1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
|
/* Test for Pthreads/mutexes.
Copyright (C) 2000 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Kurt Garloff <garloff@suse.de>, 2000.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#define _GNU_SOURCE 1
#include <unistd.h>
#include <stdio.h>
#include <errno.h>
#include <pthread.h>
struct thr_ctrl
{
pthread_mutex_t mutex;
pthread_cond_t cond;
int retval;
};
void
dump_mut (pthread_mutex_t * mut)
{
int i;
for (i = 0; i < sizeof (*mut); i++)
printf (" %02x", *((unsigned char *) mut + i));
printf ("\n");
};
/* Helper, the opposite of pthread_cond_wait (cond, mut). */
void
pthr_cond_signal_mutex (pthread_cond_t * cond, pthread_mutex_t * mut)
{
int err;
if (err = pthread_mutex_lock (mut))
printf ("mutex_lock : %s\n", strerror (err));
if (err = pthread_cond_signal (cond))
printf ("cond_signal : %s\n", strerror (err));
if (err = pthread_mutex_unlock (mut))
printf ("mutex_unlock: %s\n", strerror (err));
}
void *
thread_start (void *ptr)
{
struct thr_ctrl *tc = ptr;
int err;
/* Do initialization. */
/* ... */
/* Signal that we are ready. */
pthr_cond_signal_mutex (&tc->cond, &tc->mutex);
sleep (2);
pthr_cond_signal_mutex (&tc->cond, &tc->mutex);
tc->retval = 0;
pthread_exit (&tc->retval);
}
int
main (void)
{
struct thr_ctrl threadctrl;
pthread_t thread;
int err;
int *res = &threadctrl.retval;
pthread_mutexattr_t mutattr;
pthread_mutexattr_init (&mutattr);
pthread_mutex_init (&threadctrl.mutex, &mutattr);
pthread_cond_init (&threadctrl.cond, NULL);
if (err = pthread_mutex_lock (&threadctrl.mutex))
printf ("mutex_lock : %s\n", strerror (err));
dump_mut (&threadctrl.mutex);
pthread_create (&thread, NULL, thread_start, &threadctrl);
/* Wait until it's ready. */
if (err = pthread_cond_wait (&threadctrl.cond, &threadctrl.mutex))
printf ("cond_wait : %s\n", strerror (err));
/* Now, we should have acquired the mutex again! */
dump_mut (&threadctrl.mutex);
sleep (1);
dump_mut (&threadctrl.mutex);
if (err = pthread_cond_wait (&threadctrl.cond, &threadctrl.mutex))
printf ("cond_wait : %s\n", strerror (err));
if (err)
{
printf ("ERROR\n");
abort ();
};
dump_mut (&threadctrl.mutex);
pthread_join (thread, (void **) &res);
printf ("OK\n");
return 0;
}
|
