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