嵌入式软件异步编程：应用案例

异步编程有很多成功的应用，例如lwIP、Nginx、Node.js、Linux AIO、JavaScript等。可以将这些成功案例的设计经验引入到嵌入式软件。

lwIP

The raw TCP/IP interface allows the application program to integrate better with the TCP/IP code. Program execution is event based by having callback functions being called from within the TCP/IP code.

The raw TCP/IP interface is not only faster in terms of code execution time but is also less memory intensive.

​​lwIP​​​​lwIP@wikipedia​​

​​《基于回调的lwIP raw API》​​

Nginx

Nginx uses an asynchronous event-driven approach to handling requests. Nginx’s modular event-driven architecture can provide more predictable performance under high loads.

​​Nginx​​​​Nginx@wikipedia​​

​​《深入理解Nginx：模块开发与架构解析（第2版） 》​​

• 第8章　Nginx基础架构

• 8.2　Nginx的架构设计

• 8.2.2　事件驱动架构
• 8.2.3　请求的多阶段异步处理

Node.js

Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient.

​​Node.js​​​​Node.js@wikipedia​​

​​《深入浅出Node.js》​​

• 第 3 章　异步I/O
• 第 4 章　异步编程

Linux AIO

使用异步 I/O 可以帮助我们构建 I/O 速度更快、效率更高的应用程序。如果我们的应用程序可以对处理和 I/O 操作重叠进行，那么 AIO 就可以帮助我们构建可以更高效地使用可用 CPU 资源的应用程序。

​​《使用异步 I/O 大大提高应用程序的性能》​​

JavaScript

​​《JavaScript异步编程：设计快速响应的网络应用》​​

• 第1章 深入理解JavaScript事件
• 第2章 分布式事件

​​《你不知道的JavaScript（中卷）》​​

• 第二部分　异步和性能
• 第 1 章　异步：现在与将来
• 第 2 章　回调

libevent

The libevent API provides a mechanism to execute a callback function when a specific event occurs on a file descriptor or after a timeout has been reached. Furthermore, libevent also support callbacks due to signals or regular timeouts.

libev

A full-featured and high-performance event loop that is loosely modelled after libevent, but without its limitations and bugs.

libuv

Node.js 用的就是libuv。

libuv is a multi-platform support library with a focus on asynchronous I/O.

Redis