threading.cpp

// threaded-file-read.cpp : This file contains the 'main' function. Program execution begins and ends there.
//

#include <thread>
#include <iostream>
#include <vector>
#include <functional>
#include <fstream>
#include <string>

#define _SILENCE_EXPERIMENTAL_FILESYSTEM_DEPRECATION_WARNING

#include <experimental/filesystem>
#include <filesystem>

namespace fs = std::experimental::filesystem::v1;

const int THREAD_POOL_SIZE = 32;

class FileThread
{
public:
	FileThread(int threadID, void (*function)(FileThread*), std::string path) : threadID(threadID), function(function), path(path)
	{
		thread = std::thread(function, this);
	}

	void (*function)(FileThread*);
	std::thread thread;
	std::string path;
	bool complete = false;
	int threadID = 0;
};

void threadFunc(FileThread* callThread)
{
	int a = 0;

	std::ifstream ifs;
	ifs.open(callThread->path, std::ifstream::in);

	std::string line;

	while (ifs.good())
	{
		std::getline(ifs, line);
	}

	ifs.close();
	
	callThread->complete = true;
}

void initializeThreadPool(std::vector<FileThread*>& pool, const std::vector<std::string>& filePaths)
{
	for (int i = 0; i < THREAD_POOL_SIZE; i++)
		pool.push_back(new FileThread(i, threadFunc, filePaths[i]));
}

int main()
{
	std::vector<FileThread*> pool;
	std::vector<std::string> filePaths;
	std::string dirPath = "D:\\git\\study1-logs\\analysis\\raw_telemetry\\m";
	
	int completeCount = 0;
	int fileCount = 0;

	for (const auto& entry : fs::directory_iterator(dirPath))
		filePaths.push_back(entry.path().string());

	initializeThreadPool(pool, filePaths);	

	int numberComplete = 0;

	while (numberComplete < pool.size())
	{
		numberComplete = 0;

		for (int i = 0; i < pool.size(); i++)
		{
			if (pool[i]->complete)
			{
				numberComplete++;
				std::cout << "x";
			}
			else
				std::cout << "-";
		}

		std::cout << std::endl;
	}
	
	for (int i = 0; i < pool.size(); i++)
		pool[i]->thread.join();

	return 0;
}