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  
      23  int
      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  }
      48  versioned_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)
      52  compat_symbol (libpthread, __pthread_mutexattr_getprioceiling,
      53                 pthread_mutexattr_getprioceiling, GLIBC_2_4);
      54  #endif