Fix the locking in the receive loop to ensure we do not receive messa…

…ges on closed channels in the middle of shutting down.

connection.go

@@ -139,14 +139,17 @@ func (c *Conn) Close() {
 }
 
 func (c *Conn) close() {
+	// Allow users to do anything they need to do before we tear everything down
 	c.stopFunc()
-	_ = c.conn.Close()
 	c.responseChanMutex.Lock()
 	defer c.responseChanMutex.Unlock()
 	for key, responseChan := range c.responseChannels {
 		close(responseChan)
 		delete(c.responseChannels, key)
 	}
+
+	// Close the connection only after we have the response channel lock and we have deleted all response channels to ensure we don't receive on a closed channel
+	_ = c.conn.Close()
 }
 
 func (c *Conn) callEventListener(event *Event) {
@@ -235,29 +238,45 @@ func (c *Conn) eventLoop() {
 
 func (c *Conn) receiveLoop() {
 	for c.runningContext.Err() == nil {
-		response, err := c.readResponse()
+		err := c.doMessage()
 		if err != nil {
+			log.Println("Error receiving message", err)
 			break
 		}
+	}
+}
 
-		c.responseChanMutex.RLock()
-		responseChan, ok := c.responseChannels[response.GetHeader("Content-Type")]
-		if !ok && len(c.responseChannels) <= 0 {
-			// We must have shutdown!
-			break
-		}
-		c.responseChanMutex.RUnlock()
-		if ok && c.runningContext.Err() == nil {
-			ctx, cancel := context.WithTimeout(c.runningContext, 5*time.Second)
-			select {
-			case responseChan <- response:
-			case <-c.runningContext.Done():
-				cancel()
-				return
-			case <-ctx.Done():
-				log.Printf("No one to handle response %v\n", response)
-			}
-			cancel()
+func (c *Conn) doMessage() error {
+	response, err := c.readResponse()
+	if err != nil {
+		return err
+	}
+
+	c.responseChanMutex.RLock()
+	defer c.responseChanMutex.RUnlock()
+	responseChan, ok := c.responseChannels[response.GetHeader("Content-Type")]
+	if !ok && len(c.responseChannels) <= 0 {
+		// We must have shutdown!
+		return errors.New("no response channels")
+	}
+
+	// We have a handler
+	if ok {
+		// Only allow 5 seconds to allow the handler to receive hte message on the channel
+		ctx, cancel := context.WithTimeout(c.runningContext, 5*time.Second)
+		defer cancel()
+
+		select {
+		case responseChan <- response:
+		case <-c.runningContext.Done():
+			// Parent connection context has stopped we most likely shutdown in the middle of waiting for a handler to handle the message
+			return c.runningContext.Err()
+		case <-ctx.Done():
+			// Do not return an error since this is not fatal but log since it could be a indication of problems
+			log.Printf("No one to handle response\nIs the connection overloaded or stopping?\n%v\n\n", response)
 		}
+	} else {
+		return errors.New("no response channel for Content-Type: " + response.GetHeader("Content-Type"))
 	}
+	return nil
 }

example/events/events.go

@@ -21,7 +21,7 @@ import (
 
 func main() {
 	// Connect to FreeSWITCH
-	conn, err := eslgo.Dial("127.0.0.1:8021", "ClueCon", func() {
+	conn, err := eslgo.Dial("127.0.0.1:8021", "ClueCon1", func() {
 		fmt.Println("Inbound Connection Disconnected")
 	})
 	if err != nil {