chore: dispose stale handles to prevent oom, 1000 of a kind max (#27315)

https://github.com/microsoft/playwright/issues/6319

.github/workflows/tests_stress.yml

@@ -47,3 +47,5 @@ jobs:
       if: always()
     - run: npm run stest browsers -- --project=firefox
       if: always()
+    - run: npm run stest heap -- --project=chromium
+      if: always()

packages/playwright-core/src/client/channelOwner.ts

@@ -40,6 +40,7 @@ export abstract class ChannelOwner<T extends channels.Channel = channels.Channel
   _logger: Logger | undefined;
   readonly _instrumentation: ClientInstrumentation;
   private _eventToSubscriptionMapping: Map<string, string> = new Map();
+  _wasCollected: boolean = false;
 
   constructor(parent: ChannelOwner | Connection, type: string, guid: string, initializer: channels.InitializerTraits<T>) {
     super();
@@ -114,15 +115,16 @@ export abstract class ChannelOwner<T extends channels.Channel = channels.Channel
     child._parent = this;
   }
 
-  _dispose() {
+  _dispose(reason: 'gc' | undefined) {
     // Clean up from parent and connection.
     if (this._parent)
       this._parent._objects.delete(this._guid);
     this._connection._objects.delete(this._guid);
+    this._wasCollected = reason === 'gc';
 
     // Dispose all children.
     for (const object of [...this._objects.values()])
-      object._dispose();
+      object._dispose(reason);
     this._objects.clear();
   }
 

packages/playwright-core/src/client/connection.ts

@@ -116,6 +116,8 @@ export class Connection extends EventEmitter {
   async sendMessageToServer(object: ChannelOwner, type: string, method: string, params: any, stackTrace: ParsedStackTrace | null, wallTime: number | undefined): Promise<any> {
     if (this._closedErrorMessage)
       throw new Error(this._closedErrorMessage);
+    if (object._wasCollected)
+      throw new Error('The object has been collected to prevent unbounded heap growth.');
 
     const { apiName, frames } = stackTrace || { apiName: '', frames: [] };
     const guid = object._guid;
@@ -170,7 +172,7 @@ export class Connection extends EventEmitter {
     }
 
     if (method === '__dispose__') {
-      object._dispose();
+      object._dispose(params.reason);
       return;
     }
 

packages/playwright-core/src/server/dispatchers/dispatcher.ts

@@ -35,6 +35,11 @@ export function existingDispatcher<DispatcherType>(object: any): DispatcherType
   return object[dispatcherSymbol];
 }
 
+let maxDispatchers = 1000;
+export function setMaxDispatchersForTest(value: number | undefined) {
+  maxDispatchers = value || 1000;
+}
+
 export class Dispatcher<Type extends { guid: string }, ChannelType, ParentScopeType extends DispatcherScope> extends EventEmitter implements channels.Channel {
   private _connection: DispatcherConnection;
   // Parent is always "isScope".
@@ -55,18 +60,18 @@ export class Dispatcher<Type extends { guid: string }, ChannelType, ParentScopeT
     this._parent = parent instanceof DispatcherConnection ? undefined : parent;
 
     const guid = object.guid;
-    assert(!this._connection._dispatchers.has(guid));
-    this._connection._dispatchers.set(guid, this);
+    this._guid = guid;
+    this._type = type;
+    this._object = object;
+
+    (object as any)[dispatcherSymbol] = this;
+
+    this._connection.registerDispatcher(this);
     if (this._parent) {
       assert(!this._parent._dispatchers.has(guid));
       this._parent._dispatchers.set(guid, this);
     }
 
-    this._type = type;
-    this._guid = guid;
-    this._object = object;
-
-    (object as any)[dispatcherSymbol] = this;
     if (this._parent)
       this._connection.sendCreate(this._parent, type, guid, initializer, this._parent._object);
   }
@@ -100,9 +105,9 @@ export class Dispatcher<Type extends { guid: string }, ChannelType, ParentScopeT
     this._connection.sendEvent(this, method as string, params, sdkObject);
   }
 
