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323

answers:

2

I have a dll produced by a third party that has some sort of internal datastructure that limits it's size to X elements.

So basically, it has a Queue with X as the limit.

Now from what I've known DLL's are per process, but is it possible to load a DLL more than once? Maybe per thread? In C#? or in C++/CLI?

I'm trying to load a native c++ dll.

+3  A: 

The only way you can do it is by having multiple copies of the same dll, and then load them dynamically.

Shay Erlichmen
+3  A: 

Unfortunately, the NT core DLL loader routines don't expose a public interface to skip the pool of already-loaded DLLs. As such, you're left with just a few choices:

  • Copy, hardlink, symlink, and/or use reparse points to fool the loader into thinking you have multiple distinct DLLs.
  • Use multiple processes, and load one DLL per process.
  • Write a new DLL loader (very much not for the faint of heart!)
  • Convince the DLL's vendor to fix it (likely to be harder than writing a DLL loader :)
bdonlan
Note that options 1 and 3 can break if the DLL assumes it loads only once per process (a quite reasonable assumption). COM DLLs may be exceptionally vulnerable, as both copies could claim the same GUID/interface.
MSalters