Swoole Documents

Swoole is an high-performance network framework using an event-driven, asynchronous, non-blocking I/O model which makes it scalable and efficient. It is written in C language without 3rd party libraries as PHP extension.

It enables PHP developers to write high-performance, scalable, concurrent TCP, UDP, Unix Socket, HTTP, WebSocket services in PHP programming language without too much knowledge about non-blocking I/O programming and low-level Linux kernel.

Compared with other async programming frameworks or softwares such as Nginx, Tornado, Node.js, Swoole has the built-in async, multiple threads I/O modules. Developers can use sync or async API to write the applications.

Swoole PHP network framework enhances the efficiency of R&D team, enable them to focus on the development of innovative products.

Swoole follows the same principle as Node.js and Netty, but for PHP.

The Swoole framework is released as a PHP extension (PECL) and runs as a PHP CLI application.

Hello world

$http = new swoole_http_server("", 9501);

$http->on("start", function ($server) {
    echo "Swoole http server is started at\n";

$http->on("request", function ($request, $response) {
    $response->header("Content-Type", "text/plain");
    $response->end("Hello World\n");



  • Rapid development of high performance protocol servers & clients with PHP language
  • Event-driven, asynchronous programming for PHP
  • Both Coroutine and callback style asynchronous
  • Event loop API
  • Processes management API
  • Memory management API
  • Async TCP/UDP/HTTP/WebSocket/HTTP2 client/server side API
  • Async TCP/UDP client side API
  • Async MySQL client side API and connection pool
  • Async Redis client/server side API
  • Async DNS client side API
  • Message Queue API
  • Async Task API
  • Milliseconds scheduler
  • Async File I/O API
  • Golang style channels for inter-processes communication
  • System locks API: Filelock, Readwrite lock, semaphore, Mutex, spinlock
  • IPv4/IPv6/UnixSocket/TCP/UDP and SSL/TLS support
  • Fast serializer/unserializer

Use cases

  • Web applications and systems
  • Mobile communication systems
  • Online game systems
  • Internet of things
  • Car networking
  • Smart home systems

Swoole framework is open source and free. Released under the license of Apache 2.0.

Major change since version 4.3.0

Async clients and API are moved to a separate PHP extension swoole_async since version 4.3.0, install swoole_async:

git clone https://github.com/swoole/ext-async.git
cd ext-async
make -j 4
sudo make install

Enable it by adding a new line extension=swoole_async.so to php.ini.

Get started


Environment preparation for swoole.

Class Alias

Class Alias

Installation Guide


Swoole Modules

Swoole Server

Swoole server provides the API to write TCP / UDP / UnixSocket servers.

Swoole HTTP Server

Swoole HTTP server provides the API to write HTTP servers.

Swoole WebSocket Server

Swoole WebSocket server provides the API to write WebSocket servers.

Swoole Redis Server

Swoole Redis server provides the API to write TCP servers with Redis protocol.

Swoole TCP/UDP Client

Swoole client provides the API to write TCP/UDP/UnixSocket/HTTP clients, supports IPv4/IPv6 protocol. Developers can write sync or async client side features with swoole client API.

Swoole Process Manager

Linux process management module can be used to create new Linux process, manage the processes, and the communication between different processes.

Swoole Async File I/O

Async API includes the async File IO API, Timer, async HTTP client API, async MySQL client API, async Redis client API and async DNS client API.

Swoole MySQL Client

The swoole async MySQL client is a replacement of the other sync MySQL clients: libmysqlclient, mysqlnd, mysqli.

Swoole Redis Client

Swoole async Redis client is based on hiredis.

Swoole Async Http/WebSocket Client

Swoole Async HTTP client is a high performance and async HTTP client supports Http-Chun, Keep-Alive, form-data.

Swoole Async Http2 Client

Http2.0 client support stream and multiplexing. Multiple GET or POST request can be sent over the same TCP connection.

Swoole EventLoop

Developers can use Swoole EventLoop API to use the system EventLoop.

Swoole Scheduler

Schedule functions to run at set intervals, accurate to milliseconds.

Swoole Memory Management

Swoole provides 6 different memory operation APIs: Lock, Buffer, Table, Atomic, MMap, Channel which can be used when developing multiple process programs.

Swoole Atomic

Integer variable allows any processor to atomically test and modify. Implemented based on CPU atomic instructions.

Swoole Buffer

The memory management module enables developers managing memory like C language without worrying about memory allocation, release.

Swoole Table

Swoole table is a high performance memory management module, implemented based on shared memory and spin lock.

Swoole MMap

Swoole provides the API to use mmap for files access.

Swoole Serialize

Fast serialization for PHP.

Swoole Channel

Memory data structure likes Chan in Golang, implemented based on shared memory and Mutex locks. It can be used as high-performance message queue in memory.

Swoole Lock

Swoole locks enable PHP developers to use locks for data synchronisation between multiple threads or processes.

Swoole Coroutine

Concurrency with Swoole Conroutine.