port.close()

禁止在连接的任一端进一步发送消息。当此 MessagePort 上不会发生进一步的通信时，可以调用此方法。

¥Disables further sending of messages on either side of the connection. This method can be called when no further communication will happen over this MessagePort.

'close' 事件 在作为通道一部分的两个 MessagePort 实例上触发。

¥The 'close' event is emitted on both MessagePort instances that are part of the channel.