gdb/testsuite/gdb.base/interrupt-daemon.c

   1 /* This testcase is part of GDB, the GNU debugger.
   2
   3    Copyright 2017-2019 Free Software Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program 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
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  17
  18 #include <unistd.h>
  19 #include <stdlib.h>
  20 #include <assert.h>
  21
  22 static void
  23 daemon_main (void)
  24 {
  25 }
  26
  27 int
  28 main ()
  29 {
  30   pid_t child;
  31
  32   alarm (60);
  33
  34   /* Normally we're a progress group leader at this point, so can't
  35      create a session.  Fork so the child can create a new
  36      session.  */
  37   child = fork ();
  38   if (child == -1)
  39     return 1;
  40   else if (child != 0)
  41     return 0;
  42   else
  43     {
  44       /* In child.  Switch to a new session.  */
  45       pid_t session = setsid ();
  46       if (session == -1)
  47         return 1;
  48
  49       /* Fork again, so that the grand child (what we want to debug)
  50          can't accidentally acquire a controlling terminal, because
  51          it's not a session leader.  We're not opening any file here,
  52          but this is representative of what daemons do.  */
  53       child = fork ();
  54       if (child == -1)
  55         return 1;
  56       else if (child != 0)
  57         return 0;
  58
  59       /* In grandchild.  */
  60       daemon_main ();
  61
  62       while (1)
  63         sleep (1);
  64     }
  65
  66   return 0;
  67 }