sl@0: // Copyright (c) 2005-2009 Nokia Corporation and/or its subsidiary(-ies).
sl@0: // All rights reserved.
sl@0: // This component and the accompanying materials are made available
sl@0: // under the terms of "Eclipse Public License v1.0"
sl@0: // which accompanies this distribution, and is available
sl@0: // at the URL "http://www.eclipse.org/legal/epl-v10.html".
sl@0: //
sl@0: // Initial Contributors:
sl@0: // Nokia Corporation - initial contribution.
sl@0: //
sl@0: // Contributors:
sl@0: //
sl@0: // Description:
sl@0: // Name        : mutex.cpp
sl@0: // Part of     : pthread
sl@0: // Interface   : POSIX, pthread
sl@0: // POSIX implementation of mutexes on Symbian
sl@0: // Version     :
sl@0: //
sl@0: 
sl@0: 
sl@0: 
sl@0: #include "mutextypes.h"
sl@0: 
sl@0: /*
sl@0: This function waits on the aLock semaphore. 
sl@0: */
sl@0: int _doWait(RSemaphore* aLock, const struct timespec *abstime)
sl@0: {
sl@0:     int retval = 0;
sl@0:     if(!abstime)
sl@0:     {
sl@0:         aLock->Wait();
sl@0:     }
sl@0:     else
sl@0:     {
sl@0:         long lSleepTime = _microsleeptime(abstime);
sl@0:         if(lSleepTime <0)
sl@0:         {
sl@0:             if (EINVAL == errno)
sl@0:             {
sl@0:                 errno = 0;
sl@0:                 return EINVAL;    
sl@0:             }
sl@0:             else if(ETIMEDOUT == errno)
sl@0:             {
sl@0:                 errno = 0;
sl@0:                 return ETIMEDOUT;
sl@0:             }
sl@0:             
sl@0:         }
sl@0: 
sl@0:         retval = aLock->Wait(lSleepTime);
sl@0:         if(retval != KErrNone)
sl@0:         {
sl@0:             return  ETIMEDOUT;
sl@0:         }
sl@0: 
sl@0:     }
sl@0:     return 0;
sl@0: }
sl@0: 
sl@0: /*
sl@0: This internal function destroys the mutex object.
sl@0: */
sl@0: void _closeMutex(pthread_mutex_t* mutex)
sl@0: {
sl@0:     _pthread_mutex_t* pMutex = mutex->iPtr;
sl@0:     if(pMutex)
sl@0:     {
sl@0:         if(pMutex->iSemaphoreCreated)
sl@0:         {
sl@0:             pMutex->iSignalSemaphore.Close();       
sl@0:         }
sl@0:         if(pMutex->iDataLockCreated)
sl@0:         {
sl@0:             pMutex->iDataLock.Close();  
sl@0:         }
sl@0:         mutex->iPtr = NULL;
sl@0:         delete pMutex; 
sl@0:     }
sl@0:     return;
sl@0: }
sl@0: 
sl@0: int _mutexCreate (pthread_mutex_t * mutex, 
sl@0:                   const pthread_mutexattr_t* attr)
sl@0: {
sl@0: 
sl@0:     if( attr->iSharedType != PTHREAD_PROCESS_PRIVATE)
sl@0:     {
sl@0:         return ENOSYS;
sl@0:     }
sl@0: 
sl@0:     mutex->iState = _EInvalid;
sl@0:     _pthread_mutex_t* pMutex = new _pthread_mutex_t; 
sl@0:     mutex->iPtr = pMutex;
sl@0:     if(!pMutex)
sl@0:     {
sl@0:         return ENOMEM;
sl@0:     }
sl@0: 
sl@0:     pMutex->iSharedType = attr->iSharedType;
sl@0:     pMutex->iMutexType = attr->iMutexType;
sl@0:     pMutex->iDataLockCreated = false;
