1  /* C11 threads condition variable tests.
       2     Copyright (C) 2018-2023 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 <threads.h>
      20  #include <stdio.h>
      21  #include <unistd.h>
      22  
      23  #include <support/check.h>
      24  
      25  /* Shared condition variable between child and parent.  */
      26  static cnd_t cond;
      27  
      28  /* Mutex needed to signal and wait threads.  */
      29  static mtx_t mutex;
      30  
      31  static int
      32  signal_parent (void)
      33  {
      34    /* Acquire the lock so that cnd_signal does not run until
      35       cnd_timedwait has been called.  */
      36    if (mtx_lock (&mutex) != thrd_success)
      37      FAIL_EXIT1 ("mtx_lock failed");
      38    if (cnd_signal (&cond) != thrd_success)
      39      FAIL_EXIT1 ("cnd_signal");
      40    if (mtx_unlock (&mutex) != thrd_success)
      41      FAIL_EXIT1 ("mtx_unlock");
      42  
      43    thrd_exit (thrd_success);
      44  }
      45  
      46  static int
      47  do_test (void)
      48  {
      49    thrd_t id;
      50  
      51    if (cnd_init (&cond) != thrd_success)
      52      FAIL_EXIT1 ("cnd_init failed");
      53    if (mtx_init (&mutex, mtx_plain) != thrd_success)
      54      FAIL_EXIT1 ("mtx_init failed");
      55  
      56    if (mtx_lock (&mutex) != thrd_success)
      57      FAIL_EXIT1 ("mtx_lock failed");
      58  
      59    if (thrd_create (&id, (thrd_start_t) signal_parent, NULL)
      60        != thrd_success)
      61      FAIL_EXIT1 ("thrd_create failed");
      62  
      63    if (cnd_wait (&cond, &mutex) != thrd_success)
      64      FAIL_EXIT1 ("cnd_wait failed");
      65  
      66    /* Joining is not mandatory here, but still done to assure child thread
      67       ends correctly.  */
      68    if (thrd_join (id, NULL) != thrd_success)
      69      FAIL_EXIT1 ("thrd_join failed");
      70  
      71    if (mtx_unlock (&mutex) != thrd_success)
      72      FAIL_EXIT1 ("mtx_unlock");
      73  
      74    mtx_destroy (&mutex);
      75    cnd_destroy (&cond);
      76  
      77    return 0;
      78  }
      79  
      80  #include <support/test-driver.c>