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Diffstat (limited to 'chromium/third_party/webrtc/base/sharedexclusivelock.h')
-rw-r--r-- | chromium/third_party/webrtc/base/sharedexclusivelock.h | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/chromium/third_party/webrtc/base/sharedexclusivelock.h b/chromium/third_party/webrtc/base/sharedexclusivelock.h new file mode 100644 index 00000000000..f64d7cf5068 --- /dev/null +++ b/chromium/third_party/webrtc/base/sharedexclusivelock.h @@ -0,0 +1,76 @@ +/* + * Copyright 2011 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 WEBRTC_BASE_SHAREDEXCLUSIVELOCK_H_ +#define WEBRTC_BASE_SHAREDEXCLUSIVELOCK_H_ + +#include "webrtc/base/constructormagic.h" +#include "webrtc/base/criticalsection.h" +#include "webrtc/base/event.h" + +namespace rtc { + +// This class provides shared-exclusive lock. It can be used in cases like +// multiple-readers/single-writer model. +class SharedExclusiveLock { + public: + SharedExclusiveLock(); + + // Locking/unlocking methods. It is encouraged to use SharedScope or + // ExclusiveScope for protection. + void LockExclusive(); + void UnlockExclusive(); + void LockShared(); + void UnlockShared(); + + private: + rtc::CriticalSection cs_exclusive_; + rtc::CriticalSection cs_shared_; + rtc::Event shared_count_is_zero_; + int shared_count_; + + DISALLOW_COPY_AND_ASSIGN(SharedExclusiveLock); +}; + +class SharedScope { + public: + explicit SharedScope(SharedExclusiveLock* lock) : lock_(lock) { + lock_->LockShared(); + } + + ~SharedScope() { + lock_->UnlockShared(); + } + + private: + SharedExclusiveLock* lock_; + + DISALLOW_COPY_AND_ASSIGN(SharedScope); +}; + +class ExclusiveScope { + public: + explicit ExclusiveScope(SharedExclusiveLock* lock) : lock_(lock) { + lock_->LockExclusive(); + } + + ~ExclusiveScope() { + lock_->UnlockExclusive(); + } + + private: + SharedExclusiveLock* lock_; + + DISALLOW_COPY_AND_ASSIGN(ExclusiveScope); +}; + +} // namespace rtc + +#endif // WEBRTC_BASE_SHAREDEXCLUSIVELOCK_H_ |