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//

// RWLock_POSIX.h

//

// $Id: //poco/1.3/Foundation/include/Poco/RWLock_POSIX.h#1 $

//

// Library: Foundation

// Package: Threading

// Module:  RWLock

//

// Definition of the RWLockImpl class for POSIX Threads.

//

// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.

// and Contributors.

//

// Permission is hereby granted, free of charge, to any person or organization

// obtaining a copy of the software and accompanying documentation covered by

// this license (the "Software") to use, reproduce, display, distribute,

// execute, and transmit the Software, and to prepare derivative works of the

// Software, and to permit third-parties to whom the Software is furnished to

// do so, all subject to the following:

// 

// The copyright notices in the Software and this entire statement, including

// the above license grant, this restriction and the following disclaimer,

// must be included in all copies of the Software, in whole or in part, and

// all derivative works of the Software, unless such copies or derivative

// works are solely in the form of machine-executable object code generated by

// a source language processor.

// 

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT

// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE

// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,

// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER

// DEALINGS IN THE SOFTWARE.

//

#ifndef Foundation_RWLock_POSIX_INCLUDED

#define Foundation_RWLock_POSIX_INCLUDED

#include "Poco/Foundation.h"

#include "Poco/Exception.h"

#include <pthread.h>

#include <errno.h>

namespace Poco {

class Foundation_API RWLockImpl

{

protected:

        RWLockImpl();

        ~RWLockImpl();

        void readLockImpl();

        bool tryReadLockImpl();

        void writeLockImpl();

        bool tryWriteLockImpl();

        void unlockImpl();

private:

        pthread_rwlock_t _rwl;

};

//

// inlines

//

inline void RWLockImpl::readLockImpl()

{

        if (pthread_rwlock_rdlock(&_rwl)) 

                throw SystemException("cannot lock reader/writer lock");

}

inline bool RWLockImpl::tryReadLockImpl()

{

        int rc = pthread_rwlock_tryrdlock(&_rwl);

        if (rc == 0)

                return true;

        else if (rc == EBUSY)

                return false;

        else

                throw SystemException("cannot lock reader/writer lock");

}

inline void RWLockImpl::writeLockImpl()

{

        if (pthread_rwlock_wrlock(&_rwl)) 

                throw SystemException("cannot lock reader/writer lock");

}

inline bool RWLockImpl::tryWriteLockImpl()

{

        int rc = pthread_rwlock_trywrlock(&_rwl);

        if (rc == 0)

                return true;

        else if (rc == EBUSY)

                return false;

        else

                throw SystemException("cannot lock reader/writer lock");

}

inline void RWLockImpl::unlockImpl()

{

        if (pthread_rwlock_unlock(&_rwl))

                throw SystemException("cannot unlock mutex");

}

} // namespace Poco

#endif // Foundation_RWLock_POSIX_INCLUDED