node-threadpool

node-threadpool

WARNING: This is mostly experimental and the API is subject to change.

This package implements thread pools for node 10.5's new worker thread API (see: https://nodejs.org/api/worker_threads.html).

Usage

If you're familiar with Java's thread pool API, this should be very familiar:

import { Executors } from "node-threadpool";

const pool = Executors.newFixedThreadPool(1);
const result = pool.submit(async () => "hello world");

console.log(await result); // prints "hello world"

import { Executors } from "node-threadpool";

const pool = Executors.newFixedThreadPool(1);
const result = pool.submit(async (): Promise<string> => "hello world");

console.log(await result); // prints "hello world"

Requires node 10.5+. You must run node with the --experimental-worker flag enabled.

NODE_OPTIONS=--experimental-worker ./server.js

or

node --experimental-worker ./server.js

Detailed Usage Instructions

To install:

yarn add node-threadpool

or

npm add node-threadpool

Import node-threadpool:

import { Executors } from "node-threadpool";

Executors contains methods to create different thread pools.

Create a thread pool by calling one of these methods:

// creates a thread pool with 4 threads
const pool = Executors.newFixedThreadPool(4);

Then submit work to the pool with the submit method. This method takes in a function with no arguments that returns a Promise. The submit method itself returns a Promise which is resolved when the function has been executed.

// these execute in parallel (as long as the pool size >= 2)
const result1 = pool.submit(async () => "done 1");
const result2 = pool.submit(async () => "done 2");

console.log(await result1); // joins and prints "done1"
console.log(await result2); // joins and prints "done2"

See the documentation for full API details.

TODOs

• Figure out better function / data serialization.
• Support cached thread executor
• Clean up code
• Settle on an API (when node's api is stable)

License

MIT Licensed, see the LICENSE file.