--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/agent/src/share/classes/sun/jvm/hotspot/runtime/JNIHandles.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,80 @@
+/*
+ * Copyright 2000 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.types.*;
+
+public class JNIHandles {
+  private static AddressField      globalHandlesField;
+  private static AddressField      weakGlobalHandlesField;
+  private static OopField          deletedHandleField;
+
+  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("JNIHandles");
+
+    globalHandlesField = type.getAddressField("_global_handles");
+    weakGlobalHandlesField = type.getAddressField("_weak_global_handles");
+    deletedHandleField = type.getOopField("_deleted_handle");
+
+  }
+
+  public JNIHandles() {
+  }
+
+  public JNIHandleBlock globalHandles() {
+    Address handleAddr  = globalHandlesField.getValue();
+    if (handleAddr == null) {
+      return null;
+    }
+    return new JNIHandleBlock(handleAddr);
+  }
+
+  public JNIHandleBlock weakGlobalHandles() {
+    Address handleAddr  = weakGlobalHandlesField.getValue();
+    if (handleAddr == null) {
+      return null;
+    }
+    return new JNIHandleBlock(handleAddr);
+  }
+
+  public OopHandle deletedHandle() {
+    return deletedHandleField.getValue();
+  }
+
+  public boolean isDeletedHandle(OopHandle handle) {
+    return (handle != null && handle.equals(deletedHandle()));
+  }
+
+}