Enhanced handling of some discoveries states

Author: silvanocerza

arduino/discovery/discoverymanager/discoverymanager.go

@@ -58,6 +58,11 @@ func (dm *DiscoveryManager) Add(disc *discovery.PluggableDiscovery) error {
 // returns the first error it meets or nil
 func (dm *DiscoveryManager) RunAll() error {
 	for _, d := range dm.discoveries {
+		if d.IsAlive() {
+			// This discovery is already running, nothing to do
+			continue
+		}
+
 		if err := d.Run(); err != nil {
 			return err
 		}
@@ -81,6 +86,11 @@ func (dm *DiscoveryManager) StartAll() error {
 func (dm *DiscoveryManager) StartSyncAll() (<-chan *discovery.Event, []error) {
 	errs := []error{}
 	for _, d := range dm.discoveries {
+		if d.IsEventMode() {
+			// Already started, nothing to do
+			continue
+		}
+
 		eventCh := d.EventChannel(5)
 		if err := d.StartSync(); err != nil {
 			errs = append(errs, err)

commands/board/list.go

@@ -273,11 +273,11 @@ func Watch(instanceID int32, interrupt <-chan bool) (<-chan *rpc.BoardListWatchR
 					Error:     boardsError,
 				}
 			case <-interrupt:
-				err := pm.DiscoveryManager().QuitAll()
+				err := pm.DiscoveryManager().StopAll()
 				if err != nil {
 					outChan <- &rpc.BoardListWatchResponse{
 						EventType: "error",
-						Error:     err.Error(),
+						Error:     fmt.Sprintf("stopping discoveries: %s", err),
 					}
 					// Don't close the channel if quitting all discoveries
 					// failed, otherwise some processes might be left running.

commands/daemon/daemon.go

@@ -17,6 +17,7 @@ package daemon
 
 import (
 	"context"
+	"fmt"
 	"io"
 
 	"github.com/arduino/arduino-cli/arduino/utils"
@@ -28,6 +29,7 @@ import (
 	"github.com/arduino/arduino-cli/commands/sketch"
 	"github.com/arduino/arduino-cli/commands/upload"
 	rpc "github.com/arduino/arduino-cli/rpc/cc/arduino/cli/commands/v1"
+	"github.com/sirupsen/logrus"
 )
 
 // ArduinoCoreServerImpl FIXMEDOC
@@ -73,14 +75,37 @@ func (s *ArduinoCoreServerImpl) BoardListWatch(stream rpc.ArduinoCoreService_Boa
 		return err
 	}
 
-	interrupt := make(chan bool)
+	if msg.Instance == nil {
+		err = fmt.Errorf("no instance specified")
+		stream.Send(&rpc.BoardListWatchResponse{
+			EventType: "error",
+			Error:     err.Error(),
+		})
+		return err
+	}
+
+	interrupt := make(chan bool, 1)
 	go func() {
-		msg, err := stream.Recv()
-		if err != nil {
-			interrupt <- true
-		}
-		if msg != nil {
-			interrupt <- msg.Interrupt
+		defer close(interrupt)
+		for {
+			msg, err := stream.Recv()
+			// Handle client closing the stream and eventual errors
+			if err == io.EOF {
+				logrus.Info("boards watcher stream closed")
+				interrupt <- true
+				return
+			} else if err != nil {
+				logrus.Infof("interrupting boards watcher: %v", err)
+				interrupt <- true
+				return
+			}
+
+			// Message received, does the client want to interrupt?
+			if msg != nil && msg.Interrupt {
+				logrus.Info("boards watcher interrupted by client")
+				interrupt <- msg.Interrupt
+				return
+			}
 		}
 	}()
 
@@ -90,7 +115,10 @@ func (s *ArduinoCoreServerImpl) BoardListWatch(stream rpc.ArduinoCoreService_Boa
 	}
 
 	for event := range eventsChan {
-		stream.Send(event)
+		err = stream.Send(event)
+		if err != nil {
+			logrus.Infof("sending board watch message: %v", err)
+		}
 	}
 
 	return nil