--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/services/memTrackWorker.hpp	Thu Jun 28 17:03:16 2012 -0400
@@ -0,0 +1,74 @@
+/*
+ * Copyright (c) 2012, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_SERVICES_MEM_TRACK_WORKER_HPP
+#define SHARE_VM_SERVICES_MEM_TRACK_WORKER_HPP
+
+#include "memory/allocation.hpp"
+#include "runtime/thread.hpp"
+#include "services/memRecorder.hpp"
+
+// Maximum MAX_GENERATIONS generation data can be tracked.
+#define MAX_GENERATIONS  512
+
+
+class MemTrackWorker : public NamedThread {
+ private:
+  // circular buffer. This buffer contains recorders to be merged into global
+  // snaphsot.
+  // Each slot holds a linked list of memory recorders, that contains one
+  // generation of memory data.
+  MemRecorder*  _gen[MAX_GENERATIONS];
+  int           _head, _tail; // head and tail pointers to above circular buffer
+
+  bool          _has_error;
+
+ public:
+  MemTrackWorker();
+  ~MemTrackWorker();
+  _NOINLINE_ void* operator new(size_t size);
+  _NOINLINE_ void* operator new(size_t size, const std::nothrow_t& nothrow_constant);
+
+  void start();
+  void run();
+
+  inline bool has_error() const { return _has_error; }
+
+  // task at synchronization point
+  void at_sync_point(MemRecorder* pending_recorders);
+
+  // for debugging purpose, they are not thread safe.
+  NOT_PRODUCT(static int count_recorder(const MemRecorder* head);)
+  NOT_PRODUCT(int count_pending_recorders() const;)
+
+  NOT_PRODUCT(int _sync_point_count;)
+  NOT_PRODUCT(int _merge_count;)
+  NOT_PRODUCT(int _last_gen_in_use;)
+
+  inline int generations_in_use() const {
+    return (_tail <= _head ? (_head - _tail + 1) : (MAX_GENERATIONS - (_tail - _head) + 1));
+  }
+};
+
+#endif // SHARE_VM_SERVICES_MEM_TRACK_WORKER_HPP