reconnect to gpsd if it disappears while we wait for fix/time

In some cases, gpsd might die while we are waiting to receive a valid
fix/time information.  In that case, we have to reconnect to gpsd
again and again, until a valid time has been received (and set as
system clock).
master
Harald Welte 10 years ago
parent cb65bc5348
commit c77a9b3342

@ -143,39 +143,82 @@ static int my_gps_mainloop(struct gps_data_t *gdata,
return 0;
}
static int attempt_reconnect(const char *host, const char *port,
struct gps_data_t *gpsdata)
{
int rc;
rc = gps_open(host, port, gpsdata);
if (rc)
return -1;
syslog(LOG_INFO, "(re)connected to gpsd\n");
gps_stream(gpsdata, WATCH_ENABLE|WATCH_JSON, NULL);
return 0;
}
enum state {
S_CONNECTED,
S_RECONNECT,
};
int main(int argc, char **argv)
{
char *host = "localhost";
int i, rc;
enum state state;
openlog("gpsdate", LOG_PERROR, LOG_CRON);
if (argc > 1)
host = argv[1];
/* attempt up to NUM_RETRIES times to connect to gpsd while we are
* still running in foreground. The idea is that we will block the
* boot process (init scripts) until we have a connection */
for (i = 1; i <= NUM_RETRIES; i++) {
printf("Attempt #%d to connect to gpsd at %s...\n", i, host);
rc = gps_open(host, DEFAULT_GPSD_PORT, &gpsdata);
if (!rc)
rc = attempt_reconnect(host, DEFAULT_GPSD_PORT, &gpsdata);
if (rc >= 0)
break;
sleep(RETRY_SLEEP);
}
if (rc) {
if (rc < 0) {
syslog(LOG_ERR, "no gpsd running or network error: %d, %s\n",
errno, gps_errstr(errno));
closelog();
exit(EXIT_FAILURE);
}
state = S_CONNECTED;
osmo_daemonize();
gps_stream(&gpsdata, WATCH_ENABLE|WATCH_JSON, NULL);
/* We run in an endless loop. The only reasonable way to exit is after
* a correct GPS timestamp has been received in callback() */
while (1)
my_gps_mainloop(&gpsdata, INT_MAX, callback);
while (1) {
switch (state) {
case S_CONNECTED:
rc = my_gps_mainloop(&gpsdata, INT_MAX, callback);
if (rc < 1) {
syslog(LOG_ERR, "connection to gpsd was "
"closed: %d, reconnecting\n", rc);
gps_close(&gpsdata);
state = S_RECONNECT;
}
break;
case S_RECONNECT:
rc = attempt_reconnect(host, DEFAULT_GPSD_PORT,
&gpsdata);
if (rc < 0)
sleep(RETRY_SLEEP);
else
state = S_CONNECTED;
break;
}
}
gps_close(&gpsdata);

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