1 /*
2 * Copyright (c) 2002-2003, Intel Corporation. All rights reserved.
3 * Created by: Rusty.Lnch REMOVE-THIS AT intel DOT com
4 * This file is licensed under the GPL license. For the full content
5 * of this license, see the COPYING file at the top level of this
6 * source tree.
7
8 Test assertion #9 by verifying that SIGCHLD signals are not sent when
9 the parent has setup a SIGCHLD signal handler with the SA_NOCLDSTOP flag set
10 * 12/18/02 - Adding in include of sys/time.h per
11 * rodrigc REMOVE-THIS AT attbi DOT com input that it needs
12 * to be included whenever the timeval struct is used.
13 *
14 */
15
16 /*
17 * adam.li@intel.com: 2004-05-26: select should block child
18 */
19
20 #include <signal.h>
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include <sys/select.h>
24 #include <sys/wait.h>
25 #include <sys/time.h>
26 #include <sys/types.h>
27 #include <unistd.h>
28
29 #define NUMSTOPS 10
30
31 volatile int child_stopped = 0;
32
handler(int signo,siginfo_t * info,void * context)33 void handler(int signo, siginfo_t * info, void *context)
34 {
35 if (info && info->si_code == CLD_STOPPED) {
36 printf("Child has been stopped\n");
37 child_stopped++;
38 }
39 }
40
main(void)41 int main(void)
42 {
43 pid_t pid;
44 struct sigaction act;
45 struct timeval tv;
46
47 act.sa_sigaction = handler;
48 act.sa_flags = SA_SIGINFO | SA_NOCLDSTOP;
49 sigemptyset(&act.sa_mask);
50 sigaction(SIGCHLD, &act, 0);
51
52 if ((pid = fork()) == 0) {
53 /* child */
54 /* wait forever, or until we are
55 interrupted by a signal */
56 select(0, NULL, NULL, NULL, NULL);
57 return 0;
58 } else {
59 /* parent */
60 int s;
61 int i;
62
63 for (i = 0; i < NUMSTOPS; i++) {
64 printf("--> Sending SIGSTOP\n");
65 kill(pid, SIGSTOP);
66
67 /*
68 If we send a bunch of SIGSTOP/SIGCONT
69 signals one after the other then it is
70 perfectly OK for the OS to not send
71 the SIGSTOP/SIGCONT combination as an
72 optimization.
73
74 I can't think of any POSIX method to determine
75 if a process has been stopped, so I'm
76 going to punt with a one second sleep and
77 assume the child process gets put to sleep
78 within that time period. This will be problem
79 when this test is run on a really stressed
80 system. (Although since we are sending multiple
81 SIGSTOP's then maybe in practice this will
82 cause any problems.)
83 */
84 tv.tv_sec = 1;
85 tv.tv_usec = 0;
86 select(0, NULL, NULL, NULL, &tv);
87
88 printf("--> Sending SIGCONT\n");
89 kill(pid, SIGCONT);
90 }
91
92 kill(pid, SIGKILL);
93 waitpid(pid, &s, 0);
94 }
95
96 if (child_stopped == 0) {
97 printf("Test PASSED\n");
98 return 0;
99 }
100
101 printf("Test FAILED\n");
102 return -1;
103 }
104