disentangle things a little more.

having a single loop for everything was too much. goroutines things were getting stuck.

relay.go

@@ -186,15 +186,12 @@ func (r *Relay) Connect(ctx context.Context) error {
 	// ping every 29 seconds
 	ticker := time.NewTicker(29 * time.Second)
 
-	// queue all messages received from the relay on this
+	// this ensures we don't send an event to the Events channel after closing it
-	messageHandler := make(chan Envelope)
+	eventsChannelCloserMutex := &sync.Mutex{}
 
-	// we'll queue all relay actions (handling received messages etc) in a single queue
+	// to be used when the connection is closed
-	// such that we can close channels safely without mutex spaghetti
 	go func() {
-		for {
+		<-r.connectionContext.Done()
-			select {
-			case <-r.connectionContext.Done():
 		// close these things when the connection is closed
 		if r.challenges != nil {
 			close(r.challenges)
@@ -210,6 +207,12 @@ func (r *Relay) Connect(ctx context.Context) error {
 			return true
 		})
 		return
+	}()
+
+	// queue all write operations here so we don't do mutex spaghetti
+	go func() {
+		for {
+			select {
 			case <-ticker.C:
 				err := wsutil.WriteClientMessage(r.Connection.conn, ws.OpPing, nil)
 				if err != nil {
@@ -217,23 +220,27 @@ func (r *Relay) Connect(ctx context.Context) error {
 					r.Close() // this should trigger a context cancelation
 					return
 				}
-			case envelope := <-messageHandler:
-				// this will run synchronously in this goroutine
-				r.HandleRelayMessage(envelope)
 			case writeRequest := <-r.writeQueue:
 				// all write requests will go through this to prevent races
 				if err := r.Connection.WriteMessage(writeRequest.msg); err != nil {
 					writeRequest.answer <- err
 				}
 				close(writeRequest.answer)
-			case toClose := <-r.subscriptionChannelCloseQueue:
-				// every time a subscription ends we use this queue to close its Events channel
-				close(toClose.Events)
-				toClose.Events = make(chan *Event)
 			}
 		}
 	}()
 
+	// every time a subscription ends we use this queue to close its .Events channel
+	go func() {
+		for toClose := range r.subscriptionChannelCloseQueue {
+			eventsChannelCloserMutex.Lock()
+			close(toClose.Events)
+			toClose.Events = make(chan *Event)
+			eventsChannelCloserMutex.Unlock()
+		}
+	}()
+
+	// general message reader loop
 	go func() {
 		for {
 			message, err := conn.ReadMessage(r.connectionContext)
@@ -249,15 +256,6 @@ func (r *Relay) Connect(ctx context.Context) error {
 				continue
 			}
 
-			messageHandler <- envelope
-		}
-	}()
-
-	return nil
-}
-
-// HandleRelayMessage handles a message received from a relay.
-func (r *Relay) HandleRelayMessage(envelope Envelope) {
 			switch env := envelope.(type) {
 			case *NoticeEnvelope:
 				// see WithNoticeHandler
@@ -300,9 +298,13 @@ func (r *Relay) HandleRelayMessage(envelope Envelope) {
 						}
 					}
 
+					go func() {
+						eventsChannelCloserMutex.Lock()
 						if subscription.live {
 							subscription.Events <- &env.Event
 						}
+						eventsChannelCloserMutex.Unlock()
+					}()
 				}
 			case *EOSEEnvelope:
 				if subscription, ok := r.Subscriptions.Load(string(*env)); ok {
@@ -315,6 +317,10 @@ func (r *Relay) HandleRelayMessage(envelope Envelope) {
 					okCallback(env.OK, *env.Reason)
 				}
 			}
+		}
+	}()
+
+	return nil
 }
 
 // Write queues a message to be sent to the relay.

subscription.go

@@ -57,20 +57,25 @@ func (sub *Subscription) GetID() string {
 // Unsub closes the subscription, sending "CLOSE" to relay as in NIP-01.
 // Unsub() also closes the channel sub.Events and makes a new one.
 func (sub *Subscription) Unsub() {
-	id := sub.GetID()
+	go sub.Close()
 
+	sub.live = false
+	id := sub.GetID()
+	sub.Relay.Subscriptions.Delete(id)
+
+	// do this so we don't have the possibility of closing the Events channel and then trying to send to it
+	sub.Relay.subscriptionChannelCloseQueue <- sub
+}
+
+// Close just sends a CLOSE message. You probably want Unsub() instead.
+func (sub *Subscription) Close() {
 	if sub.Relay.IsConnected() {
+		id := sub.GetID()
 		closeMsg := CloseEnvelope(id)
 		closeb, _ := (&closeMsg).MarshalJSON()
 		debugLog("{%s} sending %v", sub.Relay.URL, closeb)
 		sub.Relay.Write(closeb)
 	}
-
-	sub.live = false
-	sub.Relay.Subscriptions.Delete(id)
-
-	// do this so we don't have the possibility of closing the Events channel and then trying to send to it
-	sub.Relay.subscriptionChannelCloseQueue <- sub
 }
 
 // Sub sets sub.Filters and then calls sub.Fire(ctx).