diff agent/src/share/classes/sun/jvm/hotspot/memory/FreeChunk.java @ 187:790e66e5fbac

6687581: Make CMS work with compressed oops Summary: Make FreeChunk read markword instead of LSB in _klass pointer to indicate that it's a FreeChunk for compressed oops. Reviewed-by: ysr, jmasa
author coleenp
date Mon, 09 Jun 2008 11:51:19 -0400
parents a61af66fc99e
children d1605aabd0a1
line wrap: on
line diff
--- a/agent/src/share/classes/sun/jvm/hotspot/memory/FreeChunk.java	Fri Jun 06 11:47:26 2008 -0700
+++ b/agent/src/share/classes/sun/jvm/hotspot/memory/FreeChunk.java	Mon Jun 09 11:51:19 2008 -0400
@@ -28,6 +28,7 @@
 import sun.jvm.hotspot.debugger.*;
 import sun.jvm.hotspot.types.*;
 import sun.jvm.hotspot.runtime.*;
+import sun.jvm.hotspot.oops.*;
 
 public class FreeChunk extends VMObject {
    static {
@@ -42,13 +43,13 @@
       Type type = db.lookupType("FreeChunk");
       nextField = type.getAddressField("_next");
       prevField = type.getAddressField("_prev");
-      sizeField = type.getCIntegerField("_size");
+      sizeField = type.getAddressField("_size");
    }
 
    // Fields
    private static AddressField nextField;
    private static AddressField prevField;
-   private static CIntegerField sizeField;
+   private static AddressField sizeField;
 
    // Accessors
    public FreeChunk next() {
@@ -61,20 +62,34 @@
    }
 
    public long size() {
-      return sizeField.getValue(addr);
+      if (VM.getVM().isCompressedOopsEnabled()) {
+        Mark mark = new Mark(sizeField.getValue(addr));
+        return mark.getSize();
+      } else {
+        Address size = sizeField.getValue(addr);
+        Debugger dbg = VM.getVM().getDebugger();
+        return dbg.getAddressValue(size);
+      }
    }
 
    public FreeChunk(Address addr) {
       super(addr);
    }
 
-   public static boolean secondWordIndicatesFreeChunk(long word) {
-      return (word & 0x1L) == 0x1L;
+   public static boolean indicatesFreeChunk(Address cur) {
+      FreeChunk f = new FreeChunk(cur);
+      return f.isFree();
    }
 
    public boolean isFree() {
-      Debugger dbg = VM.getVM().getDebugger();
-      Address prev = prevField.getValue(addr);
-      return secondWordIndicatesFreeChunk(dbg.getAddressValue(prev));
+      if (VM.getVM().isCompressedOopsEnabled()) {
+        Mark mark = new Mark(sizeField.getValue(addr));
+        return mark.isCmsFreeChunk();
+      } else {
+        Address prev = prevField.getValue(addr);
+        Debugger dbg = VM.getVM().getDebugger();
+        long word = dbg.getAddressValue(prev);
+        return (word & 0x1L) == 0x1L;
+      }
    }
 }