Re: [Caml-list] Re: async networking

[Markus Mottl <markus.mottl@gmail.com>]

On 2/7/06, Rick Richardson <rick@eltopia.com> wrote:
> I technically don't need to officially reschedule.. since they will all
> be doing the same thing, I'll sleep the thread, then when data becomes
> available pass it the new fd and wake it up. A simple queue would be
> fine for that.

You had mentioned that you mostly care about performance in an
environment with low data volume and a high number of transactions
(connections).  Passing off data between threads requires a
context-switch, which is going to kill your performance if you have to
do that very often (as is the case here).

It would be better to attempt "straight-through processing" (STP): let
the thread that initially received the data execute the job, and only
if this would take too long (e.g. because it might block) should you
consider passing off the work to a helper thread.  In that case it
would be advisable to use two queues if you want to reduce the number
of locks required to access new jobs.  By using STP you can quite
likely improve performance by an order of magnitude for your kind of
problem.

We have implemented a library for STP and are probably going to
release it to the general public within the next couple of weeks
anyway, but the hints above might still be useful to you if you want
to implement a solution yourself (good exercise! ;).

Regards,
Markus

--
Markus Mottl        http://www.ocaml.info        markus.mottl@gmail.com