aoqi@0: /*
aoqi@0:  * Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
aoqi@0:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0:  *
aoqi@0:  * This code is free software; you can redistribute it and/or modify it
aoqi@0:  * under the terms of the GNU General Public License version 2 only, as
aoqi@0:  * published by the Free Software Foundation.
aoqi@0:  *
aoqi@0:  * This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
aoqi@0:  * version 2 for more details (a copy is included in the LICENSE file that
aoqi@0:  * accompanied this code).
aoqi@0:  *
aoqi@0:  * You should have received a copy of the GNU General Public License version
aoqi@0:  * 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0:  *
aoqi@0:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0:  * or visit www.oracle.com if you need additional information or have any
aoqi@0:  * questions.
aoqi@0:  *
aoqi@0:  */
aoqi@0: 
aoqi@0: #include "precompiled.hpp"
aoqi@0: #include "classfile/javaClasses.hpp"
aoqi@0: #include "memory/referencePolicy.hpp"
aoqi@0: #include "memory/universe.hpp"
aoqi@0: #include "runtime/arguments.hpp"
aoqi@0: #include "runtime/globals.hpp"
aoqi@0: 
aoqi@0: LRUCurrentHeapPolicy::LRUCurrentHeapPolicy() {
aoqi@0:   setup();
aoqi@0: }
aoqi@0: 
aoqi@0: // Capture state (of-the-VM) information needed to evaluate the policy
aoqi@0: void LRUCurrentHeapPolicy::setup() {
aoqi@0:   _max_interval = (Universe::get_heap_free_at_last_gc() / M) * SoftRefLRUPolicyMSPerMB;
aoqi@0:   assert(_max_interval >= 0,"Sanity check");
aoqi@0: }
aoqi@0: 
aoqi@0: // The oop passed in is the SoftReference object, and not
aoqi@0: // the object the SoftReference points to.
aoqi@0: bool LRUCurrentHeapPolicy::should_clear_reference(oop p,
aoqi@0:                                                   jlong timestamp_clock) {
aoqi@0:   jlong interval = timestamp_clock - java_lang_ref_SoftReference::timestamp(p);
aoqi@0:   assert(interval >= 0, "Sanity check");
aoqi@0: 
aoqi@0:   // The interval will be zero if the ref was accessed since the last scavenge/gc.
aoqi@0:   if(interval <= _max_interval) {
aoqi@0:     return false;
aoqi@0:   }
aoqi@0: 
aoqi@0:   return true;
aoqi@0: }
aoqi@0: 
aoqi@0: /////////////////////// MaxHeap //////////////////////
aoqi@0: 
aoqi@0: LRUMaxHeapPolicy::LRUMaxHeapPolicy() {
aoqi@0:   setup();
aoqi@0: }
aoqi@0: 
aoqi@0: // Capture state (of-the-VM) information needed to evaluate the policy
aoqi@0: void LRUMaxHeapPolicy::setup() {
aoqi@0:   size_t max_heap = MaxHeapSize;
aoqi@0:   max_heap -= Universe::get_heap_used_at_last_gc();
aoqi@0:   max_heap /= M;
aoqi@0: 
aoqi@0:   _max_interval = max_heap * SoftRefLRUPolicyMSPerMB;
aoqi@0:   assert(_max_interval >= 0,"Sanity check");
aoqi@0: }
aoqi@0: 
aoqi@0: // The oop passed in is the SoftReference object, and not
aoqi@0: // the object the SoftReference points to.
aoqi@0: bool LRUMaxHeapPolicy::should_clear_reference(oop p,
aoqi@0:                                              jlong timestamp_clock) {
aoqi@0:   jlong interval = timestamp_clock - java_lang_ref_SoftReference::timestamp(p);
aoqi@0:   assert(interval >= 0, "Sanity check");
aoqi@0: 
aoqi@0:   // The interval will be zero if the ref was accessed since the last scavenge/gc.
aoqi@0:   if(interval <= _max_interval) {
aoqi@0:     return false;
aoqi@0:   }
aoqi@0: 
aoqi@0:   return true;
aoqi@0: }