boost 对称协程symmetric_coroutine

boost 提供了两种协程类型：对称协程（symmetric_coroutine）和非对称协程（asymmetric_coroutine）。

以下示例演示 symmetric_coroutine 的基本用法，分别创建一个收协程和一个发协程，两者交替切换执行：

#include "boost_1_60_0/boost/coroutine/coroutine.hpp"

int main()
{
	using   Coroutine_t = boost::coroutines::symmetric_coroutine<int>;

	Coroutine_t::call_type coro_recv(
		[&](Coroutine_t::yield_type& yield) {
		//loop for recv
		for (;;)
		{
			std::cout << yield.get() << " recv" << endl;
			yield(); //give up time  slice and jump back to starting context
		}
	});

	Coroutine_t::call_type coro_send(
		[&](Coroutine_t::yield_type& yield) {
		//loop for send
		for (;;)
		{
			yield.get();
			std::cout << yield.get() << " send" << endl;
			yield();
		}
	});


	while (true)
	{
		coro_recv(1); //recv

		coro_send(1); // send

	}

	system("pause");

	return 0;
}

此外，可以结合 ASIO 的定时器与协程来完成定时任务。以下示例创建两个协程，分别以 1 秒和 500 毫秒为间隔轮询执行：

#include "boost_1_60_0/boost/asio/steady_timer.hpp"
#include "boost_1_60_0/boost/asio/spawn.hpp"
int main()
{
	boost::asio::io_service io;

	boost::asio::steady_timer timer(io);
	using namespace boost::asio;


	//协程1
	spawn(io, [&](yield_context yield) {
		while (true)
		{
			boost::asio::steady_timer timer(io);
			timer.expires_from_now(std::chrono::seconds(1));
			timer.async_wait(yield);

			cout << "1111111111" << endl;;
		}
	});

	//协程2
	spawn(io, [&](yield_context yield) {
		while (true)
		{
			boost::asio::steady_timer timer(io);
			timer.expires_from_now(std::chrono::milliseconds(500));
			timer.async_wait(yield);

			cout << "22222222222"<<endl;
		}
	});


	io.run();//



	while (true)
	{
		Sleep(100);
	}


	system("pause");

	return 0;
}