nptl/tst-mtx-timedlock.c

   1 /* C11 threads timed mutex 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    <http://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 mutex between child and parent.  */
  26 static mtx_t mutex;
  27
  28 /* Shared counter to check possible race conditions.  */
  29 static char shrd_counter;
  30
  31 /* Maximum amount of time waiting for mutex.  */
  32 static struct timespec wait_time;
  33
  34 /* Function to choose an action to do, depending on mtx_timedlock
  35    return value.  */
  36 static inline void
  37 choose_action (int action, char* thread_name)
  38 {
  39   switch (action)
  40     {
  41       case thrd_success:
  42         ++shrd_counter;
  43
  44         if (mtx_unlock (&mutex) != thrd_success)
  45           FAIL_EXIT1 ("mtx_unlock failed");
  46       break;
  47
  48       case thrd_timedout:
  49         break;
  50
  51       case thrd_error:
  52         FAIL_EXIT1 ("%s lock error", thread_name);
  53         break;
  54     }
  55 }
  56
  57 static int
  58 child_add (void *arg)
  59 {
  60   char child_name[] = "child";
  61
  62   /* Try to lock mutex.  */
  63   choose_action (mtx_timedlock (&mutex, &wait_time), child_name);
  64   thrd_exit (thrd_success);
  65 }
  66
  67 static int
  68 do_test (void)
  69 {
  70   thrd_t id;
  71   char parent_name[] = "parent";
  72
  73   if (mtx_init (&mutex, mtx_timed) != thrd_success)
  74     FAIL_EXIT1 ("mtx_init failed");
  75
  76   if (clock_gettime (CLOCK_REALTIME, &wait_time) != 0)
  77     FAIL_EXIT1 ("clock_gettime failed");
  78   /* Tiny amount of time, to assure that if any thread finds it busy.
  79      It will receive thrd_timedout.  */
  80   wait_time.tv_nsec += 1;
  81   if (wait_time.tv_nsec == 1000 * 1000 * 1000)
  82     {
  83       wait_time.tv_sec += 1;
  84       wait_time.tv_nsec = 0;
  85     }
  86
  87   if (thrd_create (&id, child_add, NULL) != thrd_success)
  88     FAIL_EXIT1 ("thrd_create failed");
  89
  90   choose_action (mtx_timedlock (&mutex, &wait_time), parent_name);
  91
  92   if (thrd_join (id, NULL) != thrd_success)
  93     FAIL_EXIT1 ("thrd_join failed");
  94
  95   if (shrd_counter != 2 && shrd_counter != 1)
  96     FAIL_EXIT1 ("shrd_counter != {1,2} (%d)", shrd_counter);
  97
  98   mtx_destroy (&mutex);
  99
 100   return 0;
 101 }
 102
 103 #include <support/test-driver.c>