Fail subscribe requests when the Hub's join queue is full.

Handle subscribe responses in tsung.xml in such cases.
Also, gofmt on session.go.

loadtest/tsung.xml

@@ -105,6 +105,7 @@
           <thinktime value="3" random="true"></thinktime>
 
           <request subst="true">
+            <match do="abort" when="nomatch">{"ctrl":.*"code":200.*}</match>
             <websocket type="message" frame="text">{"sub":{"id":"%%_baseid%%%%_topicx%%%%_ctr%%","topic":"%%_topicx%%","get":{"what":"desc sub data del"}}}</websocket>
           </request>
 

server/session.go

@@ -261,7 +261,7 @@ func (s *Session) queueOut(msg *ServerComMessage) bool {
 			statsAddHistSample("RequestLatency", float64(duration))
 		}
 		if 200 <= msg.Ctrl.Code && msg.Ctrl.Code < 600 {
-			statsInc(fmt.Sprintf("CtrlCodesTotal%dxx", msg.Ctrl.Code / 100), 1)
+			statsInc(fmt.Sprintf("CtrlCodesTotal%dxx", msg.Ctrl.Code/100), 1)
 		} else {
 			log.Println("Invalid response code: ", msg.Ctrl.Code)
 		}
@@ -487,9 +487,15 @@ func (s *Session) subscribe(msg *ClientComMessage) {
 	if sub := s.getSub(msg.RcptTo); sub != nil {
 		s.queueOut(InfoAlreadySubscribed(msg.Id, msg.Original, msg.Timestamp))
 	} else {
-		globals.hub.join <- &sessionJoin{
+		select {
+		case globals.hub.join <- &sessionJoin{
 			pkt:  msg,
-			sess: s}
+			sess: s}:
+		default:
+			// Reply with a 500 to the user.
+			s.queueOut(ErrUnknownReply(msg, msg.Timestamp))
+			log.Println("s.subscribe: join queue full, topic ", msg.RcptTo, s.sid)
+		}
 		// Hub will send Ctrl success/failure packets back to session
 	}
 }