chore: detect browser reuse based on the connection headers (#18230)

packages/playwright-core/src/browserServerImpl.ts

@@ -54,7 +54,7 @@ export class BrowserServerLauncherImpl implements BrowserServerLauncher {
       path = options.wsPath.startsWith('/') ? options.wsPath : `/${options.wsPath}`;
 
     // 2. Start the server
-    const server = new PlaywrightServer('use-pre-launched-browser', { path, maxConcurrentConnections: Infinity, maxIncomingConnections: Infinity, enableSocksProxy: false, preLaunchedBrowser: browser });
+    const server = new PlaywrightServer({ path, maxConnections: Infinity, enableSocksProxy: false, preLaunchedBrowser: browser });
     const wsEndpoint = await server.listen(options.port);
 
     // 3. Return the BrowserServer interface

packages/playwright-core/src/cli/driver.ts

@@ -49,10 +49,8 @@ export function runDriver() {
   };
 }
 
-export async function runServer(port: number | undefined, path = '/', maxClients = Infinity, enableSocksProxy = true, reuseBrowser = false) {
+export async function runServer(port: number | undefined, path = '/', maxConnections = Infinity, enableSocksProxy = true, reuseBrowser = false) {
-  const maxIncomingConnections = maxClients;
+  const server = new PlaywrightServer({ path, maxConnections, enableSocksProxy });
-  const maxConcurrentConnections = reuseBrowser ? 1 : maxClients;
-  const server = new PlaywrightServer(reuseBrowser ? 'reuse-browser' : 'auto', { path, maxIncomingConnections, maxConcurrentConnections, enableSocksProxy });
   const wsEndpoint = await server.listen(port);
   process.on('exit', () => server.close().catch(console.error));
   console.log('Listening on ' + wsEndpoint);  // eslint-disable-line no-console
@@ -86,7 +84,6 @@ class ProtocolHandler {
     this._controller = playwright.debugController;
     this._controller.setAutoCloseAllowed(true);
     this._controller.setTrackHierarcy(true);
-    this._controller.setReuseBrowser(true);
     this._controller.on(DebugController.Events.BrowsersChanged, browsers => {
       process.send!({ method: 'browsersChanged', params: { browsers } });
     });

packages/playwright-core/src/grid/gridBrowserWorker.ts

@@ -23,7 +23,7 @@ function launchGridBrowserWorker(gridURL: string, agentId: string, workerId: str
   const log = debug(`pw:grid:worker:${workerId}`);
   log('created');
   const ws = new WebSocket(gridURL.replace('http://', 'ws://') + `/registerWorker?agentId=${agentId}&workerId=${workerId}`);
-  new PlaywrightConnection(Promise.resolve(), 'auto', ws, false, { enableSocksProxy: true, browserName, launchOptions: {} }, { playwright: null, browser: null }, log, async () => {
+  new PlaywrightConnection(Promise.resolve(), 'launch-browser', ws, { enableSocksProxy: true, browserName, launchOptions: {} }, { playwright: null, browser: null }, log, async () => {
     log('exiting process');
     setTimeout(() => process.exit(0), 30000);
     // Meanwhile, try to gracefully close all browsers.

packages/playwright-core/src/protocol/validator.ts

@@ -350,10 +350,6 @@ scheme.DebugControllerSetTrackHierarchyParams = tObject({
   enabled: tBoolean,
 });
 scheme.DebugControllerSetTrackHierarchyResult = tOptional(tObject({}));
-scheme.DebugControllerSetReuseBrowserParams = tObject({
-  enabled: tBoolean,
-});
-scheme.DebugControllerSetReuseBrowserResult = tOptional(tObject({}));
 scheme.DebugControllerResetForReuseParams = tOptional(tObject({}));
 scheme.DebugControllerResetForReuseResult = tOptional(tObject({}));
 scheme.DebugControllerNavigateAllParams = tObject({

packages/playwright-core/src/remote/playwrightConnection.ts

@@ -21,11 +21,12 @@ import { Browser } from '../server/browser';
 import { serverSideCallMetadata } from '../server/instrumentation';
 import { gracefullyCloseAll } from '../utils/processLauncher';
 import { SocksProxy } from '../common/socksProxy';
-import type { Mode } from './playwrightServer';
 import { assert } from '../utils';
 import type { LaunchOptions } from '../server/types';
 import { DebugControllerDispatcher } from '../server/dispatchers/debugControllerDispatcher';
 
