# Abstract Class yii\mutex\DbMutex

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

DbMutex is the base class for classes, which relies on database while implementing mutex "lock" mechanism.

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

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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 generic database table based mutex implementation. | yii\mutex\DbMutex
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

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Method | Description | Defined By
--- | --- | ---
acquireLock() | This method should be extended by a concrete Mutex implementations. Acquires lock by name. | yii\mutex\Mutex
releaseLock() | This method should be extended by a concrete Mutex implementations. Releases lock by given name. | yii\mutex\Mutex

## Property Details

$db public property

The DB connection object or the application component ID of the DB connection. After the Mutex object is created, if you want to change this property, you should only assign it with a DB connection object. Starting from version 2.0.2, this can also be a configuration array for creating the object.

public yii\db\Connection|array|string $db = 'db'

## Method Details

init() public method

Initializes generic database table based mutex implementation.

public void init ( )
throws | yii\base\InvalidConfigException | if $db is invalid.