From: Charles Mills <cmills@...>
Date: 2004-12-21T02:22:04+09:00
Subject: Re: threads and errors

nobu.nokada@softhome.net wrote:
> Hi,
>
> At Mon, 20 Dec 2004 15:45:10 +0900,
> Joel VanderWerf wrote in [ruby-talk:124079]:
> > Another approach:
> >
> >    begin
> >      Thread.new(Thread.current) do |th|
> >        begin
> >          raise "error"
> >        rescue => e
> >          th.raise e
> >        end
> >      end
> >    rescue => e
> >      p e
> >    end
>
> It's not predictable when the parent thread will be
> interrupted.  It may be after the rescue block.

#### tmp.rb s/^\.//
..begin
..  Thread.new(Thread.current) do |th|
..    sleep 1
..    begin
..      raise "error"
..    rescue => e
..      th.raise e
..    end
..  end
..rescue => e
..  puts e
..end

..puts "before sleep"
..sleep 2
..puts "after sleep"
####
$ ruby tmp.rb
before sleep
tmp.rb:5: error (RuntimeError)
from tmp.rb:2:in `initialize'
from tmp.rb:2:in `new'
from tmp.rb:2
## If you comment out the 'sleep 1' line you get a much different
result: ##
$ ruby tmp.rb
error
before sleep
after sleep

Depending on the situation it may be necessary to keep the rest of the
code the begin/rescue block.

-Charlie