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List:       ms-smartcardddk
Subject:    Re: Vendor specific IOCTL:s. Resource Handler.
From:       Doug Barlow <dbarlow () MICROSOFT ! COM>
Date:       1998-03-19 18:01:40
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Perhaps something else that should be in the documentation is that the PC/SC
design assumes threading is available on the system.  Hence there was no
need for messy overlapped operations.  The thread making the SCardControl
call will politely block until the command completes, allowing other threads
to use the CPU.

Note that all requests on a single context are serialized.  Hence, to
perform overlapping operations, you'll need multiple smart card contexts.
For example, if a background thread watches for card removal using
SCardGetStatusChange, it must use a separate context, otherwise it will
block other operations.

Doug Barlow
Microsoft Corporation
        -----Original Message-----
        From:   Mats Hansson [SMTP:mats.hansson@INTERTEX.SE]
        Sent:   Thursday, March 19, 1998 1:05 AM
        To:     SmartCardDDK@DISCUSS.MICROSOFT.COM
        Subject:        Re: Vendor specific IOCTL:s. Resource Handler.

        Thanks for the informative answer. Your story about the base
component and
        the scardsvr.exe certainly deserves to be included in the
documentation, or
        have a overlooked some existing chapters?

        A last comment about the vendor IOCTL handling: This means that the
        application cannot run vendor specific IOCTL codes asynchronously,
as it can
        supply no OVERLAPPED struct and wait for the event. Correct? I
suppose the
        resource handler converts the SCardControl call to an asynchronous
IOCTL
        call (as the smclib.vxd wants an OVERLAPPED struct). However, in
this case
        it doesn't make the application happier if that wants to do other
things
        while waiting for the readers processing.


        At 10:10 1998-03-18 -0800, you wrote:
        .......
        >The answer is 'C'.  Obtain an SCARDHANDLE to your reader.  Use
DIRECT mode
        >if there isn't a card in the reader.  Then issue your special IOCTL
using
        >the SCardControl service.  This passes the supplied IOCTL code
directly to
        >the reader without interpretation.
        >
        > .....

        Mats Hansson
        Intertex Data AB
        Rissneleden 45
        174 44 Sundbyberg
        Sweden

        Tel +46-8-6282828    Fax +46-8-6286414    www:
http://www.intertex.se

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