/*
- * Copyright (c) 2008, 2009, 2010 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
monitor = 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) {
+ pid_t pid;
+ if (!pidfile) {
+ return;
+ }
+ pid = read_pidfile_if_exists(pidfile);
+ if (pid > 0) {
if (!overwrite_pidfile) {
+ VLOG_ERR("%s: %s already running as pid %ld, aborting",
+ get_pidfile(), program_name, (long int) pid);
ovs_fatal(0, "%s: already running as pid %ld",
get_pidfile(), (long int) pid);
} else {
pidfile, strerror(errno));
}
}
- free(text);
} else {
VLOG_ERR("%s: write failed: %s", tmpfile, strerror(errno));
close(fd);
}
+ free(text);
} else {
VLOG_ERR("%s: fcntl failed: %s", tmpfile, strerror(errno));
close(fd);
int fds[2];
pid_t pid;
- if (pipe(fds) < 0) {
- ovs_fatal(errno, "pipe failed");
- }
+ xpipe(fds);
pid = fork();
if (pid > 0) {
/* Running in parent process. */
+ size_t bytes_read;
char c;
close(fds[1]);
fatal_signal_fork();
- if (read(fds[0], &c, 1) != 1) {
+ if (read_fully(fds[0], &c, 1, &bytes_read) != 0) {
int retval;
int status;
exit(WEXITSTATUS(status));
}
- ovs_fatal(errno, "fork child failed to signal startup");
+ VLOG_FATAL("fork child failed to signal startup (%s)",
+ strerror(errno));
}
close(fds[0]);
*fdp = -1;
lockfile_postfork();
*fdp = fds[1];
} else {
- ovs_fatal(errno, "could not fork");
+ VLOG_FATAL("fork failed (%s)", strerror(errno));
}
return pid;
error = write_fully(fd, "", 1, &bytes_written);
if (error) {
- ovs_fatal(error, "could not write to pipe");
+ VLOG_FATAL("pipe write failed (%s)", strerror(error));
}
close(fd);
} while (retval == -1 && errno == EINTR);
if (retval == -1) {
- ovs_fatal(errno, "waitpid failed");
+ VLOG_FATAL("waitpid failed (%s)", strerror(errno));
} else if (retval == daemon_pid) {
char *s = process_status_msg(status);
if (should_restart(status)) {
}
/* If daemonization is configured, then this function notifies the parent
- * process that the child process has completed startup successfully. */
+ * process that the child process has completed startup successfully.
+ *
+ * Calling this function more than once has no additional effect. */
void
daemonize_complete(void)
{
fork_notify_startup(daemonize_fd);
+ daemonize_fd = -1;
if (detach) {
setsid();
ignore(chdir("/"));
}
close_standard_fds();
+ detach = false;
}
}
ovs_rundir(), program_name);
}
-/* Opens and reads a PID from 'pidfile'. Returns the nonnegative PID if
- * successful, otherwise a negative errno value. */
-pid_t
-read_pidfile(const char *pidfile)
+static pid_t
+read_pidfile__(const char *pidfile, bool must_exist)
{
char line[128];
struct flock lck;
file = fopen(pidfile, "r");
if (!file) {
+ if (errno == ENOENT && !must_exist) {
+ return 0;
+ }
error = errno;
VLOG_WARN("%s: open: %s", pidfile, strerror(error));
goto error;
lck.l_whence = SEEK_SET;
lck.l_start = 0;
lck.l_len = 0;
+ lck.l_pid = 0;
if (fcntl(fileno(file), F_GETLK, &lck)) {
error = errno;
VLOG_WARN("%s: fcntl: %s", pidfile, strerror(error));
}
return -error;
}
+
+/* Opens and reads a PID from 'pidfile'. Returns the positive PID if
+ * successful, otherwise a negative errno value. */
+pid_t
+read_pidfile(const char *pidfile)
+{
+ return read_pidfile__(pidfile, true);
+}
+
+
+/* Opens and reads a PID from 'pidfile', if it exists. Returns 0 if 'pidfile'
+ * doesn't exist, the positive PID if successful, otherwise a negative errno
+ * value. */
+pid_t
+read_pidfile_if_exists(const char *pidfile)
+{
+ return read_pidfile__(pidfile, false);
+}