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