projects / lttng-tools.git / blame
| Commit | Line | Data |
|---|---|---|
| f9431861 JG |
1 | /* |
| 2 | * Copyright (C) 2012 David Goulet <dgoulet@efficios.com> | |
| 3 | * Copyright (C) 2013 Jérémie Galarneau <jeremie.galarneau@efficios.com> | |
| 4 | * | |
| 5 | * SPDX-License-Identifier: LGPL-2.1-only | |
| 6 | * | |
| 7 | */ | |
| 8 | ||
| 9 | #include <common/error.h> | |
| 10 | #include <common/lockfile.h> | |
| 11 | #include <common/macros.h> | |
| 12 | ||
| 13 | #include <assert.h> | |
| 14 | ||
| 15 | #ifdef HAVE_FLOCK | |
| 16 | ||
| 17 | #else /* HAVE_FLOCK */ | |
| 18 | ||
| 19 | #include <fcntl.h> | |
| 20 | ||
| 21 | int utils_create_lock_file(const char *filepath) | |
| 22 | { | |
| 23 | int ret; | |
| 24 | int fd; | |
| 25 | struct flock lock; | |
| 26 | ||
| 27 | assert(filepath); | |
| 28 | ||
| 29 | memset(&lock, 0, sizeof(lock)); | |
| 30 | fd = open(filepath, O_CREAT | O_WRONLY, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP); | |
| 31 | if (fd < 0) { | |
| 32 | PERROR("open lock file %s", filepath); | |
| 33 | fd = -1; | |
| 34 | goto error; | |
| 35 | } | |
| 36 | ||
| 37 | /* | |
| 38 | * Attempt to lock the file. If this fails, there is | |
| 39 | * already a process using the same lock file running | |
| 40 | * and we should exit. | |
| 41 | */ | |
| 42 | lock.l_whence = SEEK_SET; | |
| 43 | lock.l_type = F_WRLCK; | |
| 44 | ||
| 45 | ret = fcntl(fd, F_SETLK, &lock); | |
| 46 | if (ret == -1) { | |
| 47 | PERROR("fcntl lock file"); | |
| 48 | ERR("Could not get lock file %s, another instance is running.", filepath); | |
| 49 | if (close(fd)) { | |
| 50 | PERROR("close lock file"); | |
| 51 | } | |
| 52 | fd = ret; | |
| 53 | goto error; | |
| 54 | } | |
| 55 | ||
| 56 | error: | |
| 57 | return fd; | |
| 58 | } | |
| 59 | ||
| 60 | #endif /* HAVE_FLOCK */ |