1  /* Get current priority ceiling of pthread_mutex_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 <shlib-compat.h>
      22  
      23  int
      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