/* If daemonization is configured, then starts daemonization, by forking and
* returning in the child process. The parent process hangs around until the
* child lets it know either that it completed startup successfully (by calling
* daemon_complete()) or that it failed to start up (by exiting with a nonzero
* exit code). */
void
daemonize_start(void)
{
daemonize_fd = -1;
if (detach) {
if (fork_and_wait_for_startup(&daemonize_fd) > 0) {
/* Running in parent process. */
exit(0);
}
/* Running in daemon or monitor process. */
}
if (monitor) {
int saved_daemonize_fd = daemonize_fd;
pid_t daemon_pid;
daemon_pid = fork_and_wait_for_startup(&daemonize_fd);
if (daemon_pid > 0) {
/* Running in monitor process. */
fork_notify_startup(saved_daemonize_fd);
close_standard_fds();
monitor_daemon(daemon_pid);
}
/* Running in daemon process. */
}
make_pidfile();
/* Make sure that the unixctl commands for vlog get registered in a
* daemon, even before the first log message. */
vlog_init();
}
/* If daemonization is configured, then starts daemonization, by forking and
* returning in the child process. The parent process hangs around until the
* child lets it know either that it completed startup successfully (by calling
* daemon_complete()) or that it failed to start up (by exiting with a nonzero
* exit code). */
void
daemonize_start(bool access_datapath)
{
assert_single_threaded();
daemonize_fd = -1;
if (switch_user) {
daemon_become_new_user__(access_datapath);
switch_user = false;
}
if (detach) {
pid_t pid;
if (fork_and_wait_for_startup(&daemonize_fd, &pid)) {
VLOG_FATAL("could not detach from foreground session");
}
if (pid > 0) {
/* Running in parent process. */
exit(0);
}
/* Running in daemon or monitor process. */
setsid();
}
if (monitor) {
int saved_daemonize_fd = daemonize_fd;
pid_t daemon_pid;
if (fork_and_wait_for_startup(&daemonize_fd, &daemon_pid)) {
VLOG_FATAL("could not initiate process monitoring");
}
if (daemon_pid > 0) {
/* Running in monitor process. */
fork_notify_startup(saved_daemonize_fd);
if (detach) {
close_standard_fds();
}
monitor_daemon(daemon_pid);
}
/* Running in daemon process. */
}
forbid_forking("running in daemon process");
if (pidfile) {
make_pidfile();
}
/* Make sure that the unixctl commands for vlog get registered in a
* daemon, even before the first log message. */
vlog_init();
}
static void
monitor_daemon(pid_t daemon_pid)
{
/* XXX Should log daemon's stderr output at startup time. */
time_t last_restart;
char *status_msg;
int crashes;
set_subprogram_name("monitor");
status_msg = xstrdup("healthy");
last_restart = TIME_MIN;
crashes = 0;
for (;;) {
int retval;
int status;
proctitle_set("monitoring pid %lu (%s)",
(unsigned long int) daemon_pid, status_msg);
do {
retval = waitpid(daemon_pid, &status, 0);
} while (retval == -1 && errno == EINTR);
if (retval == -1) {
VLOG_FATAL("waitpid failed (%s)", ovs_strerror(errno));
} else if (retval == daemon_pid) {
char *s = process_status_msg(status);
if (should_restart(status)) {
free(status_msg);
status_msg = xasprintf("%d crashes: pid %lu died, %s",
++crashes,
(unsigned long int) daemon_pid, s);
free(s);
if (WCOREDUMP(status)) {
/* Disable further core dumps to save disk space. */
struct rlimit r;
r.rlim_cur = 0;
r.rlim_max = 0;
if (setrlimit(RLIMIT_CORE, &r) == -1) {
VLOG_WARN("failed to disable core dumps: %s",
ovs_strerror(errno));
}
}
/* Throttle restarts to no more than once every 10 seconds. */
if (time(NULL) < last_restart + 10) {
VLOG_WARN("%s, waiting until 10 seconds since last "
"restart", status_msg);
for (;;) {
time_t now = time(NULL);
time_t wakeup = last_restart + 10;
if (now >= wakeup) {
break;
}
xsleep(wakeup - now);
}
}
last_restart = time(NULL);
VLOG_ERR("%s, restarting", status_msg);
daemon_pid = fork_and_wait_for_startup(&daemonize_fd);
if (!daemon_pid) {
break;
}
} else {
VLOG_INFO("pid %lu died, %s, exiting",
(unsigned long int) daemon_pid, s);
free(s);
exit(0);
}
}
}
free(status_msg);
/* Running in new daemon process. */
proctitle_restore();
set_subprogram_name("");
}
