1/*
2 * Copyright (c) 2005, Junio C Hamano
3 */
4#include <signal.h>
5#include "cache.h"
6
7static struct lock_file *lock_file_list;
8
9static void remove_lock_file(void)
10{
11 while (lock_file_list) {
12 if (lock_file_list->filename[0])
13 unlink(lock_file_list->filename);
14 lock_file_list = lock_file_list->next;
15 }
16}
17
18static void remove_lock_file_on_signal(int signo)
19{
20 remove_lock_file();
21 signal(SIGINT, SIG_DFL);
22 raise(signo);
23}
24
25static int lock_file(struct lock_file *lk, const char *path)
26{
27 int fd;
28 sprintf(lk->filename, "%s.lock", path);
29 fd = open(lk->filename, O_RDWR | O_CREAT | O_EXCL, 0666);
30 if (0 <= fd) {
31 if (!lk->next) {
32 lk->next = lock_file_list;
33 lock_file_list = lk;
34 signal(SIGINT, remove_lock_file_on_signal);
35 atexit(remove_lock_file);
36 }
37 if (adjust_shared_perm(lk->filename))
38 return error("cannot fix permission bits on %s",
39 lk->filename);
40 }
41 return fd;
42}
43
44int hold_lock_file_for_update(struct lock_file *lk, const char *path, int die_on_error)
45{
46 int fd = lock_file(lk, path);
47 if (fd < 0 && die_on_error)
48 die("unable to create '%s': %s", path, strerror(errno));
49 return fd;
50}
51
52int commit_lock_file(struct lock_file *lk)
53{
54 char result_file[PATH_MAX];
55 int i;
56 strcpy(result_file, lk->filename);
57 i = strlen(result_file) - 5; /* .lock */
58 result_file[i] = 0;
59 i = rename(lk->filename, result_file);
60 lk->filename[0] = 0;
61 return i;
62}
63
64void rollback_lock_file(struct lock_file *lk)
65{
66 if (lk->filename[0])
67 unlink(lk->filename);
68 lk->filename[0] = 0;
69}
70