#include "threadpool.h"

threadpool::threadpool() : threadpool(std::thread::hardware_concurrency())
{
}

threadpool::threadpool(std::size_t concurrency) : _concurrency(concurrency), _enabled(true)
{
	for (std::size_t i = 0; i < _concurrency; ++i)
	{
		_workers.push_back(std::thread(&threadpool::worker_func, this));
	}
}

threadpool::~threadpool()
{
	_enabled = false;
	_cv.notify_all();
	for (std::size_t i = 0; i < _workers.size(); ++i)
	{
		_workers[i].join();
	}
}

void threadpool::worker_func()
{
	while (_enabled)
	{
		std::unique_lock<std::mutex> lock(_mutex);
		_cv.wait(lock, [this] { return (!_queue.empty() || !_enabled); });

		if (_queue.empty() && !_enabled)
			return;

		auto func = _queue.front();
		_queue.pop();

		lock.unlock();

		func();
	}
}