Re: COM Local server + service + desktop application

From:
=?Utf-8?B?ZA==?= <d@discussions.microsoft.com>
Newsgroups:
microsoft.public.vc.atl
Date:
Thu, 9 Jul 2009 01:38:03 -0700
Message-ID:
<E624A6BD-DF45-4DE1-9ABA-4D00D9313E49@microsoft.com>
hi svenC

well i finally got where this code gets called but here is what i found
ATL is already doing registration with the parameter that you mentioned

here is the code snippet that gets called

Atlbase.h
///////////////////////////////////////////////////////////////////////
HRESULT PreMessageLoop(int /*nShowCmd*/) throw()
    {
        HRESULT hr = S_OK;
        T* pT = static_cast<T*>(this);
        pT;

#ifndef _ATL_NO_COM_SUPPORT

#if ((_WIN32_WINNT >= 0x0400 ) || defined(_WIN32_DCOM)) &
defined(_ATL_FREE_THREADED)

        hr = pT->RegisterClassObjects(CLSCTX_LOCAL_SERVER,
            REGCLS_MULTIPLEUSE | REGCLS_SUSPENDED);

        if (FAILED(hr))
            return hr;
///////////////////////////////////////////////////////////////////////

i suppose, i do not need to override this function to get my problem solved.

am i wrong somewhere??

regards
d

--
d

"d" wrote:

hi SvenC

thanks for your help.

i am looking into it. let me see where i could override
"RegisterClassObjects"
function to get my work done.

however while looking at the ATL code i came across this line

HRESULT PreMessageLoop(int nShowCmd) throw()
    {
        HRESULT hr = S_OK;
        if (m_bService)
        {
            m_dwThreadID = GetCurrentThreadId();

            T* pT = static_cast<T*>(this);
            hr = pT->InitializeSecurity();

            if (FAILED(hr))
                return hr;
        }

as i am not creating COM server as a service. so i suppose m_bService will
be false
hence if i override InitializeSecurity(). this would not get called. right?

from your post it occured to me that you are assuming that i am creating
service for COM server. which is not the case. it is just a EXE server. whose
instance will be created by seperate windows service.

will it make any difference to your solution?

regards
d

--
d

"SvenC" wrote:

Hi d,

yes , we are developing the COM server. we have full source of it.
i am creating this COM server (out of process) through ATL wizard code.
following is the code that gets generated by ATL.
"
class CServiceModule : public CAtlExeModuleT< CServiceModule >
{
public :
DECLARE_LIBID(LIBID_ServiceLib)
DECLARE_REGISTRY_APPID_RESOURCEID(IDR_SERVICE,
"{C39D06E5-0398-4619-BFCA-9C764B478E92}")
};

extern CServiceModule _AtlModule;
"
where should i insert the code you mentioned.


Search the code for RegisterClassObjects, IIRC that is the method
exposed by ATL to internally. It should have a flags property which
is handed to CoRegisterClassObject. Pass it REGCLS_MULTIPLEUSE.

you mean to say that by doing above steps when i call CoCreateInstance()
in
the Client (desktop) application. it will actualy actually return object
by
the instance running under system account.


To allow that you will need to use dcomcnfg.exe. Open the tree of that tool
to find a tree node DCOM config. You should find either find your service
module by name or by appid. The name should be what your IDR_SERVICE
resource text contains. The AppID would be your {C39d06ef...}

Right click that entry in DCOM config and select Properties. You should see
a security tab where you can customize launch and access permissions.
If your service is set to manual start you will need to set launch
permissions
for all accounts allowed to start your COM server (and hence the service)

Customize the Access rights to allow other users to access the running
COM server.

I never use CoInitializeSecurity myself, but that would be the place where
you could specify access rights in code - I found later configuration in
DCOM config more convenient as I would never know the accounts
at development time but only when configuring the system.

--
SvenC

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