//----------------------------------------------------------------------------
//
//  Microsoft Windows
//  Copyright (C) Microsoft Corporation, 1995 - 1996.
//
//  File:       dll.hxx
//
//  Contents:   Classes for maintaining reference counts required to
//              implement
//
//  Classes:    CDll
//              CDllRef
//
//  History:    1/24/1996  RaviR      Created
//              08-14-96   DavidMun   Stolen for this project
//
//----------------------------------------------------------------------------

#ifndef __DLLREF_HXX_
#define __DLLREF_HXX_


//+---------------------------------------------------------------------------
//
//  Class:      CDll
//
//  Purpose:    Maintains reference and lock counts.
//
//  History:    08-14-96   DavidMun   Created
//
//  Notes:      Everything in this class is static, so nowhere is there an
//              instantiation of this class.
//
//----------------------------------------------------------------------------

class CDll
{
public:

    static ULONG AddRef() { if (!s_cObjs) InitGlobals(); return InterlockedIncrement((LONG*)&s_cObjs); }
    static ULONG Release() { if (s_cObjs == 1) FreeGlobals(); return InterlockedDecrement((LONG*)&s_cObjs); }

    static void LockServer(BOOL fLock) {
        (fLock == TRUE) ? InterlockedIncrement((LONG*)&s_cLocks)
                        : InterlockedDecrement((LONG*)&s_cLocks);
    }

    static HRESULT CanUnloadNow(void) {
        return (0L == s_cObjs && 0L == s_cLocks) ? S_OK : S_FALSE;
    }

    static ULONG s_cObjs;
    static ULONG s_cLocks;

};  // class CDll




//+---------------------------------------------------------------------------
//
//  Class:      CDllRef
//
//  Purpose:    Helper class to automatically maintain object count.
//
//  History:    08-14-96   DavidMun   Created
//
//  Notes:      All objects returned to the outside world should contain
//              a CDllRef member.
//
//----------------------------------------------------------------------------

class CDllRef
{
public:

    CDllRef(void) { CDll::AddRef(); }
    ~CDllRef(void) { CDll::Release(); }

}; // class CDllRef



#endif // __DLLREF_HXX_