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Date: Mon, 9 Oct 2006 12:04:20 +0200
From: Peter Ekberg <peda AT lysator DOT liu DOT se>
To: cygwin AT cygwin DOT com
Subject: Re: How to select on a win32 handle?
Message-ID: <20061009100420.GC23365@arnhem.lysator.liu.se>
References: <20061007025233 DOT GA24180 AT sellafield DOT lysator DOT liu DOT se> <20061009085518 DOT GD13105 AT calimero DOT vinschen DOT de>
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On Mon, Oct 09, 2006 at 10:55:18AM +0200, Corinna Vinschen wrote:
> On Oct  7 04:52, Peter Ekberg wrote:
> > Hello!
> > 
> > I'm finding that I have a need to select on a win32 handle. I found the
> > function cygwin_attach_handle_to_fd which sounded promising, but I do
> > not have any luck when I try to use it.
> 
> That won't work.  The Windows select function is only implemented for
> sockets.

Yes, it is pretty damn broken.

>           To implement a POSIX select function which allows to select on
> any descriptor one needs to implement it specificially for each known,
> resp. useful file type.  Naturally this won't work with a generic
> Windows handle since Cygein doesn't know what it represents.  So Cygwin
> is unable to provide a matching select function.

I assumed that cygwin as a last step issued a WaitFor... on the underlying
win32 handles associated with the fds in its select implementation. Perhaps
this assumption was wrong? But if not, it would be neat to somehow add an
extra win32 handle to the array, that would break out of the cygwin select
when the win32 handle is signaled.

But I understand that this is pretty far from "Linux compatibility" so I'm
not expecting any sympathy for my twisted needs. :-)

Cheers,
Peter

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