Can someone point me to a good tutorial/articles/books on writing DLL in C?

Question

Also some good books on C .. best practicies.. writing C apps in multi-threaded environment.. I basically need to write a DLL..which will be used in a multi-threaded environment.

Answer 1

http://www.google.com/search?q=how+to+write+dll

Answer 2

I think it is important to understand that you have only one instance of your dll for all programs, unless you are running side-by-side with other versions of your dll (supported since XP). Thus, you have to be careful about assumptions you make regarding the number of dll instances running simultaneously.

Some tips about what to do and not to do in a DLLMain: http://blogs.msdn.com/larryosterman/archive/2004/04/23/118979.aspx

Some tips about multi threading: http://www.codeproject.com/KB/threads/sync.aspx