php-concurrency

name	php-concurrency
description	Handling concurrency and non-blocking I/O in modern PHP. Use when implementing concurrent requests, async processing, or non-blocking I/O in PHP. (triggers: **/*.php, Fiber, suspend, resume, non-blocking, async)

PHP Concurrency

Priority: P2 (MEDIUM)

Structure

src/
└── Async/
    ├── Schedulers/
    └── Clients/

Implementation Guidelines

PHP Fibers (8.1+)

• Multitasking: Use new Fiber() for low-level cooperative multitasking.
• Yielding Control: Use Fiber::suspend('paused') to yield execution back to the caller.
• Resuming: Call $fiber->resume('hello') to continue execution. Catch exceptions via $fiber->getReturn().
• Isolation: Use separate PDO connections per Fiber to avoid shared mutable state.

Non-blocking I/O & Event Loops

• Loop Setup: Use ReactPHP or Amp. Call Loop::get() to access the event loop.
• HTTP Clients: Use react/http or the Guzzle Pool($client, ...) for concurrent requests.
• I/O Safety: Never use blocking file_get_contents or sleep() inside a Fiber or EventLoop.
• Entry Point: Run Loop::run() at your application entry point to start the async loop.

Concurrency Strategies

• Queued Jobs: For heavy concurrency, prefer Laravel Horizon or Symfony Messenger over raw PHP Fibers.
• Self-Contained Logic: Ensure Fibers manage their own state and exceptions to prevent cross-contamination.

Anti-Patterns

• No deeply nested Fiber suspends: Keep Fiber logic traceable.
• No blocking I/O inside Fibers: Use async-compatible libraries.
• No custom scheduler code: Use Amp or ReactPHP instead.

References

• Fiber Implementation Guide