记录灵感、技术、思考

笔记:Sinatra源码踹门

•

版本： sinatra git:(72be291d)

有趣的点

  1. 启动时间点 竟然在 at_exit
# lib/sinatra.rb

at_exit do
  Sinatra::Server.new.start unless Sinatra::Server.running
end

at_exit 他是让程序在脚本执行结束的时候执行的。

  1. Trap
# ....
  class Server
    # ....
    def start
      begin
        Rack::Handler::Mongrel.run(Sinatra::Dispatcher.new, :Port => 4567) do |server|
          logger.info "== Sinatra has taken the stage on port #{server.port}!"
          trap("INT") do
            server.stop
            self.class.running = false
            logger.info "\n== Sinatra has ended his set (crowd applauds)"
          end
        end
        self.class.running = true
      rescue => e
        logger.exception e
      end
    end
  end

# ....

trap 专门用于处理系统信号

详细可以参考 《理解Unix进程》16.9 Page 64

  trap("INT") do
    server.stop
    self.class.running = false
    logger.info "\n== Sinatra has ended his set (crowd applauds)"
  end

trap在这里是重新定义信号，做一些响应信号之前的工作。而 INT 是 SIGINT 信号名字,可以在 Linux上查看

kill -l 列出所有信号

man kill 然后搜索 INT


2       INT (interrupt)
3       QUIT (quit)
6       ABRT (abort)
9       KILL (non-catchable, non-ignorable kill)
14      ALRM (alarm clock)
15      TERM (software termination signal)

INT就是 Ctrl+C 是中断的意思。

所以这里中断对中断信号做了处理。

Mark24

Everything can Mix.