hotspot/src/share/vm/memory/referencePolicy.cpp
changeset 1 489c9b5090e2
child 1606 dcf9714addbe
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/memory/referencePolicy.cpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,70 @@
+/*
+ * Copyright 2000-2003 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.
+ *
+ */
+
+# include "incls/_precompiled.incl"
+# include "incls/_referencePolicy.cpp.incl"
+
+LRUCurrentHeapPolicy::LRUCurrentHeapPolicy() {
+  _max_interval = (Universe::get_heap_free_at_last_gc() / M) * SoftRefLRUPolicyMSPerMB;
+  assert(_max_interval >= 0,"Sanity check");
+}
+
+// The oop passed in is the SoftReference object, and not
+// the object the SoftReference points to.
+bool LRUCurrentHeapPolicy::should_clear_reference(oop p) {
+  jlong interval = java_lang_ref_SoftReference::clock() - java_lang_ref_SoftReference::timestamp(p);
+  assert(interval >= 0, "Sanity check");
+
+  // The interval will be zero if the ref was accessed since the last scavenge/gc.
+  if(interval <= _max_interval) {
+    return false;
+  }
+
+  return true;
+}
+
+/////////////////////// MaxHeap //////////////////////
+
+LRUMaxHeapPolicy::LRUMaxHeapPolicy() {
+  size_t max_heap = MaxHeapSize;
+  max_heap -= Universe::get_heap_used_at_last_gc();
+  max_heap /= M;
+
+  _max_interval = max_heap * SoftRefLRUPolicyMSPerMB;
+  assert(_max_interval >= 0,"Sanity check");
+}
+
+// The oop passed in is the SoftReference object, and not
+// the object the SoftReference points to.
+bool LRUMaxHeapPolicy::should_clear_reference(oop p) {
+  jlong interval = java_lang_ref_SoftReference::clock() - java_lang_ref_SoftReference::timestamp(p);
+  assert(interval >= 0, "Sanity check");
+
+  // The interval will be zero if the ref was accessed since the last scavenge/gc.
+  if(interval <= _max_interval) {
+    return false;
+  }
+
+  return true;
+}