nptl/tst-cnd-broadcast.c

   1 /* C11 threads condition broadcast variable tests.
   2    Copyright (C) 2018-2019 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 <stdbool.h>
  21 #include <stdio.h>
  22 #include <unistd.h>
  23
  24 #include <support/check.h>
  25
  26 /* Condition variable where child threads will wait.  */
  27 static cnd_t cond;
  28
  29 /* Mutex to control wait on cond.  */
  30 static mtx_t mutex;
  31
  32 /* Number of threads which have entered the cnd_wait region.  */
  33 static unsigned int waiting_threads;
  34
  35 /* Code executed by each thread.  */
  36 static int
  37 child_wait (void* data)
  38 {
  39   /* Wait until parent thread sends broadcast here.  */
  40   mtx_lock (&mutex);
  41   ++waiting_threads;
  42   cnd_wait (&cond, &mutex);
  43   mtx_unlock (&mutex);
  44
  45   thrd_exit (thrd_success);
  46 }
  47
  48 #define N 5
  49
  50 static int
  51 do_test (void)
  52 {
  53   thrd_t ids[N];
  54   unsigned char i;
  55
  56   if (cnd_init (&cond) != thrd_success)
  57     FAIL_EXIT1 ("cnd_init failed");
  58   if (mtx_init (&mutex, mtx_plain) != thrd_success)
  59     FAIL_EXIT1 ("mtx_init failed");
  60
  61   /* Create N new threads.  */
  62   for (i = 0; i < N; ++i)
  63     {
  64       if (thrd_create (&ids[i], child_wait, NULL) != thrd_success)
  65         FAIL_EXIT1 ("thrd_create failed");
  66     }
  67
  68   /* Wait for other threads to reach their wait func.  */
  69   while (true)
  70     {
  71       mtx_lock (&mutex);
  72       TEST_VERIFY (waiting_threads <= N);
  73       bool done_waiting = waiting_threads == N;
  74       mtx_unlock (&mutex);
  75       if (done_waiting)
  76         break;
  77       thrd_sleep (&((struct timespec){.tv_nsec = 100 * 1000 * 1000}), NULL);
  78     }
  79
  80   mtx_lock (&mutex);
  81   if (cnd_broadcast (&cond) != thrd_success)
  82     FAIL_EXIT1 ("cnd_broadcast failed");
  83   mtx_unlock (&mutex);
  84
  85   for (i = 0; i < N; ++i)
  86     {
  87       if (thrd_join (ids[i], NULL) != thrd_success)
  88         FAIL_EXIT1 ("thrd_join failed");
  89     }
  90
  91   mtx_destroy (&mutex);
  92   cnd_destroy (&cond);
  93
  94   return 0;
  95 }
  96
  97 #include <support/test-driver.c>