Bugfix and performance improvements

benchmark/benchmark.cjs

@@ -0,0 +1,103 @@
+const Benchmark = require('benchmark')
+const nativeFn = require('./native.cjs')
+const syncThreadsFn = require('./sync-threads.cjs')
+const synckitFn = require('./synckit.cjs')
+
+let previousMemory = 0;
+
+function memoryUsage(name) {
+  const currentMemory = process.memoryUsage().rss
+  const diff = currentMemory-previousMemory
+  const sign = diff > 0 ? '+' : '';
+
+  console.log(`[${name}] Memory usage ${currentMemory/1000000}MB (${sign}${diff/1000000}MB)`);
+
+  previousMemory = currentMemory;
+}
+
+memoryUsage('initial')
+
+function runAndPrint(suite) {
+  // add listeners
+  suite
+    .on('cycle', function (event) {
+      memoryUsage(`after ${event.target.name}`)
+    })
+    .on('complete', function () {
+      console.log()
+      const fastest = this.filter('fastest').map('name')
+      console.log('Fastest is ' + fastest)
+
+      var bySpeed = this.filter('successful').sort(function (a, b) {
+        a = a.stats
+        b = b.stats
+        return a.mean + a.moe > b.mean + b.moe ? -1 : 1
+      })
+
+      const results = []
+      let result
+      while ((result = bySpeed.pop())) {
+        //console.log(result)
+        results.push({
+          'Task Name': result.name,
+          'ops/sec': result.hz.toLocaleString('en-US', {
+            maximumFractionDigits: 0,
+          }),
+          //'Average Time (ns)': result.stats.mean * 1e9,
+          Margin: `\xB1 ${result.stats.rme.toFixed(2)}%`,
+          Samples: result.stats.sample.length,
+        })
+      }
+
+      console.table(results)
+    })
+    .run()
+}
+
+console.log('Load time')
+const loadBench = new Benchmark.Suite()
+loadBench
+  .add('native', () => {
+    return require('./native.cjs')
+  })
+  .add('sync-threads', () => {
+    return require('./sync-threads.cjs')
+  })
+  .add('synckit', () => {
+    return require('./synckit.cjs')
+  })
+
+runAndPrint(loadBench)
+
+console.log('Execution time')
+const hotBench = new Benchmark.Suite()
+hotBench
+  .add('native', () => {
+    return nativeFn(__filename)
+  })
+  .add('sync-threads', () => {
+    return syncThreadsFn(__filename)
+  })
+  .add('synckit', () => {
+    return synckitFn(__filename)
+  })
+
+runAndPrint(hotBench)
+
+console.log('Total time')
+const totalBench = new Benchmark.Suite()
+totalBench
+  .add('native', () => {
+    const fn = require('./native.cjs')
+    return fn(__filename)
+  })
+  .add('sync-threads', () => {
+    const fn = require('./sync-threads.cjs')
+    return fn(__filename)
+  })
+  .add('synckit', () => {
+    const fn = require('./synckit.cjs')
+    return fn(__filename)
+  })
+
+runAndPrint(totalBench)

benchmark/native.cjs

@@ -0,0 +1,3 @@
+const fs = require('node:fs')
+
+module.exports = filename => fs.readFileSync(filename, 'utf8')

benchmark/sync-threads.cjs

@@ -0,0 +1,8 @@
+const { createSyncFn } = require('../src/index.js')
+
+/**
+ * @type {() => string}
+ */
+const syncFn = createSyncFn(require.resolve('./sync-threads.worker.cjs'))
+
+module.exports = syncFn

benchmark/sync-threads.worker.cjs

@@ -0,0 +1,5 @@
+const fs = require('node:fs')
+
+const { runAsWorker } = require('../src/index.js')
+
+runAsWorker((filename) => fs.promises.readFile(filename, 'utf8'))

benchmark/synckit.cjs

@@ -0,0 +1,10 @@
+// Using 'synckit' here could skew the benchmark as it would need
+// to apply module resolution that isn't needed for sync-threads.
+const { createSyncFn } = require('../node_modules/synckit/lib/index.cjs')
+
+/**
+ * @type {() => string}
+ */
+const syncFn = createSyncFn(require.resolve('./synckit.worker.cjs'))
+
+module.exports = syncFn

benchmark/synckit.worker.cjs

@@ -0,0 +1,7 @@
+const fs = require('node:fs')
+
+// Using 'synckit' here could skew the benchmark as it would need
+// to apply module resolution that isn't needed for sync-threads.
+const { runAsWorker } = require('../node_modules/synckit/lib/index.cjs')
+
+runAsWorker((filename) => fs.promises.readFile(filename, 'utf8'))

package.json

@@ -13,16 +13,19 @@
   ],
   "devDependencies": {
     "@types/node": "^12.19.3",
+    "benchmark": "^2.1.4",
     "eslint": "^7.12.1",
     "eslint-config-prettier": "^6.15.0",
     "prettier": "^2.1.2",
+    "synckit": "^0.8.8",
     "typescript": "^4.0.5"
   },
   "scripts": {
     "declaration": "tsc -p declaration.tsconfig.json",
     "build": "npm run declaration",
     "prepare": "npm run build",
-    "lint": "prettier -c . && eslint ."
+    "lint": "prettier -c . && eslint .",
+    "test": "node --test test/index.test.js"
   },
   "prettier": {
     "semi": false,

src/SharedArrayBuffer.d.ts

@@ -0,0 +1,33 @@
+// Adds definitions missing from TypeScript, this feature is available since Node.js 20
+
+interface SharedArrayBufferOptions {
+  maxByteLength?: number
+}
+
+interface SharedArrayBufferConstructor {
+  readonly prototype: SharedArrayBuffer
+  new (
+    byteLength: number,
+    options?: SharedArrayBufferOptions,
+  ): SharedArrayBuffer
+}
+
+/**
+ * https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/SharedArrayBuffer/grow#specifications
+ */
+interface SharedArrayBuffer {
+  /**
+   * returns whether this SharedArrayBuffer can be grow or not.
+   */
+  readonly growable?: boolean
+
+  /**
+   * returns the maximum length (in bytes) that this SharedArrayBuffer can be grown to.
+   */
+  readonly maxByteLength?: number
+
+  /**
+   * grows the SharedArrayBuffer to the specified size, in bytes.
+   */
+  grow?(newLength: number): void
+}