sl@0:     pMutex->iSemaphoreCreated = false;
sl@0: 
sl@0:     if(pMutex->iSignalSemaphore.CreateLocal(1) != KErrNone)
sl@0:     {
sl@0:         _closeMutex(mutex);
sl@0:         return EAGAIN;
sl@0:     }
sl@0:     pMutex->iSemaphoreCreated = true;
sl@0: 
sl@0:     if(pMutex->iDataLock.CreateLocal() != KErrNone)
sl@0:     {
sl@0:         _closeMutex(mutex);
sl@0:         return EAGAIN;
sl@0:     }
sl@0:     pMutex->iDataLockCreated = true;
sl@0: 
sl@0:     pMutex->iCount = 0;
sl@0:     pMutex->iSemaphoreState = SEM_FREE;
sl@0:     pMutex->iLockingThread = 0;
sl@0:     mutex->iState = _EInitialized;
sl@0:     return 0;
sl@0: }
sl@0: 
sl@0: 
sl@0: /*
sl@0: This function is an internal  harness function used to resolve the race to dynamically initialize a static mutex
sl@0: */
sl@0: bool _InitOnce(pthread_mutex_t* mutex)
sl@0: {
sl@0: 
sl@0:     pthread_mutexattr_t defaultattributes = 
sl@0:                             PTHREAD_MUTEX_ATTRIBUTE_DEFAULT_INITIALIZER;
sl@0:     pthread_mutexattr_t recursiveattributes = 
sl@0:                             PTHREAD_MUTEX_ATTRIBUTE_RECURSIVE_INITIALIZER;
sl@0:     pthread_mutexattr_t errorcheckattributes = 
sl@0:                             PTHREAD_MUTEX_ATTRIBUTE_ERRORCHECK_INITIALIZER;
sl@0: 
sl@0:     if(mutex->iState == _EInitialized)
sl@0:     {
sl@0:         return true;
sl@0:     }
sl@0:    
sl@0:     mutex->iReentry = 0xBABA;
sl@0: 
sl@0:     pthread_mutexattr_t* attr;
sl@0:     switch(mutex->iState)
sl@0:     {
sl@0:         case _ENeedsNormalInit:
sl@0:         {
sl@0:             attr = &defaultattributes;
sl@0:             break;
sl@0:         }
sl@0: 
sl@0:         case _ENeedsRecursiveInit:
sl@0:         {
sl@0:             attr = &recursiveattributes;
sl@0:             break;
sl@0:         }
sl@0: 
sl@0:         case _ENeedsErrorCheckInit:
sl@0:         {
sl@0:             attr = &errorcheckattributes;
sl@0:             break;
sl@0:         }
sl@0: 
sl@0:         default:
sl@0:             return false;
sl@0:     }
sl@0: 
sl@0: #ifndef NOUSE_INTERNALS
sl@0:     void* tlsPtr;
sl@0: 
sl@0:     // Get the TLS pointer
sl@0:     tlsPtr = _pthread_getTls(); 
sl@0: 
sl@0:     if(!tlsPtr)
sl@0:     {
sl@0:         return false;
sl@0:     }
sl@0: #endif    
sl@0: 
sl@0:     int retval=0;
sl@0: #ifndef NOUSE_INTERNALS
sl@0:     _pthread_atomicMutexLock(tlsPtr);
sl@0: #endif
sl@0:     if(mutex->iState != _EInitialized)
sl@0:     {
sl@0:         retval = _mutexCreate(mutex,attr);
sl@0:     }
sl@0: #ifndef NOUSE_INTERNALS   
sl@0:     _pthread_atomicMutexUnlock(tlsPtr);
sl@0: #endif   
sl@0:      
sl@0:     if(retval == 0)
sl@0:     {
sl@0:         return true;
sl@0:     }
sl@0:     else 
sl@0:     {
sl@0:         return false;
sl@0:     }
sl@0: }
sl@0: 
sl@0: 
sl@0: /*
sl@0: This function is an internal function used to provide the POSIX mutex lock 
sl@0: functionality.