+export type ClientType = 'controller' | 'playwright' | 'launch-browser' | 'reuse-browser' | 'pre-launched-browser';
+
 type Options = {
   enableSocksProxy: boolean,
   browserName: string | null,
@@ -48,13 +49,13 @@ export class PlaywrightConnection {
   private _options: Options;
   private _root: DispatcherScope;
 
-  constructor(lock: Promise<void>, mode: Mode, ws: WebSocket, isDebugControllerClient: boolean, options: Options, preLaunched: PreLaunched, log: (m: string) => void, onClose: () => void) {
+  constructor(lock: Promise<void>, clientType: ClientType, ws: WebSocket, options: Options, preLaunched: PreLaunched, log: (m: string) => void, onClose: () => void) {
     this._ws = ws;
     this._preLaunched = preLaunched;
     this._options = options;
-    if (mode === 'reuse-browser' || mode === 'use-pre-launched-browser')
+    if (clientType === 'reuse-browser' || clientType === 'pre-launched-browser')
       assert(preLaunched.playwright);
-    if (mode === 'use-pre-launched-browser')
+    if (clientType === 'pre-launched-browser')
       assert(preLaunched.browser);
     this._onClose = onClose;
     this._debugLog = log;
@@ -73,19 +74,21 @@ export class PlaywrightConnection {
     ws.on('close', () => this._onDisconnect());
     ws.on('error', error => this._onDisconnect(error));
 
-    if (isDebugControllerClient) {
+    if (clientType === 'controller') {
       this._root = this._initDebugControllerMode();
       return;
     }
 
     this._root = new RootDispatcher(this._dispatcherConnection, async scope => {
-      if (mode === 'reuse-browser')
+      if (clientType === 'reuse-browser')
         return await this._initReuseBrowsersMode(scope);
-      if (mode === 'use-pre-launched-browser')
+      if (clientType === 'pre-launched-browser')
         return await this._initPreLaunchedBrowserMode(scope);
-      if (!options.browserName)
+      if (clientType === 'launch-browser')
+        return await this._initLaunchBrowserMode(scope);
+      if (clientType === 'playwright')
         return await this._initPlaywrightConnectMode(scope);
-      return await this._initLaunchBrowserMode(scope);
+      throw new Error('Unsupported client type: ' + clientType);
     });
   }
 

packages/playwright-core/src/remote/playwrightServer.ts

@@ -21,7 +21,7 @@ import type { Browser } from '../server/browser';
 import type { Playwright } from '../server/playwright';
 import { createPlaywright } from '../server/playwright';
 import { PlaywrightConnection } from './playwrightConnection';
-import { assert } from '../utils';
+import type { ClientType } from './playwrightConnection';
 import type  { LaunchOptions } from '../server/types';
 import { ManualPromise } from '../utils/manualPromise';
 
@@ -35,13 +35,9 @@ function newLogger() {
   return (message: string) => debugLog(`[id=${id}] ${message}`);
 }
 
-// TODO: replace 'reuse-browser' with 'allow-reuse' in 1.27.
-export type Mode = 'use-pre-launched-browser' | 'reuse-browser' | 'auto';
-
 type ServerOptions = {
   path: string;
-  maxIncomingConnections: number;
+  maxConnections: number;
-  maxConcurrentConnections: number;
   enableSocksProxy: boolean;
   preLaunchedBrowser?: Browser
 };
@@ -49,16 +45,12 @@ type ServerOptions = {
 export class PlaywrightServer {
   private _preLaunchedPlaywright: Playwright | null = null;
   private _wsServer: WebSocketServer | undefined;
-  private _mode: Mode;
   private _options: ServerOptions;
 