-  _dispose() {
+  _dispose(reason?: 'gc') {
     this._disposeRecursively();
-    this._connection.sendDispose(this);
+    this._connection.sendDispose(this, reason);
   }
 
   protected _onDispose() {
@@ -115,8 +120,9 @@ export class Dispatcher<Type extends { guid: string }, ChannelType, ParentScopeT
     eventsHelper.removeEventListeners(this._eventListeners);
 
     // Clean up from parent and connection.
-    if (this._parent)
-      this._parent._dispatchers.delete(this._guid);
+    this._parent?._dispatchers.delete(this._guid);
+    const list = this._connection._dispatchersByType.get(this._type);
+    list?.delete(this._guid);
     this._connection._dispatchers.delete(this._guid);
 
     // Dispose all children.
@@ -159,6 +165,8 @@ export class RootDispatcher extends Dispatcher<{ guid: '' }, any, any> {
 
 export class DispatcherConnection {
   readonly _dispatchers = new Map<string, DispatcherScope>();
+  // Collect stale dispatchers by type.
+  readonly _dispatchersByType = new Map<string, Set<string>>();
   onmessage = (message: object) => {};
   private _waitOperations = new Map<string, CallMetadata>();
   private _isLocal: boolean;
@@ -183,8 +191,8 @@ export class DispatcherConnection {
     this._sendMessageToClient(parent._guid, dispatcher._type, '__adopt__', { guid: dispatcher._guid });
   }
 
-  sendDispose(dispatcher: DispatcherScope) {
-    this._sendMessageToClient(dispatcher._guid, dispatcher._type, '__dispose__', {});
+  sendDispose(dispatcher: DispatcherScope, reason?: 'gc') {
+    this._sendMessageToClient(dispatcher._guid, dispatcher._type, '__dispose__', { reason });
   }
 
   private _sendMessageToClient(guid: string, type: string, method: string, params: any, sdkObject?: SdkObject) {
@@ -224,6 +232,32 @@ export class DispatcherConnection {
     throw new ValidationError(`${path}: expected dispatcher ${names.toString()}`);
   }
 
+  registerDispatcher(dispatcher: DispatcherScope) {
+    assert(!this._dispatchers.has(dispatcher._guid));
+    this._dispatchers.set(dispatcher._guid, dispatcher);
+    const type = dispatcher._type;
+
+    let list = this._dispatchersByType.get(type);
+    if (!list) {
+      list = new Set();
+      this._dispatchersByType.set(type, list);
+    }
+    list.add(dispatcher._guid);
+    if (list.size > maxDispatchers)
+      this._disposeStaleDispatchers(type, list);
+  }
+
+  private _disposeStaleDispatchers(type: string, dispatchers: Set<string>) {
+    const dispatchersArray = [...dispatchers];
+    this._dispatchersByType.set(type, new Set(dispatchersArray.slice(maxDispatchers / 10)));
+    for (let i = 0; i < maxDispatchers / 10; ++i) {
+      const d = this._dispatchers.get(dispatchersArray[i]);
+      if (!d)
+        continue;
+      d._dispose('gc');
+    }
+  }
+
   async dispatch(message: object) {
     const { id, guid, method, params, metadata } = message as any;
     const dispatcher = this._dispatchers.get(guid);

tests/stress/heap.spec.ts

@@ -18,6 +18,7 @@ import { contextTest as test, expect } from '../config/browserTest';
 import { queryObjectCount } from '../config/queryObjects';
 
 test.describe.configure({ mode: 'serial' });
+test.skip(({ browserName }) => browserName !== 'chromium');
 
