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
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
|
/* Copyright (C) 2002-2021 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 <errno.h>
#include <pthread.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/wait.h>
static int
do_test (void)
{
size_t ps = sysconf (_SC_PAGESIZE);
char tmpfname[] = "/tmp/tst-rwlock4.XXXXXX";
char data[ps];
void *mem;
int fd;
pthread_rwlock_t *r;
pthread_rwlockattr_t a;
pid_t pid;
char *p;
int err;
int s;
fd = mkstemp (tmpfname);
if (fd == -1)
{
printf ("cannot open temporary file: %m\n");
return 1;
}
/* Make sure it is always removed. */
unlink (tmpfname);
/* Create one page of data. */
memset (data, '\0', ps);
/* Write the data to the file. */
if (write (fd, data, ps) != (ssize_t) ps)
{
puts ("short write");
return 1;
}
mem = mmap (NULL, ps, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
if (mem == MAP_FAILED)
{
printf ("mmap failed: %m\n");
return 1;
}
r = (pthread_rwlock_t *) (((uintptr_t) mem + __alignof (pthread_rwlock_t))
& ~(__alignof (pthread_rwlock_t) - 1));
p = (char *) (r + 1);
if (pthread_rwlockattr_init (&a) != 0)
{
puts ("rwlockattr_init failed");
return 1;
}
if (pthread_rwlockattr_getpshared (&a, &s) != 0)
{
puts ("1st rwlockattr_getpshared failed");
return 1;
}
if (s != PTHREAD_PROCESS_PRIVATE)
{
puts ("default pshared value wrong");
return 1;
}
if (pthread_rwlockattr_setpshared (&a, PTHREAD_PROCESS_SHARED) != 0)
{
puts ("rwlockattr_setpshared failed");
return 1;
}
if (pthread_rwlockattr_getpshared (&a, &s) != 0)
{
puts ("2nd rwlockattr_getpshared failed");
return 1;
}
if (s != PTHREAD_PROCESS_SHARED)
{
puts ("pshared value after setpshared call wrong");
return 1;
}
if (pthread_rwlock_init (r, &a) != 0)
{
puts ("rwlock_init failed");
return 1;
}
if (pthread_rwlock_rdlock (r) != 0)
{
puts ("rwlock_rdlock failed");
return 1;
}
if (pthread_rwlockattr_destroy (&a) != 0)
{
puts ("rwlockattr_destroy failed");
return 1;
}
err = pthread_rwlock_trywrlock (r);
if (err == 0)
{
puts ("rwlock_trywrlock succeeded");
return 1;
}
else if (err != EBUSY)
{
puts ("rwlock_trywrlock didn't return EBUSY");
return 1;
}
*p = 0;
puts ("going to fork now");
pid = fork ();
if (pid == -1)
{
puts ("fork failed");
return 1;
}
else if (pid == 0)
{
/* Play some lock ping-pong. It's our turn to unlock first. */
if ((*p)++ != 0)
{
puts ("child: *p != 0");
return 1;
}
if (pthread_rwlock_unlock (r) != 0)
{
puts ("child: 1st rwlock_unlock failed");
return 1;
}
puts ("child done");
}
else
{
if (pthread_rwlock_wrlock (r) != 0)
{
puts ("parent: rwlock_wrlock failed");
return 1;
}
if (*p != 1)
{
puts ("*p != 1");
return 1;
}
puts ("parent done");
}
return 0;
}
#define TEST_FUNCTION do_test ()
#include "../test-skeleton.c"
|
