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
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
|
/* Copyright (C) 2002-2023 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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; if not, see
<https://www.gnu.org/licenses/>. */
#include <error.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
static pthread_mutex_t mut = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
static pthread_barrier_t bar;
static void *
tf (void *a)
{
int i = (long int) a;
int err;
printf ("child %d: lock\n", i);
err = pthread_mutex_lock (&mut);
if (err != 0)
error (EXIT_FAILURE, err, "locking in child failed");
printf ("child %d: sync\n", i);
int e = pthread_barrier_wait (&bar);
if (e != 0 && e != PTHREAD_BARRIER_SERIAL_THREAD)
{
puts ("child: barrier_wait failed");
exit (1);
}
printf ("child %d: wait\n", i);
err = pthread_cond_wait (&cond, &mut);
if (err != 0)
error (EXIT_FAILURE, err, "child %d: failed to wait", i);
printf ("child %d: woken up\n", i);
err = pthread_mutex_unlock (&mut);
if (err != 0)
error (EXIT_FAILURE, err, "child %d: unlock[2] failed", i);
printf ("child %d: done\n", i);
return NULL;
}
#define N 10
static int
do_test (void)
{
pthread_t th[N];
int i;
int err;
printf ("&cond = %p\n&mut = %p\n", &cond, &mut);
if (pthread_barrier_init (&bar, NULL, 2) != 0)
{
puts ("barrier_init failed");
exit (1);
}
pthread_attr_t at;
if (pthread_attr_init (&at) != 0)
{
puts ("attr_init failed");
return 1;
}
if (pthread_attr_setstacksize (&at, 1 * 1024 * 1024) != 0)
{
puts ("attr_setstacksize failed");
return 1;
}
for (i = 0; i < N; ++i)
{
printf ("create thread %d\n", i);
err = pthread_create (&th[i], &at, tf, (void *) (long int) i);
if (err != 0)
error (EXIT_FAILURE, err, "cannot create thread %d", i);
printf ("wait for child %d\n", i);
/* Wait for the child to start up and get the mutex for the
conditional variable. */
int e = pthread_barrier_wait (&bar);
if (e != 0 && e != PTHREAD_BARRIER_SERIAL_THREAD)
{
puts ("barrier_wait failed");
exit (1);
}
}
if (pthread_attr_destroy (&at) != 0)
{
puts ("attr_destroy failed");
return 1;
}
puts ("get lock ourselves");
err = pthread_mutex_lock (&mut);
if (err != 0)
error (EXIT_FAILURE, err, "mut locking failed");
puts ("broadcast");
/* Wake up all threads. */
err = pthread_cond_broadcast (&cond);
if (err != 0)
error (EXIT_FAILURE, err, "parent: broadcast failed");
err = pthread_mutex_unlock (&mut);
if (err != 0)
error (EXIT_FAILURE, err, "mut unlocking failed");
/* Join all threads. */
for (i = 0; i < N; ++i)
{
printf ("join thread %d\n", i);
err = pthread_join (th[i], NULL);
if (err != 0)
error (EXIT_FAILURE, err, "join of child %d failed", i);
}
puts ("done");
return 0;
}
#define TEST_FUNCTION do_test ()
#include "../test-skeleton.c"
|
