Amp is a set of seamlessly integrated concurrency libraries for PHP based on [Revolt](https://revolt.run/). This package provides futures and cancellations as a base for asynchronous programming. Amp makes heavy use of fibers shipped with PHP 8.1 to write asynchronous code just like synchronous, blocking code. In contrast to earlier versions, there's no need for generator based coroutines or callbacks. Similar to threads, each fiber has its own call stack, but fibers are scheduled cooperatively by the event loop. Use `Amp\async()` to run things concurrently. ## Motivation Traditionally, PHP has a synchronous execution flow, doing one thing at a time. If you query a database, you send the query and wait for the response from the database server in a blocking manner. Once you have the response, you can start doing the next thing. Instead of sitting there and doing nothing while waiting, we could already send the next database query, or do an HTTP call to an API. Making use of the time we usually spend on waiting for I/O can speed up the total execution time. The following diagram shows the execution flow with dependencies between the different tasks, once executed sequentially and once concurrently.  Amp allows such concurrent I/O operations while keeping the cognitive load low by avoiding callbacks. Instead, the results of asynchronous operations can be awaited using `Future::await()` resulting in code which is structured like traditional blocking I/O code. ## Installation This package can be installed as a [Composer](https://getcomposer.org/) dependency. ```bash composer require amphp/amp ``` If you use this library, it's very likely you want to schedule events using [Revolt's event loop](https://revolt.run), which you should require separately, even if it's automatically installed as a dependency. ```bash composer require revolt/event-loop ``` These packages provide the basic building blocks for asynchronous applications in PHP. We offer a lot of repositories building on top of these repositories, e.g. - [`amphp/byte-stream`](https://github.com/amphp/byte-stream) providing a stream abstraction - [`amphp/socket`](https://github.com/amphp/socket) providing a socket layer for UDP and TCP including TLS - [`amphp/parallel`](https://github.com/amphp/parallel) providing parallel processing to utilize multiple CPU cores and offload blocking operations - [`amphp/http-client`](https://github.com/amphp/http-client) providing an HTTP/1.1 and HTTP/2 client - [`amphp/http-server`](https://github.com/amphp/http-server) providing an HTTP/1.1 and HTTP/2 application server - [`amphp/mysql`](https://github.com/amphp/mysql) and [`amphp/postgres`](https://github.com/amphp/postgres) for non-blocking database access - and [many more packages](https://github.com/amphp?type=source) ## Documentation Documentation can be found on [amphp.org](https://amphp.org/) as well as in the [`./docs`](./docs) directory. Each packages has it's own `./docs` directory. ## Requirements This package requires PHP 8.0 (with [`ext-fiber`](https://github.com/amphp/ext-fiber)), or PHP 8.1 or later. No extensions required! ##### Optional Extensions [Extensions](https://revolt.run/extensions) are only needed if your app necessitates a high numbers of concurrent socket connections, usually this limit is configured up to 1024 file descriptors. ## Versioning `amphp/amp` follows the [semver](http://semver.org/) semantic versioning specification like all other `amphp` packages. ## Compatible Packages Compatible packages should use the [`amphp`](https://github.com/search?utf8=%E2%9C%93&q=topic%3Aamphp) topic on GitHub. ## Security If you discover any security related issues, please email [`me@kelunik.com`](mailto:me@kelunik.com) instead of using the issue tracker. ## License The MIT License (MIT). Please see [`LICENSE`](./LICENSE) for more information.