Merge remote-tracking branch 'arduino/main' into remove-global-clients

Imported #1032

Author: cmaglie

hub.go

@@ -25,6 +25,7 @@ import (
 	"runtime/debug"
 	"strconv"
 	"strings"
+	"sync"
 
 	"github.com/arduino/arduino-create-agent/systray"
 	"github.com/arduino/arduino-create-agent/tools"
@@ -56,6 +57,10 @@ type hub struct {
 	tools *tools.Tools
 
 	systray *systray.Systray
+
+	// This lock is used to prevent multiple threads from trying to open the same port at the same time.
+	// It presents issues with the serial port driver on some OS's: https://github.com/arduino/arduino-create-agent/issues/1031
+	spHandlerOpenLock sync.Mutex
 }
 
 func newHub(tools *tools.Tools, systray *systray.Systray) *hub {

serial.go

@@ -31,7 +31,7 @@ import (
 
 type serialhub struct {
 	// Opened serial ports.
-	ports map[*serport]bool
+	ports map[string]*serport
 
 	mu sync.Mutex
 
@@ -41,7 +41,7 @@ type serialhub struct {
 
 func newSerialHub(onRegister func(port *serport), onUnregister func(port *serport)) *serialhub {
 	return &serialhub{
-		ports:        make(map[*serport]bool),
+		ports:        make(map[string]*serport),
 		onRegister:   onRegister,
 		onUnregister: onUnregister,
 	}
@@ -75,15 +75,15 @@ type SpPortItem struct {
 func (sh *serialhub) Register(port *serport) {
 	sh.mu.Lock()
 	sh.onRegister(port)
-	sh.ports[port] = true
+	sh.ports[port.portName] = port
 	sh.mu.Unlock()
 }
 
 // Unregister requests from connections.
 func (sh *serialhub) Unregister(port *serport) {
 	sh.mu.Lock()
 	sh.onUnregister(port)
-	delete(sh.ports, port)
+	delete(sh.ports, port.portName)
 	close(port.sendBuffered)
 	close(port.sendNoBuf)
 	sh.mu.Unlock()
@@ -93,8 +93,8 @@ func (sh *serialhub) FindPortByName(portname string) (*serport, bool) {
 	sh.mu.Lock()
 	defer sh.mu.Unlock()
 
-	for port := range sh.ports {
-		if strings.EqualFold(port.portConf.Name, portname) {
+	for name, port := range sh.ports {
+		if strings.EqualFold(name, portname) {
 			// we found our port
 			return port, true
 		}

serialport.go

@@ -284,6 +284,8 @@ func (p *serport) writerRaw() {
 
 // FIXME: move this into the `hub.go` file
 func (h *hub) spHandlerOpen(portname string, baud int, buftype string) {
+	h.spHandlerOpenLock.Lock()
+	defer h.spHandlerOpenLock.Unlock()
 
 	log.Print("Inside spHandler")
 
@@ -305,11 +307,14 @@ func (h *hub) spHandlerOpen(portname string, baud int, buftype string) {
 	sp, err := serial.Open(portname, mode)
 	log.Print("Just tried to open port")
 	if err != nil {
-		//log.Fatal(err)
-		log.Print("Error opening port " + err.Error())
-		//h.broadcastSys <- []byte("Error opening port. " + err.Error())
-		h.broadcastSys <- []byte("{\"Cmd\":\"OpenFail\",\"Desc\":\"Error opening port. " + err.Error() + "\",\"Port\":\"" + conf.Name + "\",\"Baud\":" + strconv.Itoa(conf.Baud) + "}")
-
+		existingPort, ok := h.serialHub.FindPortByName(portname)
+		if ok && existingPort.portConf.Baud == baud && existingPort.BufferType == buftype {
+			log.Print("Port already opened")
+			h.broadcastSys <- []byte("{\"Cmd\":\"Open\",\"Desc\":\"Port already opened.\",\"Port\":\"" + existingPort.portConf.Name + "\",\"Baud\":" + strconv.Itoa(existingPort.portConf.Baud) + ",\"BufferType\":\"" + existingPort.BufferType + "\"}")
+		} else {
+			log.Print("Error opening port " + err.Error())
+			h.broadcastSys <- []byte("{\"Cmd\":\"OpenFail\",\"Desc\":\"Error opening port. " + err.Error() + "\",\"Port\":\"" + conf.Name + "\",\"Baud\":" + strconv.Itoa(conf.Baud) + "}")
+		}
 		return
 	}
 	log.Print("Opened port successfully")
@@ -348,7 +353,6 @@ func (h *hub) spHandlerOpen(portname string, baud int, buftype string) {
 	p.bufferwatcher = bw
 
 	h.serialHub.Register(p)
-	defer h.serialHub.Unregister(p)
 
 	h.serialPortList.MarkPortAsOpened(portname)
 	h.serialPortList.List()
@@ -359,10 +363,12 @@ func (h *hub) spHandlerOpen(portname string, baud int, buftype string) {
 	go p.writerNoBuf()
 	// this is thread to send to serial port but with base64 decoding
 	go p.writerRaw()
-
-	p.reader(buftype)
-
-	h.serialPortList.List()
+	// this is the thread that reads from the serial port
+	go func() {
+		p.reader(buftype)
+		h.serialPortList.List()
+		h.serialHub.Unregister(p)
+	}()
 }
 
 func (p *serport) Close() {