 for (let i = 0; i < 3; ++i) {
   test(`test #${i} to request page and context`, async ({ page, context }) => {
@@ -65,7 +66,7 @@ test('should not leak dispatchers after closing page', async ({ context, server
   expect(await queryObjectCount(require('../../packages/playwright-core/lib/server/page').Page)).toBe(COUNT);
   expect(await queryObjectCount(require('../../packages/playwright-core/lib/server/dispatchers/networkDispatchers').RequestDispatcher)).toBe(COUNT);
   expect(await queryObjectCount(require('../../packages/playwright-core/lib/server/dispatchers/networkDispatchers').ResponseDispatcher)).toBe(COUNT);
-  expect(await queryObjectCount(require('../../packages/playwright-core/lib/server/dispatchers/consoleMessageDispatcher').ConsoleMessageDispatcher)).toBe(COUNT);
+  expect(await queryObjectCount(require('../../packages/playwright-core/lib/server/console').ConsoleMessage)).toBe(0);
 
   for (const page of pages)
     await page.close();
@@ -74,10 +75,46 @@ test('should not leak dispatchers after closing page', async ({ context, server
   expect(await queryObjectCount(require('../../packages/playwright-core/lib/server/page').Page)).toBe(0);
   expect(await queryObjectCount(require('../../packages/playwright-core/lib/server/dispatchers/networkDispatchers').RequestDispatcher)).toBe(0);
   expect(await queryObjectCount(require('../../packages/playwright-core/lib/server/dispatchers/networkDispatchers').ResponseDispatcher)).toBe(0);
-  expect(await queryObjectCount(require('../../packages/playwright-core/lib/server/dispatchers/consoleMessageDispatcher').ConsoleMessageDispatcher)).toBe(0);
+  expect(await queryObjectCount(require('../../packages/playwright-core/lib/server/console').ConsoleMessage)).toBe(0);
 
   expect(await queryObjectCount(require('../../packages/playwright-core/lib/client/page').Page)).toBeLessThan(COUNT);
   expect(await queryObjectCount(require('../../packages/playwright-core/lib/server/page').Page)).toBe(0);
   expect(await queryObjectCount(require('../../packages/playwright-core/lib/client/network').Request)).toBe(0);
   expect(await queryObjectCount(require('../../packages/playwright-core/lib/client/network').Response)).toBe(0);
 });
+
+test.describe(() => {
+  test.beforeEach(() => {
+    require('../../packages/playwright-core/lib/server/dispatchers/dispatcher').setMaxDispatchersForTest(100);
+  });
+
+  test('should collect stale handles', async ({ page, server }) => {
+    page.on('request', () => {});
+    const response = await page.goto(server.PREFIX + '/title.html');
+    for (let i = 0; i < 200; ++i) {
+      await page.evaluate(async () => {
+        const response = await fetch('/');
+        await response.text();
+      });
+    }
+    const e = await response.allHeaders().catch(e => e);
+    expect(e.message).toContain('The object has been collected to prevent unbounded heap growth.');
+
+    const counts = [
+      { count: await queryObjectCount(require('../../packages/playwright-core/lib/client/network').Request), message: 'client.Request' },
+      { count: await queryObjectCount(require('../../packages/playwright-core/lib/client/network').Response), message: 'client.Response' },
+      { count: await queryObjectCount(require('../../packages/playwright-core/lib/server/network').Request), message: 'server.Request' },
+      { count: await queryObjectCount(require('../../packages/playwright-core/lib/server/network').Response), message: 'server.Response' },
+      { count: await queryObjectCount(require('../../packages/playwright-core/lib/server/dispatchers/networkDispatchers').RequestDispatcher), message: 'dispatchers.RequestDispatcher' },
+      { count: await queryObjectCount(require('../../packages/playwright-core/lib/server/dispatchers/networkDispatchers').ResponseDispatcher), message: 'dispatchers.ResponseDispatcher' },
+    ];
+    for (const { count, message } of counts) {
+      expect(count, { message }).toBeGreaterThan(50);
+      expect(count, { message }).toBeLessThan(150);
+    }
+  });
+
+  test.afterEach(() => {
+    require('../../packages/playwright-core/lib/server/dispatchers/dispatcher').setMaxDispatchersForTest(null);
+  });
+});