WaitForSingleObject never returns

Scott Kooy

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Jun 27, 2003, 11:19:23 AM6/27/03

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I have a thread which is blocked on the call:

bob = WaitForSingleObject(hRXEvent, 5000);

This function works for a long time, and then after a
while, the function never returns (even though the timeout
value is 5000 ms).

the hRXEvent object is created in the beginning with

CreateEvent(NULL, 0, 0, "VWCommEvent");

Then in response to an IRP in a driver, the object is
passed to the driver memory by

ObReferenceObjectByHandle(Mozart, SYNCHRONIZE, NULL,
KernelMode, &deviceExtension->hEvent, NULL);

Also in the driver in an ISR, the object is set by the
following code:

KeSetEvent(deviceExtension->hEvent, 0, 0);

In response, the WaitForSingleObject returns.

And as I said, this works many many times, and then it
just decides never to return from the WaitForSingleObject
even though there is a timeout. Also I know that
KeSetEvent continues to be called.

Gary G. Little

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Jun 27, 2003, 11:35:10 AM6/27/03

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First of all ... KeSetEvent cannot be called in an ISR. It can only be
called at DISPATCH_LEVEL if _wait_ is set to FALSE, otherwise it must be
called at PASSIVE_LEVEL ISRs run at DIRQL and in arbitrary thread context.
Move your call to KeSetEvent into a DPC and set _wait_ to false. You
describe a classic synchronization situation.

--
Gary G. Little
Seagate Technologies, LLC
gary.g...@seagate.com

"Scott Kooy" <the_ho...@yahoo.com> wrote in message
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Doron Holan [MS]

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Jun 27, 2003, 1:31:43 PM6/27/03

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not related, but in your call to ObReferenceObjectByHandle, the 3rd
parameter (you have NULL), should be *ExEventObjectType, otherwise any
random handle passed will be valid and if incorrect, crash the system.

d

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

"Scott Kooy" <the_ho...@yahoo.com> wrote in message
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Alexander Grigoriev

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Jun 27, 2003, 11:29:04 PM6/27/03

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Also using a named event is not necessary (unless the event is shared
between different processes),
UserMode should be used in OROBH call, and access mask should be then
EVENT_MODIFY_STATE.

"Doron Holan [MS]" <dor...@online.microsoft.com> wrote in message
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Bikramjeet Singh Assal

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Jun 30, 2003, 3:36:01 PM6/30/03

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Hello,

I have a question.

I am using Win32 CryptHashData(...) and CryptDecrypt() functions to
encrypt and decrypt the string respectively.

When I run a sample program using these functions, it successfully
encrypts and decrypts the alphanumeric string.

But when I incorporate that same set of functions in customized Gina DLL
which uses a mix of UNICODE and ANSI character sets, decrypt doesn't
work properly.

Encrypting and writing to the registry part works fine.

But when I read the registry from within one of Gina's exported
functions which uses a mix of UNICODE and ANSI character sets, it
decrypts the string but adds some junk characters at the end of the
decrypted string.

It is actually very wierd. I am actually calling the function twice to
decrypt 2 passwords stored in registry.

At the time of first call, decrypt works fine but not on second call.

I am not sure whats causing it.

I hope I am not doing any silly mistake :).

But if somebody has encountered similar kind of problem or knows what is
going wrong in my case, it will be of great help if u wud share it with
me.

Thanks,

- Bikram.