--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/utilities/nativeCallStack.hpp	Wed Aug 27 08:19:12 2014 -0400
@@ -0,0 +1,95 @@
+/*
+ * Copyright (c) 2014, 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_UTILITIES_NATIVE_CALL_STACK_HPP
+#define SHARE_VM_UTILITIES_NATIVE_CALL_STACK_HPP
+
+#include "memory/allocation.hpp"
+#include "services/nmtCommon.hpp"
+#include "utilities/ostream.hpp"
+
+/*
+ * This class represents a native call path (does not include Java frame)
+ *
+ * This class is developed in the context of native memory tracking, it can
+ * be an useful tool for debugging purpose.
+ *
+ * For example, following code should print out native call path:
+ *
+ *   ....
+ *   NativeCallStack here;
+ *   here.print_on(tty);
+ *   ....
+ *
+ * However, there are a couple of restrictions on this class. If the restrictions are
+ * not strictly followed, it may break native memory tracking badly.
+ *
+ * 1. Number of stack frames to capture, is defined by native memory tracking.
+ *    This number has impacts on how much memory to be used by native
+ *    memory tracking.
+ * 2. The class is strict stack object, no heap or virtual memory can be allocated
+ *    from it.
+ */
+class NativeCallStack : public StackObj {
+ private:
+  address   _stack[NMT_TrackingStackDepth];
+  int       _hash_value;
+
+ public:
+  NativeCallStack(int toSkip = 0, bool fillStack = false);
+  NativeCallStack(address* pc, int frameCount);
+
+
+  // if it is an empty stack
+  inline bool is_empty() const {
+    return _stack[0] == NULL;
+  }
+
+  // number of stack frames captured
+  int frames() const;
+
+  inline int compare(const NativeCallStack& other) const {
+    return memcmp(_stack, other._stack, sizeof(_stack));
+  }
+
+  inline bool equals(const NativeCallStack& other) const {
+    // compare hash values
+    if (hash() != other.hash()) return false;
+    // compare each frame
+    return compare(other) == 0;
+  }
+
+  inline address get_frame(int index) const {
+    assert(index >= 0 && index < NMT_TrackingStackDepth, "Index out of bound");
+    return _stack[index];
+  }
+
+  // Hash code. Any better algorithm?
+  int hash() const;
+
+  void print_on(outputStream* out) const;
+  void print_on(outputStream* out, int indent) const;
+};
+
+#endif