// CriticalSection.h
// 
// A class using Resource Management technique(RM: see 
// http://www.relisoft.com/resource/resource.html for
// discussion) to handle critical section code that 
// guarantees no memory leaks or open locks.
//
// Revision Log
//
// Date       Who SAR     Notes
// ========== === ======= =====================================
//                        (c) Reliable Software, 1997, 98
//                        Bartosz Milewski, www.relisoft.com
// 

#ifdef SAMPLE_CODE

   // somewhere with the resource to protect
   CCriticalSection _critSect;

   // later in the code...
   {
      CLock lock(_critSect);
      // perform action which may throw
      myVar += 10;
      // guaranteed automatic destructor of lock
      // when it goes out of scope
   }
}
#endif


#ifndef RFC_CRITICAL_SECTION_H
#define RFC_CRITICAL_SECTION_H

#include <windows.h>

class CCriticalSection
{
   friend class CLock;
public:
   CCriticalSection() { InitializeCriticalSection(&_critSectStruct); }
   ~CCriticalSection() { DeleteCriticalSection(&_critSectStruct); }
private: 
   // these must only be used by CLock object, never directly
   void Enter() { EnterCriticalSection(&_critSectStruct); }
   void Leave() { LeaveCriticalSection(&_critSectStruct); }

   CCriticalSection(CCriticalSection& o); // not allowed
   CCriticalSection& operator=(CCriticalSection& o); // not allowed

   CRITICAL_SECTION _critSectStruct;
};

class CLock 
{
public:
    CLock(CCriticalSection& critSect) 
        : _critSectObj(critSect) 
    {
        _critSectObj.Enter();
    }
    ~CLock()
    {
        _critSectObj.Leave();
    }
private:
    CCriticalSection & _critSectObj;
};

#endif