//+------------------------------------------------------------------+
//|                                                     DXHandle.mqh |
//|                             Copyright 2000-2025, MetaQuotes Ltd. |
//|                                             https://www.mql5.com |
//+------------------------------------------------------------------+
#include "DXObjectBase.mqh"

//+------------------------------------------------------------------+
//| Class CDXHandle                                                  |
//+------------------------------------------------------------------+
class CDXHandle : public CDXObjectBase
  {
protected:
   int               m_handle;         // DX handle

protected:
                     CDXHandle(void);
   virtual          ~CDXHandle(void);

public:
   int               Handle(void) const { return(m_handle); }
  };
//+------------------------------------------------------------------+
//| CDXHandle constructor                                            |
//+------------------------------------------------------------------+
CDXHandle::CDXHandle(void) : m_handle(-1)
  {
  }
//+------------------------------------------------------------------+
//| CDXHandle destructor                                             |
//+------------------------------------------------------------------+
CDXHandle::~CDXHandle(void)
  {
   if(m_handle!=-1)
     {
      DXRelease(m_handle);
      m_handle=-1;
     }
  }
//+------------------------------------------------------------------+
//| Class CDXHandleShared                                            |
//+------------------------------------------------------------------+
class CDXHandleShared : public CDXHandle
  {
protected:
   ulong             m_references;     // reference count to the shared object

protected:
   virtual          ~CDXHandleShared(void);

public:
                     CDXHandleShared(void);

   virtual ulong     AddRef(void);
   virtual ulong     References(void);
   virtual ulong     Release(void);

   bool              operator!(void) const
     {
      return(m_handle==INVALID_HANDLE);
     }
  };
//+------------------------------------------------------------------+
//| CDXHandleShared constructor                                      |
//+------------------------------------------------------------------+
CDXHandleShared::CDXHandleShared(void) : m_references(1)
  {
  }
//+------------------------------------------------------------------+
//| CDXHandleShared destructor                                       |
//+------------------------------------------------------------------+
CDXHandleShared::~CDXHandleShared(void)
  {
//--- check reference count for the debuging reason
#ifdef _DEBUG
   if(m_references)
     {
      Alert("CDXHandleShared object was deleted with non-zero references count!");
      DebugBreak();
     }
#endif
  }
//+------------------------------------------------------------------+
//| Add reference to the shared object                               |
//+------------------------------------------------------------------+
ulong CDXHandleShared::AddRef(void)
  {
//--- return new reference count for the debugging reason
   return(++m_references);
  }
//+------------------------------------------------------------------+
//| Get references count to the shared object                        |
//+------------------------------------------------------------------+
ulong CDXHandleShared::References(void)
  {
//--- return new reference count for the debugging reason
   return(m_references);
  }
//+------------------------------------------------------------------+
//| Remove reference from the shared object                          |
//+------------------------------------------------------------------+
ulong CDXHandleShared::Release(void)
  {
   if(!m_references)
      return(0);
//---
   m_references--;
//--- delete shared object if there no any references
   if(!m_references)
     {
      delete &this;
      return(0);
     }
//--- return new reference count for the debugging reason
   return(m_references);
  }
//+------------------------------------------------------------------+