feat: add an example 'shared-resource'

README.md

@@ -39,6 +39,8 @@ await locks.request('Resource name', async lock => {
 });
 ```
 
+More examples [here](./examples/README.md)
+
 ## License
 
 This implementation of Web Locks API is [MIT licensed](./LICENSE).

examples/README.md

@@ -0,0 +1,7 @@
+## shared-resource
+
+* A simple example of parallel working on the same resource from several threads
+* run
+```bash
+node  examples/shared-resource/thread-main.js
+```

examples/shared-resource/thread-main.js

@@ -0,0 +1,44 @@
+'use strict';
+
+const path = require('path');
+const threads = require('worker_threads');
+const { locks } = require('../..');
+
+const startWork = () =>
+  new Promise(resolve => {
+    const workerFile = path.resolve(__dirname, 'thread-worker.js');
+
+    const resource = new SharedArrayBuffer(8);
+
+    const worker1 = new threads.Worker(workerFile, { workerData: resource });
+    const worker2 = new threads.Worker(workerFile, { workerData: resource });
+    const worker3 = new threads.Worker(workerFile, { workerData: resource });
+
+    locks.attach(worker1);
+    locks.attach(worker2);
+    locks.attach(worker3);
+
+    let counter = 0;
+    const done = message => {
+      if (message.status === 'done') {
+        counter++;
+        if (counter === 3) {
+          console.log('After processing:', resource);
+
+          resolve();
+        }
+      }
+    };
+
+    worker1.on('message', done);
+    worker2.on('message', done);
+    worker3.on('message', done);
+
+    locks.request('resource', async () => {
+      worker1.postMessage({ isMyProgram: true, task: 'someWorkWithData' });
+      worker2.postMessage({ isMyProgram: true, task: 'someWorkWithData' });
+      worker3.postMessage({ isMyProgram: true, task: 'someWorkWithData' });
+    });
+  });
+
+startWork();

examples/shared-resource/thread-worker.js

@@ -0,0 +1,38 @@
+'use strict';
+
+const threads = require('worker_threads');
+const { locks } = require('../../');
+
+const SLEEPING_TIME_MS = 1000;
+
+const sleep = () =>
+  new Promise(resolve => {
+    setTimeout(resolve, SLEEPING_TIME_MS);
+  });
+
+const someWorkWithData = async () => {
+  await locks.request('resource', {}, async () => {
+    await sleep();
+    const view = new Int8Array(threads.workerData);
+    for (let i = 0; i < view.length; i++) {
+      view[i] *= threads.threadId;
+      view[i] += threads.threadId;
+    }
+
+    console.log('info', threads.threadId, view);
+  });
+  threads.parentPort.postMessage({ status: 'done' });
+  process.exit(0);
+};
+
+const worksMapper = {
+  someWorkWithData,
+};
+
+threads.parentPort.on('message', async message => {
+  if (!message.isMyProgram) {
+    return;
+  }
+
+  await worksMapper[message.task]();
+});