Thu, 13 Jun 2013 22:02:40 -0700
8014431: cleanup warnings indicated by the -Wunused-value compiler option on linux
Reviewed-by: dholmes, coleenp
Contributed-by: jeremymanson@google.com, calvin.cheung@oracle.com
1 /*
2 * Copyright (c) 2000, 2012, 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
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23 */
25 #ifndef SHARE_VM_MEMORY_REFERENCEPOLICY_HPP
26 #define SHARE_VM_MEMORY_REFERENCEPOLICY_HPP
28 // referencePolicy is used to determine when soft reference objects
29 // should be cleared.
32 class ReferencePolicy : public CHeapObj<mtGC> {
33 public:
34 virtual bool should_clear_reference(oop p, jlong timestamp_clock) {
35 ShouldNotReachHere();
36 return true;
37 }
39 // Capture state (of-the-VM) information needed to evaluate the policy
40 virtual void setup() { /* do nothing */ }
41 };
43 class NeverClearPolicy : public ReferencePolicy {
44 public:
45 virtual bool should_clear_reference(oop p, jlong timestamp_clock) {
46 return false;
47 }
48 };
50 class AlwaysClearPolicy : public ReferencePolicy {
51 public:
52 virtual bool should_clear_reference(oop p, jlong timestamp_clock) {
53 return true;
54 }
55 };
57 class LRUCurrentHeapPolicy : public ReferencePolicy {
58 private:
59 jlong _max_interval;
61 public:
62 LRUCurrentHeapPolicy();
64 // Capture state (of-the-VM) information needed to evaluate the policy
65 void setup();
66 virtual bool should_clear_reference(oop p, jlong timestamp_clock);
67 };
69 class LRUMaxHeapPolicy : public ReferencePolicy {
70 private:
71 jlong _max_interval;
73 public:
74 LRUMaxHeapPolicy();
76 // Capture state (of-the-VM) information needed to evaluate the policy
77 void setup();
78 virtual bool should_clear_reference(oop p, jlong timestamp_clock);
79 };
81 #endif // SHARE_VM_MEMORY_REFERENCEPOLICY_HPP