Re: Where should I call CoUninitialize

From:

"Doug Harrison [MVP]" <dsh@mvps.org>

Newsgroups:

microsoft.public.vc.mfc

Date:

Mon, 02 Apr 2007 11:00:39 -0500

Message-ID:

<sn9213dat23pqsoddqh954h9e61uvnjm4g@4ax.com>

On 1 Apr 2007 23:32:59 -0700, "Hariom Tiwari" <hariomtiwari2103@gmail.com>
wrote:

Hi,
I have declared a smart pointer of COM interface globally.
When I call CoUninitialize in ExitInstance it throws an exception.
Because it is trying to release interface pointer twice.
How can I overcome this problem?
I have to declare interface pointer globally.

You could probably make it a member of your application class. That said,
if it must be a global, then you should make your CoInitialize/Uninitialize
global as well. You can accomplish this with a class:

struct ComInitializer
{
   ComInitializer()
   {
      CoInitialize();
   }

   ~ComInitializer()
   {
      CoUninitialize();
   }
};

Then, in the same file:

ComInitializer g_comInitializer;
IMyPointer g_myPointer;

This works because globals defined in the same translation unit are
constructed in the order of their definitions and destroyed in the reverse
order. Just don't do this in a DLL, because DLL globals are constructed and
destroyed in DllMain context, and these COM operations are among the many
things forbidden in DllMain.

--
Doug Harrison
Visual C++ MVP