Overview
KB
Technical FAQ
PHP Manual
CSS2 Manual
HTML Manual
JS Guide
JS Reference
PhpDock Manual
Nu-Coder Manual
PhpExpress Manual
PHP Joomla
Development
Learn PHP
 
<PoolPool::__construct>
^PoolLast updated: Mon, 26 Oct 2026

Pool::collect

(PECL pthreads >= 2.0.0)

Pool::collect — Collect references to completed tasks

Description

public function Pool::collect(Callable $collector = ?): int

Allows the pool to collect references determined to be garbage by the optionally given collector.

Parameters

collector

A Callable collector that returns a boolean on whether the task can be collected or not. Only in rare cases should a custom collector need to be used.

Return Values

The number of remaining tasks in the pool to be collected.

Changelog

Version Description
PECL pthreads 3.0.0 An integer is now returned, and the collector parameter is now optional.

Examples

Example #1 A basic example of Pool::collect()

<?php
$pool = new Pool(4);

for ($i = 0; $i < 15; ++$i) {
    $pool->submit(new class extends Threaded {});
}

while ($pool->collect()); // blocks until all tasks have finished executing

$pool->shutdown();

<PoolPool::__construct>
^PoolLast updated: Mon, 26 Oct 2026