> I'm facing odd hang-ups in a mixed unmanaged/Win Form app (actually this is > a VS 2005 with a managed add-in loaded) > that I think might be of interest here. The stack trace of the UI thread > (captured using WinDbg) is posted below. Basically, > what is happening here is some system event > (Microsoft.Win32.SystemEvents.OnUserPreferenceChanged) being dispatched and > handled via Control.MarshaledInvoke. However, the latter seems to never > return. From the user perspective, the application > appears to be unresponsive (i.e. it doesn't react to keyboard input), but it > paints its windows, as WM_PAINT messages seem > to be passed via the message filter in the CoWaitForMultipleHandles (I > checked this by breaking in a WndProc of one of the windows).
Unfortunately, I have no experience with VS 2005 addins, so I can only analyze the stack trace. For me, it looks like the UserPreferenceChanged event needs to be handled on a UI thread, so it is posted via a synchronization context and a control's Invoke method. This is synchronous, i.e. Invoke waits until the posted message has been handled, forever, as it seems. Invoke definitely seems to think it is dealing with a UI thread that differs from the current thread, so if this is true, the target UI thread seems to be blocked somehow; this should be analyzed. If it is not true and Invoke is posting the event to the same thread, this would seem like a bug. Fabian =================================== This list is hosted by DevelopMentor® http://www.develop.com View archives and manage your subscription(s) at http://discuss.develop.com
