C# Interop

[Rainer Schuetze]

Richard Webb wrote:
>>> Also, DLLs can be used in multi-threading environments.
> 
> On a related note, i'm having a bit of a problem with a D dll at the moment.
> 
> I have an Outlook COM Addin that is written in D2 using the Juno library and that
> is running ok, but i'm now trying to use a D dll from a COM addin written in C++
> and i'm getting a crash inside dll_process_attach.
> 
> The only thing i get in the call stack is gcx.mark, but it appears that the crash
> is due to the GC running midway through the thread setup code. Disabling the GC
> during the thread_moduleTlsCtor() calls avoids the crash, but that might just be
> covering the problem up.

If there is a garbage collection going on, I assume that you do quite a 
lot of initialization for TLS. Are you using callbacks into the C++ DLL 
from the module ctors? This might be dangerous...

You might want to try this version of impersonate thread(), that might 
work better if the C++ part also uses thread local storage:

         // execute function on the TLS for the given thread
         static void impersonate_thread( uint id, void function() fn )
         {
             if( id == GetCurrentThreadId() )
             {
                 fn();
                 return;
             }

             // temporarily set current TLS array pointer to the array 
pointer of the referenced thread
             void** curteb = getTEB();
             void** teb    = getTEB( id );
             assert( teb && curteb );

             void** curtlsarray = cast(void**) curteb[11];
             void** tlsarray    = cast(void**) teb[11];
             if( !curtlsarray || !tlsarray )
                 return;

             curteb[11] = tlsarray;
             fn();
             curteb[11] = curtlsarray;
         }

Especially loading more DLLs from the TLS init code will still be 
troublesome...

Rainer