webrtc/system_wrappers/interface/rw_lock_wrapper.h

77 lines
1.8 KiB
C++

/*
* 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 WEBRTC_SYSTEM_WRAPPERS_INTERFACE_RW_LOCK_WRAPPER_H_
#define WEBRTC_SYSTEM_WRAPPERS_INTERFACE_RW_LOCK_WRAPPER_H_
// Note, Windows pre-Vista version of RW locks are not supported nativly. For
// these OSs regular critical sections have been used to approximate RW lock
// functionality and will therefore have worse performance.
namespace webrtc {
class RWLockWrapper
{
public:
static RWLockWrapper* CreateRWLock();
virtual ~RWLockWrapper();
virtual void AcquireLockExclusive() = 0;
virtual void ReleaseLockExclusive() = 0;
virtual void AcquireLockShared() = 0;
virtual void ReleaseLockShared() = 0;
protected:
virtual int Init() = 0;
};
// RAII extensions of the RW lock. Prevents Acquire/Release missmatches and
// provides more compact locking syntax.
class ReadLockScoped
{
public:
ReadLockScoped(RWLockWrapper& rwLock)
:
_rwLock(rwLock)
{
_rwLock.AcquireLockShared();
}
~ReadLockScoped()
{
_rwLock.ReleaseLockShared();
}
private:
RWLockWrapper& _rwLock;
};
class WriteLockScoped
{
public:
WriteLockScoped(RWLockWrapper& rwLock)
:
_rwLock(rwLock)
{
_rwLock.AcquireLockExclusive();
}
~WriteLockScoped()
{
_rwLock.ReleaseLockExclusive();
}
private:
RWLockWrapper& _rwLock;
};
} // namespace webrtc
#endif // WEBRTC_SYSTEM_WRAPPERS_INTERFACE_RW_LOCK_WRAPPER_H_