chore: refactor mutex (#10816)

packages/puppeteer-core/src/common/IsolatedWorld.ts

@@ -30,6 +30,7 @@ import {CDPJSHandle} from './JSHandle.js';
 import {LifecycleWatcher, PuppeteerLifeCycleEvent} from './LifecycleWatcher.js';
 import {BindingPayload, EvaluateFunc, HandleFor} from './types.js';
 import {
+  Mutex,
   addPageBinding,
   createJSHandle,
   debugError,
@@ -222,7 +223,8 @@ export class IsolatedWorld extends Realm {
       return;
     }
 
-    await this.#mutex.acquire();
+    // eslint-disable-next-line @typescript-eslint/no-unused-vars
+    using _ = await this.#mutex.acquire();
     try {
       await context._client.send(
         'Runtime.addBinding',
@@ -256,8 +258,6 @@ export class IsolatedWorld extends Realm {
       }
 
       debugError(error);
-    } finally {
-      this.#mutex.release();
     }
   }
 
@@ -344,28 +344,3 @@ export class IsolatedWorld extends Realm {
     this.#client.off('Runtime.bindingCalled', this.#onBindingCalled);
   }
 }
-
-class Mutex {
-  #locked = false;
-  #acquirers: Array<() => void> = [];
-
-  // This is FIFO.
-  acquire(): Promise<void> {
-    if (!this.#locked) {
-      this.#locked = true;
-      return Promise.resolve();
-    }
-    const deferred = Deferred.create<void>();
-    this.#acquirers.push(deferred.resolve.bind(deferred));
-    return deferred.valueOrThrow();
-  }
-
-  release(): void {
-    const resolve = this.#acquirers.shift();
-    if (!resolve) {
-      this.#locked = false;
-      return;
-    }
-    resolve();
-  }
-}

packages/puppeteer-core/src/common/util.ts

@@ -669,3 +669,42 @@ export function validateDialogType(
   assert(dialogType, `Unknown javascript dialog type: ${type}`);
   return dialogType as 'alert' | 'confirm' | 'prompt' | 'beforeunload';
 }
+
+/**
+ * @internal
+ */
+export class Mutex {
+  static Guard = class Guard {
+    #mutex: Mutex;
+    constructor(mutex: Mutex) {
+      this.#mutex = mutex;
+    }
+    [Symbol.dispose](): void {
+      return this.#mutex.release();
+    }
+  };
+
+  #locked = false;
+  #acquirers: Array<() => void> = [];
+
+  // This is FIFO.
+  async acquire(): Promise<InstanceType<typeof Mutex.Guard>> {
+    if (!this.#locked) {
+      this.#locked = true;
+      return new Mutex.Guard(this);
+    }
+    const deferred = Deferred.create<void>();
+    this.#acquirers.push(deferred.resolve.bind(deferred));
+    await deferred.valueOrThrow();
+    return new Mutex.Guard(this);
+  }
+
+  release(): void {
+    const resolve = this.#acquirers.shift();
+    if (!resolve) {
+      this.#locked = false;
+      return;
+    }
+    resolve();
+  }
+}