Yii Mutex Library - MySQL PDO Driver

1.1.0 2021-10-19 07:18 UTC



Yii Mutex Library - MySQL PDO Driver

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This library provides a MySQL mutex implementation for yiisoft/mutex.


  • PHP 7.4 or higher.
  • PDO PHP extension.


The package could be installed with composer:

composer require yiisoft/mutex-pdo-mysql --prefer-dist

General usage

The package provides two classes implementing MutexInterface and MutexFactoryInterface from the yiisoft/mutex package:

 * @var \PDO $connection Configured for MySQL.

$mutex = new \Yiisoft\Mutex\Mysql\MysqlMutex('mutex-name', $connection);

$mutexFactory = new \Yiisoft\Mutex\Mysql\MysqlMutexFactory($connection);

There are multiple ways you can use the package. You can execute a callback in a synchronized mode i.e. only a single instance of the callback is executed at the same time:

$synchronizer = new \Yiisoft\Mutex\Synchronizer($mutexFactory);

$newCount = $synchronizer->execute('critical', function () {
    return $counter->increase();
}, 10);

Another way is to manually open and close mutex:

$simpleMutex = \Yiisoft\Mutex\SimpleMutex($mutexFactory);

if (!$simpleMutex->acquire('critical', 10)) {
    throw new \Yiisoft\Mutex\Exception\MutexLockedException('Unable to acquire the "critical" mutex.');

$newCount = $counter->increase();

It could be done on lower level:

$mutex = $mutexFactory->createAndAcquire('critical', 10);
$newCount = $counter->increase();

And if you want even more control, you can acquire mutex manually:

$mutex = $mutexFactory->create('critical');

if (!$mutex->acquire(10)) {
    throw new \Yiisoft\Mutex\Exception\MutexLockedException('Unable to acquire the "critical" mutex.');

$newCount = $counter->increase();

The MysqlMutex supports the "wait for a lock for a certain time" functionality. Using the withRetryDelay() method, you can override the number of milliseconds between each try until specified timeout times out:

$mutex = $mutex->withRetryDelay(100);

By default, it is 50 milliseconds - it means that we may try to acquire lock up to 20 times per second.


Unit testing

The package is tested with PHPUnit. To run tests:


Mutation testing

The package tests are checked with Infection mutation framework with Infection Static Analysis Plugin. To run it:


Static analysis

The code is statically analyzed with Psalm. To run static analysis:



The Yii MySQL mutex is free software. It is released under the terms of the BSD License. Please see LICENSE for more information.

Maintained by Yii Software.

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