1 /******************************************************************************/ 2 /* */ 3 /* Copyright (c) 2009 FUJITSU LIMITED */ 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 */ 13 /* the 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ 18 /* */ 19 /* Author: Shi Weihua <shiwh (at) cn.fujitsu.com> */ 20 /* */ 21 /******************************************************************************/ 22 23 #include <sys/types.h> 24 #include <sys/wait.h> 25 #include <err.h> 26 #include <errno.h> 27 #include <signal.h> 28 #include <stdlib.h> 29 #include <unistd.h> 30 #include <stdio.h> 31 32 #define UNUSED __attribute__ ((unused)) 33 34 static int test_switch = 0; 35 36 void sighandler(UNUSED int signo) 37 { 38 test_switch = !test_switch; 39 } 40 41 int main(void) 42 { 43 sigset_t signalset; 44 struct sigaction sa; 45 pid_t pid; 46 int status; 47 int count = 0; 48 49 sa.sa_handler = sighandler; 50 if (sigemptyset(&sa.sa_mask) < 0) 51 err(1, "sigemptyset()"); 52 53 sa.sa_flags = 0; 54 if (sigaction(SIGUSR1, &sa, NULL) < 0) 55 err(1, "sigaction()"); 56 57 if (sigemptyset(&signalset) < 0) 58 err(1, "sigemptyset()"); 59 60 /* wait for the signal SIGUSR1 to start testing */ 61 sigsuspend(&signalset); 62 if (errno != EINTR) 63 err(1, "sigsuspend()"); 64 65 do { 66 count++; 67 pid = fork(); 68 if (pid == -1) 69 err(1, "fork()"); 70 else if (pid == 0) { 71 return 0; 72 } else { 73 wait(&status); 74 } 75 } while (test_switch); 76 77 return 0; 78 } 79
