support/delayed_exit.c

   1 /* Time-triggered process termination.
   2    Copyright (C) 2016-2023 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 <support/xthread.h>
  20 #include <support/xsignal.h>
  21
  22 #include <stdint.h>
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <support/check.h>
  26 #include <support/support.h>
  27 #include <time.h>
  28 #include <unistd.h>
  29
  30 struct delayed_exit_request
  31 {
  32   void (*exitfunc) (int);
  33   int seconds;
  34 };
  35
  36 static void *
  37 delayed_exit_thread (void *closure)
  38 {
  39   struct delayed_exit_request *request = closure;
  40   void (*exitfunc) (int) = request->exitfunc;
  41   struct timespec delay = { request->seconds, 0 };
  42   struct timespec remaining = { 0 };
  43   free (request);
  44
  45   if (nanosleep (&delay, &remaining) != 0)
  46     FAIL_EXIT1 ("nanosleep: %m");
  47   /* Exit the process successfully.  */
  48   exitfunc (0);
  49   return NULL;
  50 }
  51
  52 static void
  53 delayed_exit_1 (int seconds, void (*exitfunc) (int))
  54 {
  55   /* Create the new thread with all signals blocked.  */
  56   sigset_t all_blocked;
  57   sigfillset (&all_blocked);
  58   sigset_t old_set;
  59   xpthread_sigmask (SIG_SETMASK, &all_blocked, &old_set);
  60   struct delayed_exit_request *request = xmalloc (sizeof (*request));
  61   request->seconds = seconds;
  62   request->exitfunc = exitfunc;
  63   /* Create a detached thread. */
  64   pthread_t thr = xpthread_create (NULL, delayed_exit_thread, request);
  65   xpthread_detach (thr);
  66   /* Restore the original signal mask.  */
  67   xpthread_sigmask (SIG_SETMASK, &old_set, NULL);
  68 }
  69
  70 void
  71 delayed_exit (int seconds)
  72 {
  73   delayed_exit_1 (seconds, exit);
  74 }
  75
  76 void
  77 delayed__exit (int seconds)
  78 {
  79   delayed_exit_1 (seconds, _exit);
  80 }