1/* 2 * Copyright (c) 2011 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#ifndef WEBRTC_SYSTEM_WRAPPERS_INTERFACE_RW_LOCK_WRAPPER_H_ 12#define WEBRTC_SYSTEM_WRAPPERS_INTERFACE_RW_LOCK_WRAPPER_H_ 13 14// Note, Windows pre-Vista version of RW locks are not supported nativly. For 15// these OSs regular critical sections have been used to approximate RW lock 16// functionality and will therefore have worse performance. 17 18namespace webrtc { 19class RWLockWrapper 20{ 21public: 22 static RWLockWrapper* CreateRWLock(); 23 virtual ~RWLockWrapper(); 24 25 virtual void AcquireLockExclusive() = 0; 26 virtual void ReleaseLockExclusive() = 0; 27 28 virtual void AcquireLockShared() = 0; 29 virtual void ReleaseLockShared() = 0; 30 31protected: 32 virtual int Init() = 0; 33}; 34 35// RAII extensions of the RW lock. Prevents Acquire/Release missmatches and 36// provides more compact locking syntax. 37class ReadLockScoped 38{ 39public: 40 ReadLockScoped(RWLockWrapper& rwLock) 41 : 42 _rwLock(rwLock) 43 { 44 _rwLock.AcquireLockShared(); 45 } 46 47 ~ReadLockScoped() 48 { 49 _rwLock.ReleaseLockShared(); 50 } 51 52private: 53 RWLockWrapper& _rwLock; 54}; 55 56class WriteLockScoped 57{ 58public: 59 WriteLockScoped(RWLockWrapper& rwLock) 60 : 61 _rwLock(rwLock) 62 { 63 _rwLock.AcquireLockExclusive(); 64 } 65 66 ~WriteLockScoped() 67 { 68 _rwLock.ReleaseLockExclusive(); 69 } 70 71private: 72 RWLockWrapper& _rwLock; 73}; 74} // namespace webrtc 75 76#endif // WEBRTC_SYSTEM_WRAPPERS_INTERFACE_RW_LOCK_WRAPPER_H_ 77