Pool::acquire

(PHP 8.6+, True Async 1.0)

public Pool::acquire(int $timeout = 0): mixed

Acquires a resource from the pool. If no free resources are available and the maximum limit has been reached, the coroutine blocks until a resource becomes available.

If the pool has a free resource, it is returned immediately. If there are no free resources but the max limit has not been reached, a new resource is created via factory. Otherwise, the call waits for a resource to be released.

Parameters

timeout: Maximum wait time in milliseconds. 0 — wait indefinitely. If the timeout is exceeded, a PoolException is thrown.

Return Value

Returns a resource from the pool.

Errors

Throws Async\PoolException if:

The wait timeout is exceeded.
The pool is closed.

Examples

Example #1 Basic usage

<?php

use Async\Pool;

$pool = new Pool(
    factory: fn() => new PDO('mysql:host=localhost;dbname=app', 'user', 'pass'),
    max: 5
);

// Get a connection (waits if necessary)
$conn = $pool->acquire();

try {
    $stmt = $conn->prepare('SELECT * FROM users WHERE id = ?');
    $stmt->execute([42]);
    $user = $stmt->fetch();
} finally {
    $pool->release($conn);
}

Example #2 With timeout

<?php

use Async\Pool;
use Async\PoolException;

$pool = new Pool(
    factory: fn() => new PDO('mysql:host=localhost;dbname=app', 'user', 'pass'),
    max: 2
);

try {
    $conn = $pool->acquire(timeout: 5000); // wait no more than 5 seconds
    // work with connection...
    $pool->release($conn);
} catch (PoolException $e) {
    echo "Failed to acquire resource: {$e->getMessage()}\n";
}

Documentation