--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/agent/src/share/classes/sun/jvm/hotspot/runtime/PerfMemory.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,109 @@
+/*
+ * Copyright 2004 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.
+ *
+ */
+
+package sun.jvm.hotspot.runtime;
+
+import java.util.*;
+import sun.jvm.hotspot.debugger.*;
+import sun.jvm.hotspot.oops.*;
+import sun.jvm.hotspot.types.*;
+
+public class PerfMemory {
+    private static AddressField  startField;
+    private static AddressField  endField;
+    private static AddressField  topField;
+    private static CIntegerField capacityField;
+    private static AddressField  prologueField;
+    private static JIntField     initializedField;
+
+    static {
+        VM.registerVMInitializedObserver(new Observer() {
+                public void update(Observable o, Object data) {
+                    initialize(VM.getVM().getTypeDataBase());
+                }
+            });
+    }
+
+    private static synchronized void initialize(TypeDataBase db) {
+        Type type = db.lookupType("PerfMemory");
+        startField = type.getAddressField("_start");
+        endField = type.getAddressField("_end");
+        topField = type.getAddressField("_top");
+        capacityField = type.getCIntegerField("_capacity");
+        prologueField = type.getAddressField("_prologue");
+        initializedField = type.getJIntField("_initialized");
+    }
+
+    // Accessors
+    public static Address start() {
+        return startField.getValue();
+    }
+
+    public static Address end() {
+        return endField.getValue();
+    }
+
+    public static Address top() {
+        return topField.getValue();
+    }
+
+    public static long capacity() {
+        return capacityField.getValue();
+    }
+
+    public static boolean initialized() {
+        return ((int) initializedField.getValue()) != 0;
+    }
+
+    public static PerfDataPrologue prologue() {
+        return (PerfDataPrologue) VMObjectFactory.newObject(
+                   PerfDataPrologue.class, prologueField.getValue());
+    }
+
+    public static boolean contains(Address addr) {
+        return start() != null &&
+            addr.minus(start()) >= 0 &&
+            end().minus(addr) > 0;
+    }
+
+    // an interface supplied to iterate PerfDataEntries
+    public static interface PerfDataEntryVisitor {
+        // returns false to stop the iteration
+        public boolean visit(PerfDataEntry pde);
+    }
+
+    public static void iterate(PerfDataEntryVisitor visitor) {
+        PerfDataPrologue header = prologue();
+        int off = header.entryOffset();
+        int num = header.numEntries();
+        Address addr = header.getAddress();
+
+        for (int i = 0; i < num; i++) {
+            PerfDataEntry pde = (PerfDataEntry) VMObjectFactory.newObject(
+                               PerfDataEntry.class, addr.addOffsetTo(off));
+            off += pde.entryLength();
+            if (visitor.visit(pde) == false) return;
+        }
+    }
+}