feat: allow using atomics to communicate between threads (#2758)

Author: sheremet-va

docs/config/index.md

@@ -489,6 +489,16 @@ Maximum number of threads. You can also use `VITEST_MAX_THREADS` environment var
 
 Minimum number of threads. You can also use `VITEST_MIN_THREADS` environment variable.
 
+### useAtomics
+
+- **Type:** `boolean`
+- **Default:** `false`
+- **Version:** Since Vitest 0.28.3
+
+Use Atomics to synchronize threads.
+
+This can improve performance in some cases, but might cause segfault in older Node versions.
+
 ### testTimeout
 
 - **Type:** `number`

packages/vitest/package.json

@@ -133,7 +133,7 @@
     "std-env": "^3.3.1",
     "strip-literal": "^1.0.0",
     "tinybench": "^2.3.1",
-    "tinypool": "^0.3.0",
+    "tinypool": "^0.3.1",
     "tinyspy": "^1.0.2",
     "vite": "^3.0.0 || ^4.0.0",
     "vite-node": "workspace:*",

packages/vitest/src/node/pool.ts

@@ -43,7 +43,7 @@ export function createPool(ctx: Vitest): WorkerPool {
     filename: workerPath,
     // TODO: investigate further
     // It seems atomics introduced V8 Fatal Error https://github.com/vitest-dev/vitest/issues/1191
-    useAtomics: false,
+    useAtomics: ctx.config.useAtomics ?? false,
 
     maxThreads,
     minThreads,
@@ -141,7 +141,7 @@ export function createPool(ctx: Vitest): WorkerPool {
       // node before 16.17 has a bug that causes FATAL ERROR because of the race condition
       const nodeVersion = Number(process.version.match(/v(\d+)\.(\d+)/)?.[0].slice(1))
       if (nodeVersion >= 16.17)
-        await Promise.all(pool.threads.map(w => w.terminate()))
+        await pool.destroy()
     },
   }
 }

packages/vitest/src/types/config.ts

@@ -235,6 +235,15 @@ export interface InlineConfig {
    */
   minThreads?: number
 
+  /**
+   * Use Atomics to synchronize threads
+   *
+   * This can improve performance in some cases, but might cause segfault in older Node versions.
+   *
+   * @default false
+   */
+  useAtomics?: boolean
+
   /**
    * Default timeout of a test in milliseconds
    *