Add worker thread pool example

waldemarnt · waldemarnt · commit cf1bcb33dd08 · 2019-07-27T13:22:51.000+10:00
diff --git a/.dockerignore b/.dockerignore
@@ -0,0 +1 @@
+node_modules/
diff --git a/.eslintrc.json b/.eslintrc.json
@@ -3,7 +3,7 @@
   "extends": ["eslint:recommended", "plugin:node/recommended"],
   "rules": {
     "node/exports-style": ["error", "module.exports"],
-    "no-console": ["warning"]
+    "no-console": 0
   },
   "env": {
     "jest": true
diff --git a/package-lock.json b/package-lock.json
diff --git a/package.json b/package.json
@@ -28,7 +28,8 @@
     "lightship": "^4.3.0",
     "mongoose": "^4.13.19",
     "request": "^2.88.0",
-    "request-promise": "^4.2.4"
+    "request-promise": "^4.2.4",
+    "worker-threads-pool": "^2.0.0"
   },
   "devDependencies": {
     "dtrace-provider": "^0.8.7",
diff --git a/src/routes/threads.js b/src/routes/threads.js
@@ -1,6 +1,7 @@
 const express = require('express');
 const fb = require('fibonacci');
 const runFibonacci = require('../workers/fibonacciWorker');
+const runFibonacciPool = require('../workers/fibonacciWorkerPool');
 const log = require('../log');
 
 const router = express.Router();
@@ -15,4 +16,9 @@ router.get('/fibonacciThreaded', async (req, res) => {
   res.send('processing');
 });
 
+router.get('/fibonacciThreadedPool', async (req, res) => {
+  runFibonacciPool({ iterations: 10000 }).then(result => log.info(result));
+  res.send('processing');
+});
+
 module.exports = router;
diff --git a/src/workers/fibonacciWorkerPool.js b/src/workers/fibonacciWorkerPool.js
@@ -0,0 +1,26 @@
+const fb = require('fibonacci');
+const { isMainThread, parentPort, workerData } = require('worker_threads');
+const Pool = require('worker-threads-pool');
+const CPUs = require('os').cpus().length;
+const pool = new Pool({ max: CPUs });
+
+const runFibonacci = workerData => {
+  return new Promise((resolve, reject) => {
+    pool.acquire(__filename, { workerData }, (err, worker) => {
+      if (err) reject(err);
+      console.log(`started worker ${worker} (pool size: ${pool.size})`);
+      worker.on('message', resolve);
+      worker.on('error', reject);
+      worker.on('exit', code => {
+        if (code !== 0) reject(new Error(`Worker stopped with exit code ${code}`));
+      });
+    });
+  });
+};
+
+if (!isMainThread) {
+  const number = fb.iterate(workerData.iterations);
+  parentPort.postMessage({ number });
+}
+
+module.exports = runFibonacci;
