--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/agent/src/share/classes/sun/jvm/hotspot/memory/HeapBlock.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,96 @@
+/*
+ * Copyright 2000-2005 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.memory;
+
+import java.util.*;
+import sun.jvm.hotspot.debugger.*;
+import sun.jvm.hotspot.runtime.*;
+import sun.jvm.hotspot.types.*;
+
+public class HeapBlock extends VMObject {
+  private static long          heapBlockSize;
+  private static Field         headerField;
+  // Fields for class Header
+  private static CIntegerField headerLengthField;
+  private static CIntegerField headerUsedField;
+
+  static {
+    VM.registerVMInitializedObserver(new Observer() {
+        public void update(Observable o, Object data) {
+          initialize(VM.getVM().getTypeDataBase());
+        }
+      });
+  }
+
+  private static void initialize(TypeDataBase db) {
+    // HeapBlock
+    Type type = db.lookupType("HeapBlock");
+    heapBlockSize     = type.getSize();
+    headerField       = type.getField("_header");
+
+    // Header
+    type = db.lookupType("HeapBlock::Header");
+    headerLengthField = type.getCIntegerField("_length");
+    headerUsedField   = type.getCIntegerField("_used");
+  }
+
+  public HeapBlock(Address addr) {
+    super(addr);
+  }
+
+  public long getLength() {
+    return getHeader().getLength();
+  }
+
+  public boolean isFree() {
+    return getHeader().isFree();
+  }
+
+  public Address getAllocatedSpace() {
+    return addr.addOffsetTo(heapBlockSize);
+  }
+
+  //--------------------------------------------------------------------------------
+  // Internals only below this point
+  //
+
+  public static class Header extends VMObject {
+    public Header(Address addr) {
+      super(addr);
+    }
+
+    public long getLength() {
+      return headerLengthField.getValue(addr);
+    }
+
+    public boolean isFree() {
+      return (headerUsedField.getValue(addr) == 0);
+    }
+  }
+
+  private Header getHeader() {
+    return (Header) VMObjectFactory.newObject(HeapBlock.Header.class, addr.addOffsetTo(headerField.getOffset()));
+  }
+}