1/*
2 * Copyright (c) 2014, 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
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.
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23 */
24
25#ifndef SHARE_GC_G1_G1CODECACHEREMSET_HPP
26#define SHARE_GC_G1_G1CODECACHEREMSET_HPP
27
28class CodeBlobClosure;
29class G1CodeRootSetTable;
30class HeapRegion;
31class nmethod;
32
33// Implements storage for a set of code roots.
34// All methods that modify the set are not thread-safe except if otherwise noted.
35class G1CodeRootSet {
36 friend class G1CodeRootSetTest;
37 private:
38
39 const static size_t SmallSize = 32;
40 const static size_t Threshold = 24;
41 const static size_t LargeSize = 512;
42
43 G1CodeRootSetTable* _table;
44 G1CodeRootSetTable* load_acquire_table();
45
46 size_t _length;
47
48 void move_to_large();
49 void allocate_small_table();
50
51 public:
52 G1CodeRootSet() : _table(NULL), _length(0) {}
53 ~G1CodeRootSet();
54
55 static void purge();
56
57 static size_t static_mem_size();
58
59 void add(nmethod* method);
60
61 bool remove(nmethod* method);
62
63 // Safe to call without synchronization, but may return false negatives.
64 bool contains(nmethod* method);
65
66 void clear();
67
68 void nmethods_do(CodeBlobClosure* blk) const;
69
70 // Remove all nmethods which no longer contain pointers into our "owner" region
71 void clean(HeapRegion* owner);
72
73 bool is_empty() {
74 bool empty = length() == 0;
75 assert(empty == (_table == NULL), "is empty only if table is deallocated");
76 return empty;
77 }
78
79 // Length in elements
80 size_t length() const { return _length; }
81
82 // Memory size in bytes taken by this set.
83 size_t mem_size();
84
85};
86
87#endif // SHARE_GC_G1_G1CODECACHEREMSET_HPP
88