1/* Get priority ceiling setting from pthread_mutexattr_t.
2 Copyright (C) 2006-2023 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 <pthreadP.h>
20#include <atomic.h>
21#include <shlib-compat.h>
22
23int
24__pthread_mutexattr_getprioceiling (const pthread_mutexattr_t *attr,
25 int *prioceiling)
26{
27 const struct pthread_mutexattr *iattr;
28 int ceiling;
29
30 iattr = (const struct pthread_mutexattr *) attr;
31
32 ceiling = ((iattr->mutexkind & PTHREAD_MUTEXATTR_PRIO_CEILING_MASK)
33 >> PTHREAD_MUTEXATTR_PRIO_CEILING_SHIFT);
34
35 if (! ceiling)
36 {
37 /* See __init_sched_fifo_prio. */
38 if (atomic_load_relaxed (&__sched_fifo_min_prio) == -1)
39 __init_sched_fifo_prio ();
40 if (ceiling < atomic_load_relaxed (&__sched_fifo_min_prio))
41 ceiling = atomic_load_relaxed (&__sched_fifo_min_prio);
42 }
43
44 *prioceiling = ceiling;
45
46 return 0;
47}
48versioned_symbol (libc, __pthread_mutexattr_getprioceiling,
49 pthread_mutexattr_getprioceiling, GLIBC_2_34);
50
51#if OTHER_SHLIB_COMPAT (libpthread, GLIBC_2_4, GLIBC_2_34)
52compat_symbol (libpthread, __pthread_mutexattr_getprioceiling,
53 pthread_mutexattr_getprioceiling, GLIBC_2_4);
54#endif
55