# Abstract Class yii\mutex\Mutex

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

The Mutex component allows mutual execution of concurrent processes in order to prevent "race conditions".

This is achieved by using a "lock" mechanism. Each possibly concurrent thread cooperates by acquiring a lock before accessing the corresponding data.

Usage example:

    if ($mutex->acquire($mutexName)) {
        // business logic execution
    } else {
        // execution is blocked!
    }

This is a base class, which should be extended in order to implement the actual lock mechanism.

## 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

## 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 the Mutex component. | yii\mutex\Mutex
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() | 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

$autoRelease public property

Whether all locks acquired in this process (i.e. local locks) must be released automatically before finishing script execution. Defaults to true. Setting this property to true means that all locks acquired in this process must be released (regardless of errors or exceptions).

public boolean $autoRelease = true

## Method Details

acquire() public method

Acquires a lock by name.

public boolean acquire ( $name, $timeout = 0 )
$name | string | Of the lock to be acquired. Must be unique.
$timeout | integer | Time (in seconds) to wait for lock to be released. Defaults to zero meaning that method will return false immediately in case lock was already acquired.
return | boolean | Lock acquiring result.

acquireLock() protected abstract method

This method should be extended by a concrete Mutex implementations. Acquires lock by name.

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

init() public method

Initializes the Mutex component.

public void init ( )

isAcquired() public method (available since version 2.0.36)

Checks if a lock is currently acquired

public boolean isAcquired ( $name )
$name | string | Of the lock to check
return | boolean | Returns true if currently acquired

release() public method

Releases acquired lock. This method will return false in case the lock was not found.

public boolean release ( $name )
$name | string | Of the lock to be released. This lock must already exist.
return | boolean | Lock release result: false in case named lock was not found..

releaseLock() protected abstract method

This method should be extended by a concrete Mutex implementations. Releases lock by given name.

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