// File: lock.hpp

//

// Copyright (c) 2002,2003,2011

// Kevin Atkinson

//

// Permission to use, copy, modify, distribute and sell this software

// and its documentation for any purpose is hereby granted without

// fee, provided that the above copyright notice appear in all copies

// and that both that copyright notice and this permission notice

// appear in supporting documentation.  Kevin Atkinson makes no

// representations about the suitability of this software for any

// purpose.  It is provided "as is" without express or implied

// warranty.

#ifndef DISTRIBNET_LOCK__HPP

#define DISTRIBNET_LOCK__HPP

#include <assert.h>

#include "settings.h"

#ifdef USE_POSIX_MUTEX

#  include <pthread.h>

#endif

namespace acommon {

#define LOCK(l) const Lock the_lock(l);

#ifdef USE_POSIX_MUTEX

  class Mutex {

    pthread_mutex_t l_;

  private:

    Mutex(const Mutex &);

    void operator=(const Mutex &);

  public:

    Mutex() {pthread_mutex_init(&l_, 0);}

    ~Mutex() {pthread_mutex_destroy(&l_);}

    void lock() {pthread_mutex_lock(&l_);}

    void unlock() {pthread_mutex_unlock(&l_);}

  };

#else

  class Mutex {

  private:

    Mutex(const Mutex &);

    void operator=(const Mutex &);

  public:

    Mutex() {}

    ~Mutex() {}

    void lock() {}

    void unlock() {}

  };

#endif

  class Lock {

  private:

    Lock(const Lock &);

    void operator= (const Lock &);

    Mutex * lock_;

  public:

    Lock(Mutex * l) : lock_(l) {if (lock_) lock_->lock();}

    void set(Mutex * l) {assert(!lock_); lock_ = l; if (lock_) lock_->lock();}

    void release() {if (lock_) lock_->unlock(); lock_ = NULL;}

    ~Lock() {if (lock_) lock_->unlock();}

  };

};

#endif