From: Eric Wong <normalperson@...>
Date: 2011-08-02T08:14:52+09:00
Subject: [ruby-core:38671] Re: [Ruby 1.9 - Bug #5138][Open] Add nonblocking IO that does not use exceptions for EOF and EWOULDBLOCK

Urabe Shyouhei <shyouhei@ruby-lang.org> wrote:
> So when you  do a read loop,  nothing bothers you, as long  as you use
> readpartial.

That use of select + readpartial is unsafe.  Spurious wakeup is a
documented behavior of the select() system call, data can be received
but checksums can be incorrect and data is discarded (after process is
woken up from select()).

Calling IO#nread (from io/wait) before IO#readpartial /may/ be OK, but
I'm not sure how portable that is.

-- 
Eric Wong