1 /* $OpenBSD: switch.c,v 1.7 2022/12/04 23:50:46 cheloha Exp $ */
2 /*
3 * Copyright (c) 1993, 1994, 1995, 1996 by Chris Provenzano and contributors,
4 * proven@mit.edu All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
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 * 3. All advertising materials mentioning features or use of this software
15 * must display the following acknowledgement:
16 * This product includes software developed by Chris Provenzano,
17 * the University of California, Berkeley, and contributors.
18 * 4. Neither the name of Chris Provenzano, the University, nor the names of
19 * contributors may be used to endorse or promote products derived
20 * from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY CHRIS PROVENZANO AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL CHRIS PROVENZANO, THE REGENTS OR
26 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
27 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
28 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
29 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
30 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
31 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
32 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 */
34
35 /* ==== test_switch.c ========================================================
36 * Copyright (c) 1993 by Chris Provenzano, proven@athena.mit.edu
37 *
38 * Description : Test context switch functionality.
39 *
40 * 1.00 93/08/04 proven
41 * -Started coding this file.
42 */
43
44 #include <pthread.h>
45 #include <stdio.h>
46 #include <err.h>
47 #include <errno.h>
48 #include <unistd.h>
49 #include <stdlib.h>
50
51 #include "test.h"
52
53 const char buf[] = "abcdefghijklmnopqrstuvwxyz";
54 char x[sizeof(buf)];
55
56 volatile int ending = 0;
57
58 /* ==========================================================================
59 * usage();
60 */
61 static __dead void
usage(void)62 usage(void)
63 {
64 fprintf(stderr, "usage: %s [-c count]\n", getprogname());
65 fprintf(stderr, "count is number of theads, between 2 and 26\n");
66 exit(1);
67 }
68
69 static void *
new_thread(void * arg)70 new_thread(void *arg)
71 {
72 int i;
73
74 SET_NAME("writer");
75 while (!ending) {
76 CHECKe(write(STDOUT_FILENO, (char *) arg, 1));
77 x[(char *)arg - buf] = 1;
78 for (i = 0; i < 999999; i += 1)
79 ;
80 }
81 return NULL;
82 }
83
84 int
main(int argc,char * argv[])85 main(int argc, char *argv[])
86 {
87 pthread_t thread;
88 int ch, count = 4;
89 long i;
90 const char *errstr;
91
92 while ((ch = getopt(argc, argv, "c:")) != -1) {
93 switch (ch) {
94 case 'c':
95 count = strtonum(optarg, 2, 26, &errstr);
96 if (errstr != NULL)
97 errx(1, "count is %s: %s", errstr, optarg);
98 break;
99 default:
100 usage();
101 }
102 }
103
104 /* create the threads */
105 for (i = 0; i < count; i++)
106 CHECKr(pthread_create(&thread, NULL, new_thread,
107 (void*)(buf+i)));
108
109 /* give all threads a chance to run */
110 sleep (2);
111
112 ending = 1;
113 for (i = 0; i < count; i++)
114 ASSERT(x[i]); /* make sure each thread ran */
115
116 CHECKe(write(STDOUT_FILENO, "\n", 1));
117 SUCCEED;
118 }
119