TaskGroup::__construct ​

(PHP 8.6+, True Async 1.0)

public TaskGroup::__construct(?int $concurrency = null, ?Async\Scope $scope = null)

Creates a new task group.

Parameters ​

concurrency : Maximum number of concurrently running coroutines. null --- no limit, all tasks are started immediately. When the limit is reached, new tasks are placed in a queue and started automatically when a slot becomes available.

scope : Parent scope. TaskGroup creates a child scope for its coroutines. null --- the current scope is inherited.

Examples ​

Example #1 Without limits ​

<?php

use Async\TaskGroup;

$group = new TaskGroup();
$group->spawn(fn() => "task 1"); // starts immediately
$group->spawn(fn() => "task 2"); // starts immediately
$group->spawn(fn() => "task 3"); // starts immediately

Example #2 With concurrency limit ​

<?php

use Async\TaskGroup;

$group = new TaskGroup(concurrency: 2);
$group->spawn(fn() => "task 1"); // starts immediately
$group->spawn(fn() => "task 2"); // starts immediately
$group->spawn(fn() => "task 3"); // waits in queue

See Also ​

• TaskGroup::spawn --- Add a task
• Scope --- Coroutine lifecycle management