Overlapped IO in KMDF

NTDEV
1

Hi,
This is not a specific doubt.

How do we handle overlapped I/O in KMDF driver? Should I use the same WDM codes in KMDF driver to handle overlapped IO?

sree

2

In a KMDF driver I/O is overlapped by default: when a KMDF driver receives
an IRP, it marks it as pending and puts it in an I/O queue. When your KMDF
driver processes the request and completes it, the framework takes care of
completing the original IRP.

Hope it helps
GV

–
Gianluca Varenni
CACE Technologies, Inc.
Windows DDK MVP

----- Original Message -----
From:
To: “Windows System Software Devs Interest List”
Sent: Friday, September 19, 2008 6:55 AM
Subject: [ntdev] Overlapped IO in KMDF

> Hi,
> This is not a specific doubt.
>
> How do we handle overlapped I/O in KMDF driver? Should I use the same WDM
> codes in KMDF driver to handle overlapped IO?
>
> sree
>
> —
> NTDEV is sponsored by OSR
>
> For our schedule of WDF, WDM, debugging and other seminars visit:
> http://www.osr.com/seminars
>
> To unsubscribe, visit the List Server section of OSR Online at
> http://www.osronline.com/page.cfm?name=ListServer

3

thanks for your reply

4

I have one more doubt regarding this. Is it possible overlapped io by
keeping my device object’s scope is WdfSynchronizationScopeDevice. ie by
creating specific queue or alike?

Please tell me which is the best way.

sree

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Gianluca Varenni
Sent: Friday, September 19, 2008 10:20 PM
To: Windows System Software Devs Interest List
Subject: Re: [ntdev] Overlapped IO in KMDF

In a KMDF driver I/O is overlapped by default: when a KMDF driver
receives an IRP, it marks it as pending and puts it in an I/O queue.
When your KMDF driver processes the request and completes it, the
framework takes care of completing the original IRP.

Hope it helps
GV

–
Gianluca Varenni
CACE Technologies, Inc.
Windows DDK MVP

----- Original Message -----
From:
To: “Windows System Software Devs Interest List”
Sent: Friday, September 19, 2008 6:55 AM
Subject: [ntdev] Overlapped IO in KMDF

> Hi,
> This is not a specific doubt.
>
> How do we handle overlapped I/O in KMDF driver? Should I use the same
WDM
> codes in KMDF driver to handle overlapped IO?
>
> sree
>
> —
> NTDEV is sponsored by OSR
>
> For our schedule of WDF, WDM, debugging and other seminars visit:
> http://www.osr.com/seminars
>
> To unsubscribe, visit the List Server section of OSR Online at
> http://www.osronline.com/page.cfm?name=ListServer

—
NTDEV is sponsored by OSR

For our schedule of WDF, WDM, debugging and other seminars visit:
http://www.osr.com/seminars

To unsubscribe, visit the List Server section of OSR Online at
http://www.osronline.com/page.cfm?name=ListServer

5

All io, regardless of sync scope or execution level is always pended from the sender’s (the app in your case) point of view. WdfSynchronizationScopeDevice just means that one callback at a time is executed, not that the other pending callbacks are blocked.

d

-----Original Message-----
From: xxxxx@lists.osr.com [mailto:xxxxx@lists.osr.com] On Behalf Of Sreejesh S. Warrier
Sent: Sunday, October 12, 2008 9:36 PM
To: Windows System Software Devs Interest List
Subject: RE: [ntdev] Overlapped IO in KMDF

I have one more doubt regarding this. Is it possible overlapped io by
keeping my device object’s scope is WdfSynchronizationScopeDevice. ie by
creating specific queue or alike?

Please tell me which is the best way.

sree

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Gianluca Varenni
Sent: Friday, September 19, 2008 10:20 PM
To: Windows System Software Devs Interest List
Subject: Re: [ntdev] Overlapped IO in KMDF

In a KMDF driver I/O is overlapped by default: when a KMDF driver
receives an IRP, it marks it as pending and puts it in an I/O queue.
When your KMDF driver processes the request and completes it, the
framework takes care of completing the original IRP.

Hope it helps
GV

–
Gianluca Varenni
CACE Technologies, Inc.
Windows DDK MVP

----- Original Message -----
From:
To: “Windows System Software Devs Interest List”
Sent: Friday, September 19, 2008 6:55 AM
Subject: [ntdev] Overlapped IO in KMDF

> Hi,
> This is not a specific doubt.
>
> How do we handle overlapped I/O in KMDF driver? Should I use the same
WDM
> codes in KMDF driver to handle overlapped IO?
>
> sree
>
> —
> NTDEV is sponsored by OSR
>
> For our schedule of WDF, WDM, debugging and other seminars visit:
> http://www.osr.com/seminars
>
> To unsubscribe, visit the List Server section of OSR Online at
> http://www.osronline.com/page.cfm?name=ListServer

—
NTDEV is sponsored by OSR

For our schedule of WDF, WDM, debugging and other seminars visit:
http://www.osr.com/seminars

To unsubscribe, visit the List Server section of OSR Online at
http://www.osronline.com/page.cfm?name=ListServer

—
NTDEV is sponsored by OSR

For our schedule of WDF, WDM, debugging and other seminars visit:
http://www.osr.com/seminars

To unsubscribe, visit the List Server section of OSR Online at http://www.osronline.com/page.cfm?name=ListServer