Check for alive before rx or tx

connection.go

@@ -113,6 +113,7 @@ func Connect(parameters ConnectionParameters) (c *Connection, err error) {
 	defer func() {
 		if c != nil && err != nil {
 			c.conn.Close()
+			c.alive = false
 		}
 	}()
 
@@ -121,6 +122,7 @@ func Connect(parameters ConnectionParameters) (c *Connection, err error) {
 	c.buf = bytes.NewBuffer(make([]byte, 0, c.bufSize))
 	c.RuntimeParams = make(map[string]string)
 	c.preparedStatements = make(map[string]*preparedStatement)
+	c.alive = true
 
 	msg := newStartupMessage()
 	msg.options["user"] = c.parameters.User
@@ -144,7 +146,6 @@ func Connect(parameters ConnectionParameters) (c *Connection, err error) {
 				}
 			case readyForQuery:
 				c.rxReadyForQuery(r)
-				c.alive = true
 				return c, nil
 			default:
 				if err = c.processContextFreeMsg(t, r); err != nil {
@@ -619,12 +620,6 @@ func (c *Connection) processContextFreeMsg(t byte, r *MessageReader) (err error)
 }
 
 func (c *Connection) rxMsg() (t byte, r *MessageReader, err error) {
-	defer func() {
-		if err != nil {
-			c.die(err)
-		}
-	}()
-
 	var bodySize int32
 	t, bodySize, err = c.rxMsgHeader()
 	if err != nil {
@@ -641,6 +636,17 @@ func (c *Connection) rxMsg() (t byte, r *MessageReader, err error) {
 }
 
 func (c *Connection) rxMsgHeader() (t byte, bodySize int32, err error) {
+	if !c.alive {
+		err = errors.New("Connection is dead")
+		return
+	}
+
+	defer func() {
+		if err != nil {
+			c.die(err)
+		}
+	}()
+
 	buf := c.getBuf()
 	if _, err = io.CopyN(buf, c.conn, 5); err != nil {
 		return 0, 0, err
@@ -656,6 +662,17 @@ func (c *Connection) rxMsgHeader() (t byte, bodySize int32, err error) {
 }
 
 func (c *Connection) rxMsgBody(bodySize int32) (buf *bytes.Buffer, err error) {
+	if !c.alive {
+		err = errors.New("Connection is dead")
+		return
+	}
+
+	defer func() {
+		if err != nil {
+			c.die(err)
+		}
+	}()
+
 	buf = c.getBuf()
 	_, err = io.CopyN(buf, c.conn, int64(bodySize))
 	return
@@ -774,6 +791,10 @@ func (c *Connection) txStartupMessage(msg *startupMessage) (err error) {
 }
 
 func (c *Connection) txMsg(identifier byte, buf *bytes.Buffer, flush bool) (err error) {
+	if !c.alive {
+		return errors.New("Connection is dead")
+	}
+
 	defer func() {
 		if err != nil {
 			c.die(err)