BUG: Concurrent access of ToolbarWindow32 window class causes lockup when using Active Accessibility (221580)


The information in this article applies to:

  • Microsoft Platform Software Development Kit (SDK) 1.0, when used with:
    • the operating system: Microsoft Windows NT
    • the operating system: Microsoft Windows 95
    • the operating system: Microsoft Windows 98
This article was previously published under Q221580

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
Modification Type:MinorLast Reviewed:7/11/2005
Keywords:kbAAcc kbbug kbpending KB221580
©2004 Microsoft Corporation. All rights reserved.