From: Eric Wong <normalperson@...>
Date: 2012-04-14T10:23:56+09:00
Subject: [ruby-core:44353] Re: [ruby-trunk - Feature #6293][Open] new queue / blocking queues

"tenderlovemaking (Aaron Patterson)" <aaron@tenderlovemaking.com> wrote:
> Whenever I use queues, I either use them in a blocking or non-blocking
> manner only, so I have separated them in to two classes Thread::Queue,
> and Thread::BlockingQueue.

I don't think queues should be limited to strictly
blocking/non-blocking.

Outside of Ruby, but I've occassionally needed queues that could
toggle between blocking/non-blocking (even in the same thread)
to enforce some sort of fairness.  Something like:

  while task = queue.take
    while task.run_one_timeslice

      if pending_task = queue.trytake # non-blocking

        # reschedule task if another task shows up
        queue.push(task)
        task = pending_task
      end

    end
  end

Also, I very often use queues (often Unix pipes) where one end is
blocking and the other end is not (though you don't implement
non-blocking push at all)