1 /*-
2  * Copyright (c) 2008 Ganbold Tsagaankhuu
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer
10  *    in this position and unchanged.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  *
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/types.h>
33 #include <sys/wait.h>
34 #include <err.h>
35 #include <pthread.h>
36 #include <signal.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #include <unistd.h>
41 
42 #define NUM_THREADS 100
43 
44 static void *
45 vfork_test(void *threadid __unused)
46 {
47 	pid_t pid, wpid;
48 	int status;
49 
50 	for (;;) {
51 		pid = vfork();
52 		if (pid == 0)
53 			_exit(0);
54 		else if (pid == -1)
55 			err(1, "Failed to vfork");
56 		else {
57 			wpid = waitpid(pid, &status, 0);
58 			if (wpid == -1)
59 				err(1, "waitpid");
60 		}
61 	}
62 	return (NULL);
63 }
64 
65 static void
66 sighandler(int signo __unused)
67 {
68 }
69 
70 /*
71  * This program invokes multiple threads and each thread calls
72  * vfork() system call.
73  */
74 int
75 main(void)
76 {
77 	pthread_t threads[NUM_THREADS];
78 	struct sigaction reapchildren;
79 	sigset_t sigchld_mask;
80 	int rc, t;
81 
82 	memset(&reapchildren, 0, sizeof(reapchildren));
83 	reapchildren.sa_handler = sighandler;
84 	if (sigaction(SIGCHLD, &reapchildren, NULL) == -1)
85 		err(1, "Could not sigaction(SIGCHLD)");
86 
87 	sigemptyset(&sigchld_mask);
88 	sigaddset(&sigchld_mask, SIGCHLD);
89 	if (sigprocmask(SIG_BLOCK, &sigchld_mask, NULL) == -1)
90 		err(1, "sigprocmask");
91 
92 	for (t = 0; t < NUM_THREADS; t++) {
93 		rc = pthread_create(&threads[t], NULL, vfork_test, &t);
94 		if (rc)
95 			errc(1, rc, "pthread_create");
96 	}
97 	pause();
98 	return (0);
99 }
100