sysdeps/pthread/eintr.c

   1 /* Copyright (C) 2003-2022 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <pthread.h>
  19 #include <signal.h>
  20 #include <unistd.h>
  21 #include <support/xthread.h>
  22 #include <support/xsignal.h>
  23 #include <support/xthread.h>
  24
  25
  26 static int the_sig;
  27
  28
  29 static void
  30 eintr_handler (int sig)
  31 {
  32   if (sig != the_sig)
  33     {
  34       write (STDOUT_FILENO, "eintr_handler: signal number wrong\n", 35);
  35       _exit (1);
  36     }
  37   write (STDOUT_FILENO, ".", 1);
  38 }
  39
  40
  41 static void *
  42 eintr_source (void *arg)
  43 {
  44   struct timespec ts = { .tv_sec = 0, .tv_nsec = 500000 };
  45
  46   if (arg == NULL)
  47     {
  48       sigset_t ss;
  49       sigemptyset (&ss);
  50       sigaddset (&ss, the_sig);
  51       xpthread_sigmask (SIG_BLOCK, &ss, NULL);
  52     }
  53
  54   while (1)
  55     {
  56       if (arg != NULL)
  57         pthread_kill (*(pthread_t *) arg, the_sig);
  58       else
  59         kill (getpid (), the_sig);
  60
  61       nanosleep (&ts, NULL);
  62     }
  63
  64   /* NOTREACHED */
  65   return NULL;
  66 }
  67
  68
  69 static void
  70 setup_eintr (int sig, pthread_t *thp)
  71 {
  72   struct sigaction sa;
  73   sigemptyset (&sa.sa_mask);
  74   sa.sa_flags = 0;
  75   sa.sa_handler = eintr_handler;
  76   if (sigaction (sig, &sa, NULL) != 0)
  77     {
  78       puts ("setup_eintr: sigaction failed");
  79       exit (1);
  80     }
  81   the_sig = sig;
  82
  83   /* Create the thread which will fire off the signals.  */
  84   xpthread_create (NULL, eintr_source, thp);
  85 }