and
-         // clear it again when we're done.
-         bool has_last_Java_frame = jt->has_last_Java_frame();
-         if (!has_last_Java_frame)
-           jt->set_last_Java_frame();
-         st->print("Java frames:");
-
-         // If the top frame is a Shark frame and the frame anchor isn't
-         // set up then it's possible that the information in the frame
-         // is garbage: it could be from a previous decache, or it could
-         // simply have never been written.  So we print a warning...
-         StackFrameStream sfs(jt);
-         if (!has_last_Java_frame && !sfs.is_done()) {
-           if (sfs.current()->zeroframe()->is_shark_frame()) {
-             st->print(" (TOP FRAME MAY BE JUNK)");
-           }
-         }
-         st->cr();
-
-         // Print the frames
-         for(int i = 0; !sfs.is_done(); sfs.next(), i++) {
-           sfs.current()->zero_print_on_error(i, st, buf, sizeof(buf));
-           st->cr();
-         }
-
-         // Reset the frame anchor if necessary
-         if (!has_last_Java_frame)
-           jt->reset_last_Java_frame();
-       }
-#else
-       if (jt->has_last_Java_frame()) {
-         st->print_cr("Java frames: (J=compiled Java code, j=interpreted, Vv=VM code)");
-         for(StackFrameStream sfs(jt); !sfs.is_done(); sfs.next()) {
-           sfs.current()->print_on_error(st, buf, sizeof(buf));
-           st->cr();
-         }
-       }
-#endif // ZERO
+       print_stack_trace(st, (JavaThread*)_thread, buf, sizeof(buf));
      }
 
   STEP(135, "(printing target Java thread stack)" )
@@ -509,13 +512,7 @@
        JavaThread*  jt = ((NamedThread *)_thread)->processed_thread();
        if (jt != NULL) {
          st->print_cr("JavaThread " PTR_FORMAT " (nid = " UINTX_FORMAT ") was being processed", jt, jt->osthread()->thread_id());
-         if (jt->has_last_Java_frame()) {
-           st->print_cr("Java frames: (J=compiled Java code, j=interpreted, Vv=VM code)");
-           for(StackFrameStream sfs(jt); !sfs.is_done(); sfs.next()) {
-             sfs.current()->print_on_error(st, buf, sizeof(buf), true);
-             st->cr();
-           }
-         }
+         print_stack_trace(st, jt, buf, sizeof(buf), true);
        }
      }
 
diff -r e0a1a502e402 -r 7b03170e1fcb src/share/vm/utilities/vmError.hpp
--- a/src/share/vm/utilities/vmError.hpp	Thu Apr 22 16:54:23 2010 -0700
+++ b/src/share/vm/utilities/vmError.hpp	Thu Apr 29 15:18:27 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright 2003-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2003-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -70,6 +70,10 @@
   // generate an error report
   void report(outputStream* st);
 
+  // generate a stack trace
+  static void print_stack_trace(outputStream* st, JavaThread* jt,
+                                char* buf, int buflen, bool verbose = false);
+
   // accessor
   const char* message()         { return _message; }
 
