Deliver/include/SyncEvent.hpp

#pragma once

#include <condition_variable>
#include <mutex>
#include <chrono>


//-----------------------------------------------------------------------------
//		SyncEvent
//-----------------------------------------------------------------------------

namespace SyncEvent
{
	class _Base
	{
	protected:
		bool m_bEvent = false;
		std::mutex m_EventMutex;
		std::condition_variable m_EventCond;

	protected:
		_Base ()
		{
			m_bEvent = false;
		}

	public:
		void Set ()
		{
			m_bEvent = true;
			m_EventCond.notify_all ();
		}

		void Reset ()
		{
			m_bEvent = false;
		}

		void Pulse ()
		{
			m_bEvent = false;
			m_bEvent = true;
			m_EventCond.notify_all ();
		}

//		用于测试
		void _SetOne ()
		{
			m_bEvent = true;
			m_EventCond.notify_one ();
		}
	};


	//-----------------------------------------------------------------------------
	//		Manual
	//-----------------------------------------------------------------------------

	class Manual : public _Base
	{
	public:
		using _Base::_Base;

	public:
		void Wait ()
		{
			std::unique_lock <std::mutex> lk (m_EventMutex);
			m_EventCond.wait (lk, [this] () { return m_bEvent; });
		}

		//	返回 true : 确实等到了事件通知
		//	返回 false: 超时
		bool Wait (const std::chrono::milliseconds & dur)
		{
			std::unique_lock <std::mutex> lk (m_EventMutex);
			auto rc = m_EventCond.wait_for (lk, dur, [this] () { return m_bEvent; });
			return rc;
		}
	};


	//-----------------------------------------------------------------------------
	//		Auto
	//-----------------------------------------------------------------------------

	class Auto : public _Base
	{
	public:
		using _Base::_Base;

	public:
		void Wait ()
		{
			std::unique_lock <std::mutex> lk (m_EventMutex);
			m_EventCond.wait (lk, [this] ()
				{
					if (! m_bEvent)  return false;
					m_bEvent = false;
					return true;
				});
		}

		//	返回 true : 确实等到了事件通知
		//	返回 false: 超时
		bool Wait (const std::chrono::milliseconds & dur)
		{
			std::unique_lock <std::mutex> lk (m_EventMutex);
			auto rc = m_EventCond.wait_for (lk, dur, [this] ()
				{
					if (! m_bEvent)  return false;
					m_bEvent = false;
					return true;
				});

			return rc;
		}
	};

}



/*//-----------------------------------------------------------------------------
	Manual 类型:
	 - 在 Set 之后, 所有的 Wait 线程都得到解锁, 开始执行下一步
	 - 再次 Wait 之前, 必须手动调用 Reset, 否则 Wait 直接返回 (相当于直接解锁)

	Auto 类型:
	 - 在 Set 之后, 所有 Wait 线程中只有 1 个得到解锁, 开始执行下一步
	 - 可以随时 Wait, 无需手动调用 Reset

*///-----------------------------------------------------------------------------


/*//-----------------------------------------------------------------------------
	测试代码:

static int  THTest (int num)
{
	time_t t;
	time (& t);
	printf ("%d enter at %s", num, ctime (&t));

	evt.Wait ();
	time (& t);
	printf ("%d.1 -   at %s ", num, ctime (&t));

	evt.Reset ();

	evt.Wait ();
	time (& t);
	printf ("%d.2 -   at %s ", num, ctime (&t));

	evt.Wait ();
	time (& t);
	printf ("%d.3 -   at %s ", num, ctime (&t));

	time (& t);
	printf ("%d exit  at %s", num, ctime (&t));

	return num;
}

static void SyncTest ()
{
	std::thread (THTest, 12).detach ();
	std::thread (THTest, 34).detach ();
	std::thread (THTest, 56).detach ();
	std::thread (THTest, 78).detach ();

	for (int Index = 0; Index < 20; Index++)
	{
//		printf ("--> ");
		Sleep (1000);
		evt.Set ();
	}
}


如果是 SyncEvent::Manual evt, 则输出如下:

78 enter at 21:30:11 2020
34 enter at 21:30:11 2020
56 enter at 21:30:11 2020
12 enter at 21:30:11 2020

12.1 -   at 21:30:12 2020
56.1 -   at 21:30:12 2020
34.1 -   at 21:30:12 2020
78.1 -   at 21:30:12 2020

34.2 -   at 21:30:13 2020
34.3 -   at 21:30:13 2020
56.2 -   at 21:30:13 2020
12.2 -   at 21:30:13 2020
78.2 -   at 21:30:13 2020
34 exit  at 21:30:13 2020
56.3 -   at 21:30:13 2020
12.3 -   at 21:30:13 2020
78.3 -   at 21:30:13 2020
78 exit  at 21:30:13 2020
56 exit  at 21:30:13 2020
12 exit  at 21:30:13 2020



如果是 SyncEvent::Auto evt, 则输出如下

12 enter at 21:41:26 2020
78 enter at 21:41:26 2020
56 enter at 21:41:26 2020
34 enter at 21:41:26 2020

34.1 -   at 21:41:27 2020
56.1 -   at 21:41:28 2020
12.1 -   at 21:41:29 2020
78.1 -   at 21:41:30 2020
12.2 -   at 21:41:31 2020
78.2 -   at 21:41:32 2020
56.2 -   at 21:41:33 2020
56.3 -   at 21:41:34 2020
56 exit  at 21:41:34 2020
34.2 -   at 21:41:35 2020
12.3 -   at 21:41:36 2020
12 exit  at 21:41:36 2020
78.3 -   at 21:41:37 2020
78 exit  at 21:41:37 2020
34.3 -   at 21:41:38 2020
34 exit  at 21:41:38 2020


*///-----------------------------------------------------------------------------