lockfile.c

   1 /*
   2  * Copyright (c) 2005, Junio C Hamano
   3  */
   4 #include <signal.h>
   5 #include "cache.h"
   6
   7 static struct lock_file *lock_file_list;
   8
   9 static 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
  18 static void remove_lock_file_on_signal(int signo)
  19 {
  20         remove_lock_file();
  21         signal(SIGINT, SIG_DFL);
  22         raise(signo);
  23 }
  24
  25 int hold_lock_file_for_update(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 (fd >=0 && !lk->next) {
  31                 lk->next = lock_file_list;
  32                 lock_file_list = lk;
  33                 signal(SIGINT, remove_lock_file_on_signal);
  34                 atexit(remove_lock_file);
  35         }
  36         return fd;
  37 }
  38
  39 int commit_lock_file(struct lock_file *lk)
  40 {
  41         char result_file[PATH_MAX];
  42         int i;
  43         strcpy(result_file, lk->filename);
  44         i = strlen(result_file) - 5; /* .lock */
  45         result_file[i] = 0;
  46         i = rename(lk->filename, result_file);
  47         lk->filename[0] = 0;
  48         return i;
  49 }
  50
  51 void rollback_lock_file(struct lock_file *lk)
  52 {
  53         if (lk->filename[0])
  54                 unlink(lk->filename);
  55         lk->filename[0] = 0;
  56 }
  57