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/types.h>
30 #include <sys/wait.h>
31 #include <err.h>
32 #include <pthread.h>
33 #include <signal.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include <unistd.h>
38 
39 #define NUM_THREADS 100
40 
41 static void *
42 vfork_test(void *threadid __unused)
43 {
44 	pid_t pid, wpid;
45 	int status;
46 
47 	for (;;) {
48 		pid = vfork();
49 		if (pid == 0)
50 			_exit(0);
51 		else if (pid == -1)
52 			err(1, "Failed to vfork");
53 		else {
54 			wpid = waitpid(pid, &status, 0);
55 			if (wpid == -1)
56 				err(1, "waitpid");
57 		}
58 	}
59 	return (NULL);
60 }
61 
62 static void
63 sighandler(int signo __unused)
64 {
65 }
66 
67 /*
68  * This program invokes multiple threads and each thread calls
69  * vfork() system call.
70  */
71 int
72 main(void)
73 {
74 	pthread_t threads[NUM_THREADS];
75 	struct sigaction reapchildren;
76 	sigset_t sigchld_mask;
77 	int rc, t;
78 
79 	memset(&reapchildren, 0, sizeof(reapchildren));
80 	reapchildren.sa_handler = sighandler;
81 	if (sigaction(SIGCHLD, &reapchildren, NULL) == -1)
82 		err(1, "Could not sigaction(SIGCHLD)");
83 
84 	sigemptyset(&sigchld_mask);
85 	sigaddset(&sigchld_mask, SIGCHLD);
86 	if (sigprocmask(SIG_BLOCK, &sigchld_mask, NULL) == -1)
87 		err(1, "sigprocmask");
88 
89 	for (t = 0; t < NUM_THREADS; t++) {
90 		rc = pthread_create(&threads[t], NULL, vfork_test, &t);
91 		if (rc)
92 			errc(1, rc, "pthread_create");
93 	}
94 	pause();
95 	return (0);
96 }
97