/* Name of pidfile (null if none). */
static char *pidfile;
+/* Create pidfile even if one already exists and is locked? */
+static bool force;
+
/* Returns the file name that would be used for a pidfile if 'name' were
* provided to set_pidfile(). The caller must free the returned string. */
char *
pidfile = make_pidfile_name(name);
}
+/* Returns an absolute path to the configured pidfile, or a null pointer if no
+ * pidfile is configured. The caller must not modify or free the returned
+ * string. */
+const char *
+get_pidfile(void)
+{
+ return pidfile;
+}
+
+/* Normally, die_if_already_running() will terminate the program with a message
+ * if a locked pidfile already exists. If this function is called,
+ * die_if_already_running() will merely log a warning. */
+void
+ignore_existing_pidfile(void)
+{
+ force = true;
+}
+
/* Sets up a following call to daemonize() to detach from the foreground
* session, running this process in the background. */
void
detach = true;
}
+/* If a pidfile has been configured and that pidfile already exists and is
+ * locked by a running process, returns the pid of the running process.
+ * Otherwise, returns 0. */
+static pid_t
+already_running(void)
+{
+ pid_t pid = 0;
+ if (pidfile) {
+ int fd = open(pidfile, O_RDWR);
+ if (fd >= 0) {
+ struct flock lck;
+ lck.l_type = F_WRLCK;
+ lck.l_whence = SEEK_SET;
+ lck.l_start = 0;
+ lck.l_len = 0;
+ if (fcntl(fd, F_GETLK, &lck) != -1 && lck.l_type != F_UNLCK) {
+ pid = lck.l_pid;
+ }
+ close(fd);
+ }
+ }
+ return pid;
+}
+
+/* If a locked pidfile exists, issue a warning message and, unless
+ * ignore_existing_pidfile() has been called, terminate the program. */
+void
+die_if_already_running(void)
+{
+ pid_t pid = already_running();
+ if (pid) {
+ if (!force) {
+ ofp_fatal(0, "%s: already running as pid %ld",
+ get_pidfile(), (long int) pid);
+ } else {
+ VLOG_WARN("%s: %s already running as pid %ld",
+ get_pidfile(), program_name, (long int) pid);
+ }
+ }
+}
+
/* If a pidfile has been configured, creates it and stores the running process'
* pid init. Ensures that the pidfile will be deleted when the process
* exits. */
lck.l_whence = SEEK_SET;
lck.l_start = 0;
lck.l_len = 0;
- if (fcntl(fd, F_SETLK, &lck) >= 0) {
+ if (fcntl(fd, F_SETLK, &lck) != -1) {
char *text = xasprintf("%ld\n", pid);
if (write(fd, text, strlen(text)) == strlen(text)) {
fatal_signal_add_file_to_unlink(pidfile);
char c = 0;
int fds[2];
if (pipe(fds) < 0) {
- fatal(errno, "pipe failed");
+ ofp_fatal(errno, "pipe failed");
}
switch (fork()) {
case -1:
/* Error. */
- fatal(errno, "could not fork");
+ ofp_fatal(errno, "could not fork");
break;
}
} else {