diff options
Diffstat (limited to 'pthread_mutex_destroy.c')
| -rw-r--r-- | pthread_mutex_destroy.c | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/pthread_mutex_destroy.c b/pthread_mutex_destroy.c new file mode 100644 index 0000000..c9c1426 --- /dev/null +++ b/pthread_mutex_destroy.c @@ -0,0 +1,134 @@ +/* + * pthread_mutex_destroy.c + * + * Description: + * This translation unit implements mutual exclusion (mutex) primitives. + * + * -------------------------------------------------------------------------- + * + * Pthreads-win32 - POSIX Threads Library for Win32 + * Copyright(C) 1998 John E. Bossom + * Copyright(C) 1999,2002 Pthreads-win32 contributors + * + * Contact Email: rpj@ise.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 "pthread.h" +#include "implement.h" + + +int +pthread_mutex_destroy(pthread_mutex_t *mutex) +{ + int result = 0; + pthread_mutex_t mx; + + if (mutex == NULL + || *mutex == NULL) + { + return EINVAL; + } + + /* + * Check to see if we have something to delete. + */ + if (*mutex != PTHREAD_MUTEX_INITIALIZER) + { + mx = *mutex; + + result = pthread_mutex_trylock(&mx); + + /* + * The mutex type may not be RECURSIVE therefore trylock may return EBUSY if + * we already own the mutex. Here we are assuming that it's OK to destroy + * a mutex that we own and have locked recursively. Is this correct? + * + * For FAST mutexes we record the owner as ANONYMOUS for speed. In this + * case we assume that the thread calling pthread_mutex_destroy() is the + * owner, if the mutex is owned at all. + */ + if (result == 0 + || mx->ownerThread == (pthread_t) PTW32_MUTEX_OWNER_ANONYMOUS + || pthread_equal( mx->ownerThread, pthread_self() ) ) + { + /* + * FIXME!!! + * The mutex isn't held by another thread but we could still + * be too late invalidating the mutex below since another thread + * may already have entered mutex_lock and the check for a valid + * *mutex != NULL. + */ + *mutex = NULL; + + result = pthread_mutex_unlock(&mx); + + if (result == 0) + { + (void) sem_destroy( &mx->wait_sema ); + DeleteCriticalSection( &mx->wait_cs ); + free(mx); + } + else + { + /* + * Restore the mutex before we return the error. + */ + *mutex = mx; + } + } + } + else + { + /* + * See notes in ptw32_mutex_check_need_init() above also. + */ + EnterCriticalSection(&ptw32_mutex_test_init_lock); + + /* + * Check again. + */ + if (*mutex == PTHREAD_MUTEX_INITIALIZER) + { + /* + * This is all we need to do to destroy a statically + * initialised mutex that has not yet been used (initialised). + * If we get to here, another thread + * waiting to initialise this mutex will get an EINVAL. + */ + *mutex = NULL; + } + else + { + /* + * The mutex has been initialised while we were waiting + * so assume it's in use. + */ + result = EBUSY; + } + + LeaveCriticalSection(&ptw32_mutex_test_init_lock); + } + + return(result); +} |