Machine Independent Delay

NTDEV
1

Hi all,

I am interesetd in generating 1 or 2 microsec delay in the driver code.
Driver code is on 2k as well as on 98.
Is there any API which supports this. ( Similar to Sleep call)
Any body can help in this case.

Thanks in advance,
Tushar

2

See KeStallExecutionProcessor and KeDelayExecutionThread.

-----Original Message-----
From: Tushar Samnerkar [mailto:xxxxx@nital.stpp.soft.net]
Sent: Sunday, May 11, 2003 9:36 PM
To: NT Developers Interest List
Subject: [ntdev] Machine Independent Delay

Hi all,

I am interesetd in generating 1 or 2 microsec delay in the driver code.
Driver code is on 2k as well as on 98.
Is there any API which supports this. ( Similar to Sleep call)
Any body can help in this case.

Thanks in advance,
Tushar

You are currently subscribed to ntdev as: xxxxx@troikanetworks.com
To unsubscribe send a blank email to xxxxx@lists.osr.com

3

Mukul Kotwani wrote:

See KeStallExecutionProcessor and KeDelayExecutionThread.

Yes and no.

That is, KeStallExecutionProcessor will do exactly what he asked for by
interposing a few microseconds worth of delay.

But: KeDelayExecutionThread is a PASSIVE_LEVEL thing that will delay for
a minimum of whatever granularity the system clock has, which is
typically 10ms.

–
Walter Oney, Consulting and Training
Basic and Advanced Driver Programming Seminars
Now teaming with John Hyde for USB Device Engineering Seminars
Check out our schedule at http://www.oneysoft.com

4

> But: KeDelayExecutionThread is a PASSIVE_LEVEL thing that will delay for

a minimum of whatever granularity the system clock has, which is
typically 10ms.

Um, is it really a *minimum*? What if you ask for a 5ms delay, and you are
in the middle of a scheduling quanta when you ask? I’d think you will
probably get close to your requested delay in this case. Of course, if you
ask right after a tick (the usual case), then indeed you will get virtually
a full quantum before waking up.

Also note multimedia timers affect the tick frequency, typically setting it
to 1ms.
(Of course none of this affects the real scheduler accounting quanta, which
is fixed by a define at 16ms or so. But it does affect the accuracy with
which you can wake up.)

Loren

5

Loren Wilton wrote:

Um, is it really a *minimum*? What if you ask for a 5ms delay, and you are
in the middle of a scheduling quanta when you ask? I’d think you will
probably get close to your requested delay in this case. Of course, if you
ask right after a tick (the usual case), then indeed you will get virtually
a full quantum before waking up.

Also note multimedia timers affect the tick frequency, typically setting it
to 1ms.
(Of course none of this affects the real scheduler accounting quanta, which
is fixed by a define at 16ms or so. But it does affect the accuracy with
which you can wake up.)

Right on both counts, but irrelevant. He was asking about *microsecond*
delays. KeDelayExecutionThread is almost certainly not what he wants.

–
Walter Oney, Consulting and Training
Basic and Advanced Driver Programming Seminars
Now teaming with John Hyde for USB Device Engineering Seminars
Check out our schedule at http://www.oneysoft.com

6

KeStallExecutionProcessor

----- Original Message -----
From: “Tushar Samnerkar”
To: “NT Developers Interest List”
Sent: Monday, May 12, 2003 8:36 AM
Subject: [ntdev] Machine Independent Delay

> Hi all,
>
> I am interesetd in generating 1 or 2 microsec delay in the driver
code.
> Driver code is on 2k as well as on 98.
> Is there any API which supports this. ( Similar to Sleep call)
> Any body can help in this case.
>
> Thanks in advance,
> Tushar
>
>
>
> —
> You are currently subscribed to ntdev as: xxxxx@storagecraft.com
> To unsubscribe send a blank email to
xxxxx@lists.osr.com