1 /* $NetBSD: test_readhappy.c,v 1.1 2018/04/20 00:06:45 kamil Exp $ */
2
3 /*
4 * Copyright (c) 2018 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29 #include <err.h>
30 #include <errno.h>
31 #include <pthread.h>
32 #include <stdio.h>
33 #include <stdlib.h>
34
35 /*
36 * Compile this program with -pthread and run it to test the readhappy_mpsafe
37 * module. This program should print out happy numbers read from /dev/happy_mpsafe.
38 * Insert the module and make the /dev/happy_mpsafe node before executing this file.
39 */
40
41
42 static void* read_happy(void *);
43
44 static FILE *fp;
45
46 /*
47 * thread function used to read /dev/happy_mpsafe and print them out.
48 */
49 static void *
read_happy(void * unused)50 read_happy(void *unused)
51 {
52 int line;
53
54 for (;;) {
55 fscanf(fp, "%d", &line);
56 printf("%d\n", line);
57 fflush(stdout);
58 }
59 /* NOTREACHED */
60 return NULL;
61 }
62
63 /*
64 * main function : opens /dev/happy_mpsafe and sets the global file descriptor
65 * creates 100 threads which try to use the file descriptor to read
66 * from /dev/happy_mpsafe.
67 * This function does not return anything and will run in an infinite loop.
68 */
69 int
main(int argc,const char * argv[])70 main(int argc, const char *argv[])
71 {
72 pthread_t thr[100];
73
74 fp = fopen("/dev/happy_mpsafe","r");
75 if (fp == NULL)
76 err(EXIT_FAILURE, "open");
77 for (int i = 0; i < 100; i++)
78 pthread_create(&thr[i], NULL, read_happy, NULL);
79 (void)read_happy(NULL);
80 /* NOTREACHED */
81 return EXIT_SUCCESS;
82 }
83