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

ID: Q235899

The information in this article applies to:

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:

SCardEstablishContext
SCardConnect
SCardGetStatusChange(SCARD_STATE_UNWARE,.....)
SCardBeginTransaction
SCARDTransmit (many times)
.....
SCardEndTransaction
SCardDisconnect
SCardReleaseContext

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 unaccessible. 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.


RESOLUTION

A supported fix that corrects this problem is now available from Microsoft, but it has not been fully regression tested and should be applied only to systems experiencing this specific problem. If you are not severely affected by this specific problem, Microsoft recommends that you wait for the next Windows NT 4.0 service pack that contains this fix.

To resolve this problem immediately, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information on support costs, please go to the following address on the World Wide Web:

http://www.microsoft.com/support/supportnet/overview/overview.asp
The English version of this fix should have the following file attributes or later:

   Date      Time     Size     File name      Platform
   ----------------------------------------------------
   6/17/99   8:53AM   65,536   Scardsvr.exe   x86

NOTE: If this product was already installed on your computer when you purchased it from the Original Equipment Manufacturer (OEM) and you need this fix, please call the Pay Per Incident number listed on the above Web site. If you contact Microsoft to obtain this fix, and if it is determined that you only require the fix you requested, no fee will be charged. However, if you request additional technical support, and if your no-charge technical support period has expired, or if you are not eligible for standard no-charge technical support, you may be charged a non-refundable fee.

For more information about eligibility for no-charge technical support, see the following article in the Microsoft Knowledge Base:
Q154871 Determining If You Are Eligible for No-Charge Technical Support


STATUS

Microsoft has confirmed this to be a problem in Windows NT 4.0.

Additional query words: 


Keywords          : kbbug4.00 kbfix4.00 
Version           : winnt:4.0
Platform          : winnt 
Issue type        : kbbug

Last Reviewed: August 9, 1999