学步园

一、同步定时器

1.1 代码

#include <iostream>
using namespace std;

#include <boost/asio.hpp>
#include <boost/date_time/posix_time/posix_time.hpp>
using namespace boost;
using namespace boost::asio;


int main(int argc, char*argv[])
{
	io_service ios;
	deadline_timer t(ios, posix_time::seconds(3));

	cout<<t.expires_from_now()<<", "<<t.expires_at()<<endl;

	t.wait();
	cout<<"hello"<<endl;
	
	return 0;
}

1.2 结果

二、异步定时器

2.1 代码

#include <iostream>
using namespace std;

#include <boost/asio.hpp>
#include <boost/date_time/posix_time/posix_time.hpp>
using namespace boost;
using namespace boost::asio;

void print(const system::error_code& e)
{
	cout<<"async hello."<<endl;
}

int main(int argc, char*argv[])
{
	io_service ios;
	deadline_timer t(ios, posix_time::seconds(3));

	t.async_wait(print);

	ios.run();
	
	return 0;
}

2.2 结果

三、异步定时器使用bind

3.1 代码

#include <iostream>
using namespace std;

#include <boost/asio.hpp>
#include <boost/date_time/posix_time/posix_time.hpp>
#include <boost/bind.hpp>
using namespace boost;
using namespace boost::asio;

class a_timer
{
public:
	template<typename F>
	a_timer(io_service &ios, int c, F func) : count(0), max_count(c), t(ios, posix_time::millisec(500)), f(func)
	{
		t.async_wait(boost::bind(&a_timer::func_proc, this, boost::asio::placeholders::error));
	}

	void func_proc(const system::error_code& e)
	{
		if(count >= max_count)
			return;

		++count;

		f();

		t.expires_at(t.expires_at() + posix_time::millisec(500));
		t.async_wait(boost::bind(&a_timer::func_proc, this, boost::asio::placeholders::error));
	}

private:
	int count, max_count;
	deadline_timer t;
	boost::function<void ()> f;
};

void print1()
{
	cout<<"timer 1."<<endl;
}

void print2()
{
	cout<<"timer 2."<<endl;
}

int main(int argc, char*argv[])
{
	io_service ios;
	a_timer a1(ios, 5, print1);
	a_timer a2(ios, 3, print2);
	ios.run();
	
	return 0;
}

3.2 结果

参考资料：

      《Boost程序库完全开发指南》    12.2.2 节和12.2.3节    （P507）