From: Jeremy Hinegardner <jeremy@...>
Date: 2008-05-01T00:32:45+09:00
Subject: Re: forkoff - parallel processing for ruby enumerables

On Wed, Apr 30, 2008 at 08:02:36AM +0900, ara.t.howard wrote:
>
> On Apr 29, 2008, at 4:15 PM, Abdul-rahman Advany wrote:
>> Sorry, just figured out calling fork makes the thread a child process...
>> just need to find out how to set a timeout on the thread... anyone
>> suggestions?
>
> require 'timeout'
>
> begin
>   Timeout.timeout(seconds){ thread.join }
> rescue Timeout::Error
>   thread.kill rescue nil
> end

That'll kill the thread, but not the child process that was forked, at least
that's what I remember.

Try this as a general strategy:

  parent_t = Thread.new(cmd) do |exec_me|
                    if cpid = fork then
                      Thread.current[:cpid] = cpid
                      cpid, exit_status = Process.waitpid2(cpid)
                      Thread.current[:exit_status] = exit_status
                    else
                      exec exec_me
                    end
              end   


  unless parent_t.join( seconds )   # seconds contains your timeout value
  cpid = parent_t[:cpid]
  %w[ TERM KILL ].each do |sig|
    Process.kill(sig, cpid)
    break if parent_t.join(1)
  end

  # Do something with Thread.current[:exit_status] to report the child
  # process exit status.

enjoy,

-jeremy


-- 
========================================================================
 Jeremy Hinegardner                              jeremy@hinegardner.org