src/share/vm/memory/referencePolicy.hpp

Thu, 21 Aug 2014 13:57:51 -0700

author
iklam
date
Thu, 21 Aug 2014 13:57:51 -0700
changeset 7089
6e0cb14ce59b
parent 4153
b9a9ed0f8eeb
child 6876
710a3c8b516e
permissions
-rw-r--r--

8046070: Class Data Sharing clean up and refactoring
Summary: Cleaned up CDS to be more configurable, maintainable and extensible
Reviewed-by: dholmes, coleenp, acorn, mchung

duke@435 1 /*
mikael@4153 2 * Copyright (c) 2000, 2012, 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 #ifndef SHARE_VM_MEMORY_REFERENCEPOLICY_HPP
stefank@2314 26 #define SHARE_VM_MEMORY_REFERENCEPOLICY_HPP
stefank@2314 27
duke@435 28 // referencePolicy is used to determine when soft reference objects
duke@435 29 // should be cleared.
duke@435 30
duke@435 31
zgu@3900 32 class ReferencePolicy : public CHeapObj<mtGC> {
duke@435 33 public:
johnc@3188 34 virtual bool should_clear_reference(oop p, jlong timestamp_clock) {
johnc@3188 35 ShouldNotReachHere();
johnc@3188 36 return true;
johnc@3188 37 }
johnc@3188 38
ysr@888 39 // Capture state (of-the-VM) information needed to evaluate the policy
ysr@892 40 virtual void setup() { /* do nothing */ }
duke@435 41 };
duke@435 42
duke@435 43 class NeverClearPolicy : public ReferencePolicy {
duke@435 44 public:
johnc@3188 45 virtual bool should_clear_reference(oop p, jlong timestamp_clock) {
johnc@3188 46 return false;
johnc@3188 47 }
duke@435 48 };
duke@435 49
duke@435 50 class AlwaysClearPolicy : public ReferencePolicy {
duke@435 51 public:
johnc@3188 52 virtual bool should_clear_reference(oop p, jlong timestamp_clock) {
johnc@3188 53 return true;
johnc@3188 54 }
duke@435 55 };
duke@435 56
duke@435 57 class LRUCurrentHeapPolicy : public ReferencePolicy {
duke@435 58 private:
duke@435 59 jlong _max_interval;
duke@435 60
duke@435 61 public:
duke@435 62 LRUCurrentHeapPolicy();
duke@435 63
ysr@888 64 // Capture state (of-the-VM) information needed to evaluate the policy
ysr@892 65 void setup();
johnc@3188 66 virtual bool should_clear_reference(oop p, jlong timestamp_clock);
duke@435 67 };
duke@435 68
duke@435 69 class LRUMaxHeapPolicy : public ReferencePolicy {
duke@435 70 private:
duke@435 71 jlong _max_interval;
duke@435 72
duke@435 73 public:
duke@435 74 LRUMaxHeapPolicy();
duke@435 75
ysr@888 76 // Capture state (of-the-VM) information needed to evaluate the policy
ysr@892 77 void setup();
johnc@3188 78 virtual bool should_clear_reference(oop p, jlong timestamp_clock);
duke@435 79 };
stefank@2314 80
stefank@2314 81 #endif // SHARE_VM_MEMORY_REFERENCEPOLICY_HPP

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