1  /* Returns whether Priority Inheritance support CLOCK_MONOTONIC.
       2     Copyright (C) 2021-2023 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 <support/xthread.h>
      20  #include <sys/syscall.h>
      21  #include <unistd.h>
      22  
      23  bool
      24  support_mutex_pi_monotonic (void)
      25  {
      26  #ifdef __linux__
      27  # ifndef __NR_futex
      28  #  define __NR_futex __NR_futex_time64
      29  # endif
      30    int r = syscall (__NR_futex, &(unsigned int){0}, 13 /* FUTEX_LOCK_PI2  */,
      31  		   0, NULL);
      32    return r == 0;
      33  #else
      34    return false;
      35  #endif
      36  }