async_hooks.executionAsyncId()

• 返回: <number> 当前执行上下文的 asyncId。 当有调用时对跟踪很有用。

import { executionAsyncId } from 'node:async_hooks';

console.log(executionAsyncId());  // 1 - 引导
fs.open(path, 'r', (err, fd) => {
  console.log(executionAsyncId());  // 6 - open()
});const async_hooks = require('node:async_hooks');

console.log(async_hooks.executionAsyncId());  // 1 - 引导
fs.open(path, 'r', (err, fd) => {
  console.log(async_hooks.executionAsyncId());  // 6 - open()
});

executionAsyncId() 返回的 ID 与执行时机有关，与因果无关（被 triggerAsyncId() 涵盖）：

const server = net.createServer((conn) => {
  // 返回服务器的 ID，而不是新连接的 ID，
  // 因为回调在服务器的 MakeCallback() 的执行范围内运行。
  async_hooks.executionAsyncId();

}).listen(port, () => {
  // 返回 TickObject (process.nextTick()) 的 ID，
  // 因为传给 .listen() 的所有回调都包含在 nextTick() 中。
  async_hooks.executionAsyncId();
});

默认情况下，promise 上下文可能无法获得精确的 executionAsyncIds。 请参阅 promise 执行跟踪部分。

• Returns: <number> The asyncId of the current execution context. Useful to track when something calls.

import { executionAsyncId } from 'node:async_hooks';

console.log(executionAsyncId());  // 1 - bootstrap
fs.open(path, 'r', (err, fd) => {
  console.log(executionAsyncId());  // 6 - open()
});const async_hooks = require('node:async_hooks');

console.log(async_hooks.executionAsyncId());  // 1 - bootstrap
fs.open(path, 'r', (err, fd) => {
  console.log(async_hooks.executionAsyncId());  // 6 - open()
});

The ID returned from executionAsyncId() is related to execution timing, not causality (which is covered by triggerAsyncId()):

const server = net.createServer((conn) => {
  // Returns the ID of the server, not of the new connection, because the
  // callback runs in the execution scope of the server's MakeCallback().
  async_hooks.executionAsyncId();

}).listen(port, () => {
  // Returns the ID of a TickObject (process.nextTick()) because all
  // callbacks passed to .listen() are wrapped in a nextTick().
  async_hooks.executionAsyncId();
});

Promise contexts may not get precise executionAsyncIds by default. See the section on promise execution tracking.