1  /* Check that error checking mutexes are not subject to lock elision.
       2     Copyright (C) 2016-2023 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 <stdio.h>
      20  #include <errno.h>
      21  #include <time.h>
      22  #include <pthread.h>
      23  #include <support/check.h>
      24  
      25  static int
      26  do_test (void)
      27  {
      28    struct timespec tms = { 0 };
      29    pthread_mutex_t mutex;
      30    pthread_mutexattr_t mutexattr;
      31    int ret = 0;
      32  
      33    TEST_COMPARE (pthread_mutexattr_init (&mutexattr), 0);
      34    TEST_COMPARE (pthread_mutexattr_settype (&mutexattr,
      35                                             PTHREAD_MUTEX_ERRORCHECK), 0);
      36  
      37    TEST_COMPARE (pthread_mutex_init (&mutex, &mutexattr), 0);
      38    TEST_COMPARE (pthread_mutexattr_destroy (&mutexattr), 0);
      39  
      40    /* The call to pthread_mutex_timedlock erroneously enabled lock elision
      41       on the mutex, which then triggered an assertion failure in
      42       pthread_mutex_unlock.  It would also defeat the error checking nature
      43       of the mutex.  */
      44    TEST_COMPARE (pthread_mutex_timedlock (&mutex, &tms), 0);
      45    TEST_COMPARE (pthread_mutex_timedlock (&mutex, &tms), EDEADLK);
      46  
      47    TEST_COMPARE (pthread_mutex_unlock (&mutex), 0);
      48  
      49    return ret;
      50  }
      51  
      52  #include <support/test-driver.c>