A number of poorly written IE BHO's crash IE if ChromeFrame is the currently ...

chrome_frame/buggy_bho_handling.h

Index: chrome_frame/buggy_bho_handling.h
===================================================================
--- chrome_frame/buggy_bho_handling.h	(revision 74374)
+++ chrome_frame/buggy_bho_handling.h	(working copy)
@@ -11,7 +11,8 @@
 
 #include <vector>
 
-#include "base/threading/thread_local.h"
+#include "base/synchronization/lock.h"
+#include "base/threading/platform_thread.h"
 
 namespace buggy_bho {
 
@@ -21,22 +22,28 @@
                                         DISPPARAMS* params, VARIANT* result,
                                         EXCEPINFO* ei, UINT* err);
 
-// Construct an instance of this class on the stack when firing web browser
-// events that can be sent to buggy BHOs.  This class will intercept those
+// Construct an instance of this class before firing web browser events that
+// can be sent to buggy BHOs.  This class will intercept those
 // BHOs (see list in cc file) and ignore notifications to those components
-// for as long as the BuggyBhoTls instance on the stack lives.
-class BuggyBhoTls {
+// as long as ChromeFrame is the active view.
+class BuggyBhoHandler {
  public:
-  BuggyBhoTls();
-  ~BuggyBhoTls();
+  BuggyBhoHandler();
+  ~BuggyBhoHandler();
 
-  // Call after instantiating an instance of BuggyBhoTls.  This method traverses
-  // the list of DWebBrowserEvents and DWebBrowserEvents2 subscribers and checks
-  // if any of the sinks belong to a list of known-to-be-buggy BHOs.
-  // For each of those, a patch will be applied that temporarily ignores certain
-  // invokes.
+  // Call after instantiating an instance of BuggyBhoHandler.  This method
+  // traverses the list of DWebBrowserEvents and DWebBrowserEvents2 subscribers
+  // and checks if any of the sinks belong to a list of known-to-be-buggy BHOs.
+  // For each of those, a patch will be applied that temporarily ignores
+  // certain invokes.
   static HRESULT PatchBuggyBHOs(IWebBrowser2* browser);
 
+  // Returns a pointer to the global BuggyBhoHandler instance.
+  static BuggyBhoHandler* GetInstance();
+
+  // Removes buggy object information for the thread passed in.
+  static void ClearBuggyObjectsForThread(base::PlatformThreadId thread_id);
+
  protected:
   // internal implementation:
 
@@ -48,13 +55,10 @@
   // object running on the same thread (e.g. IE6) with one running CF and the
   // other MSHTML.  We don't want to drop events being fired by MSHTML, only
   // events fired by CF since these BHOs should handle MSHTML correctly.
-  bool IsBuggyObject(IDispatch* obj) const;
+  bool ShouldSkipInvoke(IDispatch* obj);
 
   // Static, protected member methods
 
-  // Returns the currently registered (TLS) BuggyBhoTls instance or NULL.
-  static BuggyBhoTls* FromCurrentThread();
-
   // Patches a subscriber if it belongs to a buggy dll.
   static bool PatchIfBuggy(CONNECTDATA* cd, const IID& diid);
 
@@ -69,16 +73,17 @@
       VARIANT* result, EXCEPINFO* ei, UINT* err);
 
  protected:
+  struct ObjectInfo {
+    // The object interface pointer.
+    IDispatch* disp_interface;
+    // The thread with which the object interface is associated.
+    base::PlatformThreadId object_thread_id;
+  };
   // List of buggy subscribers.
-  std::vector<IDispatch*> bad_objects_;
-
-  // Pointer to a previous instance of BuggyBhoTls on this thread if any.
-  // Under regular circumstances, this will be NULL.  However, there's a chance
-  // that we could get reentrant calls, hence we maintain a stack.
-  BuggyBhoTls* previous_instance_;
-
-  // Where we store the current thread's instance.
-  static base::ThreadLocalPointer<BuggyBhoTls> s_bad_object_tls_;
+  std::vector<ObjectInfo> bad_objects_;
+  // used to serialize access to the list of buggy bho's as these could be
+  // accessed from multiple IE UI threads.

[tommi (sloooow) - chröme, 2011/02/11 14:49:02]

Would it be better to store this list with the TLS and have no locks?  That
would also separate the list of objects so that we only ever access an object
pointer from the correct thread.

+  base::Lock lock_;
 };
 
 }  // end namespace buggy_bho