eventhandler.cpp

/*
Copyright (c) 2024 James Baker

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.

The official repository for this library is at https://github.com/VA7ODR/EasyAppBase

*/

#include "eventhandler.hpp"
#include <condition_variable>
#include <map>

namespace EventHandler
{

	static std::mutex &mtx()
	{
		static std::mutex ret;
		return ret;
	}

	static std::condition_variable & cv()
	{
		static std::condition_variable ret;
		return ret;
	}

	void EventBase::Set()
	{
		bValue = true;
		cv().notify_all();
	}

	void EventBase::Reset()
	{
		if (eType == auto_reset) {
			return;
		}
		std::unique_lock<std::mutex> lck(mtx());
		bValue = false;
	}

	const std::string &EventBase::Name()
	{
		return sName;
	}

	void EventBase::Waiting()
	{
		if (eType == auto_reset) {
			waitCount++;
		}
	}

	void EventBase::AutoReset()
	{
		if (eType == auto_reset) {
			if (waitCount && --waitCount == 0) {
				bValue = false;
			}
		}
	}

	class CleanupAfterWait
	{
		public:
			CleanupAfterWait(std::vector<Event> & vEventsIn) : vEvents(vEventsIn)
			{
				for (auto & event : vEvents) {
					event->Waiting();
				}
			}
			~CleanupAfterWait()
			{
				for (auto & event : vEvents) {
					event->AutoReset();
				}
			}
		private:
			std::vector<Event> vEvents;
	};

	static Event & ExitEvent()
	{
		static Event ret = std::make_shared<EventBase>("ExitEvent", manual_reset);
		return ret;
	}

	class Map
	{
		public:
			Map(const std::string & sFile, const std::string & sFunc, int iLine, std::vector<Event> & vEventsIn) :
				sFile(sFile),
				sFunc(sFunc),
				iLine(iLine),
				vEvents(vEventsIn)
			{
				{
					std::unique_lock<std::mutex> lck(mtx());
					static size_t nextIndex = 0;
					index = nextIndex++;
					map()[sFile][sFunc][iLine][index] = this;
				}
				// std::cout << "Waiting for " << sFile << ":" << iLine << " (" << sFunc << ") " << Map::Status() << std::endl;
			}

			~Map()
			{
				{
					std::unique_lock<std::mutex> lck(mtx());
					map()[sFile][sFunc][iLine].erase(index);
				}
				// std::cout << "Done waiting for " << sFile << ":" << iLine << " (" << sFunc << ") " << Map::Status() << std::endl;
			}

			std::string MyStatus()
			{
				std::string ret("{");
				bool bStart = true;
				for (auto & event : vEvents) {
					if (bStart) {
						bStart = false;
					} else {
						ret += ", ";
					}
					ret += event->Name() + ": " + (event->bValue ? "true" : "false");
				}
				ret.push_back('}');
				return ret;
			}

			static std::string Status();

			static std::mutex & mtx();
			static std::map<std::string, std::map<std::string, std::map<int, std::map<size_t, Map*>>>> & map();

			std::string sFile;
			std::string sFunc;
			int iLine;
			size_t index;
			std::vector<Event> & vEvents;
	};

	std::mutex & Map::mtx()
	{
		static std::mutex ret;
		return ret;
	}

	std::map<std::string, std::map<std::string, std::map<int, std::map<size_t, Map*>>>> & Map::map()
	{
		static std::map<std::string, std::map<std::string, std::map<int, std::map<size_t, Map*>>>> ret;
		return ret;
	}

	std::string Map::Status()
	{
		std::unique_lock<std::mutex> lck(mtx());
		std::string ret;
		bool bStart = true;
		for (auto & file : map()) {
			for (auto & func : file.second) {
				for (auto & line : func.second) {
					bool bStart = true;
					std::string sHeader = file.first + ":" + std::to_string(line.first) + " (" + func.first + ")";
					for (auto & index : line.second) {
						if (bStart) {
							bStart = false;
							ret += sHeader;
						} else {
							ret.append(sHeader.size(), ' ');
						}
						std::string sIndex = std::to_string(index.first);
						ret.append(32 - sIndex.size(), ' ');
						ret += sIndex + " -> " + index.second->MyStatus() + "\n";
					}
				}
			}
		}
		return ret;
	}

	int Wait(const std::string & sFile, const std::string & sFunc, int iLine, std::vector<Event> vEvents, std::chrono::milliseconds timeout)
	{
		Map map(sFile, sFunc, iLine, vEvents);
		std::unique_lock<std::mutex> lck(mtx());
		while (ExitEvent()->bValue == false) {
			CleanupAfterWait cleanup(vEvents);
			size_t i = 0;
			for (auto & e : vEvents) {
				if (e->bValue) {
					return i;
				}
			}
			if (timeout == std::chrono::milliseconds::max()) {
				cv().wait(lck, [&vEvents] { if (ExitEvent()->bValue) return true; for (auto & e : vEvents) { if (e->bValue) { return true; } } return false; });
			} else if (timeout.count() > 0) {
				bool bRet = cv().wait_for(lck, timeout, [&vEvents] { if (ExitEvent()->bValue) return true; for (auto & e : vEvents) { if (e->bValue) { return true; } } return false; });
				if (!bRet) {
					return TIMEOUT;
				}
			}
			if (ExitEvent()->bValue) {
				return EXIT_ALL;
			}
			for (auto & e : vEvents) {
				if (e->bValue) {
					return i;
				}
			}
			if (timeout.count() == 0) {
				break;
			}
		}
		return TIMEOUT;
	}

	void Set(Event e)
	{
		e->Set();
	}

	void Reset(Event e)
	{
		e->Reset();
	}

	Event CreateEvent(const std::string &sName, event_type eType)
	{
		return std::make_shared<EventBase>(sName, eType);
	}

	void ExitAll()
	{
		ExitEvent()->Set();
	}
} // EventHandler