c++ windows service -main entry point - how to debug - c++

Question

I created a service for Windows using a complete example found at https://msdn.microsoft.com/en-us/library/bb540476(VS.85).aspx.
I do not know if it is the best example. A lot of people say Microsoft's examples are not the best. But it works. I can install, start, stop and delete the service without problems.
But now I need to effectively put the part of the code that should be what the service will do.
Reading the code I understood that this part creates a list and in it is placed the main of the service:
// TO_DO: Add any additional services for the process to this table.
SERVICE_TABLE_ENTRY DispatchTable[] =
{
{ SVCNAME, (LPSERVICE_MAIN_FUNCTION) SvcMain },
{ NULL, NULL }
};
// This call returns when the service has stopped.
// The process should simply terminate when the call returns.
if (!StartServiceCtrlDispatcher( DispatchTable ))
{
SvcReportEvent(TEXT("StartServiceCtrlDispatcher"));
}
If I understood correctly when the service was started the SvcMain function would be executed.
// Purpose:
// Entry point for the service
//
// Parameters:
// dwArgc - Number of arguments in the lpszArgv array
// lpszArgv - Array of strings. The first string is the name of
// the service and subsequent strings are passed by the process
// that called the StartService function to start the service.
//
// Return value:
// None.
//
VOID WINAPI SvcMain( DWORD dwArgc, LPTSTR *lpszArgv )
{
// Register the handler function for the service
LOGD << "passing 1";
gSvcStatusHandle = RegisterServiceCtrlHandler(
SVCNAME,
SvcCtrlHandler);
LOGD << "passing 2";
if( !gSvcStatusHandle )
{
SvcReportEvent(TEXT("RegisterServiceCtrlHandler"));
return;
}
// These SERVICE_STATUS members remain as set here
LOGD << "passing 3";
gSvcStatus.dwServiceType = SERVICE_WIN32_OWN_PROCESS;
gSvcStatus.dwServiceSpecificExitCode = 0;
// Report initial status to the SCM
LOGD << "passing 4";
ReportSvcStatus( SERVICE_START_PENDING, NO_ERROR, 3000 );
// Perform service-specific initialization and work.
LOGD << "passing 5";
SvcInit( dwArgc, lpszArgv );
}
I put log messages on multiple lines and I did not get any results. Nothing was recorded in the log file.
Log messages work during the service installation, but nothing is logged from within the SvcMain function.
Note:: Everything has been tested and works fine when run as a program, including in Debug.
1 - Is this function that executes the service code?
2 - Is it possible to write a log file from within a service?
3 - What other option would I have to debug inside the service?