BUG: Concurrent access of ToolbarWindow32 window class causes lockup when using Active Accessibility

ID: Q221580

The information in this article applies to:

Microsoft Win32 Software Development Kit (SDK)
on the following platforms: NT, Win95, Win98

SYMPTOMS

Multi-threaded Active Accessibility client applications that concurrently access the ToolbarWindow32 window class result in system lockup.

CAUSE

This behavior is a result of the fact that calling AccessibleObjectFromEvent() and AccessibleObjectFromWindow() results in a call to SendMessage(). This causes concurrent access problems for multi-threaded clients that can call these APIs from more than one of their threads.

STATUS

This has been identified as a problem in Microsoft Active Accessibility version 1.x. It will be fixed in a future version of Microsoft Active Accessibility.

REFERENCES

Microsoft Active Accessibility

Additional query words: kbAAcc

Keywords : kbAAcc kbNTOS400 kbSDKPlatform kbWinOS95 kbWinOS98
Version : WINDOWS:
Platform : WINDOWS
Issue type : kbbug