diff -r 74533f63b116 -r d2a62e0f25eb src/share/vm/services/memPtrArray.hpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/services/memPtrArray.hpp	Thu Jun 28 17:03:16 2012 -0400
@@ -0,0 +1,310 @@
+/*
+ * 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_UTILITIES_MEM_PTR_ARRAY_HPP
+#define SHARE_VM_UTILITIES_MEM_PTR_ARRAY_HPP
+
+#include "memory/allocation.hpp"
+#include "services/memPtr.hpp"
+
+class MemPtr;
+class MemRecorder;
+class ArenaInfo;
+class MemSnapshot;
+
+extern "C" {
+  typedef int (*FN_SORT)(const void *, const void *);
+}
+
+
+// Memory pointer array interface. This array is used by NMT to hold
+// various memory block information.
+// The memory pointer arrays are usually walked with their iterators.
+
+class MemPointerArray : public CHeapObj<mtNMT> {
+ public:
+  virtual ~MemPointerArray() { }
+
+  // return true if it can not allocate storage for the data
+  virtual bool out_of_memory() const = 0;
+  virtual bool is_empty() const = 0;
+  virtual bool is_full() = 0;
+  virtual int  length() const = 0;
+  virtual void clear() = 0;
+  virtual bool append(MemPointer* ptr) = 0;
+  virtual bool insert_at(MemPointer* ptr, int pos) = 0;
+  virtual bool remove_at(int pos) = 0;
+  virtual MemPointer* at(int index) const = 0;
+  virtual void sort(FN_SORT fn) = 0;
+  virtual size_t instance_size() const = 0;
+  virtual bool shrink() = 0;
+
+  debug_only(virtual int capacity() const = 0;)
+};
+
+// Iterator interface
+class MemPointerArrayIterator VALUE_OBJ_CLASS_SPEC {
+ public:
+  // return the pointer at current position
+  virtual MemPointer* current() const = 0;
+  // return the next pointer and advance current position
+  virtual MemPointer* next() = 0;
+  // return next pointer without advancing current position
+  virtual MemPointer* peek_next() const = 0;
+  // return previous pointer without changing current position
+  virtual MemPointer* peek_prev() const = 0;
+  // remove the pointer at current position
+  virtual void        remove() = 0;
+  // insert the pointer at current position
+  virtual bool        insert(MemPointer* ptr) = 0;
+  // insert specified element after current position and
+  // move current position to newly inserted position
+  virtual bool        insert_after(MemPointer* ptr) = 0;
+};
+
+// implementation class
+class MemPointerArrayIteratorImpl : public MemPointerArrayIterator {
+#ifdef ASSERT
+ protected:
+#else
+ private:
+#endif
+  MemPointerArray*  _array;
+  int               _pos;
+
+ public:
+  MemPointerArrayIteratorImpl(MemPointerArray* arr) {
+    assert(arr != NULL, "Parameter check");
+    _array = arr;
+    _pos = 0;
+  }
+
+  virtual MemPointer* current() const {
+    if (_pos < _array->length()) {
+      return _array->at(_pos);
+    }
+    return NULL;
+  }
+
+  virtual MemPointer* next() {
+    if (_pos + 1 < _array->length()) {
+      return _array->at(++_pos);
+    }
+    _pos = _array->length();
+    return NULL;
+  }
+
+  virtual MemPointer* peek_next() const {
+    if (_pos + 1 < _array->length()) {
+      return _array->at(_pos + 1);
+    }
+    return NULL;
+  }
+
+  virtual MemPointer* peek_prev() const {
+    if (_pos > 0) {
+      return _array->at(_pos - 1);
+    }
+    return NULL;
+  }
+
+  virtual void remove() {
+    if (_pos < _array->length()) {
+      _array->remove_at(_pos);
+    }
+  }
+
+  virtual bool insert(MemPointer* ptr) {
+    return _array->insert_at(ptr, _pos);
+  }
+
+  virtual bool insert_after(MemPointer* ptr) {
+    if (_array->insert_at(ptr, _pos + 1)) {
+      _pos ++;
+      return true;
+    }
+    return false;
+  }
+};
+
+
+
+// Memory pointer array implementation.
