text: /* This testcase is part of GDB, the GNU debugger.
  
     Copyright 2004 Free Software Foundation, Inc.
  
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
     the Free Software Foundation; either version 2 of the License, or
     (at your option) any later version.
  
     This program is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     GNU General Public License for more details.
   
     You should have received a copy of the GNU General Public License
     along with this program; if not, write to the Free Software
     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  
  */
  
  #include <stdio.h>
  #include <string.h>
  #include <signal.h>
  #include <sys/time.h>
  
  static volatile int done;
  
  static void
  handler (int sig)
  {
    done = 1;
  } /* handler */
  
  struct itimerval itime;
  struct sigaction action;
  
  /* The enum is so that GDB can easily see these macro values.  */
  enum {
    itimer_real = ITIMER_REAL,
    itimer_virtual = ITIMER_VIRTUAL
  } itimer = ITIMER_VIRTUAL;
  
  main ()
  {
  
    /* Set up the signal handler.  */
    memset (&action, 0, sizeof (action));
    action.sa_handler = handler;
    sigaction (SIGVTALRM, &action, NULL);
    sigaction (SIGALRM, &action, NULL);
  
    /* The values needed for the itimer.  This needs to be at least long
       enough for the setitimer() call to return.  */
    memset (&itime, 0, sizeof (itime));
    itime.it_value.tv_usec = 250 * 1000;
  
    /* Loop for ever, constantly taking an interrupt.  */
    while (1)
      {
        /* Set up a one-off timer.  A timer, rather than SIGSEGV, is
  	 used as after a timer handler finishes the interrupted code
  	 can safely resume.  */
        setitimer (itimer, &itime, NULL);
        /* Wait.  */
        while (!done);
        done = 0;
      }
  }
  