MutexImpl.cpp

Go to the documentation of this file.

/*******************************************************************************
* Copyright (C) 2005, Vintela, Inc. All rights reserved.
* Copyright (C) 2006, Novell, Inc. All rights reserved.
* 
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* 
*     * Redistributions of source code must retain the above copyright notice,
*       this list of conditions and the following disclaimer.
*     * Redistributions in binary form must reproduce the above copyright
*       notice, this list of conditions and the following disclaimer in the
*       documentation and/or other materials provided with the distribution.
*     * Neither the name of 
*       Vintela, Inc., 
*       nor Novell, Inc., 
*       nor the names of its contributors or employees may be used to 
*       endorse or promote products derived from this software without 
*       specific prior written permission.
* 
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*******************************************************************************/


#include "blocxx/BLOCXX_config.h"
#include "blocxx/MutexImpl.hpp"
#include <cerrno>
#include <cassert>

namespace BLOCXX_NAMESPACE
{

namespace MutexImpl
{

#if defined (BLOCXX_USE_PTHREAD)

#if !defined (BLOCXX_NCR)

int
createMutex(Mutex_t& handle)
{
   pthread_mutexattr_t attr;
   int res = pthread_mutexattr_init(&attr);
   assert(res == 0);
   if (res != 0)
   {
      return -1;
   }
 
#if defined(BLOCXX_HAVE_PTHREAD_MUTEXATTR_SETTYPE)
   res = pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
   assert(res == 0);
   if (res != 0)
   {
      pthread_mutexattr_destroy(&attr);
      return -1;
   }
#endif

   res = pthread_mutex_init(&handle.mutex, &attr);
   pthread_mutexattr_destroy(&attr);
   if (res != 0)
   {
      return -1;
   }
 
#if !defined(BLOCXX_HAVE_PTHREAD_MUTEXATTR_SETTYPE)
   res = pthread_cond_init(&handle.unlocked, PTHREAD_COND_ATTR_DEFAULT);
   if (res != 0)
   {
      pthread_mutex_destroy(&handle.mutex);
      return -1;
   }
   
   handle.valid_id = false;
   handle.count = 0;
#endif
   return 0;
}

#else //#if !defined (BLOCXX_NCR)

int
createMutex(Mutex_t& handle)
{
   pthread_mutexattr_t attr;
   int res = pthread_mutexattr_create(&attr);
   assert(res == 0);
   if (res != 0)
   {
      return -1;
   }
 
#if defined(BLOCXX_HAVE_PTHREAD_MUTEXATTR_SETTYPE)
   res = pthread_mutexattr_setkind_np(&attr, MUTEX_RECURSIVE_NP);
   assert(res == 0);
   if (res != 0)
   {
      pthread_mutexattr_delete(&attr);
      return -1;
   }
#endif

   res = pthread_mutex_init(&handle.mutex, attr);

   pthread_mutexattr_delete(&attr);
   if (res != 0)
   {
      return -1;
   }
 
#if !defined(BLOCXX_HAVE_PTHREAD_MUTEXATTR_SETTYPE)
   res = pthread_cond_init(&handle.unlocked, PTHREAD_COND_ATTR_DEFAULT);
   if (res != 0)
   {
      pthread_mutex_destroy(&handle.mutex);
      return -1;
   }
   
   handle.valid_id = false;
   handle.count = 0;
#endif
   return 0;
}

#endif //#ifndef BLOCXX_NCR

int
destroyMutex(Mutex_t& handle)
{
   switch (pthread_mutex_destroy(&handle.mutex))
   {
      case 0:
         break;
      case EBUSY:
         return -1;
         break;
      default:
         return -2;
   }
   int res = 0;
#if !defined(BLOCXX_HAVE_PTHREAD_MUTEXATTR_SETTYPE)
   res = pthread_cond_destroy(&handle.unlocked);
   assert(res == 0);
#endif
   return res;
}

int
acquireMutex(Mutex_t& handle)
{
   int res = pthread_mutex_lock(&handle.mutex);
   assert(res == 0);
 
#if !defined(BLOCXX_HAVE_PTHREAD_MUTEXATTR_SETTYPE)
   pthread_t tid = pthread_self();
   if (handle.valid_id && pthread_equal(handle.thread_id, tid))
   {
      ++handle.count;
   }
   else
   {
      while (handle.valid_id)
      {
         res = pthread_cond_wait(&handle.unlocked, &handle.mutex);
         assert(res == 0 || res == EINTR);
         if (res == EINTR)
         {
            try
            {
               Thread::testCancel();
            }
            catch (...)
            {
               pthread_mutex_unlock(&handle.mutex);
               throw;
            }
         }
      }
 
      handle.thread_id = tid;
      handle.valid_id = true;
      handle.count = 1;
   }
 
   res = pthread_mutex_unlock(&handle.mutex);
   assert(res == 0);
#endif
   return res;
}

int
releaseMutex(Mutex_t& handle)
{
#if defined(BLOCXX_HAVE_PTHREAD_MUTEXATTR_SETTYPE)
   int res = pthread_mutex_unlock(&handle.mutex);
   assert(res == 0);
   return res;
#else
   int res = 0;
   res = pthread_mutex_lock(&handle.mutex);
   assert(res == 0);
 
   pthread_t tid = pthread_self();
   if (handle.valid_id && !pthread_equal(handle.thread_id, tid))
   {
      res = pthread_mutex_unlock(&handle.mutex);
      assert(res == 0);
      return -1;
   }
 
   if (--handle.count == 0)
   {
      assert(handle.valid_id);
      handle.valid_id = false;
 
      res = pthread_cond_signal(&handle.unlocked);
      assert(res == 0);
   }
 
   res = pthread_mutex_unlock(&handle.mutex);
   assert(res == 0);
   return res;
#endif //#if defined(BLOCXX_HAVE_PTHREAD_MUTEXATTR_SETTYPE)
}

#endif //#if defined (BLOCXX_USE_PTHREAD)

#if defined(BLOCXX_WIN32)

int
createMutex(Mutex_t& handle)
{
   handle = new CRITICAL_SECTION;
   assert(handle);
   InitializeCriticalSection(handle);
   return 0;
}

int
destroyMutex(Mutex_t& handle)
{
   if(handle)
   {
      DeleteCriticalSection(handle);
      delete handle;
      handle = 0;
   }
   return 0;
}

int
acquireMutex(Mutex_t& handle)
{
   EnterCriticalSection(handle);
   return 0;
}

int
releaseMutex(Mutex_t& handle)
{
   LeaveCriticalSection(handle);
   return 0;
}

#endif //#if defined(BLOCXX_WIN32)

} // end namespace MutexImpl
} // end namespace BLOCXX_NAMESPACE