Windows2003-3790/enduser/troubleshoot/bn/refcnt.h
2020-09-30 16:53:55 +02:00

186 lines
3.5 KiB
C++

//+-------------------------------------------------------------------------
//
// Microsoft Windows
//
// Copyright (C) Microsoft Corporation, 1997 - 1997
//
// File: refcnt.h
//
//--------------------------------------------------------------------------
//
// refcnt.h: base class for reference-counted objects
//
#ifndef _REFCNT_H_
#define _REFCNT_H_
class REFCNT
{
public:
// Bind the object again
void Bind () { IncRef(1) ; }
// Release the object
void Unbind () { IncRef(-1) ; }
// Return the reference count
UINT CRef() const { return _cref; }
protected:
REFCNT() : _cref(0) {}
// Virtual call-out when reference count goes to zero
virtual void NoRef () {}
private:
UINT _cref; // Number of references to this
protected:
void IncRef ( int i = 1 )
{
if ((_cref += i) > 0 )
return;
_cref = 0;
NoRef();
}
// Hide the assignment operator
HIDE_AS(REFCNT);
};
////////////////////////////////////////////////////////////////////
// template REFPOBJ: Smart pointer wrapper template. Knows
// to destroy the pointed object when it itself is destroyed.
////////////////////////////////////////////////////////////////////
class ZSREF;
template<class T>
class REFPOBJ
{
// Friendship is required for manipulation by the symbol table
friend pair<ZSREF, REFPOBJ<T> >;
friend map<ZSREF, REFPOBJ<T>, less<ZSREF> >;
public:
~ REFPOBJ ()
{ Deref(); }
// Return the real object
T * Pobj () const
{ return _pobj ; }
// Allow a REFPOBJ to be used wherever a T * is required
operator T * () const
{ return _pobj ; }
// Operator == compares only pointers.
bool operator == ( const REFPOBJ & pobj ) const
{ return _pobj == pobj._pobj; }
T * MoveTo (REFPOBJ & pobj)
{
pobj = Pobj();
_pobj = NULL;
return pobj;
};
REFPOBJ & operator = ( T * pobj )
{
Deref();
_pobj = pobj;
return *this;
}
protected:
REFPOBJ ()
: _pobj(NULL)
{}
protected:
T * _pobj;
private:
void Deref ()
{
delete _pobj;
_pobj = NULL;
}
HIDE_AS(REFPOBJ);
};
////////////////////////////////////////////////////////////////////
// template REFCWRAP: Smart pointer wrapper template for objects
// using REFCNT semantics.
////////////////////////////////////////////////////////////////////
template<class T>
class REFCWRAP
{
public:
REFCWRAP (T * pobj = NULL)
: _pobj(NULL)
{
Ref( pobj );
}
~ REFCWRAP ()
{
Deref();
}
REFCWRAP ( const REFCWRAP & refp )
: _pobj(NULL)
{
Ref( refp._pobj );
}
// Return true if there's a referenced object
bool BRef () const
{ return _pobj != NULL; }
// Return the real object
T * Pobj () const
{ return _pobj ; }
// Allow a REFPOBJ to be used wherever a T * is required
operator T * () const
{ return _pobj ; }
// Operator == compares only pointers.
bool operator == ( const REFCWRAP & pobj ) const
{ return _pobj == pobj._pobj; }
T * operator -> () const
{
assert( _pobj );
return _pobj;
}
REFCWRAP & operator = ( T * pobj )
{
Ref(pobj);
return *this;
}
REFCWRAP & operator = ( const REFCWRAP & refp )
{
Ref(refp._pobj);
return *this;
}
void Deref ()
{
if ( _pobj )
{
_pobj->Unbind();
_pobj = NULL;
}
}
protected:
T * _pobj;
private:
void Ref ( T * pobj )
{
Deref();
if ( pobj )
{
pobj->Bind();
_pobj = pobj;
}
}
};
#endif