Windows DLLs and TLS

[Jakob Ovrum]

On Monday, 8 October 2012 at 17:20:03 UTC, Regan Heath wrote:
> Could XChat be loading your dll using:
> http://msdn.microsoft.com/en-us/library/windows/desktop/ms684179(v=vs.85).aspx
>
> and the flag DONT_RESOLVE_DLL_REFERENCES, or similar.
>
> To debug, I would write a debug file using *C* IO functions 
> from DllMain, check it loads/runs/outputs to the file from your 
> dummy C host application, then try again with XChat and see 
> what you get.
>
> You could also alter the dummy C host application to call 
> LoadLibraryEx and pass DONT_RESOLVE_DLL_REFERENCES and see what 
> happens.
>
> R

Upon loading the application, which is when plugins are loaded, 
DLL_PROCESS_ATTACH is invoked once. Subsequently, 
DLL_THREAD_ATTACH is invoked 4 times. Then after about a second, 
still during startup, DLL_THREAD_DETACH is invoked twice. 
DLL_PROCESS_DETACH is then invoked once when closing the 
application.

XChat uses gmodule - part of glib - to load plugins. I looked at 
gmodule's Windows implementation, and it uses LoadLibraryW.

Despite finding all this, I still tried modifying the dummy host 
to use LoadLibraryEx out of curiosity. An access violation occurs 
in some druntime exception handling code as soon as I call into 
the plugin's init function.