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
|
#include "ruby/config.h"
#if defined _WIN32
#elif defined HAVE_FCNTL && defined HAVE_FCNTL_H
/* These are the flock() constants. Since this sytems doesn't have
flock(), the values of the constants are probably not available.
*/
# ifndef LOCK_SH
# define LOCK_SH 1
# endif
# ifndef LOCK_EX
# define LOCK_EX 2
# endif
# ifndef LOCK_NB
# define LOCK_NB 4
# endif
# ifndef LOCK_UN
# define LOCK_UN 8
# endif
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
int
flock(int fd, int operation)
{
struct flock lock;
switch (operation & ~LOCK_NB) {
case LOCK_SH:
lock.l_type = F_RDLCK;
break;
case LOCK_EX:
lock.l_type = F_WRLCK;
break;
case LOCK_UN:
lock.l_type = F_UNLCK;
break;
default:
errno = EINVAL;
return -1;
}
lock.l_whence = SEEK_SET;
lock.l_start = lock.l_len = 0L;
return fcntl(fd, (operation & LOCK_NB) ? F_SETLK : F_SETLKW, &lock);
}
#elif defined(HAVE_LOCKF)
#include <unistd.h>
#include <errno.h>
/* Emulate flock() with lockf() or fcntl(). This is just to increase
portability of scripts. The calls might not be completely
interchangeable. What's really needed is a good file
locking module.
*/
# ifndef F_ULOCK
# define F_ULOCK 0 /* Unlock a previously locked region */
# endif
# ifndef F_LOCK
# define F_LOCK 1 /* Lock a region for exclusive use */
# endif
# ifndef F_TLOCK
# define F_TLOCK 2 /* Test and lock a region for exclusive use */
# endif
# ifndef F_TEST
# define F_TEST 3 /* Test a region for other processes locks */
# endif
/* These are the flock() constants. Since this sytems doesn't have
flock(), the values of the constants are probably not available.
*/
# ifndef LOCK_SH
# define LOCK_SH 1
# endif
# ifndef LOCK_EX
# define LOCK_EX 2
# endif
# ifndef LOCK_NB
# define LOCK_NB 4
# endif
# ifndef LOCK_UN
# define LOCK_UN 8
# endif
int
flock(int fd, int operation)
{
switch (operation) {
/* LOCK_SH - get a shared lock */
case LOCK_SH:
rb_notimplement();
return -1;
/* LOCK_EX - get an exclusive lock */
case LOCK_EX:
return lockf (fd, F_LOCK, 0);
/* LOCK_SH|LOCK_NB - get a non-blocking shared lock */
case LOCK_SH|LOCK_NB:
rb_notimplement();
return -1;
/* LOCK_EX|LOCK_NB - get a non-blocking exclusive lock */
case LOCK_EX|LOCK_NB:
return lockf (fd, F_TLOCK, 0);
/* LOCK_UN - unlock */
case LOCK_UN:
return lockf (fd, F_ULOCK, 0);
/* Default - can't decipher operation */
default:
errno = EINVAL;
return -1;
}
}
#else
int
flock(int fd, int operation)
{
rb_notimplement();
return -1;
}
#endif
|
