1 /* 2 * Copyright 2020 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 #include "rtc_base/synchronization/mutex.h" 12 13 #include "rtc_base/checks.h" 14 #include "rtc_base/synchronization/yield.h" 15 16 namespace webrtc { 17 18 #if !defined(WEBRTC_ABSL_MUTEX) Lock()19void GlobalMutex::Lock() { 20 while (mutex_locked_.exchange(1)) { 21 YieldCurrentThread(); 22 } 23 } 24 Unlock()25void GlobalMutex::Unlock() { 26 int old = mutex_locked_.exchange(0); 27 RTC_DCHECK_EQ(old, 1) << "Unlock called without calling Lock first"; 28 } 29 GlobalMutexLock(GlobalMutex * mutex)30GlobalMutexLock::GlobalMutexLock(GlobalMutex* mutex) : mutex_(mutex) { 31 mutex_->Lock(); 32 } 33 ~GlobalMutexLock()34GlobalMutexLock::~GlobalMutexLock() { 35 mutex_->Unlock(); 36 } 37 #endif // #if !defined(WEBRTC_ABSL_MUTEX) 38 39 } // namespace webrtc 40