1/*
2 *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
3 *
4 *  Use of this source code is governed by a BSD-style license
5 *  that can be found in the LICENSE file in the root of the source
6 *  tree. An additional intellectual property rights grant can be found
7 *  in the file PATENTS.  All contributing project authors may
8 *  be found in the AUTHORS file in the root of the source tree.
9 */
10
11#ifndef WEBRTC_SYSTEM_WRAPPERS_INTERFACE_CRITICAL_SECTION_WRAPPER_H_
12#define WEBRTC_SYSTEM_WRAPPERS_INTERFACE_CRITICAL_SECTION_WRAPPER_H_
13
14// If the critical section is heavily contended it may be beneficial to use
15// read/write locks instead.
16
17#include "common_types.h"
18
19namespace webrtc {
20class CriticalSectionWrapper
21{
22public:
23    // Factory method, constructor disabled
24    static CriticalSectionWrapper* CreateCriticalSection();
25
26    virtual ~CriticalSectionWrapper() {}
27
28    // Tries to grab lock, beginning of a critical section. Will wait for the
29    // lock to become available if the grab failed.
30    virtual void Enter() = 0;
31
32    // Returns a grabbed lock, end of critical section.
33    virtual void Leave() = 0;
34};
35
36// RAII extension of the critical section. Prevents Enter/Leave mismatches and
37// provides more compact critical section syntax.
38class CriticalSectionScoped
39{
40public:
41    // Deprecated, don't add more users of this constructor.
42    // TODO(mflodman) Remove this version of the constructor when no one is
43    // using it any longer.
44    explicit CriticalSectionScoped(CriticalSectionWrapper& critsec)
45        : _ptrCritSec(&critsec)
46    {
47        _ptrCritSec->Enter();
48    }
49
50    explicit CriticalSectionScoped(CriticalSectionWrapper* critsec)
51        : _ptrCritSec(critsec)
52    {
53      _ptrCritSec->Enter();
54    }
55
56    ~CriticalSectionScoped()
57    {
58        if (_ptrCritSec)
59        {
60            Leave();
61        }
62    }
63
64private:
65    void Leave()
66    {
67        _ptrCritSec->Leave();
68        _ptrCritSec = 0;
69    }
70
71    CriticalSectionWrapper* _ptrCritSec;
72};
73} // namespace webrtc
74#endif // WEBRTC_SYSTEM_WRAPPERS_INTERFACE_CRITICAL_SECTION_WRAPPER_H_
75