Mark Storer wrote:

...

The MS APIs do not give you any means with which to cleanup data allocated to TLS, and they recommend you add this in DllMain.

What can you do in DllMain that you can't do with atexit, or some Loki-like priority singleton system?

Notifications of thread creation and exit from the current process. DllMain gets called every time a thread is created or exited in the process in which it is loaded. /Michel