ScardGetStatusChange() API May Cause Deadlock in Smart Card Resource Manager (235899)

SYMPTOMS

The Smart Card Resource Manager may stop responding (hang) in the following situation:

There are two processes (A and B) each with a single thread gaining access to the same card (in the same reader) simultaneously. Each of the processes runs the following sequence in a finite loop:
The two processes run exactly the same code. After running the code for several minutes (from 2 to 15 minutes), the two processes hang and no other program may be able to gain access to the same reader. However, another reader connected to the system can be accessed through the Resource manager.

Even if you are forced to quit the two programs, the reader is still inaccessible. To "unblock" the reader, the computer must either be restarted or you must quit the Resource Manager program through a utility like Pview.exe. You can also use Task Manager and then restart Resource Manager. If you quit then restart Resource Manager, the two other programs are immediately unblocked.