Fix rare 'panic: send on closed channel' with dmsg.Transport

skycoin · Jun 27, 2019 · 4957070 · 4957070
1 parent b9db401
commit 4957070
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Showing 3 changed files with 23 additions and 12 deletions.
diff --git a/go.mod b/go.mod
@@ -25,6 +25,7 @@ require (
 	go.etcd.io/bbolt v1.3.3
 	golang.org/x/crypto v0.0.0-20190621222207-cc06ce4a13d4
 	golang.org/x/net v0.0.0-20190620200207-3b0461eec859
-	golang.org/x/sys v0.0.0-20190624142023-c5567b49c5d0 // indirect
+	golang.org/x/sys v0.0.0-20190626221950-04f50cda93cb // indirect
 	golang.org/x/text v0.3.2 // indirect
+	golang.org/x/tools v0.0.0-20190627033414-4874f863e654 // indirect
 )
diff --git a/go.sum b/go.sum
@@ -109,11 +109,13 @@ golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACk
 golang.org/x/crypto v0.0.0-20190621222207-cc06ce4a13d4 h1:ydJNl0ENAG67pFbB+9tfhiL2pYqLhfoaZFw/cjLhY4A=
 golang.org/x/crypto v0.0.0-20190621222207-cc06ce4a13d4/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/net v0.0.0-20181114220301-adae6a3d119a/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190620200207-3b0461eec859 h1:R/3boaszxrf1GEUWTVDzSKVwLmSJpwZ1yqXm8j0v2QI=
 golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/sync v0.0.0-20181108010431-42b317875d0f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20180905080454-ebe1bf3edb33/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20181116152217-5ac8a444bdc5/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20181205085412-a5c9d58dba9a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
@@ -123,10 +125,16 @@ golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20190422165155-953cdadca894/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190624142023-c5567b49c5d0 h1:HyfiK1WMnHj5FXFXatD+Qs1A/xC2Run6RzeW1SyHxpc=
 golang.org/x/sys v0.0.0-20190624142023-c5567b49c5d0/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20190626221950-04f50cda93cb h1:fgwFCsaw9buMuxNd6+DQfAuSFqbNiQZpcgJQAgJsK6k=
+golang.org/x/sys v0.0.0-20190626221950-04f50cda93cb/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20190612231717-10539ce30318/go.mod h1:/rFqwRUd4F7ZHNgwSSTFct+R/Kf4OFW1sUzUTQQTgfc=
+golang.org/x/tools v0.0.0-20190627033414-4874f863e654 h1:a5iTclD5417yiTAwxzAQY6HG6HeJS4MqmPCoTlbd+0I=
+golang.org/x/tools v0.0.0-20190627033414-4874f863e654/go.mod h1:F+l5rz3/Uc0BJWNSxc0r6FcPZ3lxfduWytgpR5peIOQ=
+golang.org/x/tools/gopls v0.1.0/go.mod h1:p8Q0IUu6EEeGxqmoN/g6Et3gReLCGA7PtNRdyOxcWJE=
 gopkg.in/alecthomas/kingpin.v2 v2.2.6 h1:jMFz6MfLP0/4fUyZle81rXUoxOBFi19VUFKVDOQfozc=
 gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLkstjWtayDeSgw=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

diff --git a/pkg/dmsg/transport.go b/pkg/dmsg/transport.go
@@ -32,8 +32,8 @@ type Transport struct {
 	local  cipher.PubKey // local PK
 	remote cipher.PubKey // remote PK
 
-	inCh chan Frame   // handles incoming frames (from dmsg.Client)
-	inMx sync.RWMutex // protects 'inCh'
+	inCh chan Frame // handles incoming frames (from dmsg.Client)
+	inMx sync.Mutex // protects 'inCh'
 
 	ackWaiter ioutil.Uint16AckWaiter // awaits for associated ACK frames
 	ackBuf    []byte                 // buffer for unsent ACK frames
@@ -130,17 +130,17 @@ func (tp *Transport) Type() string {
 
 // HandleFrame allows 'tp.Serve' to handle the frame (typically from 'ClientConn').
 func (tp *Transport) HandleFrame(f Frame) error {
-	tp.inMx.RLock()
-	defer tp.inMx.RUnlock()
+	tp.inMx.Lock()
+	defer tp.inMx.Unlock()
 
 handleFrame:
+	if tp.IsClosed() {
+		return io.ErrClosedPipe
+	}
 	select {
 	case tp.inCh <- f:
 		return nil
 	default:
-		if tp.IsClosed() {
-			return io.ErrClosedPipe
-		}
 		goto handleFrame
 	}
 }
@@ -275,10 +275,12 @@ func (tp *Transport) Serve() {
 				// add payload to 'buf'
 				tp.buf = append(tp.buf, p[2:])
 
-				// notify of new data via 'bufCh'
-				select {
-				case tp.bufCh <- struct{}{}:
-				default:
+				// notify of new data via 'bufCh' (only if not closed)
+				if !tp.IsClosed() {
+					select {
+					case tp.bufCh <- struct{}{}:
+					default:
+					}
 				}
 
 				log.WithField("bufSize", fmt.Sprintf("%d/%d", tp.bufSize, tpBufCap)).Infoln("Injected [FWD]")