Pool::idleCount

Number of idle resources in the pool.

Pool::idleCount ​

(PHP 8.6+, True Async 1.0)

php
public Pool::idleCount(): int

Returns the number of idle (unused) resources that are ready to be acquired.

Parameters ​

This method takes no parameters.

Return Value ​

The number of idle resources in the pool.

Examples ​

Example #1 Tracking idle resources ​

php
<?php

use Async\Pool;

$pool = new Pool(
    factory: fn() => new PDO('mysql:host=localhost;dbname=app', 'user', 'pass'),
    min: 3,
    max: 10
);

echo $pool->idleCount() . "\n"; // 3

$conn = $pool->acquire();
echo $pool->idleCount() . "\n"; // 2

$pool->release($conn);
echo $pool->idleCount() . "\n"; // 3

Example #2 Adaptive strategy ​

php
<?php

use Async\Pool;

$pool = new Pool(
    factory: fn() => createExpensiveResource(),
    min: 1,
    max: 20
);

// If few idle resources remain — reduce load
if ($pool->idleCount() < 2 && $pool->count() >= 18) {
    echo "Warning: pool is nearly exhausted\n";
}

See Also ​