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FAQ

Why workers and not child_process?​

Spawning a child process is heavy — a new V8 instance per process, expensive setup, no shared memory. Worker threads share the same process, are an order of magnitude faster to spin up, and let you transfer ArrayBuffers without copying. Workers are almost always the right choice for CPU-bound JavaScript.

Should I use a worker for I/O?​

Usually no. Node's I/O is already non-blocking and lives on the event loop. Workers are for CPU-bound work: image processing, hashing, parsing, math. If your bottleneck is disk or network, optimize the I/O itself first.

Why does my worker hang?​

Probably you forgot to await thread.terminate() or await pool.terminate(). Workers are real OS-level resources; the Node process won't exit while they're alive.

Why didn't my bus.on listener fire?​

If the worker is inside a synchronous loop, it can't process incoming messages until the loop ends. Yield to the event loop periodically:

for (let i = 0; i < n; i++) {
  doWork(i);
  if (i % 1_000_000 === 0) await new Promise((r) => setImmediate(r));
}

Can I pass functions / class instances over the bus?​

No — payloads cross via Node's structured clone algorithm, same rules as postMessage. Functions, class instances with custom prototypes, and DOM nodes don't survive the trip. Plain objects, Map, Set, Date, typed arrays all work.

Can I share memory between workers?​

Yes — use SharedArrayBuffer and pass it via workerData or transferList. Same rules as Node worker_threads.

Does hurried work in the browser?​

No — hurried is built on Node.js worker_threads. For browser workers, look at libraries like comlink or threads.js.

Does it work with tsx / ts-node?​

Yes. Thread.fromFunction works out of the box. Thread.fromFile pointing at a .ts file needs execArgv: ['--import', 'tsx']:

Thread.fromFile(new URL('./worker.ts', import.meta.url), {
  execArgv: ['--import', 'tsx'],
});

How big is the bundle?​

About 20 kB minified. Zero runtime dependencies.

What's the Node version requirement?​

Node 18.17+ for availableParallelism() and modern AbortSignal semantics. The CI matrix tests Node 18, 20, and 22 on Ubuntu, macOS, and Windows.

Where do I report bugs?​

https://github.com/yankouskia/hurried/issues. Stars and PRs welcome too.

What's the latest version?​

2.0.1 on npm. See the full changelog.