/* * pthread_rwlock_unlock.c * * Description: * This translation unit implements read/write lock primitives. * * -------------------------------------------------------------------------- * * Pthreads-embedded (PTE) - POSIX Threads Library for embedded systems * Copyright(C) 2008 Jason Schmidlapp * * Contact Email: jschmidlapp@users.sourceforge.net * * * Based upon 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 original list of contributors to the Pthreads-win32 project * is contained in the file CONTRIBUTORS.ptw32 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 #include #include "pthread.h" #include "implement.h" int pthread_rwlock_unlock (pthread_rwlock_t * rwlock) { int result, result1; pthread_rwlock_t rwl; if (rwlock == NULL || *rwlock == NULL) { return (EINVAL); } if (*rwlock == PTHREAD_RWLOCK_INITIALIZER) { /* * Assume any race condition here is harmless. */ return 0; } rwl = *rwlock; if (rwl->nMagic != PTE_RWLOCK_MAGIC) { return EINVAL; } if (rwl->nExclusiveAccessCount == 0) { if ((result = pthread_mutex_lock (&(rwl->mtxSharedAccessCompleted))) != 0) { return result; } if (++rwl->nCompletedSharedAccessCount == 0) { result = pthread_cond_signal (&(rwl->cndSharedAccessCompleted)); } result1 = pthread_mutex_unlock (&(rwl->mtxSharedAccessCompleted)); } else { rwl->nExclusiveAccessCount--; result = pthread_mutex_unlock (&(rwl->mtxSharedAccessCompleted)); result1 = pthread_mutex_unlock (&(rwl->mtxExclusiveAccess)); } return ((result != 0) ? result : result1); }