diff -r e0a1a502e402 -r 7b03170e1fcb test/compiler/6431242/Test.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/compiler/6431242/Test.java	Thu Apr 29 15:18:27 2010 -0700
@@ -0,0 +1,176 @@
+/*
+ * Copyright 2006 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+/*
+ * @test
+ * @bug 6431242
+ * @run main/othervm -server -XX:+PrintCompilation Test
+ */
+
+public class Test{
+
+  int    _len      = 8;
+  int[]  _arr_i    = new int[_len];
+  long[] _arr_l    = new long[_len];
+
+  int[]  _arr_i_cp = new int [_len];
+  long[] _arr_l_cp = new long [_len];
+
+  int _k     = 0x12345678;
+  int _j     = 0;
+  int _ir    = 0x78563412;
+  int _ir1   = 0x78563413;
+  int _ir2   = 0x79563412;
+
+  long _m    = 0x123456789abcdef0L;
+  long _l    = 0L;
+  long _lr   = 0xf0debc9a78563412L;
+  long _lr1  = 0xf0debc9a78563413L;
+  long _lr2  = 0xf1debc9a78563412L;
+
+  void init() {
+    for (int i=0; i<_arr_i.length; i++) {
+      _arr_i[i] = _k;
+      _arr_l[i] = _m;
+    }
+  }
+
+  public int test_int_reversed(int i) {
+    return Integer.reverseBytes(i);
+  }
+
+  public long test_long_reversed(long i) {
+    return Long.reverseBytes(i);
+  }
+
+  public void test_copy_ints(int[] dst, int[] src) {
+    for(int i=0; i<src.length; i++) {
+      dst[i] = Integer.reverseBytes(src[i]);
+    }
+  }
+
+  public void test_copy_ints_reversed(int[] dst, int[] src) {
+    for (int i=0; i<src.length; i++) {
+      dst[i] = 1 + Integer.reverseBytes(src[i]);
+    }
+  }
+
+  public void test_copy_ints_store_reversed(int[] dst, int[] src) {
+    for(int i=0; i<src.length; i++) {
+      dst[i] = Integer.reverseBytes(1 + src[i]);
+    }
+  }
+
+  public void test_copy_longs(long[] dst, long[] src) {
+    for(int i=0; i<src.length; i++) {
+      dst[i] = Long.reverseBytes(src[i]);
+    }
+  }
+
+  public void test_copy_longs_reversed(long[] dst, long[] src) {
+    for (int i=0; i<src.length; i++) {
+      dst[i] = 1 + Long.reverseBytes(src[i]);
+    }
+  }
+
+  public void test_copy_longs_store_reversed(long[] dst, long[] src) {
+    for(int i=0; i<src.length; i++) {
+      dst[i] = Long.reverseBytes(1 + src[i]);
+    }
+  }
+
+  public void test() throws Exception {
+    int up_limit=90000;
+
+
+    //test single
+
+    for (int loop=0; loop<up_limit; loop++) {
+      _j = test_int_reversed(_k);
+      if (_j != _ir ) {
+        throw new Exception("Interger.reverseBytes failed " + _j + " iter " + loop);
+      }
+      _l = test_long_reversed(_m);
+      if (_l != _lr ) {
+        throw new Exception("Long.reverseBytes failed " + _l + " iter " + loop);
+      }
+    }
+
+    // test scalar load/store
+    for (int loop=0; loop<up_limit; loop++) {
+
+      test_copy_ints(_arr_i_cp, _arr_i);
+      for (int j=0; j< _arr_i.length; j++) {
+        if (_arr_i_cp[j] != _ir) {
+          throw new Exception("Interger.reverseBytes failed test_copy_ints iter " + loop);
+        }
+      }
+
+      test_copy_ints_reversed(_arr_i_cp, _arr_i);
+      for (int j=0; j< _arr_i.length; j++) {
+        if (_arr_i_cp[j] != _ir1) {
+          throw new Exception("Interger.reverseBytes failed test_copy_ints_reversed iter " + loop);
+        }
+      }
+      test_copy_ints_store_reversed(_arr_i_cp, _arr_i);
+      for (int j=0; j< _arr_i.length; j++) {
+        if (_arr_i_cp[j] != _ir2) {
+          throw new Exception("Interger.reverseBytes failed test_copy_ints_store_reversed iter " + loop);
+        }
+      }
+
+      test_copy_longs(_arr_l_cp, _arr_l);
+      for (int j=0; j< _arr_i.length; j++) {
+        if (_arr_l_cp[j] != _lr) {
+          throw new Exception("Long.reverseBytes failed test_copy_longs iter " + loop);
+        }
+      }
+      test_copy_longs_reversed(_arr_l_cp, _arr_l);
+      for (int j=0; j< _arr_i.length; j++) {
+        if (_arr_l_cp[j] != _lr1) {
+          throw new Exception("Long.reverseBytes failed test_copy_longs_reversed iter " + loop);
+        }
+      }
+      test_copy_longs_store_reversed(_arr_l_cp, _arr_l);
+      for (int j=0; j< _arr_i.length; j++) {
+        if (_arr_l_cp[j] != _lr2) {
+          throw new Exception("Long.reverseBytes failed test_copy_longs_store_reversed iter " + loop);
+        }
+      }
+
+    }
+  }
+
+  public static void main(String args[]) {
+    try {
+      Test t = new Test();
+      t.init();
+      t.test();
+      System.out.println("Passed");
+    }catch (Exception e) {
+      e.printStackTrace();
+      System.out.println("Failed");
+    }
+  }
+}
diff -r e0a1a502e402 -r 7b03170e1fcb test/compiler/6946040/TestCharShortByteSwap.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/compiler/6946040/TestCharShortByteSwap.java	Thu Apr 29 15:18:27 2010 -0700
@@ -0,0 +1,88 @@
+/*
+ * Copyright 2010 Google, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+/*
+ * @test
+ * @bug 6946040
+ * @summary Tests Character/Short.reverseBytes and their intrinsics implementation in the server compiler
+ * @run main/othervm -Xbatch -server -XX:CompileOnly=.testChar,.testShort TestCharShortByteSwap
+ */
+
+// This test must run without any command line arguments.
+
+public class TestCharShortByteSwap {
+
+  private static short initShort(String[] args, short v) {
+    if (args.length > 0) {
+      try {
+        return (short) Integer.valueOf(args[0]).intValue();
+      } catch (NumberFormatException e) { }
+    }
+    return v;
+  }
+
+  private static char initChar(String[] args, char v) {
+    if (args.length > 0) {
+      try {
+        return (char) Integer.valueOf(args[0]).intValue();
+      } catch (NumberFormatException e) { }
+    }
+    return v;
+  }
+
+  private static void testChar(char a, char b) {
+    if (a != Character.reverseBytes(b)) {
+      throw new RuntimeException("FAIL: " + (int)a + " != Character.reverseBytes(" + (int)b + ")");
+    }
+    if (b != Character.reverseBytes(a)) {
+      throw new RuntimeException("FAIL: " + (int)b + " != Character.reverseBytes(" + (int)a + ")");
+    }
+  }
+
+  private static void testShort(short a, short b) {
+    if (a != Short.reverseBytes(b)) {
+      throw new RuntimeException("FAIL: " + (int)a + " != Short.reverseBytes(" + (int)b + ")");
+    }
+    if (b != Short.reverseBytes(a)) {
+      throw new RuntimeException("FAIL: " + (int)b + " != Short.reverseBytes(" + (int)a + ")");
+    }
+  }
+
+  public static void main(String[] args) {
+    for (int i = 0; i < 100000; ++i) { // Trigger compilation
+      char c1 = initChar(args, (char) 0x0123);
+      char c2 = initChar(args, (char) 0x2301);
+      char c3 = initChar(args, (char) 0xaabb);
+      char c4 = initChar(args, (char) 0xbbaa);
+      short s1 = initShort(args, (short) 0x0123);
+      short s2 = initShort(args, (short) 0x2301);
+      short s3 = initShort(args, (short) 0xaabb);
+      short s4 = initShort(args, (short) 0xbbaa);
+      testChar(c1, c2);
+      testChar(c3, c4);
+      testShort(s1, s2);
+      testShort(s3, s4);
+    }
+  }
+}