I don't know much about it, but I've heard here and there about Swoole, a "PHP extension for Async IO, Coroutines and Fibers".
> Swoole is a complete PHP async solution that has built-in support for async programming via fibers/coroutines, a range of multi-threaded I/O modules (HTTP Server, WebSockets, TaskWorkers, Process Pools) and support for popular PHP clients like PDO for MySQL, Redis and CURL.
> Swoole is a complete PHP async solution that has built-in support for async programming via fibers/coroutines, a range of multi-threaded I/O modules (HTTP Server, WebSockets, TaskWorkers, Process Pools) and support for popular PHP clients like PDO for MySQL, Redis and CURL.
https://www.swoole.co.uk/