1/*
2 * Copyright (c) 2001, 2019, 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
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23 */
24
25#ifndef SHARE_GC_SHARED_SOFTREFPOLICY_HPP
26#define SHARE_GC_SHARED_SOFTREFPOLICY_HPP
27
28#include "memory/allocation.hpp"
29
30class SoftRefPolicy {
31 private:
32 // Set to true when policy wants soft refs cleared.
33 // Reset to false by gc after it clears all soft refs.
34 bool _should_clear_all_soft_refs;
35
36 // Set to true by the GC if the just-completed gc cleared all
37 // softrefs. This is set to true whenever a gc clears all softrefs, and
38 // set to false each time gc returns to the mutator. For example, in the
39 // ParallelScavengeHeap case the latter would be done toward the end of
40 // mem_allocate() where it returns op.result()
41 bool _all_soft_refs_clear;
42
43 public:
44 SoftRefPolicy();
45
46 bool should_clear_all_soft_refs() { return _should_clear_all_soft_refs; }
47 void set_should_clear_all_soft_refs(bool v) { _should_clear_all_soft_refs = v; }
48 // Returns the current value of _should_clear_all_soft_refs.
49 // _should_clear_all_soft_refs is set to false as a side effect.
50 bool use_should_clear_all_soft_refs(bool v);
51 bool all_soft_refs_clear() { return _all_soft_refs_clear; }
52 void set_all_soft_refs_clear(bool v) { _all_soft_refs_clear = v; }
53
54 // Called by the GC after Soft Refs have been cleared to indicate
55 // that the request in _should_clear_all_soft_refs has been fulfilled.
56 virtual void cleared_all_soft_refs();
57};
58
59class ClearedAllSoftRefs : public StackObj {
60 bool _clear_all_soft_refs;
61 SoftRefPolicy* _soft_ref_policy;
62 public:
63 ClearedAllSoftRefs(bool clear_all_soft_refs, SoftRefPolicy* soft_ref_policy) :
64 _clear_all_soft_refs(clear_all_soft_refs),
65 _soft_ref_policy(soft_ref_policy) {}
66
67 ~ClearedAllSoftRefs() {
68 if (_clear_all_soft_refs) {
69 _soft_ref_policy->cleared_all_soft_refs();
70 }
71 }
72
73 bool should_clear() { return _clear_all_soft_refs; }
74};
75
76#endif // SHARE_GC_SHARED_SOFTREFPOLICY_HPP
77