From: Ilari Liusvaara <ilari.liusvaara@elisanet.fi>
Date: Thu, 12 Aug 2010 10:21:25 GMT
Subject: Re: What's cooking in git.git (Aug 2010, #02; Wed, 11)
Message-ID: <20100812102125.GA19498@LK-Perkele-V2.elisa-laajakaista.fi>
In-Reply-To: <4C63BD9B.6000608@viscovery.net>

On Thu, Aug 12, 2010 at 11:23:39AM +0200, Johannes Sixt wrote:

> > * il/rfc-remote-fd-ext (2010-07-31) 4 commits
> >  - Rewrite bidirectional traffic loop
> >  - gitignore: Ignore the new /git-remote-{ext,fd} helpers
> >  - New remote helper: git-remote-ext
> >  - New remote helper git-remote-fd
> 
> We do not have EWOULDBLOCK on Windows. Is it needed or could the
> respective write() loop in remote-ext.c not be replaced by write_in_full()?

No, the writes can't be replaced by write_in_full() without changing what
the code does, because write_in_full() retries short writes, whereas current
code does not retry reads nor writes. And retrying reads/writes in code
juggling with multiple fds is usally no-no.

The EWOULDBLOCK is needed on some systems if fds involved are nonblocking[1]. I
think the easiest way to handle system that has EAGAIN but not EWOULDBLOCK
would be:

#ifndef EWOULDBLOCK
#define EWOULDBLOCK EGAIN
#endif

[1] Some systems return EAGAIN on read/write failed due to blocking (with
EAGAIN == EWOULDBLOCK), others return EWOULDBLOCK.

-Ilari