--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/memory/referencePolicy.hpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,62 @@
+/*
+ * 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.
+ *
+ */
+
+// referencePolicy is used to determine when soft reference objects
+// should be cleared.
+
+
+class ReferencePolicy : public ResourceObj {
+ public:
+  virtual bool should_clear_reference(oop p)       { ShouldNotReachHere(); return true; }
+};
+
+class NeverClearPolicy : public ReferencePolicy {
+ public:
+  bool should_clear_reference(oop p) { return false; }
+};
+
+class AlwaysClearPolicy : public ReferencePolicy {
+ public:
+  bool should_clear_reference(oop p) { return true; }
+};
+
+class LRUCurrentHeapPolicy : public ReferencePolicy {
+ private:
+  jlong _max_interval;
+
+ public:
+  LRUCurrentHeapPolicy();
+
+  bool should_clear_reference(oop p);
+};
+
+class LRUMaxHeapPolicy : public ReferencePolicy {
+ private:
+  jlong _max_interval;
+
+ public:
+  LRUMaxHeapPolicy();
+
+  bool should_clear_reference(oop p);
+};