nptl/pthread_mutexattr_setprioceiling.c

   1 /* Change priority ceiling setting in 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 <errno.h>
  20 #include <pthreadP.h>
  21 #include <atomic.h>
  22 #include <shlib-compat.h>
  23
  24 int
  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