1 /* Change priority ceiling setting in pthread_mutexattr_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 <atomic.h>
22 #include <shlib-compat.h>
23 
24 int
__pthread_mutexattr_setprioceiling(pthread_mutexattr_t * attr,int prioceiling)25 __pthread_mutexattr_setprioceiling (pthread_mutexattr_t *attr, int prioceiling)
26 {
27   /* See __init_sched_fifo_prio.  */
28   if (atomic_load_relaxed (&__sched_fifo_min_prio) == -1
29       || atomic_load_relaxed (&__sched_fifo_max_prio) == -1)
30     __init_sched_fifo_prio ();
31 
32   if (__glibc_unlikely (prioceiling
33 			< atomic_load_relaxed (&__sched_fifo_min_prio))
34       || __glibc_unlikely (prioceiling
35 			   > atomic_load_relaxed (&__sched_fifo_max_prio))
36       || __glibc_unlikely ((prioceiling
37 			    & (PTHREAD_MUTEXATTR_PRIO_CEILING_MASK
38 			       >> PTHREAD_MUTEXATTR_PRIO_CEILING_SHIFT))
39 			   != prioceiling))
40     return EINVAL;
41 
42   struct pthread_mutexattr *iattr = (struct pthread_mutexattr *) attr;
43 
44   iattr->mutexkind = ((iattr->mutexkind & ~PTHREAD_MUTEXATTR_PRIO_CEILING_MASK)
45 		      | (prioceiling << PTHREAD_MUTEXATTR_PRIO_CEILING_SHIFT));
46 
47   return 0;
48 }
49 versioned_symbol (libc, __pthread_mutexattr_setprioceiling,
50 		  pthread_mutexattr_setprioceiling, GLIBC_2_34);
51 
52 #if OTHER_SHLIB_COMPAT (libpthread, GLIBC_2_4, GLIBC_2_34)
53 compat_symbol (libpthread, __pthread_mutexattr_setprioceiling,
54                pthread_mutexattr_setprioceiling, GLIBC_2_4);
55 #endif
56