Added error handling in sendworkers (compression threads) to avoid th…

…e "send on closed channel" panic

Changed how hashback is closed down when Interrupt or Kill signals are received
Fixed a design mistake where recovery cache was not saved on panics
Debug web server now only listens to 127.0.0.1 to avoid firewall pop-ups on Windows

core/client.go

@@ -54,7 +54,7 @@ type Client struct {
 
 	sendqueue []*sendQueueEntry
 
-	handlerSignal chan error
+	handlerErrorSignal chan error
 
 	dispatchChannel chan *messageDispatch
 	storeChannel    chan *messageDispatch
@@ -75,8 +75,8 @@ func NewClient(conn net.Conn, account string, accesskey Byte128) *Client {
 		dispatchChannel: make(chan *messageDispatch, 1024),
 		storeChannel:    make(chan *messageDispatch, 1),
 	}
+	client.handlerErrorSignal = make(chan error, 1)
 	client.wg.Add(1)
-	client.handlerSignal = make(chan error, 1)
 	go client.ioHandler()
 
 	{ // Say hello
@@ -104,8 +104,10 @@ func (c *Client) Paint(what string) {
 	}
 }
 
-func (c *Client) Close() {
-	c.dispatchAndWait(MsgTypeGoodbye, nil)
+func (c *Client) Close(polite bool) {
+	if (polite) {
+		c.dispatchAndWait(MsgTypeGoodbye, nil)
+	}
 
 	c.dispatchMutex.Lock()
 	if !c.closing {
@@ -135,6 +137,17 @@ func (c *Client) sendQueue(what Byte128) {
 		if c.sendworkers < int32(runtime.NumCPU()) {
 			atomic.AddInt32(&c.sendworkers, 1)
 			go func() {
+				defer func() {	// a panic was raised inside the goroutine (most likely the channel was closed)
+					if r := recover(); !c.closing && r != nil {
+						err, _ := <-c.handlerErrorSignal
+						if err != nil {
+							panic(err)
+						} else {
+							panic(r)
+						}
+					}
+				}()
+
 				for done := false; !done; {
 					var workItem *sendQueueEntry
 
@@ -243,9 +256,9 @@ func (c *Client) singleExchange(outgoing *messageDispatch) *ProtocolMessage {
 func (c *Client) ioHandler() {
 	defer func() {
 		if r := recover(); !c.closing && r != nil { // a panic was raised inside the goroutine
-			fmt.Println("ioHandler", r)
-			c.handlerSignal <- r.(error)
-			close(c.handlerSignal)
+//			fmt.Println("ioHandler error:", r)
+			c.handlerErrorSignal <- r.(error)
+			close(c.handlerErrorSignal)
 		}
 
 		c.dispatchMutex.Lock()
@@ -283,8 +296,8 @@ func (c *Client) ioHandler() {
 // dispatchMessage returns a result channel if a returnChannel was specified, otherwise it just returns nil
 func (c *Client) dispatchMessage(msgType uint32, msgData interface{}, returnChannel chan interface{}) {
 	defer func() {
-		if r := recover(); !c.closing && r != nil { // a panic was raised inside the goroutine
-			err, _ := <-c.handlerSignal
+		if r := recover(); !c.closing && r != nil { // a panic was raised (most likely the channel was closed)
+			err, _ := <-c.handlerErrorSignal
 			if err != nil {
 				panic(err)
 			} else {
@@ -321,8 +334,7 @@ func (c *Client) dispatchAndWait(msgType uint32, msgData interface{}) interface{
 				return t.Data
 			}
 		}
-		fmt.Println("här", R)
-	case err := <-c.handlerSignal:
+	case err := <-c.handlerErrorSignal:
 		if err != nil {
 			panic(err)
 		}

hashback/hashback.go

@@ -292,8 +292,14 @@ func (session *BackupSession) Connect() *core.Client {
 	session.Client = client
 	return session.Client
 }
-func (session *BackupSession) Close() {
-	session.Client.Close()
+func (session *BackupSession) Close(polite bool) {
+	if session.reference != nil {
+		session.reference.Close()
+	}
+	if session.Client != nil {
+		session.Client.Close(polite)
+	}
+
 	Debug("Disconnected from %s", session.ServerString)
 }
 
@@ -341,7 +347,7 @@ func main() {
 
 	runtime.SetBlockProfileRate(1000)
 	go func() {
-		log.Println(http.ListenAndServe(":6060", nil))
+		log.Println(http.ListenAndServe("127.0.0.1:6060", nil))
 	}()
 
 	defer func() {
@@ -428,7 +434,7 @@ func main() {
 
 	cmd.Command("info", "", func() {
 		session.Connect()
-		defer session.Close()
+		defer session.Close(true)
 
 		info := session.Client.GetAccountInfo()
 		var hashbackEnabled bool = false
@@ -466,7 +472,7 @@ func main() {
 		}
 
 		session.Connect()
-		defer session.Close()
+		defer session.Close(true)
 
 		list := session.Client.ListDataset(cmd.Args[2])
 		if len(list.States) > 0 {
@@ -583,7 +589,7 @@ func main() {
 
 			func() {
 				session.Connect()
-				defer session.Close()
+				defer session.Close(true)
 				if latestBackup > 0 || intervalBackup == 0 {
 					session.State = &core.DatasetState{StateID: session.Client.SessionNonce}
 					session.Store(cmd.Args[2], cmd.Args[3:]...)
@@ -625,7 +631,7 @@ func main() {
 		}
 
 		session.Connect()
-		defer session.Close()
+		defer session.Close(true)
 
 		list := session.Client.ListDataset(cmd.Args[2])
 
@@ -669,7 +675,7 @@ func main() {
 		}
 
 		session.Connect()
-		defer session.Close()
+		defer session.Close(true)
 
 		list := session.Client.ListDataset(cmd.Args[2])
 
@@ -713,7 +719,7 @@ func main() {
 		}
 
 		session.Connect()
-		defer session.Close()
+		defer session.Close(true)
 
 		list := session.Client.ListDataset(cmd.Args[2])
 
@@ -739,8 +745,8 @@ func main() {
 	signal.Notify(signalchan, os.Kill)
 	go func() {
 		for range signalchan {
-			if session.reference != nil {
-				session.reference.Close()
+			if session != nil {
+				session.Close(false)
 			}
 			if lockFile != nil {
 				lockFile.Unlock()