/* This file is part of Machina.
 * Copyright 2007-2012 David Robillard <http://drobilla.net>
 *
 * Machina is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Machina is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Machina.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef MACHINA_SLAVE_HPP
#define MACHINA_SLAVE_HPP

#include "raul/Semaphore.hpp"
#include "raul/Thread.hpp"

namespace Machina {

/** Thread driven by (realtime safe) signals.
 *
 * Use this to perform some task in a separate thread you want to 'drive'
 * from a realtime (or otherwise) thread.
 */
class Slave
		: public Raul::Thread
{
public:
	Slave() : _whip(0) {}
	~Slave() { _exit_flag = true; _whip.post(); }

	virtual void join() {
		_exit_flag = true;
		_whip.post();
		Thread::join();
	}

	/** Tell the slave to do whatever work it does.  Realtime safe. */
	inline void whip() { _whip.post(); }

protected:
	/** Worker method.
	 *
	 * This is called once from this thread every time whip() is called.
	 * Implementations likely want to put a single (non loop) chunk of code
	 * here, e.g. to process an event.
	 */
	virtual void _whipped() = 0;

	Raul::Semaphore _whip;

private:
	inline void _run() {
		while (true) {
			_whip.wait();
			if (_exit_flag) {
				break;
			}
			_whipped();
		}
	}

};

} // namespace Machina

#endif // MACHINA_SLAVE_HPP