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@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
sighandler(UNUSED int signo)36 void sighandler(UNUSED int signo)
37 {
38 test_switch = !test_switch;
39 }
40
main(void)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