From 3ef98898333255b8000e9ab4801652c42fd5aacc Mon Sep 17 00:00:00 2001 From: rpj Date: Mon, 25 Apr 2005 14:42:37 +0000 Subject: '' --- sem_wait.c | 324 ++++++++++++++++++++++++++++++------------------------------- 1 file changed, 162 insertions(+), 162 deletions(-) (limited to 'sem_wait.c') diff --git a/sem_wait.c b/sem_wait.c index d838aa1..bcb17e8 100644 --- a/sem_wait.c +++ b/sem_wait.c @@ -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 */ -- cgit v1.2.3