From: Nikodemus Siivola <tsiivola@...>
Date: 2002-05-10T06:56:16+09:00
Subject: timeout.rb problem


Nested timeouts considered nasty ;)

The scripts below prints out "achived enlightenment, exiting
gracefully...", which is in this context quite understandable -- but
extremely surprising if the inner timeout is "more distant", in a library
module for example.

#!/usr/bin/ruby

require 'timeout'

def meditate
  begin
    timeout(10) { loop { self.inspect } }
  rescue TimeoutError
    puts "achived enlightenment, exiting gracefully..."
    exit
  end
end

def try_to_meditate
  begin
    timeout(1) { meditate }
  rescue TimeoutError
    puts "meditation takes too long, rush to abort!"
    abort
  end
end

try_to_meditate

__END__


 - Is this technically correct? Should a rescue block rescue
   an exception that is raised from outside of it's scope?

 - Is this really the way timeout's should behave? Maybe TimeoutError
   could contain information of it's nesting level so that when
   rescuing a timeout one could reraise it so that the higher level
   code would have a chance to rescue it too...

 - Is this a timeout problem, a thread problem or an exception problem?


 -- Nikodemus