Subject: bug#34618: 26.1.92; timerfd interface causes slowdown on Cygwin

From: Eli Zaretskii <[email-masked]>
Date: Sat, 09 Mar 2019 21:42:38 +0200

> From: Ken Brown <[email-masked]>
> CC: "[email-masked]" <[email-masked]>
> Date: Sat, 9 Mar 2019 19:27:34 +0000
> 
> The Cygwin problems with the timerfd functions have been fixed as of 
> cygwin-3.0.2, so I've re-enabled the use of these functions on the master 
> branch.  To play it safe, we should probably leave them disabled on the emacs-26 
> branch.

Isn't there a way to get at the version of Cygwin at run time?  I
think the best solution is to allow timerfd functions only for
versions whose support is not buggy, and that's not a compile-time
decision, right?