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
|
/* test whether fcntl locking works on this system */
#if defined(HAVE_UNISTD_H)
#include <unistd.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
#ifdef HAVE_SYS_FCNTL_H
#include <sys/fcntl.h>
#endif
#ifdef HAVE_SYS_WAIT_H
#include <sys/wait.h>
#endif
#include <errno.h>
#define DATA "conftest.fcntl"
#ifndef SEEK_SET
#define SEEK_SET 0
#endif
/* lock a byte range in a open file */
int main(int argc, char *argv[])
{
struct flock lock;
int fd, ret, status=1;
pid_t pid;
char *testdir = NULL;
testdir = getenv("TESTDIR");
if (testdir) chdir(testdir);
alarm(10);
if (!(pid=fork())) {
sleep(2);
fd = open(DATA, O_RDONLY);
if (fd == -1) {
fprintf(stderr,"ERROR: failed to open %s (errno=%d)\n",
DATA, (int)errno);
exit(1);
}
lock.l_type = F_WRLCK;
lock.l_whence = SEEK_SET;
lock.l_start = 0;
lock.l_len = 4;
lock.l_pid = getpid();
lock.l_type = F_WRLCK;
/* check if a lock applies */
ret = fcntl(fd,F_GETLK,&lock);
if ((ret == -1) ||
(lock.l_type == F_UNLCK)) {
fprintf(stderr,"ERROR: lock test failed (ret=%d errno=%d)\n", ret, (int)errno);
exit(1);
} else {
exit(0);
}
}
unlink(DATA);
fd = open(DATA, O_RDWR|O_CREAT|O_EXCL, 0600);
if (fd == -1) {
fprintf(stderr,"ERROR: failed to open %s (errno=%d)\n",
DATA, (int)errno);
exit(1);
}
lock.l_type = F_WRLCK;
lock.l_whence = SEEK_SET;
lock.l_start = 0;
lock.l_len = 4;
lock.l_pid = getpid();
/* set a 4 byte write lock */
fcntl(fd,F_SETLK,&lock);
waitpid(pid, &status, 0);
unlink(DATA);
#if defined(WIFEXITED) && defined(WEXITSTATUS)
if(WIFEXITED(status)) {
status = WEXITSTATUS(status);
} else {
status = 1;
}
#else /* defined(WIFEXITED) && defined(WEXITSTATUS) */
status = (status == 0) ? 0 : 1;
#endif /* defined(WIFEXITED) && defined(WEXITSTATUS) */
if (status) {
fprintf(stderr,"ERROR: lock test failed with status=%d\n",
status);
}
exit(status);
}
|
