From: Yusuke ENDOH <mame@...>
Date: 2011-01-17T22:09:54+09:00
Subject: [ruby-core:34539] Re: [Ruby 1.9-Bug#4285][Open] Ruby don't have asynchrounous exception safe syntax and It should have.

Hi,

2011/1/17 Motohiro KOSAKI <redmine@ruby-lang.org>:
> �CPU0(thread x) � � � � � � � � � � CPU1(thread y) � � � � remark
> ---------------------------------------------------------------------------
> �enter begin block
> �[thread construct] � � � � � � � � � � � � � � � � � � � �but no assign y yet
> � � � � � � � � � � � � � � � � � � sleep sec
> � � � � � � � � � � � � � � � � � � wakeup from sleep
> � � � � � � � � � � � � � � � � � � x.raise
> �if y � � � � � � � � � � � � � � � � � � � � � � � � � � �return false. (see above)
>
>
> Therefore, CPU0 don't call y.join and leak y's thread resource.

What's the resource?
I think that the thread will terminate automatically even if it is
not join'ed.


> But unfortunately, Ruby don't have such language feature. So, We can't write
> async-exception-safe code. One of solution is to move timeout module from ruby code
> into c code as JRuby does. But I don't think timeout is only asynchrounos exception user.
> we also have Interrupt class (for Ctrl-C) and I think we need to allow to write async
> exception safe code by ruby.

Dr. akr knows a lot about that subject.

-- 
Yusuke Endoh <mame@tsg.ne.jp>