node/test/parallel/test-worker-message-port-message-before-close.js
Anna Henningsen d7c5ffc7a4
test: improve test-worker-message-port-message-before-close
Replace a wrong comment with a correct assertion and await all async
operations inside the async function.

PR-URL: https://github.com/nodejs/node/pull/29483
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
2019-09-09 22:19:42 +02:00

39 lines
1.3 KiB
JavaScript

'use strict';
const common = require('../common');
const assert = require('assert');
const { once } = require('events');
const { Worker, MessageChannel } = require('worker_threads');
// This is a regression test for the race condition underlying
// https://github.com/nodejs/node/issues/22762.
// It ensures that all messages send before a MessagePort#close() call are
// received. Previously, what could happen was a race condition like this:
// - Thread 1 sends message A
// - Thread 2 begins receiving/emitting message A
// - Thread 1 sends message B
// - Thread 1 closes its side of the channel
// - Thread 2 finishes receiving/emitting message A
// - Thread 2 sees that the port should be closed
// - Thread 2 closes the port, discarding message B in the process.
async function test() {
const worker = new Worker(`
require('worker_threads').parentPort.on('message', ({ port }) => {
port.postMessage('firstMessage');
port.postMessage('lastMessage');
port.close();
});
`, { eval: true });
for (let i = 0; i < 10000; i++) {
const { port1, port2 } = new MessageChannel();
worker.postMessage({ port: port2 }, [ port2 ]);
assert.deepStrictEqual(await once(port1, 'message'), ['firstMessage']);
assert.deepStrictEqual(await once(port1, 'message'), ['lastMessage']);
}
await worker.terminate();
}
test().then(common.mustCall());