diff options
author | rpj <rpj> | 2005-04-25 14:55:16 +0000 |
---|---|---|
committer | rpj <rpj> | 2005-04-25 14:55:16 +0000 |
commit | a06bad7ea9a24a3ea93fe1e7b9b99155481ada3a (patch) | |
tree | 5d8d210afdda4bdaea3c6a6e4a7a7ccdab4b3bba /sem_wait.c | |
parent | 262895c989b395cb0c79512a34a697b1e56bcbd7 (diff) |
''
Diffstat (limited to 'sem_wait.c')
-rw-r--r-- | sem_wait.c | 324 |
1 files changed, 162 insertions, 162 deletions
@@ -1,162 +1,162 @@ -/*
- * -------------------------------------------------------------
- *
- * Module: sem_wait.c
- *
- * Purpose:
- * Semaphores aren't actually part of the PThreads standard.
- * They are defined by the POSIX Standard:
- *
- * POSIX 1003.1b-1993 (POSIX.1b)
- *
- * -------------------------------------------------------------
- *
- * --------------------------------------------------------------------------
- *
- * 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 "semaphore.h"
-#include "implement.h"
-
-
-static void PTW32_CDECL
-ptw32_sem_wait_cleanup(void * sem)
-{
- sem_t s = (sem_t) sem;
-
- if (pthread_mutex_lock (&s->lock) == 0)
- {
- ++s->value;
-#ifdef NEED_SEM
-
- if (s->value > 0)
- {
- s->leftToUnblock = 0;
- }
-#else
- /*
- * Don't release the W32 sema, it doesn't need adjustment
- * because it doesn't record the number of waiters.
- */
-#endif /* NEED_SEM */
- (void) pthread_mutex_unlock (&s->lock);
- }
-}
-
-int
-sem_wait (sem_t * sem)
- /*
- * ------------------------------------------------------
- * DOCPUBLIC
- * This function waits on a semaphore.
- *
- * PARAMETERS
- * sem
- * pointer to an instance of sem_t
- *
- * DESCRIPTION
- * This function waits on a 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 or until interrupted by
- * a signal.
- *
- * 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
- {
-
- /* Faster to test before adjusting the count */
- pthread_testcancel();
-
- if ((result = pthread_mutex_lock (&s->lock)) == 0)
- {
- int v = --s->value;
-
- (void) pthread_mutex_unlock (&s->lock);
-
- if (v < 0)
- {
-#ifdef _MSC_VER
-#pragma inline_depth(0)
-#endif
- /* Must wait */
- pthread_cleanup_push(ptw32_sem_wait_cleanup, (void *) s);
- result = pthreadCancelableWait (s->sem);
- pthread_cleanup_pop(result);
-#ifdef _MSC_VER
-#pragma inline_depth()
-#endif
- }
-#ifdef NEED_SEM
-
- if (!result && pthread_mutex_lock (&s->lock) == 0)
- {
- if (s->leftToUnblock > 0)
- {
- --s->leftToUnblock;
- SetEvent(s->sem);
- }
- (void) pthread_mutex_unlock (&s->lock);
- }
-
-#endif /* NEED_SEM */
-
- }
-
- }
-
- if (result != 0)
- {
- errno = result;
- return -1;
- }
-
- return 0;
-
-} /* sem_wait */
+/* + * ------------------------------------------------------------- + * + * Module: sem_wait.c + * + * Purpose: + * Semaphores aren't actually part of the PThreads standard. + * They are defined by the POSIX Standard: + * + * POSIX 1003.1b-1993 (POSIX.1b) + * + * ------------------------------------------------------------- + * + * -------------------------------------------------------------------------- + * + * 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 "semaphore.h" +#include "implement.h" + + +static void PTW32_CDECL +ptw32_sem_wait_cleanup(void * sem) +{ + sem_t s = (sem_t) sem; + + if (pthread_mutex_lock (&s->lock) == 0) + { + ++s->value; +#ifdef NEED_SEM + + if (s->value > 0) + { + s->leftToUnblock = 0; + } +#else + /* + * Don't release the W32 sema, it doesn't need adjustment + * because it doesn't record the number of waiters. + */ +#endif /* NEED_SEM */ + (void) pthread_mutex_unlock (&s->lock); + } +} + +int +sem_wait (sem_t * sem) + /* + * ------------------------------------------------------ + * DOCPUBLIC + * This function waits on a semaphore. + * + * PARAMETERS + * sem + * pointer to an instance of sem_t + * + * DESCRIPTION + * This function waits on a 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 or until interrupted by + * a signal. + * + * 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 + { + + /* Faster to test before adjusting the count */ + pthread_testcancel(); + + if ((result = pthread_mutex_lock (&s->lock)) == 0) + { + int v = --s->value; + + (void) pthread_mutex_unlock (&s->lock); + + if (v < 0) + { +#ifdef _MSC_VER +#pragma inline_depth(0) +#endif + /* Must wait */ + pthread_cleanup_push(ptw32_sem_wait_cleanup, (void *) s); + result = pthreadCancelableWait (s->sem); + pthread_cleanup_pop(result); +#ifdef _MSC_VER +#pragma inline_depth() +#endif + } +#ifdef NEED_SEM + + if (!result && pthread_mutex_lock (&s->lock) == 0) + { + if (s->leftToUnblock > 0) + { + --s->leftToUnblock; + SetEvent(s->sem); + } + (void) pthread_mutex_unlock (&s->lock); + } + +#endif /* NEED_SEM */ + + } + + } + + if (result != 0) + { + errno = result; + return -1; + } + + return 0; + +} /* sem_wait */ |