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/*
* Copyright (c) 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 RTC_BASE_SYNCHRONIZATION_RW_LOCK_WRAPPER_H_
#define RTC_BASE_SYNCHRONIZATION_RW_LOCK_WRAPPER_H_
#include "rtc_base/thread_annotations.h"
// Note, Windows pre-Vista version of RW locks are not supported natively. For
// these OSs regular critical sections have been used to approximate RW lock
// functionality and will therefore have worse performance.
namespace webrtc {
class RTC_LOCKABLE RWLockWrapper {
public:
static RWLockWrapper* CreateRWLock();
virtual ~RWLockWrapper() {}
virtual void AcquireLockExclusive() RTC_EXCLUSIVE_LOCK_FUNCTION() = 0;
virtual void ReleaseLockExclusive() RTC_UNLOCK_FUNCTION() = 0;
virtual void AcquireLockShared() RTC_SHARED_LOCK_FUNCTION() = 0;
virtual void ReleaseLockShared() RTC_UNLOCK_FUNCTION() = 0;
};
// RAII extensions of the RW lock. Prevents Acquire/Release missmatches and
// provides more compact locking syntax.
class RTC_SCOPED_LOCKABLE ReadLockScoped {
public:
explicit ReadLockScoped(RWLockWrapper& rw_lock)
RTC_SHARED_LOCK_FUNCTION(rw_lock)
: rw_lock_(rw_lock) {
rw_lock_.AcquireLockShared();
}
~ReadLockScoped() RTC_UNLOCK_FUNCTION() { rw_lock_.ReleaseLockShared(); }
private:
RWLockWrapper& rw_lock_;
};
class RTC_SCOPED_LOCKABLE WriteLockScoped {
public:
explicit WriteLockScoped(RWLockWrapper& rw_lock)
RTC_EXCLUSIVE_LOCK_FUNCTION(rw_lock)
: rw_lock_(rw_lock) {
rw_lock_.AcquireLockExclusive();
}
~WriteLockScoped() RTC_UNLOCK_FUNCTION() { rw_lock_.ReleaseLockExclusive(); }
private:
RWLockWrapper& rw_lock_;
};
} // namespace webrtc
#endif // RTC_BASE_SYNCHRONIZATION_RW_LOCK_WRAPPER_H_
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