question about multi queue for same device register same type request callback

NTDEV
1

Hi All:

I have a question about WDF queues. If there are multi queues for same
device, and every queue has a same type io event callback registered(say
EvtIoDeviceControl), how framework make the decision when a such type
request comes, give the request to which queue? (And
WdfDeviceConfigureRequestDispatching is not called)

In my practice, if there are a parallel & serial queue. The
EvtIoDeviceControl in parallel queue will be called, not the serial queue’s.
I looked into WDK doc queue and request flow related document, but not
touched this. Does framework has a default logic to select queue?

2

No each queue has its own callbacks defined in WDF_IO_QUEUE_CONFIG from
the WdfIoQueueCreate call.

Don Burn
Windows Filesystem and Driver Consulting
Website: http://www.windrvr.com
Blog: http://msmvps.com/blogs/WinDrvr

“Moore.Zhang” wrote in message
news:xxxxx@ntdev:

> Hi All:
>
>
>
> I have a question about WDF queues. If there are multi queues for same
> device, and every queue has a same type io event callback registered(say
> EvtIoDeviceControl), how framework make the decision when a such type
> request comes, give the request to which queue? (And
> WdfDeviceConfigureRequestDispatching is not called)
>
>
>
> In my practice, if there are a parallel & serial queue. The
> EvtIoDeviceControl in parallel queue will be called, not the serial queue’s.
> I looked into WDK doc queue and request flow related document, but not
> touched this. Does framework has a default logic to select queue?

3

When you don’t configure dispatching explicitly, io gets sent to the default queue you created with WDF_IO_QUEUE_CONFIG_INIT_DEFAULT_QUEUE, http://msdn.microsoft.com/en-us/library/windows/hardware/ff552361(v=vs.85).aspx

d

debt from my phone

From: Moore.Zhang
Sent: 8/23/2012 7:34 AM
To: Windows System Software Devs Interest List
Subject: [ntdev] question about multi queue for same device register same type request callback

Hi All:

I have a question about WDF queues. If there are multi queues for same device, and every queue has a same type io event callback registered(say EvtIoDeviceControl), how framework make the decision when a such type request comes, give the request to which queue? (And WdfDeviceConfigureRequestDispatching is not called)

In my practice, if there are a parallel & serial queue. The EvtIoDeviceControl in parallel queue will be called, not the serial queue?s. I looked into WDK doc queue and request flow related document, but not touched this. Does framework has a default logic to select queue?

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