-  constructor(mode: Mode, options: ServerOptions) {
+  constructor(options: ServerOptions) {
-    this._mode = mode;
     this._options = options;
-    if (mode === 'use-pre-launched-browser') {
+    if (options.preLaunchedBrowser)
-      assert(options.preLaunchedBrowser);
       this._preLaunchedPlaywright = options.preLaunchedBrowser.options.rootSdkObject as Playwright;
-    }
   }
 
   preLaunchedPlaywright(): Playwright {
@@ -95,13 +87,10 @@ export class PlaywrightServer {
     debugLog('Listening at ' + wsEndpoint);
 
     this._wsServer = new wsServer({ server, path: this._options.path });
-    const browserSemaphore = new Semaphore(this._options.maxConcurrentConnections);
+    const browserSemaphore = new Semaphore(this._options.maxConnections);
     const controllerSemaphore = new Semaphore(1);
+    const reuseBrowserSemaphore = new Semaphore(1);
     this._wsServer.on('connection', (ws, request) => {
-      if (browserSemaphore.requested() >= this._options.maxIncomingConnections) {
-        ws.close(1013, 'Playwright Server is busy');
-        return;
-      }
       const url = new URL('http://localhost' + (request.url || ''));
       const browserHeader = request.headers['x-playwright-browser'];
       const browserName = url.searchParams.get('browser') || (Array.isArray(browserHeader) ? browserHeader[0] : browserHeader) || null;
@@ -119,26 +108,27 @@ export class PlaywrightServer {
       const log = newLogger();
       log(`serving connection: ${request.url}`);
       const isDebugControllerClient = !!request.headers['x-playwright-debug-controller'];
-      const semaphore = isDebugControllerClient ? controllerSemaphore : browserSemaphore;
+      const shouldReuseBrowser = !!request.headers['x-playwright-reuse-context'];
+      const semaphore = isDebugControllerClient ? controllerSemaphore : (shouldReuseBrowser ? reuseBrowserSemaphore : browserSemaphore);
 
       // If we started in the legacy reuse-browser mode, create this._preLaunchedPlaywright.
       // If we get a reuse-controller request,  create this._preLaunchedPlaywright.
-      if (isDebugControllerClient || (this._mode === 'reuse-browser') && !this._preLaunchedPlaywright)
+      if (isDebugControllerClient || shouldReuseBrowser)
         this.preLaunchedPlaywright();
 
-      // If we have a playwright to reuse, consult controller for reuse mode.
+      let clientType: ClientType = 'playwright';
-      let mode = this._mode;
+      if (isDebugControllerClient)
-      if (mode === 'auto' && this._preLaunchedPlaywright?.debugController.reuseBrowser())
+        clientType = 'controller';
-        mode = 'reuse-browser';
+      else if (shouldReuseBrowser)
-
+        clientType = 'reuse-browser';
-      if (mode === 'reuse-browser')
+      else if (this._options.preLaunchedBrowser)
-        semaphore.setMax(1);
+        clientType = 'pre-launched-browser';
-      else
+      else if (browserName)
-        semaphore.setMax(this._options.maxConcurrentConnections);
+        clientType = 'launch-browser';
 
       const connection = new PlaywrightConnection(
           semaphore.aquire(),
-          mode, ws, isDebugControllerClient,
+          clientType, ws,
           { enableSocksProxy, browserName, launchOptions },
           { playwright: this._preLaunchedPlaywright, browser: this._options.preLaunchedBrowser || null },
           log, () => semaphore.release());
@@ -192,10 +182,6 @@ export class Semaphore {
     return lock;
   }
 
-  requested() {
-    return this._aquired + this._queue.length;
-  }
-
   release() {
     --this._aquired;
     this._flush();

packages/playwright-core/src/server/debugController.ts

@@ -55,7 +55,6 @@ export class DebugController extends SdkObject {
   dispose() {
     this.setTrackHierarcy(false);
     this.setAutoCloseAllowed(false);
-    this.setReuseBrowser(false);
   }
 
   setTrackHierarcy(enabled: boolean) {
@@ -72,14 +71,6 @@ export class DebugController extends SdkObject {
     }
   }
 
