1 /* 2 * Copyright (c) 2000, 2008, 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 "incls/_precompiled.incl" 26 # include "incls/_referencePolicy.cpp.incl" 27 28 LRUCurrentHeapPolicy::LRUCurrentHeapPolicy() { 29 setup(); 30 } 31 32 // Capture state (of-the-VM) information needed to evaluate the policy 33 void LRUCurrentHeapPolicy::setup() { 34 _max_interval = (Universe::get_heap_free_at_last_gc() / M) * SoftRefLRUPolicyMSPerMB; 35 assert(_max_interval >= 0,"Sanity check"); 36 } 37 38 // The oop passed in is the SoftReference object, and not 39 // the object the SoftReference points to. 40 bool LRUCurrentHeapPolicy::should_clear_reference(oop p) { 41 jlong interval = java_lang_ref_SoftReference::clock() - java_lang_ref_SoftReference::timestamp(p); 42 assert(interval >= 0, "Sanity check"); 43 44 // The interval will be zero if the ref was accessed since the last scavenge/gc. 45 if(interval <= _max_interval) { 46 return false; 47 } 48 49 return true; 50 } 51 52 /////////////////////// MaxHeap ////////////////////// 53 54 LRUMaxHeapPolicy::LRUMaxHeapPolicy() { 55 setup(); 56 } 57 58 // Capture state (of-the-VM) information needed to evaluate the policy 59 void LRUMaxHeapPolicy::setup() { 60 size_t max_heap = MaxHeapSize; 61 max_heap -= Universe::get_heap_used_at_last_gc(); 62 max_heap /= M; 63 64 _max_interval = max_heap * SoftRefLRUPolicyMSPerMB; 65 assert(_max_interval >= 0,"Sanity check"); 66 } 67 68 // The oop passed in is the SoftReference object, and not 69 // the object the SoftReference points to. 70 bool LRUMaxHeapPolicy::should_clear_reference(oop p) { 71 jlong interval = java_lang_ref_SoftReference::clock() - java_lang_ref_SoftReference::timestamp(p); 72 assert(interval >= 0, "Sanity check"); 73 74 // The interval will be zero if the ref was accessed since the last scavenge/gc. 75 if(interval <= _max_interval) { 76 return false; 77 } 78 79 return true; 80 }