Node Worker Threads

It's a basic library for works with Node.js threads. This library provides a worker pool with n workers (based on how many cores your CPU has).

Node.js Threads

Node.js provides a way for works with non-clustered threads.

The worker_threads module enables the use of threads that execute JavaScript in parallel.

WorkerPool

constructor<T, K>(javascriptFile, numWorkers)

• T any: input data type. T will be transferred in a way which is compatible with the HTML structured clone algorithm.
• K any: output data type
• javascriptFile string: path to Javascript script file
• numWorkers number: amount of workers

const workerPool = new WorkerPool<number, string>('script.js', 4);

The Javascript script example:

const { parentPort, threadId } = require('worker_threads');

/**
 * Simulates a complex task
 */

// The type of the data param must be the same as indicated in T
parentPort.on('message', (data) => {
	const randomTime = (Math.floor(Math.random() * 3) + 1) * 1000;
	setTimeout(
    	// The type of argument must be the same as indicated in K
		() => parentPort.postMessage(`${threadId} -> ${randomTime}`),
		randomTime
	);
});

setup()

Instantiates the workers. It's necessary before any task starts.

const workerPool = new WorkerPool<number, string>('script.js', 4);
await workerPool.setup();

run(data)

• data T: input data for task. Generic T is defined on class constructor.

const workerPool = new WorkerPool<number, string>('script.js', 4);
await workerPool.setup();
const result = await workerPool.run(100);