From 9b6552ab6c66cb14d531eff903c4e78f3561e9ca Mon Sep 17 00:00:00 2001
From: Ciro Santilli <ciro.santilli@gmail.com>
Date: Thu, 4 Nov 2021 22:57:02 +0000
Subject: [PATCH] worker_threads_test.js

---
 .../lkmc/nodejs/worker_threads_test.js        | 52 +++++++++++++++++++
 1 file changed, 52 insertions(+)
 create mode 100755 rootfs_overlay/lkmc/nodejs/worker_threads_test.js

diff --git a/rootfs_overlay/lkmc/nodejs/worker_threads_test.js b/rootfs_overlay/lkmc/nodejs/worker_threads_test.js
new file mode 100755
index 0000000..a606e76
--- /dev/null
+++ b/rootfs_overlay/lkmc/nodejs/worker_threads_test.js
@@ -0,0 +1,52 @@
+#!/usr/bin/env node
+// Based on: https://medium.com/@Trott/using-worker-threads-in-node-js-80494136dbb6
+'use strict';
+const { Worker, isMainThread, parentPort, workerData } = require('worker_threads');
+const min = 2;
+let primes = [];
+function generatePrimes(start, range) {
+  console.log('started: ' + start);
+  let isPrime = true;
+  let 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;
+  }
+  console.log('ended: ' + start);
+}
+if (isMainThread) {
+  const max = 1e2;
+  const threadCount = +process.argv[2] || 10;
+  const threads = new Set();;
+  const range = Math.ceil((max - min) / threadCount);
+  let start = min;
+  for (let i = 0; i < threadCount - 1; i++) {
+    const myStart = start;
+    threads.add(new Worker(__filename, { workerData: { start: myStart, 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.log(primes.sort((a, b) => a - b).join('\n'));
+      }
+    })
+    worker.on('message', (msg) => {
+      primes = primes.concat(msg);
+    });
+  }
+} else {
+  generatePrimes(workerData.start, workerData.range);
+  parentPort.postMessage(primes);
+}