1  /* Test that raise sends signal to current thread even if blocked.
       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  #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>