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From: rf on 2 Mar 2010 17:34
Hi - I am using an interface to signal an application from a kernel driver.
The driver call IoSetDeviceInterface state to change the status which is
monitored by the application via WM_DEVICECHANGE messages.

With a single instance of the interface everything works fine. However,
with multiple instances of the interface, sometimes the application does not
see all the notifications. This behavior occurs ONLY in Vista & Windows 7;
XP works fine.

The instances of the driver interface are created by specifying the
ReferenceString parameter to IoRegisterDeviceInterface().

Are there any caveats to using multiple instances of an interface in this
manner?

Thanks in advance,
Rick

From: Scott Noone on 2 Mar 2010 19:28
No, everything should "just work." You might want to write a quick app using
the SetupDi interface to enumerate all of the existing instances of your
GUID, that would at least let you know that your driver is working properly.
It is also an easier to debug the situation than involving all of the window
messaging and such.

-scott

--
Scott Noone
Consulting Associate
OSR Open Systems Resources, Inc.
http://www.osronline.com


"rf" <rf(a)discussions.microsoft.com> wrote in message
news:E66E75A1-6B20-4A5F-8B75-9CCD3A09F334(a)microsoft.com...
> Hi - I am using an interface to signal an application from a kernel
> driver.
> The driver call IoSetDeviceInterface state to change the status which is
> monitored by the application via WM_DEVICECHANGE messages.
>
> With a single instance of the interface everything works fine. However,
> with multiple instances of the interface, sometimes the application does
> not
> see all the notifications. This behavior occurs ONLY in Vista & Windows
> 7;
> XP works fine.
>
> The instances of the driver interface are created by specifying the
> ReferenceString parameter to IoRegisterDeviceInterface().
>
> Are there any caveats to using multiple instances of an interface in this
> manner?
>
> Thanks in advance,
> Rick
>
From: Doron Holan [MSFT] on 3 Mar 2010 18:22
is the ReferenceString parameter unique for each of the API calls for the
same PDEVICE_OBJECT and device interface guid?

--

This posting is provided "AS IS" with no warranties, and confers no rights.


"rf" <rf(a)discussions.microsoft.com> wrote in message
news:E66E75A1-6B20-4A5F-8B75-9CCD3A09F334(a)microsoft.com...
> Hi - I am using an interface to signal an application from a kernel
> driver.
> The driver call IoSetDeviceInterface state to change the status which is
> monitored by the application via WM_DEVICECHANGE messages.
>
> With a single instance of the interface everything works fine. However,
> with multiple instances of the interface, sometimes the application does
> not
> see all the notifications. This behavior occurs ONLY in Vista & Windows
> 7;
> XP works fine.
>
> The instances of the driver interface are created by specifying the
> ReferenceString parameter to IoRegisterDeviceInterface().
>
> Are there any caveats to using multiple instances of an interface in this
> manner?
>
> Thanks in advance,
> Rick
>
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