1/*
2 * Copyright (C) 2017 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#pragma once
27
28// This class implements "instance count" management for regression test coverage.
29// Since it adds runtime overhead to manage the count variable, the actual
30// functionality of the class is limited to debug builds.
31
32namespace WTF {
33
34template<typename T> class InstanceCounted {
35public:
36 static size_t instanceCount()
37 {
38#ifndef NDEBUG
39 return s_instanceCount;
40#else
41 return 0;
42#endif
43 }
44
45#ifndef NDEBUG
46protected:
47 InstanceCounted()
48 {
49 ++s_instanceCount;
50 }
51
52 InstanceCounted(const InstanceCounted&)
53 {
54 ++s_instanceCount;
55 }
56
57 InstanceCounted(InstanceCounted&&)
58 {
59 ++s_instanceCount;
60 }
61
62 ~InstanceCounted()
63 {
64 ASSERT(s_instanceCount);
65 --s_instanceCount;
66 }
67
68private:
69 static std::atomic_size_t s_instanceCount;
70#endif // NDEBUG
71};
72
73#ifndef NDEBUG
74template<typename T> std::atomic_size_t InstanceCounted<T>::s_instanceCount;
75#endif
76
77} // namespace WTF
78
79using WTF::InstanceCounted;
80
81