Add a lock to the cookie accountant to prevent race conditions in patching...

ceee/ie/plugin/bho/cookie_accountant.h

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // Defines the CookieAccountant class, which is responsible for observing
 // and recording all cookie-related information generated by a particular
 // IE browser session. It records and fires cookie change events, it provides
 // access to session and persistent cookies.
 
 #ifndef CEEE_IE_PLUGIN_BHO_COOKIE_ACCOUNTANT_H_
 #define CEEE_IE_PLUGIN_BHO_COOKIE_ACCOUNTANT_H_
 
 #include <string>
 
 #include "app/win/iat_patch_function.h"
+#include "base/lock.h"
 #include "base/singleton.h"
 #include "base/time.h"
 #include "ceee/ie/plugin/bho/cookie_events_funnel.h"
 #include "net/base/cookie_monster.h"
 
 // The class that accounts for all cookie-related activity for a single IE
 // browser session context. There should only need to be one of these allocated
 // per process; use ProductionCookieAccountant instead of using this class
 // directly.
 class CookieAccountant {
@@ skipping 19 matching lines @@
   static DWORD WINAPI InternetSetCookieExWPatch(
       LPCWSTR lpszURL, LPCWSTR lpszCookieName, LPCWSTR lpszCookieData,
       DWORD dwFlags, DWORD_PTR dwReserved);
 
  protected:
   // Exposed to subclasses mainly for unit testing purposes; production code
   // should use the ProductionCookieAccountant class instead.
   // Since this class has one instance per window, not per tab, we cannot
   // queue the events sent to the broker. They don't need to be sent to the BHO
   // because they don't need tab_id anyway.
-  CookieAccountant() : cookie_events_funnel_(new BrokerRpcClient) {}
+  CookieAccountant()
+      : cookie_events_funnel_(new BrokerRpcClient),
+        patching_wininet_functions_(false) {
+  }
+
   virtual ~CookieAccountant();
 
   // Records the modification or creation of a cookie. Fires off a
   // cookies.onChanged event to Chrome Frame.
   virtual void RecordCookie(
       const std::string& url, const std::string& cookie_data,
       const base::Time& current_time);
 
   // Unit test seam.
   virtual CookieEventsFunnel& cookie_events_funnel() {
     return cookie_events_funnel_;
   }
 
   // Function patches that allow us to intercept scripted cookie changes.
   app::win::IATPatchFunction internet_set_cookie_ex_a_patch_;
   app::win::IATPatchFunction internet_set_cookie_ex_w_patch_;
 
+  // Used to allow exactly one thread to attempt to apply function patches.
+  // We use this boolean instead of a simple lock so that threads that lose
+  // the race will return immediately instead of blocking on the lock.
+  // Protected by CookieAccountant::lock_.
+  bool patching_wininet_functions_;
+
+  // A lock that protects access to the function patches.
+  Lock lock_;
+
   // Cached singleton instance. Useful for unit testing.
   static CookieAccountant* singleton_instance_;
 
  private:
   // Helper functions for extracting cookie information from a scripted cookie
   // being set, to pass to the cookie onChanged event.
 
   // Sets the cookie domain for a script cookie event.
   void SetScriptCookieDomain(
       const net::CookieMonster::ParsedCookie& parsed_cookie,
@@ skipping 24 matching lines @@
 // be accessed for unit testing.
 class ProductionCookieAccountant : public CookieAccountant,
     public Singleton<ProductionCookieAccountant> {
  private:
   // This ensures no construction is possible outside of the class itself.
   friend struct DefaultSingletonTraits<ProductionCookieAccountant>;
   DISALLOW_IMPLICIT_CONSTRUCTORS(ProductionCookieAccountant);
 };
 
 #endif  // CEEE_IE_PLUGIN_BHO_COOKIE_ACCOUNTANT_H_