sysdeps/pthread/tst-pthread_kill-exiting.c

   1 /* Test that pthread_kill succeeds during thread exit.
   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 /* This test verifies that pthread_kill for a thread that is exiting
  20    succeeds (with or without actually delivering the signal).  */
  21
  22 #include <array_length.h>
  23 #include <stdbool.h>
  24 #include <stddef.h>
  25 #include <support/xsignal.h>
  26 #include <support/xthread.h>
  27 #include <unistd.h>
  28
  29 /* Set to true by timeout_thread_function when the test should
  30    terminate.  */
  31 static bool timeout;
  32
  33 static void *
  34 timeout_thread_function (void *unused)
  35 {
  36   usleep (1000 * 1000);
  37   __atomic_store_n (&timeout, true, __ATOMIC_RELAXED);
  38   return NULL;
  39 }
  40
  41 /* Used to synchronize the sending threads with the target thread and
  42    main thread.  */
  43 static pthread_barrier_t barrier_1;
  44 static pthread_barrier_t barrier_2;
  45
  46 /* The target thread to which signals are to be sent.  */
  47 static pthread_t target_thread;
  48
  49 /* Set by the main thread to true after timeout has been set to
  50    true.  */
  51 static bool exiting;
  52
  53 static void *
  54 sender_thread_function (void *unused)
  55 {
  56   while (true)
  57     {
  58       /* Wait until target_thread has been initialized.  The target
  59          thread and main thread participate in this barrier.  */
  60       xpthread_barrier_wait (&barrier_1);
  61
  62       if (exiting)
  63         break;
  64
  65       xpthread_kill (target_thread, SIGUSR1);
  66
  67       /* Communicate that the signal has been sent.  The main thread
  68          participates in this barrier.  */
  69       xpthread_barrier_wait (&barrier_2);
  70     }
  71   return NULL;
  72 }
  73
  74 static void *
  75 target_thread_function (void *unused)
  76 {
  77   target_thread = pthread_self ();
  78   xpthread_barrier_wait (&barrier_1);
  79   return NULL;
  80 }
  81
  82 static int
  83 do_test (void)
  84 {
  85   xsignal (SIGUSR1, SIG_IGN);
  86
  87   pthread_t thr_timeout = xpthread_create (NULL, timeout_thread_function, NULL);
  88
  89   pthread_t threads[4];
  90   xpthread_barrier_init (&barrier_1, NULL, array_length (threads) + 2);
  91   xpthread_barrier_init (&barrier_2, NULL, array_length (threads) + 1);
  92
  93   for (int i = 0; i < array_length (threads); ++i)
  94     threads[i] = xpthread_create (NULL, sender_thread_function, NULL);
  95
  96   while (!__atomic_load_n (&timeout, __ATOMIC_RELAXED))
  97     {
  98       xpthread_create (NULL, target_thread_function, NULL);
  99
 100       /* Wait for the target thread to be set up and signal sending to
 101          start.  */
 102       xpthread_barrier_wait (&barrier_1);
 103
 104       /* Wait for signal sending to complete.  */
 105       xpthread_barrier_wait (&barrier_2);
 106
 107       xpthread_join (target_thread);
 108     }
 109
 110   exiting = true;
 111
 112   /* Signal the sending threads to exit.  */
 113   xpthread_create (NULL, target_thread_function, NULL);
 114   xpthread_barrier_wait (&barrier_1);
 115
 116   for (int i = 0; i < array_length (threads); ++i)
 117     xpthread_join (threads[i]);
 118   xpthread_join (thr_timeout);
 119
 120   return 0;
 121 }
 122
 123 #include <support/test-driver.c>