1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
|
/*
* Copyright 2020 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#ifndef RTC_BASE_SYNCHRONIZATION_SEQUENCE_CHECKER_INTERNAL_H_
#define RTC_BASE_SYNCHRONIZATION_SEQUENCE_CHECKER_INTERNAL_H_
#include <string>
#include <type_traits>
#include "api/task_queue/task_queue_base.h"
#include "rtc_base/platform_thread_types.h"
#include "rtc_base/synchronization/mutex.h"
#include "rtc_base/system/rtc_export.h"
#include "rtc_base/thread_annotations.h"
namespace webrtc {
namespace webrtc_sequence_checker_internal {
// Real implementation of SequenceChecker, for use in debug mode, or
// for temporary use in release mode (e.g. to RTC_CHECK on a threading issue
// seen only in the wild).
//
// Note: You should almost always use the SequenceChecker class to get the
// right version for your build configuration.
class RTC_EXPORT SequenceCheckerImpl {
public:
explicit SequenceCheckerImpl(bool attach_to_current_thread);
explicit SequenceCheckerImpl(TaskQueueBase* attached_queue);
~SequenceCheckerImpl() = default;
bool IsCurrent() const;
// Changes the task queue or thread that is checked for in IsCurrent. This can
// be useful when an object may be created on one task queue / thread and then
// used exclusively on another thread.
void Detach();
// Returns a string that is formatted to match with the error string printed
// by RTC_CHECK() when a condition is not met.
// This is used in conjunction with the RTC_DCHECK_RUN_ON() macro.
std::string ExpectationToString() const;
private:
mutable Mutex lock_;
// These are mutable so that IsCurrent can set them.
mutable bool attached_ RTC_GUARDED_BY(lock_);
mutable PlatformThreadRef valid_thread_ RTC_GUARDED_BY(lock_);
mutable const TaskQueueBase* valid_queue_ RTC_GUARDED_BY(lock_);
};
// Do nothing implementation, for use in release mode.
//
// Note: You should almost always use the SequenceChecker class to get the
// right version for your build configuration.
class SequenceCheckerDoNothing {
public:
explicit SequenceCheckerDoNothing(bool /* attach_to_current_thread */) {}
explicit SequenceCheckerDoNothing(TaskQueueBase* /* attached_queue */) {}
bool IsCurrent() const { return true; }
void Detach() {}
};
template <typename ThreadLikeObject>
std::enable_if_t<std::is_base_of_v<SequenceCheckerImpl, ThreadLikeObject>,
std::string>
ExpectationToString([[maybe_unused]] const ThreadLikeObject* checker) {
#if RTC_DCHECK_IS_ON
return checker->ExpectationToString();
#else
return std::string();
#endif
}
// Catch-all implementation for types other than explicitly supported above.
template <typename ThreadLikeObject>
std::enable_if_t<!std::is_base_of_v<SequenceCheckerImpl, ThreadLikeObject>,
std::string>
ExpectationToString(const ThreadLikeObject*) {
return std::string();
}
} // namespace webrtc_sequence_checker_internal
} // namespace webrtc
#endif // RTC_BASE_SYNCHRONIZATION_SEQUENCE_CHECKER_INTERNAL_H_
|
