worker.isMainThread

• <boolean>

如果此代码不在 Worker 线程内运行，则为 true。

const { Worker, isMainThread } = require('node:worker_threads');

if (isMainThread) {
  // 这会在工作线程实例中重新加载当前文件。
  new Worker(__filename);
} else {
  console.log('Inside Worker!');
  console.log(isMainThread);  // 打印 'false'。
}

• <boolean>

Is true if this code is not running inside of a Worker thread.

const { Worker, isMainThread } = require('node:worker_threads');

if (isMainThread) {
  // This re-loads the current file inside a Worker instance.
  new Worker(__filename);
} else {
  console.log('Inside Worker!');
  console.log(isMainThread);  // Prints 'false'.
}