/*
	PIP - Platform Independent Primitives
	Mutex
	Ivan Pelipenko peri4ko@yandex.ru, 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/>.
*/

/** \class PIMutex
 * \brief Mutex
 * \details 
 * \section PIMutex_sec0 Synopsis
 * %PIMutex provides synchronization blocks between several threads.
 * Using mutex guarantees execution of some code only one of threads.
 * Mutex contains logic state and functions to change it: \a lock(),
 * \a unlock() and \a tryLock().
 * 
 * \section PIMutex_sec1 Usage
 * Block of code that should to be executed only one thread simultaniously
 * should to be started with \a lock() and ended with \a unlock().
 * \snippet pimutex.cpp main
 * "mutex" in this example is one for all threads.
 * 
 * */

#include "pimutex.h"
#include "piincludes_p.h"
#ifdef BLACKBERRY
#  include <pthread.h>
#endif


PRIVATE_DEFINITION_START(PIMutex)
#ifdef WINDOWS
	HANDLE
#else
	pthread_mutex_t
#endif
		mutex;
PRIVATE_DEFINITION_END(PIMutex)


PIMutex::PIMutex(): inited_(false) {
	//printf("new Mutex %p\n", this);
#ifdef WINDOWS
	PRIVATE->mutex = 0;
#endif
	init();
}


PIMutex::~PIMutex() {
	//printf("del Mutex %p\n", this);
	destroy();
}


void PIMutex::lock() {
#ifdef WINDOWS
//	std::cout << (ullong)PRIVATE->mutex << "locking..." << std::endl;
//	DWORD wr =
			WaitForSingleObject(PRIVATE->mutex, INFINITE);
//	std::cout << (ullong)PRIVATE->mutex << " lock wr=" << wr << std::endl;
#else
	pthread_mutex_lock(&(PRIVATE->mutex));
#endif
	locked = true;
}


void PIMutex::unlock() {
#ifdef WINDOWS
//	BOOL wr =
//			ReleaseMutex(PRIVATE->mutex);
			SetEvent(PRIVATE->mutex);
//	std::cout << (ullong)PRIVATE->mutex << " unlock wr=" << wr << std::endl;
#else
	pthread_mutex_unlock(&(PRIVATE->mutex));
#endif
	locked = false;
}


bool PIMutex::tryLock() {
	bool ret =
#ifdef WINDOWS
			(WaitForSingleObject(PRIVATE->mutex, 0) == WAIT_OBJECT_0);
#else
			(pthread_mutex_trylock(&(PRIVATE->mutex)) == 0);
#endif
	locked = true;
	return ret;
}


bool PIMutex::isLocked() const {
//	std::cout << "test " << (ullong)PRIVATE->mutex << std::endl;
	return locked;
}


void PIMutex::init() {
	if (inited_) destroy();
#ifdef WINDOWS
	PRIVATE->mutex = CreateEvent(NULL, FALSE, TRUE, NULL);
//	std::cout << "create " << (ullong)PRIVATE->mutex << std::endl;
#else
	pthread_mutexattr_t attr;
	memset(&attr, 0, sizeof(attr));
	pthread_mutexattr_init(&attr);
	pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_NORMAL);
	memset(&(PRIVATE->mutex), 0, sizeof(PRIVATE->mutex));
	pthread_mutex_init(&(PRIVATE->mutex), &attr);
	pthread_mutexattr_destroy(&attr);
#endif
	locked = false;
	inited_ = true;
}


void PIMutex::destroy() {
	if (inited_) {
#ifdef WINDOWS
//		std::cout << "destroy " << (ullong)PRIVATE->mutex << std::endl;
		if (PRIVATE->mutex) CloseHandle(PRIVATE->mutex);
		PRIVATE->mutex = 0;
#else
		pthread_mutex_destroy(&(PRIVATE->mutex));
#endif
	}
	locked = inited_ = false;
}