/*****************************************************************************
 * Author:   Valient Gough <vgough@pobox.com>
 *
 *****************************************************************************
 * Copyright (c) 2003, Valient Gough
 *
 * 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 _Mutex_incl_
#define _Mutex_incl_

#include "base/config.h"

#ifdef CMAKE_USE_PTHREADS_INIT
#include <pthread.h>
#else
#warning No thread support.
#endif

namespace encfs {

class Mutex {
 public:
#ifdef CMAKE_USE_PTHREADS_INIT
  pthread_mutex_t _mutex;
  Mutex() { pthread_mutex_init(&_mutex, 0); }
  ~Mutex() { pthread_mutex_destroy(&_mutex); }
#endif

  void lock();
  void unlock();
};

class Lock {
 public:
  explicit Lock(Mutex &mutex);
  ~Lock();

  // leave the lock as it is.  When the Lock wrapper is destroyed, it
  // will do nothing with the pthread mutex.
  void leave();

 private:
  Lock(const Lock &src);             // not allowed
  Lock &operator=(const Lock &src);  // not allowed

  Mutex *_mutex;
};

inline void Mutex::lock() {
#ifdef CMAKE_USE_PTHREADS_INIT
  pthread_mutex_lock(&_mutex);
#endif
}

inline void Mutex::unlock() {
#ifdef CMAKE_USE_PTHREADS_INIT
  pthread_mutex_unlock(&_mutex);
#endif
}

inline Lock::Lock(Mutex &mutex) : _mutex(&mutex) {
  if (_mutex) _mutex->lock();
}

inline Lock::~Lock() {
  if (_mutex) _mutex->unlock();
}

inline void Lock::leave() { _mutex = NULL; }

}  // namespace encfs

#endif