Pool::close

Close the pool and destroy all resources.

Pool::close ​

(PHP 8.6+, True Async 1.0)

php
public Pool::close(): void

Closes the resource pool. All idle resources are destroyed via the destructor (if one was provided). All coroutines waiting for a resource via acquire() receive a PoolException. After closing, any calls to acquire() and tryAcquire() throw an exception.

Parameters ​

This method takes no parameters.

Return Value ​

No value is returned.

Examples ​

Example #1 Graceful shutdown ​

php
<?php

use Async\Pool;

$pool = new Pool(
    factory: fn() => new PDO('mysql:host=localhost;dbname=app', 'user', 'pass'),
    destructor: function(PDO $pdo): void {
        // Close all prepared statements and connection
    },
    min: 2,
    max: 10
);

// ... work with the pool ...

// Close the pool when the application shuts down
$pool->close();

Example #2 Waiting coroutines receive an exception ​

php
<?php

use Async\Pool;
use Async\PoolException;

$pool = new Pool(
    factory: fn() => new \stdClass(),
    max: 1
);

$resource = $pool->acquire(); // took the only resource

spawn(function() use ($pool) {
    try {
        $pool->acquire(); // waiting for release
    } catch (PoolException $e) {
        echo "Pool closed: {$e->getMessage()}\n";
    }
});

$pool->close(); // waiting coroutine will receive PoolException

See Also ​