On 28/05/2008, Isabelle Cabrera <[EMAIL PROTECTED]> wrote:
> Hi,
>
> I have a problem using the Event module.
>
> My goal: I have several sentences that I need to parse. For a faster
> process, I have a dispatcher which sends the sentences to several hosts
> so that the processes are distributed.
>
> In my dispatcher, I register every host. For each host I create a watcher :
>
> $self->{hosts}{$host}{watcher} =
> Event->var(desc =>"Process sentence on $host",
> var => \$client->{free},
> poll => 'w',
> cb => $self->next_dag($host),
> debug => 4,
> );
>
> The callback next_dag is called every time all the process of parsing
> the sentence and sending back the results is done (more precisely when
> the host says it's ready to receive a new sentence, with variable
> $client->{free}).
>
> Of course, I would like that every host can work at the same time
> (that's the point...), but my problem is that they do the job
> subsequently, one sentence at the time.
>
> The created event mainly does the following:
> - get the next sentence from a file
> - send this sentence to the parser on the free host (through a server of
> parser accessed with Net::Telnet)
> - get the result of the parsing (yes or no) (still through Net::Telnet...)
> - if yes, connect again to the server of parser to generate one or
> several outputs and write them into one or several files
> - says "I'm ready to get a new sentence to parse", triggering the
> variable 'free'
>
> I thought that creating an event was automatically non blocking and
> several events could happen at the same time. Does the problem come from
> the I/O interactions ? If so, do I need to separate all these stages and
> watch for every I/O interactions ? And do I need to specify somewhere
> that I want non blocking I/O ?
>
> Best regards,
> Isabelle
>
> --
> Isabelle Cabrera
> Projet Alpage - INRIA Rocquencourt
> http://alpage.inria.fr
> Tel : 01 3963 5270
>
>
it sounds like each event is blocking, waiting for the computation to
return a result, and then releasing to allow EV to continue it's loop.
i have had a similar problem recently, (a multi-server irc bot), and
found i have a similar problem, each time the event was blocking and
waiting for a reply.
how i solved it was to create a readable event for each socket, so
rather than send-wait-receive as you have, its send, then assign a
receive callback to trigger when a result is returned. thus, send
commands down each socket, and allow EV to loop until each one
returns, and as each result is returned, send another query, then let
EV wait on the result again, ad infinitum.
i suspect this is a horribly confusing answer, and unfortunately i'm
away from home for a few days so i cant provide a code example, but
feel free to ask anything further.
James Clark.
