1 /* Get current priority ceiling of pthread_mutex_t.
2 Copyright (C) 2006-2022 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19 #include <errno.h>
20 #include <pthreadP.h>
21 #include <shlib-compat.h>
22
23 int
__pthread_mutex_getprioceiling(const pthread_mutex_t * mutex,int * prioceiling)24 __pthread_mutex_getprioceiling (const pthread_mutex_t *mutex, int *prioceiling)
25 {
26 /* See concurrency notes regarding __kind in struct __pthread_mutex_s
27 in sysdeps/nptl/bits/thread-shared-types.h. */
28 if (__builtin_expect ((atomic_load_relaxed (&(mutex->__data.__kind))
29 & PTHREAD_MUTEX_PRIO_PROTECT_NP) == 0, 0))
30 return EINVAL;
31
32 *prioceiling = (mutex->__data.__lock & PTHREAD_MUTEX_PRIO_CEILING_MASK)
33 >> PTHREAD_MUTEX_PRIO_CEILING_SHIFT;
34
35 return 0;
36 }
37 versioned_symbol (libc, __pthread_mutex_getprioceiling,
38 pthread_mutex_getprioceiling, GLIBC_2_34);
39
40 #if OTHER_SHLIB_COMPAT (libpthread, GLIBC_2_4, GLIBC_2_34)
41 compat_symbol (libpthread, __pthread_mutex_getprioceiling,
42 pthread_mutex_getprioceiling, GLIBC_2_4);
43 #endif
44