1 /*
2 * Copyright (c) 2008 Bret S. Lambert <blambert@openbsd.org>
3 *
4 * Permission to use, copy, modify, and distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
7 *
8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15 */
16
17 #include <err.h>
18 #include <errno.h>
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <string.h>
22 #include <unistd.h>
23 #include <pthread.h>
24
25 #define THREAD_COUNT 64
26
27 #define TEXT "barnacles"
28 #define TEXT_N "barnacles\n"
29
30 void run_threads(void (*)(void *), void *);
31
32 static pthread_rwlock_t start;
33 static void (*real_func)(void *);
34
35 static void *
thread(void * arg)36 thread(void *arg)
37 {
38 int r;
39
40 if ((r = pthread_rwlock_rdlock(&start)))
41 errc(1, r, "could not obtain lock in thread");
42 real_func(arg);
43 if ((r = pthread_rwlock_unlock(&start)))
44 errc(1, r, "could not release lock in thread");
45 return NULL;
46 }
47
48 void
run_threads(void (* func)(void *),void * arg)49 run_threads(void (*func)(void *), void *arg)
50 {
51 pthread_t self, pthread[THREAD_COUNT];
52 int i, r;
53
54 self = pthread_self();
55 real_func = func;
56 if ((r = pthread_rwlock_init(&start, NULL)))
57 errc(1, r, "could not initialize lock");
58
59 if ((r = pthread_rwlock_wrlock(&start))) /* block */
60 errc(1, r, "could not lock lock");
61
62 for (i = 0; i < THREAD_COUNT; i++)
63 if ((r = pthread_create(&pthread[i], NULL, thread, arg))) {
64 warnc(r, "could not create thread");
65 pthread[i] = self;
66 }
67
68
69 if ((r = pthread_rwlock_unlock(&start))) /* unleash */
70 errc(1, r, "could not release lock");
71
72 sleep(1);
73
74 if ((r = pthread_rwlock_wrlock(&start))) /* sync */
75 errx(1, "parent could not sync with children: %s",
76 strerror(r));
77
78 for (i = 0; i < THREAD_COUNT; i++)
79 if (! pthread_equal(pthread[i], self) &&
80 (r = pthread_join(pthread[i], NULL)))
81 warnc(r, "could not join thread");
82 }
83
84