mutex.cpp

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/**************************************************************************

   begin                : Sun Sep 10 2007
   copyright            : (C) 2007 by Ewald Arnold
   email                : log4sendpp at ewald-arnold dot de

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU Lesser General Public License as
   published by the Free Software Foundation; either version 2 of the License,
   or (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU Lesser General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

 **/

#define LOG4SENDPP_NEED_EXPORTS
#include <log4sendpp/log4sendpp.h>  // always first header

#include <cerrno>

#ifdef __unix__
#include <pthread.h>
#endif

#include <log4sendpp/mutex.h>
#include <log4sendpp/exception.h>


LOG4SENDPP_NS_START


LOG4SENDPP_API_IMPL0 Mutex::Mutex()
{
#if defined __WIN32__
  if ((handle = CreateMutex(0, false, 0)) < 0)
#else
  if (pthread_mutex_init(&handle, 0) != 0)
#endif
    LOG4SENDPP_THROW(LOG4SENDPP_NS::Exception(__LINE__, __FILE__, "Could not create mutex"));
}


LOG4SENDPP_API_IMPL0 Mutex::~Mutex()
{
#if defined __WIN32__
  CloseHandle(handle);
#elif _THREAD
  pthread_mutex_destroy(&handle);
#endif
}


LOG4SENDPP_API_IMPL(void) Mutex::lock()
{
#if defined __WIN32__
  if (WaitForSingleObject(handle, INFINITE) == WAIT_TIMEOUT)
#else
  if (pthread_mutex_lock(&handle) != 0)
#endif
    LOG4SENDPP_THROW(LOG4SENDPP_NS::Exception(__LINE__, __FILE__, "Could not lock mutex"));
}


LOG4SENDPP_API_IMPL(void) Mutex::unlock()
{
#if defined __WIN32__
  if (!ReleaseMutex(handle))
#else
  if (pthread_mutex_unlock(&handle)!=0)
#endif
    LOG4SENDPP_THROW(LOG4SENDPP_NS::Exception(__LINE__, __FILE__, "Could not unlock mutex"));
}


LOG4SENDPP_API_IMPL(bool) Mutex::tryLock()
{
#if defined __WIN32__

  DWORD ret = WaitForSingleObject(handle, 1);

  if (ret == WAIT_FAILED)
    return false;

  if (ret == WAIT_TIMEOUT)
    return false;

  if (ret == WAIT_ABANDONED)
    return false;

  if (ret != WAIT_OBJECT_0)
    return false;

#else

  int ret = pthread_mutex_trylock(&handle);
  if (ret == EBUSY)
    return false;

  if (ret != 0)
    return false;

#endif

  return true;
}


//


LOG4SENDPP_API_IMPL0 Mutex::Locker::Locker(Mutex &mtx)
  : mutex(&mtx)
{
  mutex->lock();
}


LOG4SENDPP_API_IMPL0 Mutex::Locker::~Locker()
{
  LOG4SENDPP_TRY
  {
    mutex->unlock();  // might throw, forget it
  }
  LOG4SENDPP_CATCH_ALL
  {
  }
}


//


LOG4SENDPP_API_IMPL0 Mutex::TryLocker::TryLocker(Mutex &mtx)
  : mutex(&mtx)
{
  locked = mutex->tryLock();
}


LOG4SENDPP_API_IMPL0 Mutex::TryLocker::~TryLocker()
{
  LOG4SENDPP_TRY
  {
    if (isLocked())
      mutex->unlock();  // might throw, forget it
  }
  LOG4SENDPP_CATCH_ALL
  {
  }
}


LOG4SENDPP_API_IMPL(bool) Mutex::TryLocker::isLocked()
{
  return locked;
}


LOG4SENDPP_NS_END

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