The title pretty much says it all..
What I'm trying to do is write a tool that will monitor a dll file containing a plugin and when I overwrite it, by recompiling, it should automatically reload it. I know I can make a copy, load the copy and monitor the original, but I thought there might be a better way.. If I understood it right the dll is completely loaded into memory so there shouldn't be a problem in deleting the file..
No, that's not how Windows works. Loading a DLL merely creates a memory mapped file, nothing is actually read from the file beyond the relocations (if necessary). Not until your code calls an exported function. Which causes a page fault because the code wasn't loaded yet. Now the code gets read from the file into RAM. If space is needed for other processes then the pages simply gets unmapped. Getting reloaded again on the next page fault.
The MMF puts a hard lock on the file. You can only rename it, not overwrite or delete it. That would crash the program. Release the lock with FreeLibrary().
Haven't tried it, I'm not on my Windows machine right now, but I think that Windows locks the file against writing when loading a DLL. You should check that first, can you actually overwrite the DLL (e.g. by compiling a new version) or does the compiler complain with "permission denied".
Otherwise I suppose you could use the file change notification API to achieve your goal.
