1/* Change priority ceiling setting in pthread_mutexattr_t.
2 Copyright (C) 2006-2020 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Jakub Jelinek <jakub@redhat.com>, 2006.
5
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
10
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <https://www.gnu.org/licenses/>. */
19
20#include <errno.h>
21#include <pthreadP.h>
22#include <atomic.h>
23
24
25int
26pthread_mutexattr_setprioceiling (pthread_mutexattr_t *attr, int prioceiling)
27{
28 /* See __init_sched_fifo_prio. */
29 if (atomic_load_relaxed (&__sched_fifo_min_prio) == -1
30 || atomic_load_relaxed (&__sched_fifo_max_prio) == -1)
31 __init_sched_fifo_prio ();
32
33 if (__glibc_unlikely (prioceiling
34 < atomic_load_relaxed (&__sched_fifo_min_prio))
35 || __glibc_unlikely (prioceiling
36 > atomic_load_relaxed (&__sched_fifo_max_prio))
37 || __glibc_unlikely ((prioceiling
38 & (PTHREAD_MUTEXATTR_PRIO_CEILING_MASK
39 >> PTHREAD_MUTEXATTR_PRIO_CEILING_SHIFT))
40 != prioceiling))
41 return EINVAL;
42
43 struct pthread_mutexattr *iattr = (struct pthread_mutexattr *) attr;
44
45 iattr->mutexkind = ((iattr->mutexkind & ~PTHREAD_MUTEXATTR_PRIO_CEILING_MASK)
46 | (prioceiling << PTHREAD_MUTEXATTR_PRIO_CEILING_SHIFT));
47
48 return 0;
49}
50