fix cleanup of message listeners

pkg/keepkey/keepkey.go

@@ -24,6 +24,7 @@ type Keepkey struct {
 	label, serial, id string // Used for specifying which device to send commands if multiple are connected
 	logger
 	deviceQueue, debugQueue chan *deviceResponse // for subscribing to responses over different interfaces
+	closed                  chan struct{}
 }
 
 // transport contains handles to the primary and debug interfaces of the target device
@@ -93,13 +94,15 @@ func newKeepkeyFromConfig(cfg *Config) *Keepkey {
 	kk.autoButton = cfg.AutoButton
 	kk.deviceQueue = make(chan *deviceResponse, 1)
 	kk.debugQueue = make(chan *deviceResponse, 1)
+	kk.closed = make(chan struct{}, 1)
 
 	return kk
 }
 
 // Close closes the transport connection and unassoctiates that nterface
 // with the calling Keepkey
 func (kk *Keepkey) Close() {
+	close(kk.closed) // signal message listeners to stop
 	if kk.transport.conn != nil {
 		kk.transport.conn.Close()
 		kk.transport.conn = nil

pkg/keepkey/transport.go

@@ -58,10 +58,10 @@ func GetDevicesWithConfig(cfg *Config) ([]*Keepkey, error) {
 		kk := newKeepkeyFromConfig(cfg)
 		kk.transport = dev
 		if dev.debug != nil {
-			go listenForMessages(kk.transport.debug, kk.debugQueue)
+			go listenForMessages(kk.transport.debug, kk.debugQueue, kk.closed)
 			fmt.Println("DebugLink established over WebUSB")
 		}
-		go listenForMessages(kk.transport.conn, kk.deviceQueue)
+		go listenForMessages(kk.transport.conn, kk.deviceQueue, kk.closed)
 
 		// Ping the device and ask for its features
 		features, err := kk.Initialize()
@@ -96,7 +96,7 @@ func GetDevicesWithConfig(cfg *Config) ([]*Keepkey, error) {
 			continue
 		}
 		kk.transport.conn = device
-		go listenForMessages(device, kk.deviceQueue)
+		go listenForMessages(device, kk.deviceQueue, kk.closed)
 
 		// debug HID interface
 		if debugIFace.Path != "" {
@@ -107,7 +107,7 @@ func GetDevicesWithConfig(cfg *Config) ([]*Keepkey, error) {
 			}
 			fmt.Println("Debug link established over HID")
 			kk.transport.debug = debug
-			go listenForMessages(debug, kk.debugQueue)
+			go listenForMessages(debug, kk.debugQueue, kk.closed)
 		}
 
 		// Ping the device and ask for its features
@@ -132,7 +132,7 @@ func GetDevicesWithConfig(cfg *Config) ([]*Keepkey, error) {
 }
 
 // passively listen for messages on a transport interface
-func listenForMessages(in io.Reader, out chan *deviceResponse) {
+func listenForMessages(in io.Reader, out chan *deviceResponse, closed chan struct{}) {
 	for {
 		// stream the reply back in 64 byte chunks
 		chunk := make([]byte, 64)
@@ -141,6 +141,13 @@ func listenForMessages(in io.Reader, out chan *deviceResponse) {
 		for {
 			// Read next chunk
 			if _, err := io.ReadFull(in, chunk); err != nil {
+
+				// Abort if this keepkey has closed its connections
+				select {
+				case <-closed:
+					return
+				default:
+				}
 				fmt.Println(color.RedString("Unable to read chunk from device:", err)) // TODO: move to device specific log
 				break
 			}