/*! \file pimutex.h
 * \brief PIMutex, PIMutexLocker
*/
/*
	PIP - Platform Independent Primitives
	PIMutex, PIMutexLocker
	Ivan Pelipenko peri4ko@yandex.ru, Stephan Fomenko, Andrey Bychkov work.a.b@yandex.ru

	This program is free software: you can redistribute it and/or modify
	it under the terms of the GNU Lesser General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	This program 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 Lesser General Public License for more details.

	You should have received a copy of the GNU Lesser General Public License
	along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef PIMUTEX_H
#define PIMUTEX_H

#include "piinit.h"
#include <mutex>


class PIP_EXPORT PIMutex
{
public:
	NO_COPY_CLASS(PIMutex)

	//! Constructs unlocked mutex
	explicit PIMutex();

	//! Destroy mutex
	~PIMutex();


	//! \brief Lock mutex
	//! \details If mutex is unlocked it set to locked state and returns immediate.
	//! If mutex is already locked function blocks until mutex will be unlocked
	void lock();

	//! \brief Unlock mutex
	//! \details In any case this function returns immediate
	void unlock() ;

	//! \brief Try to lock mutex
	//! \details If mutex is unlocked it set to locked state and returns "true" immediate.
	//! If mutex is already locked function returns immediate an returns "false"
	bool tryLock();

	void * handle();

private:
	void init();
	void destroy();

	PRIVATE_DECLARATION(PIP_EXPORT)

};


//! \brief PIMutexLocker
//! \details Same as std::lock_guard<std::mutex>.
//! When a PIMutexLocker object is created, it attempts to lock the mutex it is given, if "condition" true.
//! When control leaves the scope in which the PIMutexLocker object was created,
//! the PIMutexLocker is destructed and the mutex is released, if "condition" true.
//! If "condition" false this class do nothing.
//! The PIMutexLocker class is non-copyable.
class PIP_EXPORT PIMutexLocker
{
public:
	NO_COPY_CLASS(PIMutexLocker)
	PIMutexLocker(PIMutex & m, bool condition = true): mutex(m), cond(condition) {if (cond) mutex.lock();}
	~PIMutexLocker() {if (cond) mutex.unlock();}
private:
	PIMutex & mutex;
	bool cond;
};

#endif // PIMUTEX_H
