.

go/neo/connection.go

@@ -180,7 +180,7 @@ func (nl *NodeLink) Close() error {
 // sendPkt sends raw packet to peer
 // tx error, if any, is returned as is and is analyzed in serveSend
 func (nl *NodeLink) sendPkt(pkt *PktBuf) error {
-	if true {
+	if false {
 		// XXX -> log
 		fmt.Printf("%v > %v: %v\n", nl.peerLink.LocalAddr(), nl.peerLink.RemoteAddr(), pkt)
 		//defer fmt.Printf("\t-> sendPkt err: %v\n", err)
@@ -237,7 +237,7 @@ func (nl *NodeLink) recvPkt() (*PktBuf, error) {
 		}
 	}
 
-	if true {
+	if false {
 		// XXX -> log
 		fmt.Printf("%v < %v: %v\n", nl.peerLink.LocalAddr(), nl.peerLink.RemoteAddr(), pkt)
 	}
@@ -376,6 +376,7 @@ func (nl *NodeLink) serveSend() {
 
 		case txreq := <-nl.txq:
 			err = nl.sendPkt(txreq.pkt)
+			fmt.Printf("sendPkt -> %v\n", err)
 
 			if err != nil {
 				// on IO error framing over peerLink becomes broken
@@ -391,6 +392,15 @@ func (nl *NodeLink) serveSend() {
 
 			txreq.errch <- err	// XXX recheck wakeup logic for err case
 
+			// XXX we need to first wait till _both_ serveRecv & serveSend complete
+			// and only then close all Conns. Reason: e.g. when remote shutdowns
+			// both sendPkt and recvPkt get error. If recvPkt was
+			// first serveRecv will be first to mark connections as
+			// closed and even though sendPkt will return proper IO
+			// error it won't be delivered as Conn.Send waiting for
+			// it already waked up on c.closed without seeing
+			// txreq.errch being ready.
+
 			if err != nil {
 				// XXX use errMu to lock vvv if needed
 //				nl.sendErr = err
@@ -440,9 +450,17 @@ func (c *Conn) Send(pkt *PktBuf) error {
 		// NOTE after we return straight here serveSend won't be later
 		// blocked on c.txerr<- because that backchannel is a non-blocking one.
 		case <-c.closed:
-			// XXX also poll c.txerr
+
+			// also poll c.txerr here because: when there is TX error,
+			// serveSend sends to c.txerr _and_ closes c.closed .
+			// We still want to return actual transmission error to caller.
+			select {
+			case err = <-c.txerr:
+				return err
+			default:
 				return ErrClosedConn
 //				return errClosedConn(c.nodeLink.sendErr)	// XXX locking ?
+			}
 
 		case err = <-c.txerr:
 			//fmt.Printf("%v <- c.txerr\n", err)
@@ -450,7 +468,7 @@ func (c *Conn) Send(pkt *PktBuf) error {
 		}
 	}
 
-	return err
+//	return err
 }
 
 // Receive packet from connection

go/neo/connection_test.go

@@ -158,7 +158,7 @@ func nodeLinkPipe() (nl1, nl2 *NodeLink) {
 func TestNodeLink(t *testing.T) {
 	// TODO catch exception -> add proper location from it -> t.Fatal (see git-backup)
 
-///*
+/*
 	// Close vs recvPkt
 	nl1, nl2 := _nodeLinkPipe(linkNoRecvSend, linkNoRecvSend)
 	wg := WorkGroup()
@@ -323,13 +323,13 @@ func TestNodeLink(t *testing.T) {
 	xclose(c11)
 	xclose(c12)
 	xclose(nl2)
-//*/
+*/
 
 	// NodeLink.Close vs Conn.Send/Recv on another side	TODO
-	nl1, nl2 = _nodeLinkPipe(0, linkNoRecvSend)
-	c11 = nl1.NewConn()
-	c12 = nl1.NewConn()
-	wg = WorkGroup()
+	nl1, nl2 := _nodeLinkPipe(0, linkNoRecvSend)
+	c11 := nl1.NewConn()
+	c12 := nl1.NewConn()
+	wg := WorkGroup()
 	wg.Gox(func() {
 		println(">>> RECV START")
 		pkt, err := c11.Recv()
@@ -344,25 +344,23 @@ func TestNodeLink(t *testing.T) {
 		println(">>> SEND START")
 		err := c12.Send(pkt)
 		println(">>> send wakeup")
-		if err != io.ErrClosedPipe {	// XXX we are here but what the error should be?
-			exc.Raisef("Conn.Send() after peer NodeLink shutdown: err = %v", err)
+		if want := io.ErrClosedPipe; err != want {// XXX we are here but what the error should be?
+			exc.Raisef("Conn.Send() after peer NodeLink shutdown: unexpected err\nhave: %v\nwant: %v", err, want)
 		}
 		println(">>> SEND OK")
 
 	})
 	tdelay()
+	println("NL2.Close")
 	xclose(nl2)
-	println("111")
 	xwait(wg)
-	println("222")
+	// TODO check Recv/Send error on second call
 	xclose(c11)
-	println("aaa")
 	xclose(c12)
-	println("bbb")
+	// TODO check Recv/Send error after Close
 	xclose(nl1)
-	println("333")
 
-///*
+/*
 	// Conn accept + exchange
 	nl1, nl2 = nodeLinkPipe()
 	wg = WorkGroup()
@@ -448,5 +446,5 @@ func TestNodeLink(t *testing.T) {
 	xclose(c2)
 	xclose(nl1)
 	xclose(nl2)
-//*/
+*/
 }