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
|
/* ISC license. */
#include <unistd.h>
#include <errno.h>
#include <signal.h>
#include <skalibs/sgetopt.h>
#include <skalibs/strerr.h>
#include <skalibs/types.h>
#include <skalibs/tai.h>
#include <skalibs/sig.h>
#include <skalibs/alarm.h>
#include <skalibs/djbunix.h>
#include <skalibs/exec.h>
#include <s6/config.h>
#define USAGE "s6-setlock [ -r | -w ] [ -n | -N ] [ -t timeout ] [ -d fd ] lockfile prog..."
#define dieusage() strerr_dieusage(100, USAGE)
static char const *file ;
static void sigalrm_handler (int sig)
{
(void)sig ;
strerr_dief3x(1, "lock ", file, ": timed out") ;
}
int main (int argc, char const *const *argv)
{
unsigned int nb = 0, ex = 1 ;
unsigned int timeout = 0 ;
int dest = -1 ;
int fd ;
int r ;
PROG = "s6-setlock" ;
for (;;)
{
int opt = lgetopt(argc, argv, "nNrwt:d:") ;
if (opt == -1) break ;
switch (opt)
{
case 'n' : nb = 1 ; break ;
case 'N' : nb = 0 ; break ;
case 'r' : ex = 0 ; break ;
case 'w' : ex = 1 ; break ;
case 't' : if (!uint0_scan(subgetopt_here.arg, &timeout)) dieusage() ; break ;
case 'd' : { unsigned int u ; if (!uint0_scan(subgetopt_here.arg, &u)) dieusage() ; dest = u ; break ; }
default : dieusage() ;
}
}
argc -= subgetopt_here.ind ; argv += subgetopt_here.ind ;
if (argc < 2) dieusage() ;
file = argv[0] ;
if (ex)
{
fd = open_create(file) ;
if (fd == -1) strerr_diefu3sys(111, "open ", file, " for writing") ;
}
else
{
fd = open_read(file) ;
if (fd == -1)
{
if (errno != ENOENT) strerr_diefu3sys(111, "open ", file, " for reading") ;
fd = open_create(file) ;
if (fd == -1) strerr_diefu2sys(111, "create ", file) ;
fd_close(fd) ;
fd = open_read(file) ;
if (fd == -1) strerr_diefu3sys(111, "open ", file, " for reading") ;
}
}
if (timeout)
{
tain tto ;
tain_from_millisecs(&tto, timeout) ;
if (!sig_catch(SIGALRM, &sigalrm_handler))
strerr_diefu1sys(111, "set SIGALRM handler") ;
if (!alarm_timeout(&tto))
strerr_diefu1sys(111, "set timer") ;
}
r = fd_lock(fd, ex, nb) ;
if (timeout) alarm_disable() ;
if (!r) errno = EBUSY ;
if (r < 1) strerr_diefu2sys(1, "lock ", file) ;
if (dest >= 0 && fd_move(dest, fd) == -1)
strerr_diefu1sys(111, "move lock descriptor") ;
xexec(argv+1) ;
}
|
