Worker Groups

Core idea

A group is:

• read-only from the perspective of userland code
• tied to the manager that created it
• iterable
• countable
• able to wait for or signal all workers it contains

Inspect all workers

<?php

foreach ($group->all() as $worker) {
    echo $worker->getPid() . PHP_EOL;
}

Fetch a worker by PID

<?php

$worker = $group->get($pid);

if ($worker !== null) {
    echo $worker->getOutput();
}

Inspect running and stopped subsets

<?php

$running = $group->getRunning();
$stopped = $group->getStopped();

printf("running=%d stopped=%d\n", count($running), count($stopped));

Wait for the whole group

<?php

$group->wait();

Signal the whole group

<?php

use FastForward\Fork\Signal\Signal;

$group->kill(Signal::Terminate);
$group->wait();

Gotchas

• Groups do not create workers; they only expose workers created by the manager.
• A group is associated with one manager instance.
• Passing a group to another manager raises an InvalidArgumentException .
• Group membership does not change after construction.

When to use the manager instead

Use ForkManager::wait() or ForkManager::kill() directly when you need:

• to coordinate workers from multiple groups in a single call
• to target a mix of individual workers and whole groups
• to reconcile every worker managed by the same manager without tracking groups manually