Quick Crash Course into Swoole for WLP3 Plugin Developers

May 17, 2025

Written as extension of https://www.reddit.com/r/WhitelabelPress/comments/1koubo8/new_abilities_for_the_daring_plugin_developer/

🐉 “Swoole is really a new type of BEAST!”

Swoole fundamentally changes the PHP execution model from per-request stateless to long-running processes, bringing async I/O, coroutines, and performance on par with Node.js or Go. It’s a whole different paradigm from traditional PHP.

📦 “Every require/require_once choice matters.”

In Swoole:

• Files are not reloaded per request like traditional PHP (which starts fresh on each HTTP request).
• Once included in a worker process, a file required once remains in memory until the process is restarted.
• Mistakes (like requiring a dev-only script globally) persist across requests and can cause memory leaks or unexpected behavior.

This forces you to be deliberate about where and when you load code.

♻️ “Resetting static/global objects for each request is a must.”

Because Swoole reuses worker processes:

• Global/static variables persist across requests, unlike traditional PHP.
• If you’re not careful, you can leak state between requests (user sessions, input data, temporary config, etc.).
• This is one of the biggest gotchas and the #1 reason people get bitten by unexpected bugs in Swoole.

Swoole encourages (and requires) a more disciplined, stateless mindset — like writing microservices in Node.js or Go.

🍪 “Cookies/redirects/die/exit statements work differently.”

• die/exit: Still terminates the current function, but because of the async/coroutine model, if misused, it may interfere with expected cleanup or coroutine execution.
• setcookie() and headers: Must be sent explicitly using the Swoole response object ($response->header(), $response->cookie()). Native PHP setcookie() won’t work outside of certain runtime modes.
• Redirects: You handle them manually using $response->status(302) and $response->header('Location', '...').
• So yes, many classic PHP mechanisms don’t behave the same way or are not available at all — you need to use Swoole’s APIs instead.

🌱 “It weirdly forces you to become a better developer.”

You’re forced to:

• Think about memory and state.
• Write cleaner, more modular, stateless code.
• Use dependency injection and reset object state.
• Embrace async programming, which broadens your skillset.

It’s a crash course in systems-level, long-running app design — in PHP!

🚀 “It’s insanely fast + more scalable compared to classic PHP with NGINX/Apache2”

Compared to traditional setups:

• No PHP-FPM overhead per request
• No process spawning for every page hit
• Fully async (non-blocking) I/O with coroutines
• Ideal for real-time apps (WebSockets, TCP servers, etc.)

Swoole apps can handle thousands of concurrent connections with less CPU and memory overhead than traditional stacks.

Neil

Lead dev @ WLP (WhiteLabelPress)