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Diffstat (limited to 'sem_getvalue.c')
-rw-r--r-- | sem_getvalue.c | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/sem_getvalue.c b/sem_getvalue.c new file mode 100644 index 0000000..abc76c0 --- /dev/null +++ b/sem_getvalue.c @@ -0,0 +1,124 @@ +/* + * ------------------------------------------------------------- + * + * Module: sem_getvalue.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) 1999,2002 Pthreads-win32 contributors + * + * Contact Email: rpj@ise.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. + */ +{ + int result = 0; + + if ( sem == NULL || *sem == NULL || sval == NULL ) + { + result = EINVAL; + } + else + { + +#ifdef NEED_SEM + + result = ENOSYS; + +#else + long value = *sval; + + /* Note: + * The windows NT documentation says that the increment must be + * greater than zero, but it is set to zero here. If this works, + * the function will return true. If not, we can't do it this way + * so flag it as not implemented. + */ + + if ( ReleaseSemaphore( (*sem)->sem, 0L, &value) ) + { + *sval = value; + } + else + { + result = ENOSYS; + } + +#endif + } + + + if ( result != 0 ) + { + errno = result; + return -1; + } + + return 0; + +} /* sem_getvalue */ |