Hey all,

I am trying to find a way of determining if a device is currently open. I
can manage it myself by adding an IOCTL to the driver, however I wanted to
first see if there is already a way I can get the info needed.

Chris

Re: How to tell if device is open from usermode? by Chris

Chris
Tue Sep 02 12:14:00 CDT 2003

"Don Burn" <burn@acm.org> wrote:
> Well first question is why do you want this?

Certain configuration and management proceedures that my user-mode app
performs I do not want to do if another app has the device open. Note that
not all of these proceedures require interaction with the driver. So,
during those proceedures that don't have interaction with the driver I can't
simply use error returns from the driver.

> I'm not sure how an IOCTL is going to work, since step one is open the
> device to issue the IOCTL, so then is the device open?

I knew someone was going to bring this up :) I have a bus driver in my
design that I can use for this IOCTL.

Chris