ComponentsThreadPool::isClosed()

ThreadPool::isClosed() ​

(PHP 8.6+, True Async 1.0)

php
public ThreadPool::isClosed(): bool

Returns true if the pool has been shut down via close() or cancel(). Returns false while the pool is still accepting tasks.

Return Value ​

bool — true if the pool is closed; false if it is still active.

Examples ​

Example #1 Checking state before submitting ​

php
<?php

use Async\ThreadPool;
use function Async\spawn;
use function Async\await;

spawn(function() {
    $pool = new ThreadPool(workers: 2);

    $future = $pool->submit(fn() => 'done');

    var_dump($pool->isClosed()); // bool(false)

    $pool->close();

    var_dump($pool->isClosed()); // bool(true)

    echo await($future), "\n"; // done
});

Example #2 Guarding submit in shared contexts ​

php
<?php

use Async\ThreadPool;
use function Async\spawn;
use function Async\await;

function trySubmit(ThreadPool $pool, callable $task): mixed
{
    if ($pool->isClosed()) {
        return null;
    }
    return await($pool->submit($task));
}

spawn(function() {
    $pool = new ThreadPool(workers: 2);
    echo trySubmit($pool, fn() => 'hello'), "\n"; // hello
    $pool->close();
    var_dump(trySubmit($pool, fn() => 'missed')); // NULL
});

See Also ​