net_transport.go
func (n *NetworkTransport) getPooledConn(target ServerAddress) *netConn {
	n.connPoolLock.Lock()
	defer n.connPoolLock.Unlock()

	conns, ok := n.connPool[target]
	if !ok || len(conns) == 0 {
		return nil
	}

	var conn *netConn
	num := len(conns)
	conn, conns[num-1] = conns[num-1], nil
	n.connPool[target] = conns[:num-1]
	return conn
}
func (n *NetworkTransport) getPooledConn(target ServerAddress) *netConn {
	n.connPoolLock.Lock()
	defer n.connPoolLock.Unlock()

	conns, ok := n.connPool[target]
	if !ok || len(conns) == 0 {
		return nil
	}

	var conn *netConn
	num := len(conns)
	conn, conns[num-1] = conns[num-1], nil
	n.connPool[target] = conns[:num-1]
	return conn
}
func ( n * NetworkTransport ) getPooledConn ( target ServerAddress ) * netConn { n . connPoolLock . Lock ( ) defer n . connPoolLock . Unlock ( ) conns , ok := n . connPool [ target ] if ! ok || len ( conns ) == 0 { return nil } var conn * netConn num := len ( conns ) conn , conns [ num - 1 ] = conns [ num - 1 ] , nil n . connPool [ target ] = conns [ : num - 1 ] return conn }
// getExistingConn is used to grab a pooled connection.
getExistingConn is used to grab a pooled connection .