Working & waiting in php ext 0.6

[Denis Arh]

Hi,

I just can not get this working... must be something silly...

Standard client code:
$c = new GearmanClient();
$c->addServer()
$c->do('funct', 'some data');

Standard worker code:
$w = new GearmanWorker();
$w->addServer();
$w->addFunction('funct', 'funct');
$w->work()


How to include non-blocking option & wait() method?

$w->addOptions(GEARMAN_WORKER_NON_BLOCKING);
do {
$w->work();
$w->wait();
usleep(500000);
} while(true);


$w->addOptions(GEARMAN_WORKER_NON_BLOCKING);
$w->work();
do {
$w->wait();
usleep(500000);
} while(true);


Any suggestions? None of this works... if I put non-blocking option
worker does not "grab" jobs from the server...
I could do this with setTimeout() and calling work() in a loop but
somehow this does not feel right.

[Eric Day]

Hi Denis,

Well, it all depends on why you want to use non-blocking mode.Do you
have other file descriptors you want to listen on? Do you just want
the work() method to return for some type of check periodically?

I think most folks will just want to use the timeout:

$worker= new GearmanWorker();
$worker->setTimeout(5000);
$worker->addServer('127.0.0.1', 4730);
$worker->addFunction('reverse', 'my_reverse_fn');
while (@$worker->work() || $worker->returnCode() == GEARMAN_TIMEOUT)
print "Waiting for next job...\n";
print "Worker Error: " . $worker->error() . "\n";

This will allow you do some type after each job or every 5 seconds.

For non-blocking, the only use case I find useful right now is in the
client to send all requests but not block on them yet. I'm thinking
we'll be adding a new API call to just "sendTasks" and not actually
wait for results. I don't see much use in NON_BLOCKING for the worker
(unless you have other FDs outside of Gearman you need to manage
concurrently).

$worker= new GearmanWorker();
$worker->addOptions(GEARMAN_WORKER_NON_BLOCKING);
$worker->addServer('127.0.0.1', 4730);
$worker->addFunction('reverse', 'my_reverse_fn');
while (@$worker->work() ||
$worker->returnCode() == GEARMAN_IO_WAIT ||
$worker->returnCode() == GEARMAN_NO_JOBS)
{
if ($worker->returnCode() == GEARMAN_SUCCESS)
continue;

print "Waiting for next job...\n";
if (!@$worker->wait())
{
if ($worker->returnCode() == GEARMAN_NO_ACTIVE_FDS)
{
# We are not connected to any servers, so wait a bit before
# trying to reconnect.
sleep(5);
continue;
}

break;
}
}
print "Worker Error: " . $worker->error() . "\n";

As for your code, this one makes more sense than the other, but you
don't need a 'usleep' in there. The wait() method blocks on poll(),
and acts as your "sleep until file I/O".

> $w->addOptions(GEARMAN_WORKER_NON_BLOCKING);
> do {
> $w->work();
> $w->wait();
> usleep(500000);
> } while(true);

Hope this helps. :)

-Eric

[Denis Arh]

Thank you Eric for the code samples.

>
> As for your code, this one makes more sense than the other, but you
> don't need a 'usleep' in there. The wait() method blocks on poll(),
> and acts as your "sleep until file I/O".

I'm using gearmain in one of my app that uses forks to initialize
multiple workers that can then do some work in parallel. And if I use
wait() and "sleep util file I/O" PHP will not allow me to catch any
signals (like KILL).

So, in this case my only option is to use setTimeout() and work().

Regards,
Denis