diff -r 000000000000 -r a61af66fc99e src/share/vm/services/memoryUsage.hpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/services/memoryUsage.hpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,77 @@
+/*
+ * Copyright 2003-2005 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.
+ *
+ */
+
+// A memory usage contains the following attributes about memory usage:
+//  initSize - represents the initial amount of memory (in bytes) that
+//     the Java virtual machine requests from the operating system
+//     for memory management.  The Java virtual machine may request
+//     additional memory from the operating system later when appropriate.
+//     Its value may be undefined.
+//  used      - represents the amount of memory currently used (in bytes).
+//  committed - represents the amount of memory (in bytes) that is
+//     guaranteed to be available for use by the Java virtual machine.
+//     The amount of committed memory may change over time (increase
+//     or decrease).  It is guaranteed to be greater than or equal
+//     to initSize.
+//  maxSize   - represents the maximum amount of memory (in bytes)
+//     that can be used for memory management. The maximum amount of
+//     memory for memory management could be less than the amount of
+//     committed memory.  Its value may be undefined.
+
+class MemoryUsage VALUE_OBJ_CLASS_SPEC {
+private:
+  size_t _initSize;
+  size_t _used;
+  size_t _committed;
+  size_t _maxSize;
+
+public:
+  // Constructors
+  MemoryUsage(size_t i, size_t u, size_t c, size_t m) :
+    _initSize(i), _used(u), _committed(c), _maxSize(m) {};
+  MemoryUsage() :
+    _initSize(0), _used(0), _committed(0), _maxSize(0) {};
+
+  size_t init_size() const { return _initSize; }
+  size_t used()      const { return _used; }
+  size_t committed() const { return _committed; }
+  size_t max_size()  const { return _maxSize; }
+
+  inline static jlong convert_to_jlong(size_t val) {
+    // In the 64-bit vm, a size_t can overflow a jlong (which is signed).
+    jlong ret;
+    if (val == (size_t)-1) {
+      ret = -1L;
+    } else {
+      NOT_LP64(ret = val;)
+      LP64_ONLY(ret = MIN2(val, (size_t)max_jlong);)
+    }
+    return ret;
+  }
+
+  jlong init_size_as_jlong() const { return convert_to_jlong(_initSize); }
+  jlong used_as_jlong()      const { return convert_to_jlong(_used); }
+  jlong committed_as_jlong() const { return convert_to_jlong(_committed); }
+  jlong max_size_as_jlong()  const { return convert_to_jlong(_maxSize); }
+};