mutexrcptr.h

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 * This software is governed by the CeCILL-B license under
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 * You can  use, modify and/or redistribute the software under the
 * terms of the CeCILL-B license as circulated by CEA, CNRS
 * and INRIA at the following URL "http://www.cecill.info".
 *
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 */
 
 
#ifndef CARTOBASE_SMART_MUTEXRCPTR_H
#define CARTOBASE_SMART_MUTEXRCPTR_H
 
#include <cartobase/smart/rcptr.h>
#include <cartobase/thread/mutex.h>
 
namespace carto
{
 
  class MutexedObject : public RCObject
  {
  public:
#ifndef CARTO_NO_THREAD
    typedef carto::Mutex Mutex;
#else
    // fake, null mutex
    class Mutex
    {
    public:
      enum Type { Recursive=2 };
      Mutex( int = Recursive ) {}
      void lock() {}
      void unlock() {}
    };
#endif
 
    MutexedObject();
    MutexedObject( const MutexedObject & );
    virtual ~MutexedObject();
    MutexedObject & operator = ( const MutexedObject & );
 
    Mutex* mutex() const;
 
  private:
    mutable Mutex       *_mutex;
  };
 
 
  template <typename T>
  class MutexRcPtr
  {
  public:
    MutexRcPtr();
    MutexRcPtr( T* ptr );
    MutexRcPtr( MutexRcPtr<T> & ptr );
    ~MutexRcPtr();
 
    void reset( T *p=0 );
    T * get();
    const T * get() const;
    T * release();
    MutexRcPtr<T> & operator = ( MutexRcPtr<T> &other );
    T * operator -> ();
    const T * operator -> () const;
    T & operator * ();
    const T & operator * () const;
    bool operator < ( const MutexRcPtr<T> &other ) const;
    bool operator == ( const MutexRcPtr< T > &other ) const;
    bool operator != ( const MutexRcPtr< T > &other ) const;
    int refCount() const;
 
    rc_ptr<T> rcptr();
    MutexedObject::Mutex* mutex();
    void lock();
    void unlock();
 
  private:
    rc_ptr<T>   _rcptr;
  };
 
 
  // ----------------
 
  inline MutexedObject::MutexedObject()
    : _mutex( new MutexedObject::Mutex( Mutex::Recursive ) )
  {
  }
 
 
  inline MutexedObject::MutexedObject( const MutexedObject & other )
    : RCObject( other ), _mutex( new MutexedObject::Mutex( Mutex::Recursive ) )
  {
  }
 
 
  inline MutexedObject & 
  MutexedObject::operator = ( const MutexedObject & other )
  {
    if( this != &other )
      {
        RCObject::operator = ( other );
        // _mutex stays distinct
      }
    return *this;
  }
 
 
  inline MutexedObject::Mutex* MutexedObject::mutex() const
  {
    return _mutex;
  }
 
  // -----------------
 
  template <typename T>
  inline MutexRcPtr<T>::MutexRcPtr()
  {
  }
 
 
  template <typename T>
  inline MutexRcPtr<T>::MutexRcPtr( T* ptr )
  {
    if( ptr )
      {
        ptr->mutex()->lock();
        _rcptr.reset( ptr );
        ptr->mutex()->unlock();
      }
  }
 
 
  template <typename T>
  inline MutexRcPtr<T>::MutexRcPtr( MutexRcPtr<T> & ptr )
  {
    ptr.lock();
    _rcptr = ptr._rcptr;
    ptr.unlock();
  }
 
 
  template <typename T>
  inline MutexRcPtr<T>::~MutexRcPtr()
  {
    reset( 0 );
  }
 
 
  template <typename T>
  inline void MutexRcPtr<T>::reset( T* ptr )
  {
    lock();
    T   *t = _rcptr.get();
    if( t )
      {
        if( _rcptr.refCount() == 1 )
          {
            _rcptr.release();
            t->mutex()->unlock();
            delete t;
          }
        else
          {
            _rcptr.release();
            t->mutex()->unlock();
          }
      }
 
    if( ptr )
      {
        ptr->mutex()->lock();
        _rcptr.reset( ptr );
        ptr->mutex()->unlock();
      }
  }
 
 
  template <typename T>
  inline T* MutexRcPtr<T>::get()
  {
    /* lock();
    T   *t = _rcptr.get();
    unlock();
    return t; */
    return _rcptr.get();
  }
 
 
  template <typename T>
  inline const T* MutexRcPtr<T>::get() const
  {
    /* lock();
    T   *t = _rcptr.get();
    unlock();
    return t; */
    return _rcptr.get();
  }
 
 
  template <typename T>
  inline T* MutexRcPtr<T>::release()
  {
    lock();
    T   *t = _rcptr.get();
    _rcptr.release();
    if( t )
      t->mutex()->unlock();
    return t;
  }
 
  template <typename T>
  inline MutexRcPtr<T> & MutexRcPtr<T>::operator = ( MutexRcPtr<T> &other )
  {
    if( this == &other )
      return *this;
    reset( 0 );
    other.lock();
    _rcptr = other._rcptr;
    other.unlock();
  }
 
 
  template <typename T>
  inline T* MutexRcPtr<T>::operator -> ()
  {
    return get();
  }
 
 
  template <typename T>
  inline const T* MutexRcPtr<T>::operator -> () const
  {
    return get();
  }
 
 
  template <typename T>
  inline T & MutexRcPtr<T>::operator * ()
  {
    return *get();
  }
 
 
  template <typename T>
  inline const T & MutexRcPtr<T>::operator * () const
  {
    return *get();
  }
 
 
  template <typename T>
  inline bool MutexRcPtr<T>::operator < ( const MutexRcPtr<T> &other ) const
  {
    return get() < other.get();
  }
 
 
  template <typename T>
  inline bool MutexRcPtr<T>::operator == ( const MutexRcPtr<T> &other ) const
  {
    return get() == other.get();
  }
 
 
  template <typename T>
  inline bool MutexRcPtr<T>::operator != ( const MutexRcPtr<T> &other ) const
  {
    return get() != other.get();
  }
 
 
  template <typename T>
  inline int MutexRcPtr<T>::refCount() const
  {
    lock();
    int x = _rcptr.refCount();
    unlock();
    return x;
  }
 
 
  template <typename T>
  inline rc_ptr<T> MutexRcPtr<T>::rcptr()
  {
    return _rcptr;
  }
 
 
  template <typename T>
  inline MutexedObject::Mutex* MutexRcPtr<T>::mutex()
  {
    T   *t = _rcptr.get();
    return t ? t->mutex() : 0;
  }
 
 
  template <typename T>
  inline void MutexRcPtr<T>::lock()
  {
    MutexedObject::Mutex        *m = mutex();
    if( m )
      m->lock();
  }
 
 
  template <typename T>
  inline void MutexRcPtr<T>::unlock()
  {
    MutexedObject::Mutex        *m = mutex();
    if( m )
      m->unlock();
  }
 
}
 
#endif