+// This implementation implements expandable array
+#define DEFAULT_PTR_ARRAY_SIZE 1024
+
+template <class E> class MemPointerArrayImpl : public MemPointerArray {
+ private:
+  int                   _max_size;
+  int                   _size;
+  bool                  _init_elements;
+  E*                    _data;
+
+ public:
+  MemPointerArrayImpl(int initial_size = DEFAULT_PTR_ARRAY_SIZE, bool init_elements = true):
+   _max_size(initial_size), _size(0), _init_elements(init_elements) {
+    _data = (E*)raw_allocate(sizeof(E), initial_size);
+    if (_init_elements) {
+      for (int index = 0; index < _max_size; index ++) {
+        ::new ((void*)&_data[index]) E();
+      }
+    }
+  }
+
+  virtual ~MemPointerArrayImpl() {
+    if (_data != NULL) {
+      raw_free(_data);
+    }
+  }
+
+ public:
+  bool out_of_memory() const {
+    return (_data == NULL);
+  }
+
+  size_t instance_size() const {
+    return sizeof(MemPointerArrayImpl<E>) + _max_size * sizeof(E);
+  }
+
+  bool is_empty() const {
+    assert(_data != NULL, "Just check");
+    return _size == 0;
+  }
+
+  bool is_full() {
+    assert(_data != NULL, "Just check");
+    if (_size < _max_size) {
+      return false;
+    } else {
+      return !expand_array();
+    }
+  }
+
+  int length() const {
+    assert(_data != NULL, "Just check");
+    return _size;
+  }
+
+  debug_only(int capacity() const { return _max_size; })
+
+  void clear() {
+    assert(_data != NULL, "Just check");
+    _size = 0;
+  }
+
+  bool append(MemPointer* ptr) {
+    assert(_data != NULL, "Just check");
+    if (is_full()) {
+      return false;
+    }
+    _data[_size ++] = *(E*)ptr;
+    return true;
+  }
+
+  bool insert_at(MemPointer* ptr, int pos) {
+    assert(_data != NULL, "Just check");
+    if (is_full()) {
+      return false;
+    }
+    for (int index = _size; index > pos; index --) {
+      _data[index] = _data[index - 1];
+    }
+    _data[pos] = *(E*)ptr;
+    _size ++;
+    return true;
+  }
+
+  bool remove_at(int pos) {
+    assert(_data != NULL, "Just check");
+    if (_size <= pos && pos >= 0) {
+      return false;
+    }
+    -- _size;
+
+    for (int index = pos; index < _size; index ++) {
+      _data[index] = _data[index + 1];
+    }
+    return true;
+  }
+
+  MemPointer* at(int index) const {
+    assert(_data != NULL, "Just check");
+    assert(index >= 0 && index < _size, "illegal index");
+    return &_data[index];
+  }
+
+  bool shrink() {
+    float used = ((float)_size) / ((float)_max_size);
+    if (used < 0.40) {
+      E* old_ptr = _data;
+      int new_size = ((_max_size) / (2 * DEFAULT_PTR_ARRAY_SIZE) + 1) * DEFAULT_PTR_ARRAY_SIZE;
+      _data = (E*)raw_reallocate(_data, sizeof(E), new_size);
+      if (_data == NULL) {
+        _data = old_ptr;
+        return false;
+      } else {
+        _max_size = new_size;
+        return true;
+      }
+    }
+    return false;
+  }
+
+  void sort(FN_SORT fn) {
+    assert(_data != NULL, "Just check");
+    qsort((void*)_data, _size, sizeof(E), fn);
+  }
+
+ private:
+  bool  expand_array() {
+    assert(_data != NULL, "Not yet allocated");
+    E* old_ptr = _data;
+    if ((_data = (E*)raw_reallocate((void*)_data, sizeof(E),
+      _max_size + DEFAULT_PTR_ARRAY_SIZE)) == NULL) {
+      _data = old_ptr;
+      return false;
+    } else {
+      _max_size += DEFAULT_PTR_ARRAY_SIZE;
+      if (_init_elements) {
+        for (int index = _size; index < _max_size; index ++) {
+          ::new ((void*)&_data[index]) E();
+        }
+      }
+      return true;
+    }
+  }
+
+  void* raw_allocate(size_t elementSize, int items) {
+    return os::malloc(elementSize * items, mtNMT);
+  }
+
+  void* raw_reallocate(void* ptr, size_t elementSize, int items) {
+    return os::realloc(ptr, elementSize * items, mtNMT);
+  }
+
+  void  raw_free(void* ptr) {
+    os::free(ptr, mtNMT);
+  }
+};
+
+#endif // SHARE_VM_UTILITIES_MEM_PTR_ARRAY_HPP