1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/memory/referencePolicy.cpp Wed Apr 27 01:25:04 2016 +0800
1.3 @@ -0,0 +1,86 @@
1.4 +/*
1.5 + * Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 + * or visit www.oracle.com if you need additional information or have any
1.24 + * questions.
1.25 + *
1.26 + */
1.27 +
1.28 +#include "precompiled.hpp"
1.29 +#include "classfile/javaClasses.hpp"
1.30 +#include "memory/referencePolicy.hpp"
1.31 +#include "memory/universe.hpp"
1.32 +#include "runtime/arguments.hpp"
1.33 +#include "runtime/globals.hpp"
1.34 +
1.35 +LRUCurrentHeapPolicy::LRUCurrentHeapPolicy() {
1.36 + setup();
1.37 +}
1.38 +
1.39 +// Capture state (of-the-VM) information needed to evaluate the policy
1.40 +void LRUCurrentHeapPolicy::setup() {
1.41 + _max_interval = (Universe::get_heap_free_at_last_gc() / M) * SoftRefLRUPolicyMSPerMB;
1.42 + assert(_max_interval >= 0,"Sanity check");
1.43 +}
1.44 +
1.45 +// The oop passed in is the SoftReference object, and not
1.46 +// the object the SoftReference points to.
1.47 +bool LRUCurrentHeapPolicy::should_clear_reference(oop p,
1.48 + jlong timestamp_clock) {
1.49 + jlong interval = timestamp_clock - java_lang_ref_SoftReference::timestamp(p);
1.50 + assert(interval >= 0, "Sanity check");
1.51 +
1.52 + // The interval will be zero if the ref was accessed since the last scavenge/gc.
1.53 + if(interval <= _max_interval) {
1.54 + return false;
1.55 + }
1.56 +
1.57 + return true;
1.58 +}
1.59 +
1.60 +/////////////////////// MaxHeap //////////////////////
1.61 +
1.62 +LRUMaxHeapPolicy::LRUMaxHeapPolicy() {
1.63 + setup();
1.64 +}
1.65 +
1.66 +// Capture state (of-the-VM) information needed to evaluate the policy
1.67 +void LRUMaxHeapPolicy::setup() {
1.68 + size_t max_heap = MaxHeapSize;
1.69 + max_heap -= Universe::get_heap_used_at_last_gc();
1.70 + max_heap /= M;
1.71 +
1.72 + _max_interval = max_heap * SoftRefLRUPolicyMSPerMB;
1.73 + assert(_max_interval >= 0,"Sanity check");
1.74 +}
1.75 +
1.76 +// The oop passed in is the SoftReference object, and not
1.77 +// the object the SoftReference points to.
1.78 +bool LRUMaxHeapPolicy::should_clear_reference(oop p,
1.79 + jlong timestamp_clock) {
1.80 + jlong interval = timestamp_clock - java_lang_ref_SoftReference::timestamp(p);
1.81 + assert(interval >= 0, "Sanity check");
1.82 +
1.83 + // The interval will be zero if the ref was accessed since the last scavenge/gc.
1.84 + if(interval <= _max_interval) {
1.85 + return false;
1.86 + }
1.87 +
1.88 + return true;
1.89 +}
