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
|
/*
LibRCC - module responsible for application synchronization (write access to
a shared config mainly)
Copyright (C) 2005-2018 Suren A. Chilingaryan <csa@suren.me>
This library is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License version 2.1 or later
as published by the Free Software Foundation.
This 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 this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <time.h>
#include <errno.h>
#include "../config.h"
#ifdef HAVE_SYS_FILE_H
# include <sys/file.h>
#endif /* HAVE_SYS_FILE_H */
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif /* HAVE_UNISTD_H */
#ifdef HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif /* HAVE_SYS_TYPES_H */
#ifdef HAVE_SYS_STAT_H
# include <sys/stat.h>
#endif /* HAVE_SYS_STAT_H */
#ifdef HAVE_FCNTL_H
# include <fcntl.h>
#endif /* HAVE_FCNTL_H */
#include "rcchome.h"
#include "rcclock.h"
static int lockfd = -1;
int rccLock() {
# ifdef HAVE_SYS_FILE_H
int err, i;
int size;
char *stmp;
struct timespec wait = { 0, 10000000 };
if (lockfd>=0) return -1;
size = strlen(rcc_home_dir) + 32;
stmp = (char*)malloc(size*sizeof(char));
if (!stmp) return -1;
sprintf(stmp,"%s/.rcc/", rcc_home_dir);
#ifdef _WIN32
mkdir(stmp);
#else
mkdir(stmp, 00755);
#endif
sprintf(stmp,"%s/.rcc/locks/", rcc_home_dir);
#ifdef _WIN32
mkdir(stmp);
#else
mkdir(stmp, 00700);
#endif
sprintf(stmp,"%s/.rcc/locks/rcc.lock", rcc_home_dir);
lockfd = open(stmp, O_RDWR|O_CREAT, 0644);
if (lockfd >= 0) {
for (err = -1, i = 0; i < (LIBRCC_LOCK_WAIT/10); i++) {
#if defined(HAVE_FLOCK)
err = flock(lockfd, LOCK_EX|LOCK_NB);
#elif defined(HAVE_LOCKF)
err = lockf(lockfd, F_TLOCK, 1);
#else
# warning "No file locking mechanism is detected"
err = 0; // We must believe in best
#endif
if ((err)&&(errno == EWOULDBLOCK)) nanosleep(&wait, NULL);
else break;
}
if (err) {
close(lockfd);
// Removing invalid lock
if (i == (LIBRCC_LOCK_WAIT/10)) {
remove(stmp);
lockfd = open(stmp, O_RDWR|O_CREAT, 0644);
if (lockfd >= 0) {
for (err = -1, i = 0; i < (LIBRCC_LOCK_WAIT/10); i++) {
#if defined(HAVE_FLOCK)
err = flock(lockfd, LOCK_EX|LOCK_NB);
#elif defined(HAVE_LOCKF)
err = lockf(lockfd, F_TLOCK, 1);
#endif
if ((err)&&(errno == EWOULDBLOCK)) nanosleep(&wait, NULL);
else break;
}
if (err) close(lockfd);
else return 0;
}
}
lockfd = -1;
return -1;
}
return 0;
}
return -1;
# else /* HAVE_SYS_FILE_H */
return 0;
# endif /* HAVE_SYS_FILE_H */
}
void rccUnLock() {
#ifdef HAVE_SYS_FILE_H
int size;
char *stmp;
if (lockfd<0) return;
size = strlen(rcc_home_dir) + 32;
stmp = (char*)malloc(size*sizeof(char));
if (!stmp) return;
sprintf(stmp,"%s/.rcc/locks/rcc.lock", rcc_home_dir);
#if defined(HAVE_FLOCK)
flock(lockfd, LOCK_UN);
#elif defined(HAVE_LOCKF)
lockf(lockfd, F_ULOCK, 1);
#endif
close(lockfd);
lockfd = -1;
#endif /* HAVE_SYS_FILE_H */
}
|
