nptl/eintr.c

   1 /* Copyright (C) 2003-2020 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    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <pthread.h>
  20 #include <signal.h>
  21 #include <unistd.h>
  22 #include <support/xthread.h>
  23 #include <support/xsignal.h>
  24 #include <support/xthread.h>
  25
  26
  27 static int the_sig;
  28
  29
  30 static void
  31 eintr_handler (int sig)
  32 {
  33   if (sig != the_sig)
  34     {
  35       write (STDOUT_FILENO, "eintr_handler: signal number wrong\n", 35);
  36       _exit (1);
  37     }
  38   write (STDOUT_FILENO, ".", 1);
  39 }
  40
  41
  42 static void *
  43 eintr_source (void *arg)
  44 {
  45   struct timespec ts = { .tv_sec = 0, .tv_nsec = 500000 };
  46
  47   if (arg == NULL)
  48     {
  49       sigset_t ss;
  50       sigemptyset (&ss);
  51       sigaddset (&ss, the_sig);
  52       xpthread_sigmask (SIG_BLOCK, &ss, NULL);
  53     }
  54
  55   while (1)
  56     {
  57       if (arg != NULL)
  58         pthread_kill (*(pthread_t *) arg, the_sig);
  59       else
  60         kill (getpid (), the_sig);
  61
  62       nanosleep (&ts, NULL);
  63     }
  64
  65   /* NOTREACHED */
  66   return NULL;
  67 }
  68
  69
  70 static void
  71 setup_eintr (int sig, pthread_t *thp)
  72 {
  73   struct sigaction sa;
  74   sigemptyset (&sa.sa_mask);
  75   sa.sa_flags = 0;
  76   sa.sa_handler = eintr_handler;
  77   if (sigaction (sig, &sa, NULL) != 0)
  78     {
  79       puts ("setup_eintr: sigaction failed");
  80       exit (1);
  81     }
  82   the_sig = sig;
  83
  84   /* Create the thread which will fire off the signals.  */
  85   xpthread_create (NULL, eintr_source, thp);
  86 }