sysdeps/pthread/tst-pthread-raise-blocked-self.c

   1 /* Test that raise sends signal to current thread even if blocked.
   2    Copyright (C) 2021-2024 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 <signal.h>
  20 #include <support/check.h>
  21 #include <support/xsignal.h>
  22 #include <support/xthread.h>
  23 #include <pthread.h>
  24 #include <unistd.h>
  25
  26 /* Used to create a dummy thread ID distinct from all other thread
  27    IDs.  */
  28 static void *
  29 noop (void *ignored)
  30 {
  31   return NULL;
  32 }
  33
  34 static volatile pthread_t signal_thread;
  35
  36 static void
  37 signal_handler (int signo)
  38 {
  39   signal_thread = pthread_self ();
  40 }
  41
  42 /* Used to ensure that waiting_thread has launched and can accept
  43    signals.  */
  44 static pthread_barrier_t barrier;
  45
  46 static void *
  47 waiting_thread (void *ignored)
  48 {
  49   xpthread_barrier_wait (&barrier);
  50   pause ();
  51   return NULL;
  52 }
  53
  54 static int
  55 do_test (void)
  56 {
  57   xsignal (SIGUSR1, signal_handler);
  58   xpthread_barrier_init (&barrier, NULL, 2);
  59
  60   /* Distinct thread ID value to */
  61   pthread_t dummy = xpthread_create (NULL, noop, NULL);
  62   signal_thread = dummy;
  63
  64   pthread_t helper = xpthread_create (NULL, waiting_thread, NULL);
  65
  66   /* Make sure that the thread is running.  */
  67   xpthread_barrier_wait (&barrier);
  68
  69   /* Block signals on this thread.  */
  70   sigset_t set;
  71   sigfillset (&set);
  72   xpthread_sigmask (SIG_BLOCK, &set, NULL);
  73
  74   /* Send the signal to this thread.  It must not be delivered.  */
  75   raise (SIGUSR1);
  76   TEST_VERIFY (signal_thread == dummy);
  77
  78   /* Wait a bit to give a chance for signal delivery (increases
  79      chances of failure with bug 28407).  */
  80   usleep (50 * 1000);
  81
  82   /* Unblocking should cause synchronous delivery of the signal.  */
  83   xpthread_sigmask (SIG_UNBLOCK, &set, NULL);
  84   TEST_VERIFY (signal_thread == pthread_self ());
  85
  86   xpthread_cancel (helper);
  87   xpthread_join (helper);
  88   xpthread_join (dummy);
  89   return 0;
  90 }
  91
  92 #include <support/test-driver.c>