From: MenTaLguY <mental@...>
Date: 2008-02-12T02:54:39+09:00
Subject: Re: Timeout::Error

Is there a way to implement this which doesn't rely on parsing the exception
backtrace?  It's going to be nasty for other Ruby implementations, and isn't
great performance-wise.

-mental

On Sun, 10 Feb 2008 11:42:04 +0900, Nobuyoshi Nakada <nobu@ruby-lang.org> wrote:
> Hi,
> 
> At Sun, 10 Feb 2008 07:24:43 +0900,
> Joel VanderWerf wrote in [ruby-core:15458]:
>> Sorry, I wasn't clear. I'm not disagreeing with you, just suggesting
>> that timeouts could be sensitive to location on the stack.
> 
> Agreed your suggestion, even for nested timeouts.
> 
> 
> @@ -25,6 +25,10 @@
>  module Timeout
>    # Raised by Timeout#timeout when the block times out.
> -  class Error < Interrupt
> +  class Error < StandardError
>    end
> +  class ExitException < ::Exception # :nodoc:
> +  end
> +
> +  CALLER_OFFSET = ((c = caller[0]) && /\A#{Regexp.quote(__FILE__)}:/o =~
> c) ? 1 : 0
> 
>    # Executes the method's block.  If the block execution terminates
> before
> @@ -36,6 +40,7 @@ module Timeout
>    # into your classes so they have a #timeout method, as well as a module
> method,
>    # so you can call it directly as Timeout.timeout().
> -  def timeout(sec, exception = Error)   #:yield: +sec+
> +  def timeout(sec, klass = nil)   #:yield: +sec+
>      return yield(sec) if sec == nil or sec.zero?
> +    exception = klass || Class.new(ExitException)
>      begin
>        x = Thread.current
> @@ -45,4 +50,15 @@ module Timeout
>        }
>        return yield(sec)
> +    rescue exception => e
> +      rej = /\A#{Regexp.quote(__FILE__)}:#{__LINE__-4}\z/o
> +      (bt = e.backtrace).reject! {|m| rej =~ m}
> +      level = -caller(CALLER_OFFSET).size
> +      while /\A#{Regexp.quote(__FILE__)}:/o =~ bt[level]
> +        bt.delete_at(level)
> +        level += 1
> +      end
> +      raise if klass            # if exception class is specified, it
> +                                # would be expected outside.
> +      raise Error, e.message, e.backtrace
>      ensure
>        if y and y.alive?
> @@ -62,5 +78,5 @@ end
>  # Defined for backwards compatibility with earlier versions of
> timeout.rb, see
>  # Timeout#timeout.
> -def timeout(n, e = Timeout::Error, &block)
> +def timeout(n, e = nil, &block)
>    Timeout::timeout(n, e, &block)
>  end
> 
> 
>