[Node.js] Work-Thread 예시

스레드 예시(소수 찾기)

const {
    Worker, isMainThread, parentPort, workerData,
} = require('worker_threads');
 
const min =2;
let primes = [];
 
function findPrimes(start, range) {
    let isPrime = true;
    const end = start + range;
    for(let i = start; i < end; i++){
        for(let j = min; j < Math.sqrt(end); j++){
            if(i !== j && i % j === 0){
                isPrime = false;
                break;
            }
        }
 
        if(isPrime){
            primes.push(i);
        }
        isPrime = true;
    }
}
 
if(isMainThread){
    const max =10_000_000;
    const threadCount = 8;
    const threads = new Set();
    const range = Math.ceil((max - min)/ threadCount);
    let start = min;
    console.time('prime');
 
    for(let i = 0; i < threadCount -1; i++){
        const wStart = start;
        threads.add(new Worker(__filename, { workerData : {start: wStart, range}}));
        start += range;
    }
    threads.add(new Worker(__filename, {workerData : {start, range: range + ((max - min + 1)% threadCount)}}));
 
    for(let worker of threads){~
        worker.on('error', (err) => {
            throw err;
        });
        worker.on('exit',() =>{
            threads.delete(worker);
            if(threads.size === 0){
                console.timeEnd('prime');
                console.log(primes.length);
            }
        });
        worker.on('message', (msg)=> {
            primes = primes.concat(msg);
        });
    }
}else{
    findPrimes(workerData.start, workerData.range);
    parentPort.postMessage(primes);
}