Proposal: Native async/await Support in PHP

[pkfan]

Description

Dear PHP Internals Team,

I’d like to propose adding native async/await syntax to PHP, similar to implementations in JavaScript (ES2017+) and Python (3.5+). As modern applications increasingly rely on non-blocking I/O for scalability (e.g., APIs, microservices, real-time systems), PHP’s current reliance on third-party solutions like Swoole, ReactPHP, or AMPHP fragments the ecosystem and complicates maintenance .

Why This Matters

1. Alignment with Modern Languages:

   • JavaScript’s async/await (introduced in ES2017) simplified callback hell into linear, readable code. For example:

     async function fetchData() {
       const response = await fetch('https://api.example.com');
       return response.json();
     }

   • Python’s async/await (since 3.5) enabled seamless coroutine integration:

     async def fetch_data():
         async with aiohttp.ClientSession() as session:
             response = await session.get('https://api.example.com')
             return await response.json()

   Both languages saw widespread adoption due to developer ergonomics and performance gains .

2. PHP’s Current Limitations:

   • While Fibers (PHP 8.1+) provide low-level concurrency primitives, they lack syntactic sugar, forcing developers to manage suspension/resume manually . Libraries like AMPHP require verbose boilerplate (e.g., yield-based coroutines) compared to native keywords .
   • RFCs like True Async (under discussion) highlight community demand for standardized coroutines and cancellation APIs .

3. Performance and Scalability:

   • Non-blocking I/O can reduce latency for HTTP requests, database queries, and file operations by up to 80% (e.g., Guzzle Async vs. synchronous requests ). Native support would eliminate overhead from userland workarounds like pcntl_fork or exec() .

Proposed Syntax

async function fetchData(): Awaitable<string> {
    $response = await $httpClient->getAsync('https://api.example.com');
    return $response->getBody();
}

Key features to consider:

• Awaitable Type: A return type hint for async functions (analogous to JavaScript’s Promise or Python’s Coroutine).
• Structured Concurrency: Integrate with RFC proposals like scoped coroutines and cancellation tokens .
• Backward Compatibility: Allow gradual adoption by interoperating with Fibers and existing event loops (e.g., ReactPHP) .

Next Steps

1. Discuss feasibility and syntax details on the mailing list.
2. Reference prior art:
   • JavaScript’s Async Functions
   • Python’s asyncio
   • PHP’s Fibers RFC and True Async RFC .

This would position PHP as a competitive choice for modern, high-performance applications. Thank you for considering!

[iluuu1994]

Hi @pkfan. See https://wiki.php.net/rfc/true_async. PHP will likely never add colored async/await functionality. The linked RFC does provide some helper functions that syntactically mimic syntax you may know from JS or other languages.