From: Tanaka Akira <akr@...17n.org>
Date: 2004-02-27T13:59:38+09:00
Subject: Re: ruby-dev summary 22877-23014

In article <20040226144929.GP379@atdesk.com>,
  Paul Brannan <pbrannan@atdesk.com> writes:

> The question should not be whether this method is useful in most cases,
> but instead whether this method is useful in enough cases to warrant
> including it.

My point is that sysread (or sysread like method which care stdio
buffer) is better than nonblocking read.

I think they are useful in similar cases.

> If a programmer creates a child process and uses a parent processes's
> file descriptor in the child, he'd better know what he is doing, whether
> the non-blocking flag is set or not.

I think usual program expects non-blocking flag is clear.  For
example, following problem is caused because cvs (stdio) doesn't
expect stderr is nonbloking.

http://groups.google.com/groups?th=e4df2fdc1f4f4950
http://sources.redhat.com/ml/bug-glibc/2002-08/threads.html#00041
http://sources.redhat.com/ml/bug-glibc/2002-08/threads.html#00186

Since there are much code which expect file descriptor which
non-blocking flag is clear, nonblocking-mode should be avoided if
possible.  So Ruby should not recommend nonblocking IO by providing
easy-to-use method to make IO nonblocking.  However someone who know
what he is doing can make IO nonbloking using IO#fcntl anyway.
-- 
Tanaka Akira