executionAsyncId
import { executionAsyncId } from 'node:async_hooks';
import fs from 'node:fs';
console.log(executionAsyncId()); // 1 - bootstrap
const path = '.';
fs.open(path, 'r', (err, fd) => {
console.log(executionAsyncId()); // 6 - open()
});
Content copied to clipboard
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();
});
Content copied to clipboard
Promise contexts may not get precise executionAsyncIds
by default. See the section on promise execution tracking.
Since
v8.1.0
Return
The asyncId
of the current execution context. Useful to track when something calls.