webrtc/rtc_base/synchronization/sequence_checker_internal.h
Tommi 301e546a68 Remove SequenceCheckerImpl::valid_system_queue_
As pointed out in issue webrtc:15146 this Mac/iOS specific variable,
makes the SequenceChecker behave incorrectly on those platforms.

The variable was introduced in a CL that merged the previous checker
classes, ThreadChecker and SequencedTaskChecker, but curiously neither
one of them had such a variable. So I'm not exactly sure what problem
was being solved. Hence I'm wondering if we actually need it.

Reference: https://webrtc-review.googlesource.com/c/src/+/129721

Bug: webrtc:15146
Change-Id: Ia7a9eb17b993c4f8a1e8204c658bf0b3dbdaa1e0
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/304401
Reviewed-by: Peter Hanspers <peterhanspers@webrtc.org>
Commit-Queue: Tomas Gunnarsson <tommi@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#40019}
2023-05-09 09:40:51 +00:00

88 lines
3.1 KiB
C++

/*
* 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);
~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 rtc::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) {}
bool IsCurrent() const { return true; }
void Detach() {}
};
template <typename ThreadLikeObject>
std::enable_if_t<std::is_base_of_v<SequenceCheckerImpl, ThreadLikeObject>,
std::string>
ExpectationToString(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_