Date: Wed, 23 Mar 2011 11:00:38 -0400
From: Christopher Faylor <cgf-use-the-mailinglist-please@cygwin.com>
To: cygwin@cygwin.com
Subject: Re: python select() is limited to fds < 64
Message-ID: <20110323150038.GE13862@ednor.casa.cgf.cx>
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On Wed, Mar 23, 2011 at 11:31:46AM +0000, Jon TURNEY wrote:
>On 22/03/2011 20:08, Christopher Faylor wrote:
>>On Tue, Mar 22, 2011 at 08:53:34PM +0100, V??clav Haisman wrote:
>>>Jon TURNEY wrote, On 22.3.2011 20:29:
>>>>
>>>>python seems to be built with the default value of FD_SETSIZE, which is
>>>>only 64 on cygwin.
>>>Is this not because of the inherent limitation of
>>>WaitForMultipleObjects() call?
>>
>>Yep.  Without a rewrite, it's a hard limit to Cygwin's select().
>
>Please read my email more closely.  I am not saying "python select() is
>limited to waiting on 64 fds or less", I am saying "python select() is
>limited to waiting on fd which are less than 64"

I forgot to add one bit of data.  Unless you go out of your way to
change it, Cygwin's select can't wait for an fd > 63.  It's basically a
bit mask.  So, there are two limitations: 1) the number of handles that
you can wait for with WaitForMultipleObjects() and 2) the size of
Cygwin's fd_set.

cgf

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