sl@0: */
sl@0: int _internalMutexLock(pthread_mutex_t * mutex,const struct timespec *abstime)
sl@0: {
sl@0:     if( !VALID_MUTEX(mutex) )
sl@0:     {
sl@0:         return EINVAL;
sl@0:     }
sl@0: 
sl@0:     _pthread_mutex_t* pMutex = mutex->iPtr;
sl@0: 
sl@0: 
sl@0:     int retval = 0;
sl@0:     pthread_t self;
sl@0:     switch(pMutex->iMutexType)
sl@0:     {
sl@0:         case  PTHREAD_MUTEX_NORMAL:
sl@0:         	{
sl@0:         	  self = pthread_self();          
sl@0:         	  pMutex->iDataLock.Wait();
sl@0:         	  if(mutex->iState == _EDestroyed)
sl@0:         	  {
sl@0:         	     pMutex->iDataLock.Signal();
sl@0:         	     return EINVAL;
sl@0:         	  }
sl@0:         	  pMutex->iSemaphoreState++;   
sl@0:         	  pMutex->iDataLock.Signal();
sl@0:         	           
sl@0:         	  retval = _doWait(&pMutex->iSignalSemaphore,abstime);
sl@0:         	  if(retval == 0)
sl@0:         	  {
sl@0:         	     pMutex->iDataLock.Wait();
sl@0:         	     if(mutex->iState == _EDestroyed)
sl@0:         	     {
sl@0:         	        pMutex->iDataLock.Signal();
sl@0:         	        return EINVAL;
sl@0:         	     }
sl@0:         	     pMutex->iLockingThread  = self;
sl@0:         	     pMutex->iDataLock.Signal();
sl@0:                }
sl@0:         	   break;
sl@0:         	 }
sl@0: 
sl@0:         case  PTHREAD_MUTEX_RECURSIVE:
sl@0:         	
sl@0:         {
sl@0:             self = pthread_self();
sl@0:             if(pMutex->iLockingThread == self)
sl@0:             {
sl@0:                 pMutex->iDataLock.Wait();
sl@0:                 if(mutex->iState == _EDestroyed)
sl@0:                 {
sl@0:                    pMutex->iDataLock.Signal();
sl@0:                    return EINVAL;
sl@0:                 }
sl@0:                 pMutex->iCount++;
sl@0:                 pMutex->iDataLock.Signal();
sl@0:             }
sl@0:             else
sl@0:             {
sl@0:                 pMutex->iDataLock.Wait();
sl@0:                 if(mutex->iState == _EDestroyed)
sl@0:                 {
sl@0:                    pMutex->iDataLock.Signal();
sl@0:                    return EINVAL;
sl@0:                 }
sl@0:                 pMutex->iSemaphoreState++;   
sl@0:                 pMutex->iDataLock.Signal();
sl@0:                 
sl@0:                 retval = _doWait(&pMutex->iSignalSemaphore,abstime);
sl@0:                 if(retval == 0)
sl@0:                 {
sl@0:                     pMutex->iDataLock.Wait();
sl@0:                     if(mutex->iState == _EDestroyed)
sl@0:                     {
sl@0:                       pMutex->iDataLock.Signal();
sl@0:                       return EINVAL;
sl@0:                     }
sl@0:                     pMutex->iCount = 1;
sl@0:                     pMutex->iLockingThread = self;
sl@0:                     pMutex->iDataLock.Signal();
sl@0:                 }
sl@0:             }
sl@0:             break;
sl@0:         }                          
sl@0: 
sl@0:         case  PTHREAD_MUTEX_ERRORCHECK:
sl@0:         {
sl@0:             self = pthread_self();
sl@0:             if(pMutex->iLockingThread == self)
sl@0:             {
sl@0:                 return EDEADLK;
sl@0:             }
sl@0:             else
sl@0:             {
sl@0:                 pMutex->iDataLock.Wait();
sl@0:                 if(mutex->iState == _EDestroyed)
sl@0:                 {
sl@0:                    pMutex->iDataLock.Signal();
sl@0:                    return EINVAL;
sl@0:                 }
sl@0:                 pMutex->iSemaphoreState++;     
sl@0:                 pMutex->iDataLock.Signal();
sl@0:                 
sl@0:                 retval = _doWait(&pMutex->iSignalSemaphore,abstime);
sl@0:                 if(retval == 0)
sl@0:                 {
sl@0:                   pMutex->iDataLock.Wait();
sl@0:                   if(mutex->iState == _EDestroyed)
sl@0:                   {
sl@0:                      pMutex->iDataLock.Signal();
sl@0:                      return EINVAL;
sl@0:                   }
sl@0:                   pMutex->iLockingThread  = self;
sl@0:                   pMutex->iDataLock.Signal();
sl@0:                 }
sl@0:             }
sl@0:             break;
sl@0:         }
sl@0: 
sl@0:         default:
sl@0:         retval = ENOSYS;
sl@0:         break;
sl@0: 
sl@0:     }
sl@0:     return retval;
sl@0: 
sl@0: }
sl@0: 
sl@0: //End of File