演示boost::asio::deadline_timer如何使用

 /*
 标题：演示boost::asio::deadline_timer如何使用
 作者:Kagula
 知识点：[1]boost::asio::strand实例让多根线程逐个执行
        [2]boost::asio::io_service的run会等待boost::asio::strand实例
        中的线程全部执行完毕。
 测试环境：Visual Studio 2013 Update2
 最后更新日期：2014-06-04
 */
 #include "stdafx.h"

 #include
 #include
 #include
 #include
 #include

 class printer
 {
 public:
     printer(boost::asio::io_service& io)
         : strand_(io),
         timer1_(io, boost::posix_time::seconds(1)),
         timer2_(io, boost::posix_time::seconds(1)),
         count_(0)
     {
         //boost::asio::strand::wrap()确保print1和pirnt2线程不会同时运行
         timer1_.async_wait(strand_.wrap(boost::bind(&printer::print1, this)));
         timer2_.async_wait(strand_.wrap(boost::bind(&printer::print2, this)));
     }
     ~printer()
     {
         printf("Final count is %d\n", count_);
     }
     //两个回调函数共享 count_ 变量
     void print1()
     {
         if (count_ < 10)
         {
             printf("Timer 1: %d \n", count_++);
             timer1_.expires_at(timer1_.expires_at() + boost::posix_time::seconds(1));
             timer1_.async_wait(strand_.wrap(boost::bind(&printer::print1, this)));
         }
     }
     void print2()
     {
         if (count_ < 10)
         {
             printf("Timer 2: %d \n", count_++);
             timer2_.expires_at(timer2_.expires_at() + boost::posix_time::seconds(1));
             timer2_.async_wait(strand_.wrap(boost::bind(&printer::print2, this)));
         }
     }
 private:
     boost::asio::strand strand_;
     boost::asio::deadline_timer timer1_;
     boost::asio::deadline_timer timer2_;
     int count_;
 };


 int _tmain(int argc, _TCHAR* argv[])
 {
     //等待deadline_timer实例运行完毕
     boost::asio::io_service io;
     printer p(io);
     io.run();

     return 0;
 }