Deleting an event while WaitForSingleObject?

[christ2008]

What happens if I call CloseHandle() for an hEvent while that event is
being waited on using WaitForSingleObject() ?

Is the behavior in Win32 defined for such case?

Will this result in that WaitForSingleObject() entering a deadlock?

Or is the system smart enough to let WaitForSingleObject() with some
kind of diagnostic/error code?

Thanks,
Chris

[Scott McPhillips [MVP]]

"christ2008" <christ...@mailinator.com> wrote in message
news:a851791d-1c8b-4ce3...@f47g2000hsd.googlegroups.com...

If you really want to know then you'll have to try it and see. The result
is not defined by Win32, and doing this would be considered a design error.

--
Scott McPhillips [VC++ MVP]

[christ2008]

On Jan 18, 1:05 pm, "Scott McPhillips [MVP]" <org-dot-mvps-at-

scottmcp> wrote:
>
> If you really want to know then you'll have to try it and see.  The result
> is not defined by Win32, and doing this would be considered a design
> error.

Thanks, Scott. Your reply prompted me to look again at the
documentation for WaitForSingleObject() and sure enough it clearly
says that the behavior for such case is undefined. I somehow
overlooked that sentence.

So does this mean that if I initialize a subsystem in which there is a
WaitForSingleObject(), there is no way of "un-initializing" it? The
only way out is killing the process (exiting the program)?

Thanks,
Chris

[Norman Bullen]

What kind of event is it on which you are waiting?

Can you arrange for the event to become set so that the wait ends normally?

Norm

--
Norm

To reply, change domain to an adult feline.

[Jeffrey Adler]

If you want to do something like that, create a 2nd event object, do a
WaitForMultipleObjects, and if the 2nd object gets signalled it can close
the first object normally.

"Norman Bullen" <no...@BlackKittenAssociates.com> wrote in message
news:13p2ibb...@corp.supernews.com...

[Ulrich Eckhardt]

christ2008 wrote:
> [...] Your reply prompted me to look again at the

> documentation for WaitForSingleObject() and sure enough it clearly
> says that the behavior for such case is undefined. I somehow
> overlooked that sentence.
>
> So does this mean that if I initialize a subsystem in which there is a
> WaitForSingleObject(), there is no way of "un-initializing" it?

I'm not exactly sure what you are trying to do, but this should work:

h = DuplicateHandle(h);
WaitFor..(h);
CloseHandle(h);

That way, even calling CloseHandle() from a different thread doesn't destroy
the event. I'm not 100% sure if event handles can be duplicated though, but
the returnvalue and documentation of DuplicateHandle() will tell you. ;)

Other than that, you can use two events, one for the actual task, the other
to signal the thread to terminate.

Uli

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