main.js

const napa = require('napajs');
const NUMBER_OF_WORKERS = 4;

const zone = napa.zone.create('zone', { workers: NUMBER_OF_WORKERS} );

let size;
if (process.argv[2]) {
    size = parseInt(process.argv[2]);
    if (size !== size) {
        console.log('size should be an integer');
        process.exit(1);
    }
} else {
    console.log('size should be provided');
    process.exit(1);
}

const matrix = [];
const vector = [];

for (let i = 0; i < size; i++) {
    matrix.push([]);
    for (let j = 0; j < size; j++) {
        matrix[i].push(getRandomInt(0,100));
    }
}

for (let i = 0; i < size; i++) {
    vector.push([getRandomInt(0,100)]);
}

console.log('Matrix:');
console.log(matrix);
console.log('Vector:');
console.log(vector);

function multiply (row, vector) {
    let result = 0;
    for (let i = 0; i < row.length; i++) {
        result += row[i] * vector[i][0];
    }

    for (const currentTime  = new Date().getTime() + 5; new Date().getTime() < currentTime;);  //looping to simulate some work

    return result;
}

var promises = [];

const start = Date.now();

for(var i = 0; i < size; i++)
    promises[i] = zone.execute(multiply, [matrix[i], vector]);

Promise.all(promises).then((results) => {
    const end = Date.now();
    console.log('Result:');
    console.log(results.map(result => [parseInt(result._payload)]));
    console.log('Runtime: ' + (end - start) + 'ms');
});

function getRandomInt(min, max) {
    return Math.floor(Math.random() * (max - min + 1)) + min;
}