Added timer_get_runtime_ms to know how long the timer has been running

git-svn-id: https://svn.musicpd.org/mpd/trunk@6521 09075e82-0dd4-0310-85a5-a0d7c8717e4f

src/timer.h

@@ -23,6 +23,7 @@
 #include "mpd_types.h"
 
 typedef struct _Timer {
+	uint64_t start_time;
 	uint64_t time;
 	int started;
 	int rate;
@@ -40,4 +41,6 @@ void timer_add(Timer *timer, int size);
 
 void timer_sync(Timer *timer);
 
+int timer_get_runtime_ms(Timer *timer);
+
 #endif