src/share/vm/memory/referencePolicy.cpp

Tue, 16 Feb 2016 21:42:29 +0000

author
poonam
date
Tue, 16 Feb 2016 21:42:29 +0000
changeset 8308
6acf14e730dd
parent 3188
d1bdeef3e3e2
child 6876
710a3c8b516e
permissions
-rw-r--r--

8072725: Provide more granular levels for GC verification
Summary: Add option VerifySubSet to selectively verify the memory sub-systems
Reviewed-by: kevinw, jmasa

duke@435 1 /*
johnc@3188 2 * Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
duke@435 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435 4 *
duke@435 5 * This code is free software; you can redistribute it and/or modify it
duke@435 6 * under the terms of the GNU General Public License version 2 only, as
duke@435 7 * published by the Free Software Foundation.
duke@435 8 *
duke@435 9 * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435 12 * version 2 for more details (a copy is included in the LICENSE file that
duke@435 13 * accompanied this code).
duke@435 14 *
duke@435 15 * You should have received a copy of the GNU General Public License version
duke@435 16 * 2 along with this work; if not, write to the Free Software Foundation,
duke@435 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435 18 *
trims@1907 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907 20 * or visit www.oracle.com if you need additional information or have any
trims@1907 21 * questions.
duke@435 22 *
duke@435 23 */
duke@435 24
stefank@2314 25 #include "precompiled.hpp"
stefank@2314 26 #include "classfile/javaClasses.hpp"
stefank@2314 27 #include "memory/referencePolicy.hpp"
stefank@2314 28 #include "memory/universe.hpp"
stefank@2314 29 #include "runtime/arguments.hpp"
stefank@2314 30 #include "runtime/globals.hpp"
duke@435 31
duke@435 32 LRUCurrentHeapPolicy::LRUCurrentHeapPolicy() {
ysr@892 33 setup();
ysr@888 34 }
ysr@888 35
ysr@888 36 // Capture state (of-the-VM) information needed to evaluate the policy
ysr@892 37 void LRUCurrentHeapPolicy::setup() {
duke@435 38 _max_interval = (Universe::get_heap_free_at_last_gc() / M) * SoftRefLRUPolicyMSPerMB;
duke@435 39 assert(_max_interval >= 0,"Sanity check");
duke@435 40 }
duke@435 41
duke@435 42 // The oop passed in is the SoftReference object, and not
duke@435 43 // the object the SoftReference points to.
johnc@3188 44 bool LRUCurrentHeapPolicy::should_clear_reference(oop p,
johnc@3188 45 jlong timestamp_clock) {
johnc@3188 46 jlong interval = timestamp_clock - java_lang_ref_SoftReference::timestamp(p);
duke@435 47 assert(interval >= 0, "Sanity check");
duke@435 48
duke@435 49 // The interval will be zero if the ref was accessed since the last scavenge/gc.
duke@435 50 if(interval <= _max_interval) {
duke@435 51 return false;
duke@435 52 }
duke@435 53
duke@435 54 return true;
duke@435 55 }
duke@435 56
duke@435 57 /////////////////////// MaxHeap //////////////////////
duke@435 58
duke@435 59 LRUMaxHeapPolicy::LRUMaxHeapPolicy() {
ysr@892 60 setup();
ysr@888 61 }
ysr@888 62
ysr@888 63 // Capture state (of-the-VM) information needed to evaluate the policy
ysr@892 64 void LRUMaxHeapPolicy::setup() {
duke@435 65 size_t max_heap = MaxHeapSize;
duke@435 66 max_heap -= Universe::get_heap_used_at_last_gc();
duke@435 67 max_heap /= M;
duke@435 68
duke@435 69 _max_interval = max_heap * SoftRefLRUPolicyMSPerMB;
duke@435 70 assert(_max_interval >= 0,"Sanity check");
duke@435 71 }
duke@435 72
duke@435 73 // The oop passed in is the SoftReference object, and not
duke@435 74 // the object the SoftReference points to.
johnc@3188 75 bool LRUMaxHeapPolicy::should_clear_reference(oop p,
johnc@3188 76 jlong timestamp_clock) {
johnc@3188 77 jlong interval = timestamp_clock - java_lang_ref_SoftReference::timestamp(p);
duke@435 78 assert(interval >= 0, "Sanity check");
duke@435 79
duke@435 80 // The interval will be zero if the ref was accessed since the last scavenge/gc.
duke@435 81 if(interval <= _max_interval) {
duke@435 82 return false;
duke@435 83 }
duke@435 84
duke@435 85 return true;
duke@435 86 }

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