try to fix http2 panic (#54)

listener/http2/conn.go

@@ -13,6 +13,7 @@ type conn struct {
 	raddr  net.Addr
 	ctx    context.Context
 	cancel context.CancelFunc
+	closed chan struct{}
 }
 
 func (c *conn) Read(b []byte) (n int, err error) {
@@ -27,6 +28,12 @@ func (c *conn) Close() error {
 	if c.cancel != nil {
 		c.cancel()
 	}
+
+	select {
+	case <-c.closed:
+	default:
+		close(c.closed)
+	}
 	return nil
 }
 

listener/http2/listener.go

@@ -178,6 +178,7 @@ func (l *http2Listener) handleFunc(w http.ResponseWriter, r *http.Request) {
 		raddr:  remoteAddr,
 		ctx:    ctx,
 		cancel: cancel,
+		closed: make(chan struct{}),
 	}
 
 	select {
@@ -187,5 +188,6 @@ func (l *http2Listener) handleFunc(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	<-ctx.Done()
+	// NOTE: we need to wait for conn closed, or the connection will be closed.
+	<-conn.closed
 }