diff options
Diffstat (limited to 'ptw32_semwait.c')
| -rw-r--r-- | ptw32_semwait.c | 236 |
1 files changed, 118 insertions, 118 deletions
diff --git a/ptw32_semwait.c b/ptw32_semwait.c index 209c8a6..8b23d11 100644 --- a/ptw32_semwait.c +++ b/ptw32_semwait.c @@ -1,118 +1,118 @@ -/*
- * ptw32_semwait.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
- */
-
-#ifndef _UWIN
-//# include <process.h>
-#endif
-#include "pthread.h"
-#include "implement.h"
-
-
-int
-ptw32_semwait (sem_t * sem)
- /*
- * ------------------------------------------------------
- * DESCRIPTION
- * This function waits on a POSIX semaphore. If the
- * semaphore value is greater than zero, it decreases
- * its value by one. If the semaphore value is zero, then
- * the calling thread (or process) is blocked until it can
- * successfully decrease the value.
- *
- * Unlike sem_wait(), this routine is non-cancelable.
- *
- * RESULTS
- * 0 successfully decreased semaphore,
- * -1 failed, error in errno.
- * ERRNO
- * EINVAL 'sem' is not a valid semaphore,
- * ENOSYS semaphores are not supported,
- * EINTR the function was interrupted by a signal,
- * EDEADLK a deadlock condition was detected.
- *
- * ------------------------------------------------------
- */
-{
- int result = 0;
- sem_t s = *sem;
-
- if (s == NULL)
- {
- result = EINVAL;
- }
- else
- {
- if ((result = pthread_mutex_lock (&s->lock)) == 0)
- {
- int v = --s->value;
-
- (void) pthread_mutex_unlock (&s->lock);
-
- if (v < 0)
- {
- /* Must wait */
- if (WaitForSingleObject (s->sem, INFINITE) == WAIT_OBJECT_0)
- {
-#ifdef NEED_SEM
- if (pthread_mutex_lock (&s->lock) == 0)
- {
- if (s->leftToUnblock > 0)
- {
- --s->leftToUnblock;
- SetEvent(s->sem);
- }
- (void) pthread_mutex_unlock (&s->lock);
- }
-#endif
- return 0;
- }
- }
- else
- {
- return 0;
- }
- }
- }
-
- if (result != 0)
- {
- errno = result;
- return -1;
- }
-
- return 0;
-
-} /* ptw32_semwait */
+/* + * ptw32_semwait.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 + */ + +#ifndef _UWIN +//# include <process.h> +#endif +#include "pthread.h" +#include "implement.h" + + +int +ptw32_semwait (sem_t * sem) + /* + * ------------------------------------------------------ + * DESCRIPTION + * This function waits on a POSIX semaphore. If the + * semaphore value is greater than zero, it decreases + * its value by one. If the semaphore value is zero, then + * the calling thread (or process) is blocked until it can + * successfully decrease the value. + * + * Unlike sem_wait(), this routine is non-cancelable. + * + * RESULTS + * 0 successfully decreased semaphore, + * -1 failed, error in errno. + * ERRNO + * EINVAL 'sem' is not a valid semaphore, + * ENOSYS semaphores are not supported, + * EINTR the function was interrupted by a signal, + * EDEADLK a deadlock condition was detected. + * + * ------------------------------------------------------ + */ +{ + int result = 0; + sem_t s = *sem; + + if (s == NULL) + { + result = EINVAL; + } + else + { + if ((result = pthread_mutex_lock (&s->lock)) == 0) + { + int v = --s->value; + + (void) pthread_mutex_unlock (&s->lock); + + if (v < 0) + { + /* Must wait */ + if (WaitForSingleObject (s->sem, INFINITE) == WAIT_OBJECT_0) + { +#ifdef NEED_SEM + if (pthread_mutex_lock (&s->lock) == 0) + { + if (s->leftToUnblock > 0) + { + --s->leftToUnblock; + SetEvent(s->sem); + } + (void) pthread_mutex_unlock (&s->lock); + } +#endif + return 0; + } + } + else + { + return 0; + } + } + } + + if (result != 0) + { + errno = result; + return -1; + } + + return 0; + +} /* ptw32_semwait */ |