worker.isConnected()

当工作进程通过 IPC 管道连接至主进程时，这个方法返回 true，否则返回 false。 一个工作进程在创建后会自动连接到它的主进程。 当 'disconnect' 事件被触发时才会断开连接。

This function returns true if the worker is connected to its master via its IPC channel, false otherwise. A worker is connected to its master after it has been created. It is disconnected after the 'disconnect' event is emitted.