diff options
Diffstat (limited to 'sem_post.c')
| -rw-r--r-- | sem_post.c | 227 |
1 files changed, 112 insertions, 115 deletions
@@ -1,115 +1,112 @@ -/* - * ------------------------------------------------------------- - * - * Module: sem_post.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" - - -int -sem_post (sem_t * sem) - /* - * ------------------------------------------------------ - * DOCPUBLIC - * This function posts a wakeup to a semaphore. - * - * PARAMETERS - * sem - * pointer to an instance of sem_t - * - * DESCRIPTION - * This function posts a wakeup to a semaphore. If there - * are waiting threads (or processes), one is awakened; - * otherwise, the semaphore value is incremented by one. - * - * RESULTS - * 0 successfully posted semaphore, - * -1 failed, error in errno - * ERRNO - * EINVAL 'sem' is not a valid semaphore, - * ENOSYS semaphores are not supported, - * - * ------------------------------------------------------ - */ -{ - int result = 0; -#ifndef NEED_SEM - sem_t s = *sem; -#endif - - if (s == NULL) - { - result = EINVAL; - } - -#ifdef NEED_SEM - - else if (!ptw32_increase_semaphore (sem, 1)) - { - result = EINVAL; - } - -#else /* NEED_SEM */ - - else if ((result = pthread_mutex_lock (&s->lock)) == 0) - { - if (++s->value <= 0 - && !ReleaseSemaphore (s->sem, 1, NULL)) - { - result = EINVAL; - } - - (void) pthread_mutex_unlock (&s->lock); - } - -#endif /* NEED_SEM */ - - if (result != 0) - { - errno = result; - return -1; - } - - return 0; - -} /* sem_post */ +/*
+ * -------------------------------------------------------------
+ *
+ * Module: sem_post.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"
+
+
+int
+sem_post (sem_t * sem)
+ /*
+ * ------------------------------------------------------
+ * DOCPUBLIC
+ * This function posts a wakeup to a semaphore.
+ *
+ * PARAMETERS
+ * sem
+ * pointer to an instance of sem_t
+ *
+ * DESCRIPTION
+ * This function posts a wakeup to a semaphore. If there
+ * are waiting threads (or processes), one is awakened;
+ * otherwise, the semaphore value is incremented by one.
+ *
+ * RESULTS
+ * 0 successfully posted semaphore,
+ * -1 failed, error in errno
+ * ERRNO
+ * EINVAL 'sem' is not a valid semaphore,
+ * ENOSYS semaphores are not supported,
+ *
+ * ------------------------------------------------------
+ */
+{
+ int result = 0;
+ sem_t s = *sem;
+
+ if (s == NULL)
+ {
+ result = EINVAL;
+ }
+ else if ((result = pthread_mutex_lock (&s->lock)) == 0)
+ {
+#ifdef NEED_SEM
+
+ if (++s->value <= 0)
+ {
+ if (!SetEvent(s->sem))
+ {
+ result = EINVAL;
+ }
+ }
+#else
+ if (++s->value <= 0
+ && !ReleaseSemaphore (s->sem, 1, NULL))
+ {
+ result = EINVAL;
+ }
+#endif /* NEED_SEM */
+
+ (void) pthread_mutex_unlock (&s->lock);
+ }
+
+ if (result != 0)
+ {
+ errno = result;
+ return -1;
+ }
+
+ return 0;
+
+} /* sem_post */
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