From: Yukihiro Matsumoto <matz@...>
Date: 2008-02-20T05:27:31+09:00
Subject: Re: threads at end of programs in 1.8/1.9

Hi,

In message "Re: threads at end of programs in 1.8/1.9"
    on Wed, 20 Feb 2008 05:04:42 +0900, "David A. Black" <dblack@rubypal.com> writes:

|> I'm trying to get a fix on thread behavior in 1.9 vs. 1.8.6, and the
|> following things seem odd to me (unless I've just slept through some
|> known changes, which is always possible).
|>
|> Doing this:
|>
|> $ ruby19 -ve 'Thread.new { puts "a" }'
|> ruby 1.9.0 (2008-02-15 revision 0) [i686-darwin9.1.0]
|>
|> always results in no output (except the version).

The pthread context switching is far more complex than the green
thread in 1.8, so that it is tougher to predict.  I think the
complexity has its own good reason.

|> I'm not quite sure what all of this adds up to, in terms of predicting
|> thread behavior at or near the end of a program. That one can't? :-)

I am afraid that ensuring the simple predictability may hinder the
threading performance.

							matz.