Don't spin

federationsender/queue/destinationqueue.go

@@ -164,6 +164,9 @@ func (oq *destinationQueue) wakeQueueIfNeeded() {
 		} else {
 			log.WithError(err).Errorf("Can't get pending PDU count for %q destination queue", oq.destination)
 		}
+		if count > 0 {
+			oq.wakeServerCh <- true
+		}
 		// Then start the queue.
 		go oq.backgroundSend()
 	}
@@ -182,7 +185,6 @@ func (oq *destinationQueue) backgroundSend() {
 	for {
 		// If we have nothing to do then wait either for incoming events, or
 		// until we hit an idle timeout.
-		if oq.pendingPDUs.Load() == 0 && len(oq.pendingEDUs) == 0 && len(oq.pendingInvites) == 0 {
 		select {
 		case <-oq.wakeServerCh:
 			// We were woken up because there are new PDUs waiting in the
@@ -222,7 +224,6 @@ func (oq *destinationQueue) backgroundSend() {
 			// send.
 			return
 		}
-		}
 
 		// If we are backing off this server then wait for the
 		// backoff duration to complete first, or until explicitly
@@ -329,8 +330,10 @@ func (oq *destinationQueue) nextTransaction(
 	// Ask the database for any pending PDUs from the next transaction.
 	// maxPDUsPerTransaction is an upper limit but we probably won't
 	// actually retrieve that many events.
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
+	defer cancel()
 	txid, pdus, err := oq.db.GetNextTransactionPDUs(
-		context.TODO(),        // context
+		ctx,                   // context
 		oq.destination,        // server name
 		maxPDUsPerTransaction, // max events to retrieve
 	)