1 /* 2 * Copyright (c) 2000, 2010, 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 interval = java_lang_ref_SoftReference::clock() - java_lang_ref_SoftReference::timestamp(p); 46 assert(interval >= 0, "Sanity check"); 47 48 // The interval will be zero if the ref was accessed since the last scavenge/gc. 49 if(interval <= _max_interval) { 50 return false; 51 } 52 53 return true; 54 } 55 56 /////////////////////// MaxHeap ////////////////////// 57 58 LRUMaxHeapPolicy::LRUMaxHeapPolicy() { 59 setup(); 60 } 61 62 // Capture state (of-the-VM) information needed to evaluate the policy 63 void LRUMaxHeapPolicy::setup() { 64 size_t max_heap = MaxHeapSize; 65 max_heap -= Universe::get_heap_used_at_last_gc(); 66 max_heap /= M; 67 68 _max_interval = max_heap * SoftRefLRUPolicyMSPerMB; 69 assert(_max_interval >= 0,"Sanity check"); 70 } 71 72 // The oop passed in is the SoftReference object, and not 73 // the object the SoftReference points to. 74 bool LRUMaxHeapPolicy::should_clear_reference(oop p) { 75 jlong interval = java_lang_ref_SoftReference::clock() - java_lang_ref_SoftReference::timestamp(p); 76 assert(interval >= 0, "Sanity check"); 77 78 // The interval will be zero if the ref was accessed since the last scavenge/gc. 79 if(interval <= _max_interval) { 80 return false; 81 } 82 83 return true; 84 }