Sztuczki bez prawdziwej asychroniczności

Subshell

How to run a shell command with a sub shell with PHP's exec?Stack Overflow

curl_multi

PHP: curl_multi_exec - Manual

guzzle async

Guzzle, PHP HTTP client — Guzzle Documentation

mysqli::reap_asyc_query

PHP: mysqli::reap_async_query - Manual

yield / generators

Fibres

PHP: rfc:fibers