74 lines
2.2 KiB
C++
74 lines
2.2 KiB
C++
/*
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* Copyright 2020 The WebRTC Project Authors. All rights reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#ifndef RTC_BASE_SYNCHRONIZATION_MUTEX_H_
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#define RTC_BASE_SYNCHRONIZATION_MUTEX_H_
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#include <atomic>
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#include "absl/base/attributes.h"
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#include "absl/base/const_init.h"
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#include "rtc_base/checks.h"
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#include "rtc_base/thread_annotations.h"
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#if defined(WEBRTC_ABSL_MUTEX)
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#include "rtc_base/synchronization/mutex_abseil.h" // nogncheck
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#elif defined(WEBRTC_WIN)
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#include "rtc_base/synchronization/mutex_critical_section.h"
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#elif defined(WEBRTC_POSIX)
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#include "rtc_base/synchronization/mutex_pthread.h"
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#else
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#error Unsupported platform.
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#endif
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namespace webrtc {
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// The Mutex guarantees exclusive access and aims to follow Abseil semantics
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// (i.e. non-reentrant etc).
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class RTC_LOCKABLE Mutex final {
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public:
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Mutex() = default;
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Mutex(const Mutex&) = delete;
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Mutex& operator=(const Mutex&) = delete;
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void Lock() RTC_EXCLUSIVE_LOCK_FUNCTION() { impl_.Lock(); }
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ABSL_MUST_USE_RESULT bool TryLock() RTC_EXCLUSIVE_TRYLOCK_FUNCTION(true) {
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return impl_.TryLock();
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}
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// Return immediately if this thread holds the mutex, or RTC_DCHECK_IS_ON==0.
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// Otherwise, may report an error (typically by crashing with a diagnostic),
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// or may return immediately.
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void AssertHeld() const RTC_ASSERT_EXCLUSIVE_LOCK() { impl_.AssertHeld(); }
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void Unlock() RTC_UNLOCK_FUNCTION() { impl_.Unlock(); }
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private:
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MutexImpl impl_;
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};
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// MutexLock, for serializing execution through a scope.
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class RTC_SCOPED_LOCKABLE MutexLock final {
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public:
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MutexLock(const MutexLock&) = delete;
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MutexLock& operator=(const MutexLock&) = delete;
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explicit MutexLock(Mutex* mutex) RTC_EXCLUSIVE_LOCK_FUNCTION(mutex)
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: mutex_(mutex) {
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mutex->Lock();
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}
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~MutexLock() RTC_UNLOCK_FUNCTION() { mutex_->Unlock(); }
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private:
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Mutex* mutex_;
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};
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} // namespace webrtc
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#endif // RTC_BASE_SYNCHRONIZATION_MUTEX_H_
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