WorkerRuntimeCapabilities

What a WorkerRuntimeInterface can and cannot do, so the shared WorkerLoop knows which compensations to install rather than every runtime re-deciding.

The distinction that matters most is $populatesSuperglobals + $sapiOutput: a real SAPI (php-fpm, php -S, FrankenPHP) refills $_SERVER/$_GET/… per request and lets header()/echo reach the client, while a CLI-hosted server (RoadRunner, Swoole) does neither — it hands over a request object and takes a response object. Everything the loop does to bridge that gap (superglobal hydration, output capture, native session-cookie synthesis) keys off these two flags.

Synopsis

final readonly class WorkerRuntimeCapabilities

Source	Runtime/Worker/WorkerRuntimeCapabilities.php

Properties

Property	Type	Description
$forksWorkers	bool	readonly.
$persistent	bool	readonly.
$populatesSuperglobals	bool	readonly.
$sapiOutput	bool	readonly.
$streaming	bool	readonly.

Constructor

__construct()

public function __construct(bool $persistent, bool $populatesSuperglobals, bool $sapiOutput, bool $streaming, bool $forksWorkers): mixed

Worker processes are forked after bootstrap, so bootWorker() must run per child.

Parameter	Type	Description
$persistent	bool	The process survives across requests, so per-request state must be reset.
$populatesSuperglobals	bool	The runtime fills $_SERVER/$_GET/$_POST/$_COOKIE/$_FILES itself.
$sapiOutput	bool	echo/header()/http_response_code() reach the client.
$streaming	bool	The response body can be flushed incrementally (SSE).
$forksWorkers	bool	Worker processes are forked after bootstrap, so bootWorker() must run per child.

Returns mixed

Methods

Method	Description
sapi(bool $persistent = false): WorkerRuntimeCapabilities	The classic single-request SAPI shape: nothing persists, the SAPI owns input and output.

sapi()

public static function sapi(bool $persistent = false): WorkerRuntimeCapabilities

The classic single-request SAPI shape: nothing persists, the SAPI owns input and output.

Also the correct answer for a FrankenPHP worker apart from $persistent, hence the parameter.

Parameter	Type	Description
$persistent	bool

Returns WorkerRuntimeCapabilities