# Class yii\mutex\MysqlMutex

Inheritance | yii\mutex\MysqlMutex » yii\mutex\DbMutex » yii\mutex\Mutex » yii\base\Component » yii\base\BaseObject
Implements | yii\base\Configurable
Available since version | 2.0
Source Code | https://github.com/yiisoft/yii2/blob/master/framework/mutex/MysqlMutex.php

MysqlMutex implements mutex "lock" mechanism via MySQL locks.

Application configuration example:

    [
        'components' => [
            'db' => [
                'class' => 'yii\db\Connection',
                'dsn' => 'mysql:host=127.0.0.1;dbname=demo',
            ]
            'mutex' => [
                'class' => 'yii\mutex\MysqlMutex',
            ],
        ],
    ]

See also yii\mutex\Mutex.

## Public Properties

Hide inherited properties

Property | Type | Description | Defined By
--- | --- | --- | ---
$autoRelease | boolean | Whether all locks acquired in this process (i.e. local locks) must be released automatically before finishing script execution. | yii\mutex\Mutex
$behaviors | yii\base\Behavior[] | List of behaviors attached to this component. This property is read-only. | yii\base\Component
$db | yii\db\Connection|array|string | The DB connection object or the application component ID of the DB connection. | yii\mutex\DbMutex

## Public Methods

Hide inherited methods

Method | Description | Defined By
--- | --- | ---
__call() | Calls the named method which is not a class method. | yii\base\Component
__clone() | This method is called after the object is created by cloning an existing one. | yii\base\Component
__construct() | Constructor. | yii\base\BaseObject
__get() | Returns the value of a component property. | yii\base\Component
__isset() | Checks if a property is set, i.e. defined and not null. | yii\base\Component
__set() | Sets the value of a component property. | yii\base\Component
__unset() | Sets a component property to be null. | yii\base\Component
acquire() | Acquires a lock by name. | yii\mutex\Mutex
attachBehavior() | Attaches a behavior to this component. | yii\base\Component
attachBehaviors() | Attaches a list of behaviors to the component. | yii\base\Component
behaviors() | Returns a list of behaviors that this component should behave as. | yii\base\Component
canGetProperty() | Returns a value indicating whether a property can be read. | yii\base\Component
canSetProperty() | Returns a value indicating whether a property can be set. | yii\base\Component
className() | Returns the fully qualified name of this class. | yii\base\BaseObject
detachBehavior() | Detaches a behavior from the component. | yii\base\Component
detachBehaviors() | Detaches all behaviors from the component. | yii\base\Component
ensureBehaviors() | Makes sure that the behaviors declared in behaviors() are attached to this component. | yii\base\Component
getBehavior() | Returns the named behavior object. | yii\base\Component
getBehaviors() | Returns all behaviors attached to this component. | yii\base\Component
hasEventHandlers() | Returns a value indicating whether there is any handler attached to the named event. | yii\base\Component
hasMethod() | Returns a value indicating whether a method is defined. | yii\base\Component
hasProperty() | Returns a value indicating whether a property is defined for this component. | yii\base\Component
init() | Initializes MySQL specific mutex component implementation. | yii\mutex\MysqlMutex
isAcquired() | Checks if a lock is currently acquired | yii\mutex\Mutex
off() | Detaches an existing event handler from this component. | yii\base\Component
on() | Attaches an event handler to an event. | yii\base\Component
release() | Releases acquired lock. This method will return false in case the lock was not found. | yii\mutex\Mutex
trigger() | Triggers an event. | yii\base\Component

## Protected Methods

Hide inherited methods

Method | Description | Defined By
--- | --- | ---
acquireLock() | Acquires lock by given name. | yii\mutex\MysqlMutex
hashLockName() | Generate hash for lock name to avoid exceeding lock name length limit. | yii\mutex\MysqlMutex
releaseLock() | Releases lock by given name. | yii\mutex\MysqlMutex

## Method Details

acquireLock() protected method

Acquires lock by given name.

See also http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_get-lock.

protected boolean acquireLock ( $name, $timeout = 0 )
$name | string | Of the lock to be acquired.
$timeout | integer | Time (in seconds) to wait for lock to become released.
return | boolean | Acquiring result.

hashLockName() protected method (available since version 2.0.16)

Generate hash for lock name to avoid exceeding lock name length limit.

See also https://github.com/yiisoft/yii2/pull/16836.

protected string hashLockName ( $name )
$name | string |

init() public method

Initializes MySQL specific mutex component implementation.

public void init ( )
throws | yii\base\InvalidConfigException | if $db is not MySQL connection.

releaseLock() protected method

Releases lock by given name.

See also http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock.

protected boolean releaseLock ( $name )
$name | string | Of the lock to be released.
return | boolean | Release result.