107 lines
2.3 KiB
C++
107 lines
2.3 KiB
C++
/*
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* Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#include "rw_lock_generic.h"
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#include "condition_variable_wrapper.h"
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#include "critical_section_wrapper.h"
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namespace webrtc {
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RWLockWrapperGeneric::RWLockWrapperGeneric()
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: _readersActive(0),
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_writerActive(false),
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_readersWaiting(0),
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_writersWaiting(0)
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{
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_critSectPtr = CriticalSectionWrapper::CreateCriticalSection();
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_readCondPtr = ConditionVariableWrapper::CreateConditionVariable();
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_writeCondPtr = ConditionVariableWrapper::CreateConditionVariable();
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}
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RWLockWrapperGeneric::~RWLockWrapperGeneric()
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{
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delete _writeCondPtr;
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delete _readCondPtr;
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delete _critSectPtr;
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}
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int RWLockWrapperGeneric::Init()
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{
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return 0;
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}
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void RWLockWrapperGeneric::AcquireLockExclusive()
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{
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_critSectPtr->Enter();
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if (_writerActive || _readersActive > 0)
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{
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++_writersWaiting;
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while (_writerActive || _readersActive > 0)
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{
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_writeCondPtr->SleepCS(*_critSectPtr);
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}
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--_writersWaiting;
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}
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_writerActive = true;
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_critSectPtr->Leave();
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}
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void RWLockWrapperGeneric::ReleaseLockExclusive()
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{
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_critSectPtr->Enter();
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_writerActive = false;
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if (_writersWaiting > 0)
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{
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_writeCondPtr->Wake();
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}else if (_readersWaiting > 0)
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{
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_readCondPtr->WakeAll();
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}
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_critSectPtr->Leave();
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}
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void RWLockWrapperGeneric::AcquireLockShared()
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{
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_critSectPtr->Enter();
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if (_writerActive || _writersWaiting > 0)
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{
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++_readersWaiting;
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while (_writerActive || _writersWaiting > 0)
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{
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_readCondPtr->SleepCS(*_critSectPtr);
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}
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--_readersWaiting;
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}
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++_readersActive;
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_critSectPtr->Leave();
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}
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void RWLockWrapperGeneric::ReleaseLockShared()
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{
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_critSectPtr->Enter();
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--_readersActive;
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if (_readersActive == 0 && _writersWaiting > 0)
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{
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_writeCondPtr->Wake();
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}
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_critSectPtr->Leave();
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}
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} // namespace webrtc
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