/* location.c
 * Hack to show how to get location from gpsd
 * when you don't have a convenient main loop.
 */


#include <pthread.h>
#include <unistd.h>

/* Stuff that should be defined someplace else. */
struct location {
    double lat;
    double lon;
};
typedef int* gpsd_t;

extern void start_location(gpsd_t arg);
extern struct location GetLatestLocation();
extern struct location GetGpsLocation(gpsd_t arg);

/* end stuff */

struct location latest;
pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;

pthread_t thread;

static void* worker(void* arg);

void start_location(gpsd_t arg)
{
	int rc;

	latest = GetGpsLocation(arg);	/* avoid initial garbage */
	rc = pthread_create(&thread, NULL, worker, arg);
        if (rc) {
		exit(-3);
	}

};

struct location GetLatestLocation(void)
{
	struct location temp;
	pthread_mutex_lock(&mutex);
	temp = latest;
	pthread_mutex_unlock(&mutex);
	return(temp);
};

static void* worker(void* arg)
{
	gpsd_t gps = (gpsd_t) arg;
	struct location temp;

	while (1) {
	    temp = GetGpsLocation(gps);
	    pthread_mutex_lock(&mutex);
	    latest = temp;
	    pthread_mutex_unlock(&mutex);
	}

};