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
108
|
/* Tests for pthread_mutex_timedlock function.
Copyright (C) 2000, 2001, 2002 Free Software Foundation, Inc.
Contributed by Kaz Kylheku <kaz@ashi.footprints.net>, 2000.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser 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. */
#include <errno.h>
#include <error.h>
#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <time.h>
#define NUM_THREADS 10
#define NUM_ITERS 50
#define TIMEOUT_NS 100000000L
static void *thread (void *) __attribute__ ((__noreturn__));
static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
int
main (void)
{
pthread_t th;
int i;
for (i = 0; i < NUM_THREADS; i++)
{
if (pthread_create (&th, NULL, thread, NULL) != 0)
error (EXIT_FAILURE, 0, "cannot create thread");
}
(void) thread (NULL);
/* notreached */
return 0;
}
static void *
thread (void *arg)
{
int i;
pthread_t self = pthread_self ();
static int linecount; /* protected by flockfile(stdout) */
for (i = 0; i < NUM_ITERS; i++)
{
struct timespec ts;
for (;;)
{
int err;
clock_gettime (CLOCK_REALTIME, &ts);
ts.tv_nsec += TIMEOUT_NS;
if (ts.tv_nsec >= 1000000000L) {
ts.tv_sec++;
ts.tv_nsec -= 1000000000L;
}
switch ((err = pthread_mutex_timedlock (&mutex, &ts)))
{
case 0:
flockfile (stdout);
printf ("%04d: thread %lu got mutex\n", ++linecount,
(unsigned long) self);
funlockfile (stdout);
break;
case ETIMEDOUT:
flockfile (stdout);
printf ("%04d: thread %lu timed out on mutex\n", ++linecount,
(unsigned long) self);
funlockfile (stdout);
continue;
default:
error (EXIT_FAILURE, err, "pthread_mutex_timedlock failure");
}
break;
}
ts.tv_sec = 0;
ts.tv_nsec = TIMEOUT_NS;
nanosleep (&ts, NULL);
flockfile (stdout);
printf ("%04d: thread %lu releasing mutex\n", ++linecount,
(unsigned long) self);
funlockfile (stdout);
pthread_mutex_unlock (&mutex);
}
pthread_exit (NULL);
}
|
