nptl/eintr.c

   1 /* Copyright (C) 2003-2017 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@redhat.com>, 2003.
   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 <pthread.h>
  20 #include <signal.h>
  21 #include <unistd.h>
  22
  23
  24 static int the_sig;
  25
  26
  27 static void
  28 eintr_handler (int sig)
  29 {
  30   if (sig != the_sig)
  31     {
  32       write (STDOUT_FILENO, "eintr_handler: signal number wrong\n", 35);
  33       _exit (1);
  34     }
  35   write (STDOUT_FILENO, ".", 1);
  36 }
  37
  38
  39 static void *
  40 eintr_source (void *arg)
  41 {
  42   struct timespec ts = { .tv_sec = 0, .tv_nsec = 500000 };
  43
  44   if (arg == NULL)
  45     {
  46       sigset_t ss;
  47       sigemptyset (&ss);
  48       sigaddset (&ss, the_sig);
  49       pthread_sigmask (SIG_BLOCK, &ss, NULL);
  50     }
  51
  52   while (1)
  53     {
  54       if (arg != NULL)
  55         pthread_kill (*(pthread_t *) arg, the_sig);
  56       else
  57         kill (getpid (), the_sig);
  58
  59       nanosleep (&ts, NULL);
  60     }
  61
  62   /* NOTREACHED */
  63   return NULL;
  64 }
  65
  66
  67 static void
  68 setup_eintr (int sig, pthread_t *thp)
  69 {
  70   struct sigaction sa;
  71   sigemptyset (&sa.sa_mask);
  72   sa.sa_flags = 0;
  73   sa.sa_handler = eintr_handler;
  74   if (sigaction (sig, &sa, NULL) != 0)
  75     {
  76       puts ("setup_eintr: sigaction failed");
  77       exit (1);
  78     }
  79   the_sig = sig;
  80
  81   /* Create the thread which will fire off the signals.  */
  82   pthread_t th;
  83   if (pthread_create (&th, NULL, eintr_source, thp) != 0)
  84     {
  85       puts ("setup_eintr: pthread_create failed");
  86       exit (1);
  87     }
  88 }