1 /* This testcase is part of GDB, the GNU debugger. 2 3 Copyright 2004-2019 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 */ 19 20 #include <stdio.h> 21 #include <string.h> 22 #include <signal.h> 23 #include <sys/time.h> 24 #include <errno.h> 25 26 static volatile int done; 27 static volatile int dummy; 28 static volatile int no_handler; 29 30 static void 31 handler (int sig) 32 { 33 /* This is more than one write so that the breakpoint location below 34 is more than one instruction away. */ 35 done = 1; 36 done = 1; 37 done = 1; 38 done = 1; /* other handler location */ 39 } /* handler */ 40 41 struct itimerval itime; 42 struct sigaction action; 43 44 /* The enum is so that GDB can easily see these macro values. */ 45 enum { 46 itimer_real = ITIMER_REAL, 47 itimer_virtual = ITIMER_VIRTUAL 48 } itimer = ITIMER_VIRTUAL; 49 50 int 51 main () 52 { 53 int res; 54 55 /* Set up the signal handler. */ 56 memset (&action, 0, sizeof (action)); 57 action.sa_handler = no_handler ? SIG_IGN : handler; 58 sigaction (SIGVTALRM, &action, NULL); 59 sigaction (SIGALRM, &action, NULL); 60 61 /* The values needed for the itimer. This needs to be at least long 62 enough for the setitimer() call to return. */ 63 memset (&itime, 0, sizeof (itime)); 64 itime.it_value.tv_usec = 250 * 1000; 65 66 /* Loop for ever, constantly taking an interrupt. */ 67 while (1) 68 { 69 /* Set up a one-off timer. A timer, rather than SIGSEGV, is 70 used as after a timer handler finishes the interrupted code 71 can safely resume. */ 72 res = setitimer (itimer, &itime, NULL); 73 if (res == -1) 74 { 75 printf ("First call to setitimer failed, errno = %d\r\n",errno); 76 itimer = ITIMER_REAL; 77 res = setitimer (itimer, &itime, NULL); 78 if (res == -1) 79 { 80 printf ("Second call to setitimer failed, errno = %d\r\n",errno); 81 return 1; 82 } 83 } 84 /* Wait. Issue a couple writes to a dummy volatile var to be 85 reasonably sure our simple "get-next-pc" logic doesn't 86 stumble on branches. */ 87 dummy = 0; dummy = 0; while (!done); 88 done = 0; 89 } 90 return 0; 91 } 92