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
|
/* Copyright (c) 2016 Phoenix Systems
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.*/
#include <errno.h>
#include <fcntl.h>
#include <malloc.h>
#include <semaphore.h>
#include <stdarg.h>
#include <string.h>
#include <sys/dirent.h>
#include <sys/ioctl.h>
#include <sys/ipc.h>
#include <sys/stat.h>
#include <unistd.h>
int sem_init(sem_t *sem, int pshared, unsigned int value)
{
errno = ENOSYS;
return -1;
}
int sem_destroy(sem_t *sem)
{
errno = ENOSYS;
return -1;
}
sem_t *sem_open(const char *name, int oflag, ...)
{
sem_t *sem = (sem_t *) malloc(sizeof(sem_t));
if(sem == NULL) {
errno = ENOMEM;
return SEM_FAILED;
}
if (*name == '/')
++name;
char sem_name[PATH_MAX_SIZE + 24] = "/dev/ipc/sem_";
strncpy(sem_name + 13, name, PATH_MAX_SIZE + 10);
int mode = S_IRWXUGO;
int initval = 1;
if (oflag & O_CREAT) {
va_list ap;
va_start(ap, oflag);
mode = va_arg(ap, int);
initval = va_arg(ap, int);
va_end(ap);
}
sem->fd = open(sem_name, oflag, mode);
if (sem->fd != -1) {
int flags = fcntl(sem->fd, F_GETFD, 0);
if (flags >= 0) {
flags |= FD_CLOEXEC;
flags = fcntl (sem->fd, F_SETFD, flags);
}
if (flags == -1) {
close (sem->fd);
free(sem);
return SEM_FAILED;
}
}
else {
free(sem);
return SEM_FAILED;
}
if (sem != SEM_FAILED && (oflag | O_CREAT)) {
if (ioctl(sem->fd, IPC_SEM_INIT, initval) < 0) {
free(sem);
return SEM_FAILED;
}
}
return sem;
}
int sem_close(sem_t *sem)
{
if (sem == NULL || sem->fd < 0) {
errno = EINVAL;
return -1;
}
close(sem->fd);
free(sem);
return 0;
}
int sem_unlink(const char *name)
{
return unlink(name);
}
int sem_wait(sem_t *sem)
{
if(sem == NULL || sem->fd < 0) {
errno = EINVAL;
return -1;
}
return ioctl(sem->fd, IPC_SEM_DOWN, 0);
}
int sem_timedwait(sem_t * sem, const struct timespec *abs_timeout)
{
if(sem == NULL || sem->fd < 0) {
errno = EINVAL;
return -1;
}
return ioctl(sem->fd, IPC_SEM_DOWN_TIMEOUT, 0);
}
int sem_trywait(sem_t *sem)
{
if(sem == NULL || sem->fd < 0) {
errno = EINVAL;
return -1;
}
return ioctl(sem->fd, IPC_SEM_TRYDOWN, 0);
}
int sem_post(sem_t *sem)
{
if(sem == NULL || sem->fd < 0) {
errno = EINVAL;
return -1;
}
return ioctl(sem->fd, IPC_SEM_UP, 0);
}
int sem_getvalue (sem_t *sem, int *sval)
{
if(sem == NULL || sem->fd < 0) {
errno = EINVAL;
return -1;
}
return ioctl(sem->fd, IPC_SEM_GETVAL, (unsigned long) sval);
}
|
