[php-src] Issue #19026: Proposal: Native async/await Support in PHP

Issue: https://github.com/php/php-src/issues/19026 Author: 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: ```javascript 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: ```python 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** ```php 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](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/async_function) - Python’s [asyncio](https://docs.python.org/3/library/asyncio.html) - PHP’s [Fibers RFC](https://wiki.php.net/rfc/fibers) and [True Async RFC](#) . This would position PHP as a competitive choice for modern, high-performance applications. Thank you for considering!