[PATCH 2 of 2] commandserver: use selector2

[Yuya Nishihara]

On Fri, 14 Jul 2017 21:18:48 -0700, Jun Wu wrote:
> Excerpts from Yuya Nishihara's message of 2017-07-15 12:37:39 +0900:
> > On Fri, 14 Jul 2017 20:27:27 -0700, Jun Wu wrote:
> > > # HG changeset patch
> > > # User Jun Wu <quark at fb.com>
> > > # Date 1500089181 25200
> > > #      Fri Jul 14 20:26:21 2017 -0700
> > > # Node ID a6545c15171810059596259f60574011184c3412
> > > # Parent  5664763de82b48ca6882bbb624d01d467b4920d0
> > > # Available At https://bitbucket.org/quark-zju/hg-draft 
> > > #              hg pull https://bitbucket.org/quark-zju/hg-draft  -r a6545c151718
> > > commandserver: use selector2
> > > 
> > > Previously, commandserver was using select.select. That could have issue if
> > > _sock.fileno() >= FD_SETSIZE (usually 1024), which raises:
> > > 
> > >   ValueError: filedescriptor out of range in select()
> > 
> > Can we get around it without vendoring selector2, by using poll() for example?
> 
> poll is not available on OS X, which we need to support.

Oh, miserable fork of BSD.

> I tried to write some lightweight wrapper around them, then discovered I
> was basically reinventing things. SocketServer has too many issues and is
> over complicated for our usecase, but the Python 3 "selectors" interface
> looks not that bad. So I think it's okay to reuse a mature library.

Yeah, selectors API seems to do the right thing.

Queued, thanks.