gnu/dist/gdb6/gdb/testsuite/gdb.base/sigstep.c

   1 /* This testcase is part of GDB, the GNU debugger.
   2
   3    Copyright 2004 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 2 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, write to the Free Software
  17    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  18
  19 */
  20
  21 #include <stdio.h>
  22 #include <string.h>
  23 #include <signal.h>
  24 #include <sys/time.h>
  25
  26 static volatile int done;
  27
  28 static void
  29 handler (int sig)
  30 {
  31   done = 1;
  32 } /* handler */
  33
  34 struct itimerval itime;
  35 struct sigaction action;
  36
  37 /* The enum is so that GDB can easily see these macro values.  */
  38 enum {
  39   itimer_real = ITIMER_REAL,
  40   itimer_virtual = ITIMER_VIRTUAL
  41 } itimer = ITIMER_VIRTUAL;
  42
  43 main ()
  44 {
  45
  46   /* Set up the signal handler.  */
  47   memset (&action, 0, sizeof (action));
  48   action.sa_handler = handler;
  49   sigaction (SIGVTALRM, &action, NULL);
  50   sigaction (SIGALRM, &action, NULL);
  51
  52   /* The values needed for the itimer.  This needs to be at least long
  53      enough for the setitimer() call to return.  */
  54   memset (&itime, 0, sizeof (itime));
  55   itime.it_value.tv_usec = 250 * 1000;
  56
  57   /* Loop for ever, constantly taking an interrupt.  */
  58   while (1)
  59     {
  60       /* Set up a one-off timer.  A timer, rather than SIGSEGV, is
  61          used as after a timer handler finishes the interrupted code
  62          can safely resume.  */
  63       setitimer (itimer, &itime, NULL);
  64       /* Wait.  */
  65       while (!done);
  66       done = 0;
  67     }
  68 }