-  reuseBrowser(): boolean {
-    return this._reuseBrowser;
-  }
-
-  setReuseBrowser(enabled: boolean) {
-    this._reuseBrowser = enabled;
-  }
-
   async resetForReuse() {
     const contexts = new Set<BrowserContext>();
     for (const page of this._playwright.allPages())

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

@@ -40,10 +40,6 @@ export class DebugControllerDispatcher extends Dispatcher<DebugController, chann
     this._object.setTrackHierarcy(params.enabled);
   }
 
-  async setReuseBrowser(params: channels.DebugControllerSetReuseBrowserParams) {
-    this._object.setReuseBrowser(params.enabled);
-  }
-
   async resetForReuse() {
     await this._object.resetForReuse();
   }

packages/playwright-test/src/index.ts

@@ -72,10 +72,22 @@ export const test = _baseTest.extend<TestFixtures, WorkerFixtures>({
   headless: [({ launchOptions }, use) => use(launchOptions.headless ?? true), { scope: 'worker', option: true }],
   channel: [({ launchOptions }, use) => use(launchOptions.channel), { scope: 'worker', option: true }],
   launchOptions: [{}, { scope: 'worker', option: true }],
-  connectOptions: [process.env.PW_TEST_CONNECT_WS_ENDPOINT ? {
+  connectOptions: [({}, use) => {
-    wsEndpoint: process.env.PW_TEST_CONNECT_WS_ENDPOINT,
+    const wsEndpoint = process.env.PW_TEST_CONNECT_WS_ENDPOINT;
-    headers: process.env.PW_TEST_CONNECT_HEADERS ? JSON.parse(process.env.PW_TEST_CONNECT_HEADERS) : undefined,
+    if (!wsEndpoint)
-  } : undefined, { scope: 'worker', option: true }],
+      return use(undefined);
+    let headers = process.env.PW_TEST_CONNECT_HEADERS ? JSON.parse(process.env.PW_TEST_CONNECT_HEADERS) : undefined;
+    if (process.env.PW_TEST_REUSE_CONTEXT) {
+      headers = {
+        ...headers,
+        'x-playwright-reuse-context': '1',
+      };
+    }
+    return use({
+      wsEndpoint,
+      headers
+    });
+  }, { scope: 'worker', option: true }],
   screenshot: ['off', { scope: 'worker', option: true }],
   video: ['off', { scope: 'worker', option: true }],
   trace: ['off', { scope: 'worker', option: true }],

packages/protocol/src/channels.ts

@@ -599,7 +599,6 @@ export interface DebugControllerEventTarget {
 export interface DebugControllerChannel extends DebugControllerEventTarget, Channel {
   _type_DebugController: boolean;
   setTrackHierarchy(params: DebugControllerSetTrackHierarchyParams, metadata?: Metadata): Promise<DebugControllerSetTrackHierarchyResult>;
-  setReuseBrowser(params: DebugControllerSetReuseBrowserParams, metadata?: Metadata): Promise<DebugControllerSetReuseBrowserResult>;
   resetForReuse(params?: DebugControllerResetForReuseParams, metadata?: Metadata): Promise<DebugControllerResetForReuseResult>;
   navigateAll(params: DebugControllerNavigateAllParams, metadata?: Metadata): Promise<DebugControllerNavigateAllResult>;
   setRecorderMode(params: DebugControllerSetRecorderModeParams, metadata?: Metadata): Promise<DebugControllerSetRecorderModeResult>;
@@ -629,13 +628,6 @@ export type DebugControllerSetTrackHierarchyOptions = {
 
 };
 export type DebugControllerSetTrackHierarchyResult = void;
-export type DebugControllerSetReuseBrowserParams = {
-  enabled: boolean,
-};
-export type DebugControllerSetReuseBrowserOptions = {
-
-};
-export type DebugControllerSetReuseBrowserResult = void;
 export type DebugControllerResetForReuseParams = {};
 export type DebugControllerResetForReuseOptions = {};
 export type DebugControllerResetForReuseResult = void;

packages/protocol/src/protocol.yml

@@ -664,10 +664,6 @@ DebugController:
       parameters:
         enabled: boolean
 
-    setReuseBrowser:
-      parameters:
-        enabled: boolean
-
     resetForReuse:
 
     navigateAll: