https://github.com/zebrajaeger/threadpool

js threadpool
https://github.com/zebrajaeger/threadpool

Last synced: 3 months ago
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js threadpool

• Host: GitHub
• URL: https://github.com/zebrajaeger/threadpool
• Owner: zebrajaeger
• License: mit
• Created: 2020-08-09T14:04:16.000Z (over 5 years ago)
• Default Branch: master
• Last Pushed: 2020-09-04T13:42:25.000Z (over 5 years ago)
• Last Synced: 2025-03-08T17:03:20.685Z (10 months ago)
• Language: JavaScript
• Size: 7.81 KB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

          
# threadpool

[![NPM Version](https://img.shields.io/npm/v/@zebrajaeger/threadpool.svg?style=flat)](https://www.npmjs.org/package/@zebrajaeger/threadpool)

[![Install Size](https://packagephobia.now.sh/badge?p=@zebrajaeger/threadpool)](https://packagephobia.now.sh/result?p=@zebrajaeger/threadpool)

[![License](https://img.shields.io/github/license/zebrajaeger/threadpool)](https://img.shields.io/github/license/zebrajaeger/threadpool)

js threadpool

## Example

### Pool Code

``` javascript

const path = require('path')

const {StaticWorkerPool} = require('@zebrajaeger/threadpool')

const threadFile = path.resolve(__dirname, 'mythread.js');

(async () => {

    // create pool (default count = os.cpus().length)

    const p = new StaticWorkerPool(threadFile).begin();

    // start 20 jobs

    for (let i = 1; i <= 20; ++i) {

        p.exec(`foo(${i})`).promise.then(r => console.log('xxx', r))

    }

    // wait until all jobs are done

    await p.finished();

    console.log('DONE')

    // shutdown pool

    await p.destroy();

    console.log('Destroyed')

})();

```

### Worker Code (mythread.js)

``` javascript

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

// for every worker this is a new instance 

// so this 'counter' starts everytime with zero.

let counter = 0;

// the code to execute: 

// - wait a little bit and then return result

// - on every 5th execution fail 

async function toExec(msg) {

    return new Promise((resolve, reject) => {

        setTimeout(() => {

            if (++counter >= 5) {

                counter = 0;

                reject('Oh no!!');

            } else {

                resolve(`Meep(${counter}): '${msg}'`);

            }

        }, 100)

    })

}

// entry point for WorkerPool/WorkerThread

parentPort.on('message', async data => {

    // wrap errors. Not needed but more easy to handle

    try {

        parentPort.postMessage({result: await toExec(data), data});

    } catch (error) {

        parentPort.postMessage({error, data});

    }

});

```