diff options
Diffstat (limited to 'pthreads/ptw32_semwait.c')
| -rw-r--r-- | pthreads/ptw32_semwait.c | 253 |
1 files changed, 135 insertions, 118 deletions
diff --git a/pthreads/ptw32_semwait.c b/pthreads/ptw32_semwait.c index 8b23d11d6..e97784977 100644 --- a/pthreads/ptw32_semwait.c +++ b/pthreads/ptw32_semwait.c @@ -1,118 +1,135 @@ -/* - * 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;
+
+ /* See sem_destroy.c
+ */
+ if (*sem == NULL)
+ {
+ (void) pthread_mutex_unlock (&s->lock);
+ errno = EINVAL;
+ return -1;
+ }
+
+ 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 (*sem == NULL)
+ {
+ (void) pthread_mutex_unlock (&s->lock);
+ errno = EINVAL;
+ return -1;
+ }
+
+ 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 */
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