Simpler, more efficient way of deleting inactive torrents

http/announce.go

@@ -91,6 +91,10 @@ func (t *Tracker) ServeAnnounce(w http.ResponseWriter, r *http.Request, p httpro
 		if err != nil {
 			return http.StatusInternalServerError, err
 		}
+	} else if torrent.PeerCount() == 0 {
+		// Rather than deleting the torrent explicitly, let the tracker driver
+		// ensure there are no race conditions.
+		conn.PurgeInactiveTorrent(torrent.Infohash)
 	}
 
 	resp := newAnnounceResponse(ann, user, torrent)

http/http.go

@@ -31,11 +31,6 @@ func NewTracker(cfg *config.Config) (*Tracker, error) {
 		return nil, err
 	}
 
-	err = tracker.StartPurgingRoutines(tp, &cfg.Tracker)
-	if err != nil {
-		return nil, err
-	}
-
 	bc, err := backend.Open(&cfg.Backend)
 	if err != nil {
 		return nil, err