gdb/testsuite/gdb.base/sigstep.c

   1 /* This testcase is part of GDB, the GNU debugger.
   2
   3    Copyright 2004, 2007 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 */
  19
  20 #include <stdio.h>
  21 #include <string.h>
  22 #include <signal.h>
  23 #include <sys/time.h>
  24
  25 static volatile int done;
  26
  27 static void
  28 handler (int sig)
  29 {
  30   done = 1;
  31 } /* handler */
  32
  33 struct itimerval itime;
  34 struct sigaction action;
  35
  36 /* The enum is so that GDB can easily see these macro values.  */
  37 enum {
  38   itimer_real = ITIMER_REAL,
  39   itimer_virtual = ITIMER_VIRTUAL
  40 } itimer = ITIMER_VIRTUAL;
  41
  42 main ()
  43 {
  44
  45   /* Set up the signal handler.  */
  46   memset (&action, 0, sizeof (action));
  47   action.sa_handler = handler;
  48   sigaction (SIGVTALRM, &action, NULL);
  49   sigaction (SIGALRM, &action, NULL);
  50
  51   /* The values needed for the itimer.  This needs to be at least long
  52      enough for the setitimer() call to return.  */
  53   memset (&itime, 0, sizeof (itime));
  54   itime.it_value.tv_usec = 250 * 1000;
  55
  56   /* Loop for ever, constantly taking an interrupt.  */
  57   while (1)
  58     {
  59       /* Set up a one-off timer.  A timer, rather than SIGSEGV, is
  60          used as after a timer handler finishes the interrupted code
  61          can safely resume.  */
  62       setitimer (itimer, &itime, NULL);
  63       /* Wait.  */
  64       while (!done);
  65       done = 0;
  66     }
  67 }