README

Integrates zerkalica/semaphore library into Symfony2.

A generic locking Symfony bundle for PHP, that uses named locks for semaphore acquire and release, to guarantee atomicity.

Locking is useful for controlling access to resources in a multi-process or distributed environment.

The idea is that the actual locking mechanism can be implemented in any way you like, in order to fit your technology stack.

Page bundle: https://github.com/Avtonom/semaphore-bundle

Support adapters

• redis
• memcached
• sem (native functionality)
• apc
• flock (filesystem)
• • doctrine/orm , pdo, sql - (in future versions)

Features

• Check for attempts to lock the same process. There are two variants of this reaction: throw an exception or extend the lifetime of the key.
• Check before removing the key, he put this process. It is to be found that the key did not die at the time and did not put another process.
• Notification that the script finished and forgot to remove the lock.
• Logging operations with all the necessary information on a specific channel in monolog (channel: semaphore)
• Select the class for the lock manager (SemaphoreManager)
• Select the object class contains a list of key locks (KeyStorage)
• Demo mode - keeping all logging but does not execute set and validates the key.
• Setting parameters such as:
• • Number of attempts to acquire a lock
• • Waiting time between attempts to acquire a lock
• • Lifetime lock
• • Prefix key lock

Maybe in the future:

• Notice that the lock had died on key lifetimes
• Adapters for doctrine/orm, pdo, sql
• The administrative interface (Sonata Project) for a list of locks and log management actions
• Stopwatch to see semaphore usage in the timeline of the symfony debug toolbar

To Install

Run the following in your project root, assuming you have composer set up for your project

composer.phar require avtonom/semaphore-bundle ^1.4
composer require snc/redis-bundle

Switching ^1.4 for the most recent tag.

Add the bundle to app/AppKernel.php

$bundles(
    ...
       new Avtonom\SemaphoreBundle\AvtonomSemaphoreBundle(),
       new Snc\RedisBundle\SncRedisBundle(),
    ...
);

Configuration options (config.yaml):

snc_redis:
    clients:
        semaphore:
            type: predis
            alias: semaphore
            dsn: redis://localhost/2

avtonom_semaphore:
    adapter_redis_client: snc_redis.semaphore
    key_storage_class: Application\Avtonom\SemaphoreBundle\SemaphoreKeyStorage
    #mode: demo # activation of the demo mode - keeping all logging but does not execute set and validates the key. 
    # default
    #    adapter: avtonom_semaphore.adapter.redis
    #    manager_class: Avtonom\SemaphoreBundle\Model\SemaphoreManager
    #    is_exception_repeat_block_key: true # Generate an error when you try to re-key block in the same process.
    #    use_extended_methods: true

Configuration options (parameters.yaml):

parameters:
    # default
    #    avtonom_semaphore.try_count: 240 # try count, if lock not acquired. 240 count * 1/2 sec (sleep wait) = 120 sec wait
    #    avtonom_semaphore.sleep_time: 500000 # sleep time in microseconds, if lock not acquired. 1.000.000 microseconds = 1 seconds
    #    avtonom_semaphore.max_lock_time: 60 # ttl - max lock time
    #    avtonom_semaphore.prefix: 'lock_'
    

use Avtonom\SemaphoreBundle\Traits\SemaphoreTrait\SemaphoreTrait;

// or

/** @var $semaphore \Avtonom\Semaphore\Model\SemaphoreManagerInterface */
$semaphore = $container->get('avtonom_semaphore.manager');

$lockKeyStorage = $this->getLockKeyStorage();
$lockKey = [$lockKeyStorage::MY_KEY, $param1, $param2, $paramN];
$this->lockAcquire($lockKey, __METHOD__, 10 /* 10 - if you personal lock expire time in seconds. default 60 */);

// Do something thread-safe

$this->lockRelease($lockKey, __METHOD__);

Create Application\Avtonom\SemaphoreBundle\KeyStorage class:

<?php

namespace Application\Avtonom\SemaphoreBundle;

use Avtonom\SemaphoreBundle\Model\SemaphoreKeyStorageInterface;

class SemaphoreKeyStorage implements SemaphoreKeyStorageInterface
{
    const
        MY_KEY = 'M_K_',
        MY_OTHER_KEY = 'M_O_K_'
    ;
}

Need Help?

1. Please look the log file %kernel.logs_dir%/%kernel.environment%.semaphore.log
2. Create an issue if you've found a bug,