diff options
Diffstat (limited to 'pthreads/pthread_mutex_destroy.c')
| -rw-r--r-- | pthreads/pthread_mutex_destroy.c | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/pthreads/pthread_mutex_destroy.c b/pthreads/pthread_mutex_destroy.c new file mode 100644 index 000000000..95509b3df --- /dev/null +++ b/pthreads/pthread_mutex_destroy.c @@ -0,0 +1,146 @@ +/* + * 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) 1999,2005 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 "pthread.h" +#include "implement.h" + + +int +pthread_mutex_destroy (pthread_mutex_t * mutex) +{ + int result = 0; + pthread_mutex_t mx; + + /* + * Let the system deal with invalid pointers. + */ + + /* + * Check to see if we have something to delete. + */ + if (*mutex < PTHREAD_ERRORCHECK_MUTEX_INITIALIZER) + { + mx = *mutex; + + result = pthread_mutex_trylock (&mx); + + /* + * If trylock succeeded and the mutex is not recursively locked it + * can be destroyed. + */ + if (result == 0) + { + if (mx->kind != PTHREAD_MUTEX_RECURSIVE || 1 == mx->recursive_count) + { + /* + * 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. + * + * Note that this would be an unusual situation because it is not + * common that mutexes are destroyed while they are still in + * use by other threads. + */ + *mutex = NULL; + + result = pthread_mutex_unlock (&mx); + + if (result == 0) + { + if (!CloseHandle (mx->event)) + { + *mutex = mx; + result = EINVAL; + } + else + { + free (mx); + } + } + else + { + /* + * Restore the mutex before we return the error. + */ + *mutex = mx; + } + } + else /* mx->recursive_count > 1 */ + { + /* + * The mutex must be recursive and already locked by us (this thread). + */ + mx->recursive_count--; /* Undo effect of pthread_mutex_trylock() above */ + result = EBUSY; + } + } + } + else + { + /* + * See notes in ptw32_mutex_check_need_init() above also. + */ + EnterCriticalSection (&ptw32_mutex_test_init_lock); + + /* + * Check again. + */ + if (*mutex >= PTHREAD_ERRORCHECK_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); +} |