# PgsqlMutex

> PgsqlMutex implements mutex "lock" mechanism via PgSQL locks.

[API reference](/docs/api/index.md) › [yii](/docs/api/yii/index.md) › [mutex](/docs/api/yii/mutex/index.md) › PgsqlMutex

| class | `yii\mutex\PgsqlMutex` |
| --- | --- |
| Extends | [`DbMutex`](/docs/api/yii/mutex/dbmutex/index.md) » [`Mutex`](/docs/api/yii/mutex/mutex/index.md) » [`yii\base\Component`](/docs/api/yii/base/component/index.md) » [`yii\base\BaseObject`](/docs/api/yii/base/baseobject/index.md) |
| Implements | [`yii\base\Configurable`](/docs/api/yii/base/configurable/index.md) |
| Uses traits | [`RetryAcquireTrait`](/docs/api/yii/mutex/retryacquiretrait/index.md) |
| Since | 2.0.8 |
| Source | [`framework/mutex/PgsqlMutex.php`](https://github.com/yiisoft/yii2/blob/22.0/framework/mutex/PgsqlMutex.php#L37) |

PgsqlMutex implements mutex "lock" mechanism via PgSQL locks.

Application configuration example:

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

See also: [`Mutex`](/docs/api/yii/mutex/mutex/index.md).

## Properties

| Property | Type | Description | Defined by |
| --- | --- | --- | --- |
| <span id="property-autoRelease"></span>[`$autoRelease`](/docs/api/yii/mutex/mutex/index.md#property-autoRelease) | `bool` | Whether all locks acquired in this process (i.e. local locks) must be released automatically before finishing script execution. Default: `true`. | [`Mutex`](/docs/api/yii/mutex/mutex/index.md) |
| <span id="property-behaviors"></span>[`$behaviors`](/docs/api/yii/base/component/index.md#property-behaviors) read-only | `array<`[`yii\base\Behavior`](/docs/api/yii/base/behavior/index.md)`<static>>` | List of behaviors attached to this component. | [`yii\base\Component`](/docs/api/yii/base/component/index.md) |
| <span id="property-db"></span>[`$db`](/docs/api/yii/mutex/dbmutex/index.md#property-db) | [`yii\db\Connection`](/docs/api/yii/db/connection/index.md)`\|array\|string` | The DB connection object or the application component ID of the DB connection. Default: `'db'`. | [`DbMutex`](/docs/api/yii/mutex/dbmutex/index.md) |
| <span id="property-retryDelay"></span>[`$retryDelay`](/docs/api/yii/mutex/retryacquiretrait/index.md#property-retryDelay) | `int` | Number of milliseconds between each try in `acquire()` until specified timeout times out. Default: `50`. Available since 2.0.16. | [`RetryAcquireTrait`](/docs/api/yii/mutex/retryacquiretrait/index.md) |

## Methods

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

## Method details

### init() <span id="method-init"></span>

```php
public function init(): mixed
```

Initializes PgSQL specific mutex component implementation.

**Returns**

`mixed`

**Throws**

- [`yii\base\InvalidConfigException`](/docs/api/yii/base/invalidconfigexception/index.md): if [`$db`](/docs/api/yii/mutex/dbmutex/index.md#property-db) is not PgSQL connection.

### acquireLock() <span id="method-acquireLock"></span>

```php
protected function acquireLock(string $name, int $timeout = 0): bool
```

Acquires lock by given name.

**Parameters**

| Parameter | Type | Description |
| --- | --- | --- |
| `$name` | `string` | Of the lock to be acquired. |
| `$timeout` | `int` | Time (in seconds) to wait for lock to become released. |

**Returns**

`bool`: Acquiring result.

**See also**

- <https://www.postgresql.org/docs/current/functions-admin.html>

### releaseLock() <span id="method-releaseLock"></span>

```php
protected function releaseLock(string $name): bool
```

Releases lock by given name.

**Parameters**

| Parameter | Type | Description |
| --- | --- | --- |
| `$name` | `string` | Of the lock to be released. |

**Returns**

`bool`: Release result.

**See also**

- <https://www.postgresql.org/docs/current/functions-admin.html>