140 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			140 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			C
		
	
	
	
| /*
 | |
|  * pthread_rwlock_timedwrlock.c
 | |
|  *
 | |
|  * Description:
 | |
|  * This translation unit implements read/write lock primitives.
 | |
|  *
 | |
|  * --------------------------------------------------------------------------
 | |
|  *
 | |
|  *      Pthreads-win32 - POSIX Threads Library for Win32
 | |
|  *      Copyright(C) 1998 John E. Bossom
 | |
|  *      Copyright(C) 1999,2005 Pthreads-win32 contributors
 | |
|  * 
 | |
|  *      Contact Email: rpj@callisto.canberra.edu.au
 | |
|  * 
 | |
|  *      The current list of contributors is contained
 | |
|  *      in the file CONTRIBUTORS included with the source
 | |
|  *      code distribution. The list can also be seen at the
 | |
|  *      following World Wide Web location:
 | |
|  *      http://sources.redhat.com/pthreads-win32/contributors.html
 | |
|  * 
 | |
|  *      This library 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 library 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
 | |
|  *      Lesser General Public License for more details.
 | |
|  * 
 | |
|  *      You should have received a copy of the GNU Lesser General Public
 | |
|  *      License along with this library in the file COPYING.LIB;
 | |
|  *      if not, write to the Free Software Foundation, Inc.,
 | |
|  *      59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
 | |
|  */
 | |
| 
 | |
| #include <limits.h>
 | |
| 
 | |
| #include "pthread.h"
 | |
| #include "implement.h"
 | |
| 
 | |
| int
 | |
| pthread_rwlock_timedwrlock (pthread_rwlock_t * rwlock,
 | |
| 			    const struct timespec *abstime)
 | |
| {
 | |
|   int result;
 | |
|   pthread_rwlock_t rwl;
 | |
| 
 | |
|   if (rwlock == NULL || *rwlock == NULL)
 | |
|     {
 | |
|       return EINVAL;
 | |
|     }
 | |
| 
 | |
|   /*
 | |
|    * We do a quick check to see if we need to do more work
 | |
|    * to initialise a static rwlock. We check
 | |
|    * again inside the guarded section of ptw32_rwlock_check_need_init()
 | |
|    * to avoid race conditions.
 | |
|    */
 | |
|   if (*rwlock == PTHREAD_RWLOCK_INITIALIZER)
 | |
|     {
 | |
|       result = ptw32_rwlock_check_need_init (rwlock);
 | |
| 
 | |
|       if (result != 0 && result != EBUSY)
 | |
| 	{
 | |
| 	  return result;
 | |
| 	}
 | |
|     }
 | |
| 
 | |
|   rwl = *rwlock;
 | |
| 
 | |
|   if (rwl->nMagic != PTW32_RWLOCK_MAGIC)
 | |
|     {
 | |
|       return EINVAL;
 | |
|     }
 | |
| 
 | |
|   if ((result =
 | |
|        pthread_mutex_timedlock (&(rwl->mtxExclusiveAccess), abstime)) != 0)
 | |
|     {
 | |
|       return result;
 | |
|     }
 | |
| 
 | |
|   if ((result =
 | |
|        pthread_mutex_timedlock (&(rwl->mtxSharedAccessCompleted),
 | |
| 				abstime)) != 0)
 | |
|     {
 | |
|       (void) pthread_mutex_unlock (&(rwl->mtxExclusiveAccess));
 | |
|       return result;
 | |
|     }
 | |
| 
 | |
|   if (rwl->nExclusiveAccessCount == 0)
 | |
|     {
 | |
|       if (rwl->nCompletedSharedAccessCount > 0)
 | |
| 	{
 | |
| 	  rwl->nSharedAccessCount -= rwl->nCompletedSharedAccessCount;
 | |
| 	  rwl->nCompletedSharedAccessCount = 0;
 | |
| 	}
 | |
| 
 | |
|       if (rwl->nSharedAccessCount > 0)
 | |
| 	{
 | |
| 	  rwl->nCompletedSharedAccessCount = -rwl->nSharedAccessCount;
 | |
| 
 | |
| 	  /*
 | |
| 	   * This routine may be a cancelation point
 | |
| 	   * according to POSIX 1003.1j section 18.1.2.
 | |
| 	   */
 | |
| #if defined(_MSC_VER) && _MSC_VER < 1400
 | |
| #pragma inline_depth(0)
 | |
| #endif
 | |
| 	  pthread_cleanup_push (ptw32_rwlock_cancelwrwait, (void *) rwl);
 | |
| 
 | |
| 	  do
 | |
| 	    {
 | |
| 	      result =
 | |
| 		pthread_cond_timedwait (&(rwl->cndSharedAccessCompleted),
 | |
| 					&(rwl->mtxSharedAccessCompleted),
 | |
| 					abstime);
 | |
| 	    }
 | |
| 	  while (result == 0 && rwl->nCompletedSharedAccessCount < 0);
 | |
| 
 | |
| 	  pthread_cleanup_pop ((result != 0) ? 1 : 0);
 | |
| #if defined(_MSC_VER) && _MSC_VER < 1400
 | |
| #pragma inline_depth()
 | |
| #endif
 | |
| 
 | |
| 	  if (result == 0)
 | |
| 	    {
 | |
| 	      rwl->nSharedAccessCount = 0;
 | |
| 	    }
 | |
| 	}
 | |
|     }
 | |
| 
 | |
|   if (result == 0)
 | |
|     {
 | |
|       rwl->nExclusiveAccessCount++;
 | |
|     }
 | |
| 
 | |
|   return result;
 | |
| }
 |