locking.rst

Locking

To avoid concurrency issues, the library is able to lock other executions which would run at the same time. This could happen if multiple workers (e.g. cronjobs) run at the same time.

Each TaskHandler decides if and how many other Tasks will be blocked while a task with this handler is running. If the TaskHandler implements the LockingTaskHandlerInterface the Lock-Component is enabled for this handler. The interface consists of a single method getLockKey($workload) which returns a locking-key. Tasks with the same locking-key will not be executed at the same time.

Example

<?php

include __DIR__ . '/vendor/autoload.php';

class ImageResizeHandler implements Task\Lock\LockingTaskHandlerInterface
{
    public function handle($workload)
    {
        ...
    }

    public function getLockKey($workload)
    {
        return self::class;

        // or append workload data
        return self::class . '-' . $workload['id'];
    }
}