異步事件處理庫 libevent

libevent是一個異步事件處理軟件函式庫，libevent提供了一組應用程序編程接口（API），讓程式設計師可以設定某些事件發生時所執行的函式，也就是說，libevent可以用來取代網絡服務器所使用的循環檢查架構。

由于可以省去對網絡的處理，且擁有不錯的效能，有些軟件使用libevent作為網絡底層的函式庫，如：memcached、Tor。
以下這些項目證明了libevent的API非常實用：

• Chromium – Google's open-source web browser (uses Libevent on Mac and Linux)
• Memcached – a high-performance, distributed memory object caching system
• Transmission – a fast, easy, and free BitTorrent client
• NTP – the network time protocol that makes your clock right (uses Libevent in SNTP)
• tmux – A clean, modern, BSD-licensed terminal multiplexer, similar to GNU screen
• Tor – an anonymous Internet communication system.
• libevhtp – A fast and flexible replacement for libevent's httpd API
• Prosody – A Jabber/XMPP server written in Lua
• PgBouncer – Lightweight connection pooler for PostgreSQL
• redsocks – a simple transparent TCP -> Socks5/HTTPS proxy daemon.
• Vomit – Voice Over Misconfigured Internet Telephones
• Crawl – A Small and Efficient HTTP Crawler
• Libio – an input/output abstraction library
• Honeyd – a virtual honeynet daemon – can be used to fight Internet worms.
• Fragroute – an IDS testing tool
• Nylon – nested proxy server
• Disconcert – a Distributed Computing Framework for Loosely-Coupled Workstations.
• Trickle – a lightweight userspace bandwidth shaper.
• watchcatd – software watchdog designed to take actions not as drastic as the usual solutions, which reset the machine.
• ScanSSH – a fast SSH server and open proxy scanner.
• Nttlscan – a network topology scanner for Honeyd.
• NetChat – a combination of netcat and ppp's chat.
• Io – a small programming language; uses libevent for network communication.
• Systrace – a system call sandbox.
• SpyBye – detect malware on web pages.
• GreenSQL – an SQL database firewall.
• dnsscan – a fast scanner for identifying open recursive dns resolvers
• Kargo Event – a PHP extension for libevent.
• wlmproxy – a transparent proxy server for the MSN Messenger protocol

項目主頁：http://www.baiduhome.net/lib/view/home/1324994535327