node-dbus worker threads

README.md

dbus Worker Threads Demo

This gist is working through the issue of getting the dbus npm package to work with Node.js worker threads, specifically on node v12.13.0.

To run:

npm install
npm run demo
# run the same demo
# using cluster instead
# of worker threads
npm run demo:cluster

# npm run demo result

> @1.0.0 demo <path>
> node index.js

[worker online]
[worker error] Error: Module did not self-register.
    at Object.Module._extensions..node (internal/modules/cjs/loader.js:1003:18)
    at Module.load (internal/modules/cjs/loader.js:812:32)
    at Function.Module._load (internal/modules/cjs/loader.js:724:14)
    at Module.require (internal/modules/cjs/loader.js:849:19)
    at require (internal/modules/cjs/helpers.js:74:18)
    at Object.<anonymous> (<path>/node_modules/dbus/lib/dbus.js:3:13)
    at Module._compile (internal/modules/cjs/loader.js:956:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:973:10)
    at Module.load (internal/modules/cjs/loader.js:812:32)
    at Function.Module._load (internal/modules/cjs/loader.js:724:14)
[worker exit] 1

# -----

# npm run demo expected result

> @1.0.0 demo /tmp/dbus
> node index.js

[worker online]
[worker received payload] test message
[master received payload] test message
[worker exit] 1

cluster.js

(() => {
  'use strict';

  const dbus = require('dbus');
  const cluster = require('cluster')
  const {isMaster, isWorker} = cluster;

  if (isMaster) {
    const worker = cluster.fork();

    worker.on('online', () => {
      console.log('[worker online]');
    });

    worker.on('message', (...args) => {
      console.log('[master received payload]', ...args);
      worker.kill('SIGTERM');
    });

    worker.on('error', (err) => {
      console.error('[worker error]', err);
    });

    worker.on('exit', () => {
      console.log('[worker exit]');
    });

    worker.send('test message');
  } else if(isWorker) {
    process.once('message', (...args) => {
      console.log('[worker recieved payload]', ...args);
      process.send(...args);
    });
  }
})();

index.js

(() => {
  'use strict';

  const dbus = require('dbus');
  const {isMainThread, parentPort, Worker} = require('worker_threads');

  if (isMainThread) {
    const worker = new Worker(__filename);

    worker.on('online', () => {
      console.log('[worker online]');
    });

    worker.on('message', (...args) => {
      console.log('[master received payload]', ...args);
      worker.terminate();
    });

    worker.on('error', (err) => {
      console.error('[worker error]', err);
    });

    worker.on('exit', (code) => {
      console.log('[worker exit]', code);
    });

    worker.postMessage('test message');
  } else {
    parentPort.once('message', (...args) => {
      console.log('[worker received payload]', ...args);
      parentPort.postMessage(...args);
    });
  }
})();

package.json

{
  "private": true,
  "version": "1.0.0",
  "main": "index.js",
  "scripts": {
    "demo": "node index.js",
    "demo:cluster": "node cluster.js"
  },
  "dependencies": {
    "dbus": "^1.0.5"
  }
}