Access to COM methods inside Windows Service ATL

[cmacgowan]

Hi ... I have written a Windows Service using ATL COM (ATL3 / Visual Studio 6.0). The service works fine, I am able to start and stop the service. I have created a COM Class called CTest with a methof called TestBeep(). I would like to access this object and call the method from the CServiceModule::Run() method. Below is the CServiceModule::Run() Method. The code will fail on both attempts to create the ITest* pTest using CoCreateInstance(). The error message are written to the event log "Error: ITest failed" "CoCreateInstance failed" Any help is appreciated, Thanks, Chris void CServiceModule::Run() { _Module.dwThreadID = GetCurrentThreadId(); HRESULT hr = CoInitialize(NULL); // If you are running on NT 4.0 or higher you can use the following call // instead to make the EXE free threaded. // This means that calls come in on a random RPC thread // HRESULT hr = CoInitializeEx(NULL, COINIT_MULTITHREADED); _ASSERTE(SUCCEEDED(hr)); // This provides a NULL DACL which will allow access to everyone. CSecurityDescriptor sd; sd.InitializeFromThreadToken(); hr = CoInitializeSecurity(sd, -1, NULL, NULL, RPC_C_AUTHN_LEVEL_PKT, RPC_C_IMP_LEVEL_IMPERSONATE, NULL, EOAC_NONE, NULL); _ASSERTE(SUCCEEDED(hr)); hr = _Module.RegisterClassObjects(CLSCTX_LOCAL_SERVER | CLSCTX_REMOTE_SERVER, REGCLS_MULTIPLEUSE); _ASSERTE(SUCCEEDED(hr)); LogEvent(_T("Blue Service started")); LogEvent(_T("Message 1")); LogEvent(_T("Message 2")); if (m_bService) SetServiceStatus(SERVICE_RUNNING); MSG msg; while (GetMessage(&msg, 0, 0, 0)) DispatchMessage(&msg); _Module.RevokeClassObjects(); // -------------------------------------------- // We will try to call the COM Object from here char progID[] = "Blue.Test.1"; // Now make that object. CLSID clsid; wchar_t wide[80]; mbstowcs(wide, progID, 80); CLSIDFromProgID(wide, &clsid); LogEvent(_T("Attempt to use ITest")); ITest* pTest = NULL; if(SUCCEEDED(CoCreateInstance(clsid, NULL, CLSCTX_ALL, IID_ITest, (void**)&pTest))) { pTest->TestBeep(); } else { LogEvent(_T("Error: ITest failed")); } // We will try this another way !! // We have downloaded a ATL COM Server sample and it had // A COM Method in in and it was not called from within the // Service (as we are trying to do) it was called from a

[cmacgowan]

Hi ... The solution to this problem is to put the com call to ITest above the message loop. Below is the corrected code. Thanks, Chris void CServiceModule::Run() { _Module.dwThreadID = GetCurrentThreadId(); HRESULT hr = CoInitialize(NULL); // If you are running on NT 4.0 or higher you can use the following call // instead to make the EXE free threaded. // This means that calls come in on a random RPC thread // HRESULT hr = CoInitializeEx(NULL, COINIT_MULTITHREADED); _ASSERTE(SUCCEEDED(hr)); // This provides a NULL DACL which will allow access to everyone. CSecurityDescriptor sd; sd.InitializeFromThreadToken(); hr = CoInitializeSecurity(sd, -1, NULL, NULL, RPC_C_AUTHN_LEVEL_PKT, RPC_C_IMP_LEVEL_IMPERSONATE, NULL, EOAC_NONE, NULL); _ASSERTE(SUCCEEDED(hr)); hr = _Module.RegisterClassObjects(CLSCTX_LOCAL_SERVER | CLSCTX_REMOTE_SERVER, REGCLS_MULTIPLEUSE); _ASSERTE(SUCCEEDED(hr)); LogEvent(_T("Blue Service started")); LogEvent(_T("Message 1")); LogEvent(_T("Message 2")); if (m_bService) SetServiceStatus(SERVICE_RUNNING); // -------------------------------------------- // We will try to call the COM Object from here char progID[] = "Blue.Test.1"; string strTemp; char szTemp[10]; // Now make that object. CLSID clsid; wchar_t wide[80]; mbstowcs(wide, progID, 80); CLSIDFromProgID(wide, &clsid); LogEvent(_T("Attempt to create the ITest Com Object")); ITest* pTest = NULL; hr = CoCreateInstance(clsid, NULL, CLSCTX_ALL, IID_ITest, (void**)&pTest); if(SUCCEEDED(hr)) { pTest->TestBeep(); } else { // LogEvent(_T("Error: ITest failed hresult")); sprintf(szTemp, "%h", hr); strTemp = "Error: ITest failed. HResult=" + (string)szTemp; LogEvent(_T(strTemp.c_str())); } MSG msg; while (GetMessage(&msg, 0, 0, 0)) DispatchMessage(&msg); _Module.RevokeClassObjects(); CoUninitialize(); }