glibc/nptl/pthread_mutex_getprioceiling.c

36 lines
1.2 KiB
C

/* Get current priority ceiling of pthread_mutex_t.
Copyright (C) 2006-2016 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Jakub Jelinek <jakub@redhat.com>, 2006.
The GNU C 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 2.1 of the License, or (at your option) any later version.
The GNU C 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 the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <pthreadP.h>
int
pthread_mutex_getprioceiling (const pthread_mutex_t *mutex, int *prioceiling)
{
if (__builtin_expect ((mutex->__data.__kind
& PTHREAD_MUTEX_PRIO_PROTECT_NP) == 0, 0))
return EINVAL;
*prioceiling = (mutex->__data.__lock & PTHREAD_MUTEX_PRIO_CEILING_MASK)
>> PTHREAD_MUTEX_PRIO_CEILING_SHIFT;
return 0;
}