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Diffstat (limited to 'pthreads/sem_getvalue.c')
-rw-r--r-- | pthreads/sem_getvalue.c | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/pthreads/sem_getvalue.c b/pthreads/sem_getvalue.c new file mode 100644 index 000000000..baafb02cf --- /dev/null +++ b/pthreads/sem_getvalue.c @@ -0,0 +1,110 @@ +/* + * ------------------------------------------------------------- + * + * Module: sem_getvalue.c + * + * Purpose: + * Semaphores aren't actually part of PThreads. + * They are defined by the POSIX Standard: + * + * POSIX 1003.1-2001 + * + * ------------------------------------------------------------- + * + * -------------------------------------------------------------------------- + * + * 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_getvalue (sem_t * sem, int *sval) + /* + * ------------------------------------------------------ + * DOCPUBLIC + * This function stores the current count value of the + * semaphore. + * RESULTS + * + * Return value + * + * 0 sval has been set. + * -1 failed, error in errno + * + * in global errno + * + * EINVAL 'sem' is not a valid semaphore, + * ENOSYS this function is not supported, + * + * + * PARAMETERS + * + * sem pointer to an instance of sem_t + * + * sval pointer to int. + * + * DESCRIPTION + * This function stores the current count value of the semaphore + * pointed to by sem in the int pointed to by sval. + */ +{ + if (sem == NULL || *sem == NULL || sval == NULL) + { + errno = EINVAL; + return -1; + } + else + { + long value; + register sem_t s = *sem; + int result = 0; + + if ((result = pthread_mutex_lock(&s->lock)) == 0) + { + /* See sem_destroy.c + */ + if (*sem == NULL) + { + (void) pthread_mutex_unlock (&s->lock); + errno = EINVAL; + return -1; + } + + value = s->value; + (void) pthread_mutex_unlock(&s->lock); + *sval = value; + } + + return result; + } + +} /* sem_getvalue */ |