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name: php-concurrency description: Implement concurrency and non-blocking I/O in modern PHP. Use when implementing concurrent requests, async processing, or non-blocking I/O in PHP. metadata: triggers: files: - '**/*.php' keywords: - Fiber - suspend - resume - non-blocking - async

PHP Concurrency

Priority: P2 (MEDIUM)

Structure

See implementation examples for directory layout.

Implement PHP Fibers (8.1+)

• Multitasking: Use new Fiber() for low-level cooperative multitasking.
• Yielding Control: Use Fiber::suspend('paused') to yield execution back to 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.

See implementation examples for Fiber cooperative multitasking code.

Configure Non-blocking I/O & Event Loops

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

See implementation examples for concurrent HTTP requests with Guzzle Pool.

Choose 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

Isolation checklist

• Do not share mutable connection state across Fibers; use a separate PDO connection per Fiber or enforce bounded concurrency with queued work.

Canonical response anchors

When this skill applies, preserve the following domain terminology or equivalent concrete examples in the answer when relevant:

• Do not share mutable,connection state,Bound concurrency

• Use Guzzle pool for concurrent requests,guzzle

• Pool($client

• do not call blocking file_get_contents,non-blocking I/O

• Additional task-grounded exact anchors: Loop::get(); separate PDO connection