async_hooks.triggerAsyncId()

• 返回: <number> 负责调用当前正在执行的回调的资源 ID。

const server = net.createServer((conn) => {
  // 导致（或触发）此回调被调用的资源是新连接的资源。
  // 因此 triggerAsyncId() 的返回值是 "conn" 的 asyncId。
  async_hooks.triggerAsyncId();

}).listen(port, () => {
  // 即使传给 .listen() 的所有回调都包含在 nextTick() 中，
  // 但回调本身仍然存在，因为对服务器的 .listen() 进行了调用。
  // 所以返回值将是服务器的 ID。
  async_hooks.triggerAsyncId();
});

默认情况下，promise 上下文可能无法获得有效的 triggerAsyncId。 请参阅 promise 执行跟踪部分。

• Returns: <number> The ID of the resource responsible for calling the callback that is currently being executed.

const server = net.createServer((conn) => {
  // The resource that caused (or triggered) this callback to be called
  // was that of the new connection. Thus the return value of triggerAsyncId()
  // is the asyncId of "conn".
  async_hooks.triggerAsyncId();

}).listen(port, () => {
  // Even though all callbacks passed to .listen() are wrapped in a nextTick()
  // the callback itself exists because the call to the server's .listen()
  // was made. So the return value would be the ID of the server.
  async_hooks.triggerAsyncId();
});

Promise contexts may not get valid triggerAsyncIds by default. See the section on promise execution tracking.