//+-------------------------------------------------------------------
//
//  File:       comsrgt.hxx
//
//  Contents:   declarations for accessing an instance of ISurrogate
//
//  Functions:
//
//  History:     21-Oct-96  t-adame     Created
//
//--------------------------------------------------------------------

#ifndef __COMSRGT_HXX__ 
#define __COMSRGT_HXX__

#include <ole2int.h>
#include <..\com\dcomrem\locks.hxx>

extern COleStaticMutexSem   gComLock;


//+---------------------------------------------------------------------------
//
//  Class:      CCOMSurrogate
//
//  Purpose:    This class provides threadsafe access to an ISurrogate pointer
//
//  Interface:  LoadDllServer     - Loads the dll for the specified clsid
//
//              FreeSurrogate     - Tells the surrogate process to terminate
//                                  and prevents subsequent calls to LoadDll
//
//              SetISurrogate     - Set the value of the ISurrogate pointer
//
//  History:    21-Oct-96  t-adame  Created
//
//  Notes:      This class should only be declared in debug at file scope
//
//
//----------------------------------------------------------------------------
class CCOMSurrogate
{
public:

    static HRESULT LoadDllServer(REFCLSID clsid);
    static HRESULT FreeSurrogate();
    static HRESULT InitializeISurrogate(LPSURROGATE pSurrogate);

private:

    static LPSURROGATE _pSurrogate;
};

//+---------------------------------------------------------------------------
//
//  Member:     CCOMSurrogate::FreeSurrogate()
//
//  Synopsis:   Calls ISurrogate::FreeSurrogate, so the process will
//              terminate, and sets our _pSurrogate to NULL and releases
//              it so that it can't be used to load further dll servers
//
//  Returns:    S_OK if it tells the surrogate process to terminate,
//              S_FALSE if it doesn'tx
//
//  History:    21-Oct-96
//
//----------------------------------------------------------------------------
inline HRESULT CCOMSurrogate::FreeSurrogate()
{
    LOCK(gComLock);
    LPSURROGATE pSurrogate = _pSurrogate;

    if(pSurrogate)
    {
	_pSurrogate = NULL;

	CoSuspendClassObjects();

	UNLOCK(gComLock);
	(void)pSurrogate->FreeSurrogate();

	pSurrogate->Release();     // we no longer need it

	return S_OK;
    }
    UNLOCK(gComLock);
    return S_FALSE;
}


//+---------------------------------------------------------------------------
//
//  Member:     CCOMSurrogate::SetISurrogate()
//
//  Synopsis:   sets ISurrogate pointer according to the pSurrogate
//              parameter of this function.  
//
//  Notes:      calls to this function are NOT serialized
// 
//  History:    21-Oct-96
//
//----------------------------------------------------------------------------
inline HRESULT CCOMSurrogate::InitializeISurrogate(LPSURROGATE pSurrogate)
{
    ASSERT_LOCK_DONTCARE(gComLock);

    // should only be used to set an uninitialized (NULL) and
    // should not be initialized to NULL

    if(_pSurrogate)
    {
	return MAKE_SCODE(SEVERITY_ERROR, FACILITY_WIN32, ERROR_ALREADY_INITIALIZED);
    }

    if(pSurrogate)
    {
	pSurrogate->AddRef();
	_pSurrogate = pSurrogate;
	return S_OK;
    }

    return E_INVALIDARG;
}


//+---------------------------------------------------------------------------
 //
//  Member:     CCOMSurrogate::LoadDllServer
//
//  Synopsis:   Loads the server for the specified clsid
//
//  History:    21-Oct-96
//
//----------------------------------------------------------------------------
inline HRESULT CCOMSurrogate::LoadDllServer(REFCLSID clsid)
{

    HRESULT hr = CO_E_SERVER_STOPPING;

    ASSERT_LOCK_DONTCARE(gComLock);

    LOCK(gComLock);
    LPSURROGATE pSurrogate = _pSurrogate;
    UNLOCK(gComLock);

    // if _pSurrogate is NULL, then the surrogate process either
    // failed to register its ISurrogate with CoRegisterSurrogate,
    // a requirement for surrogate processes, or (more likely),
    // the surrogate is shutting down -- in either case, we
    // return CO_E_SERVER_STOPPING so that activation will
    // try to start up another surrogate
    if (pSurrogate)
    {
        hr = pSurrogate->LoadDllServer(clsid);
    }


    
    return hr;
}
#endif // !__COMSRGT_HXX__