dll process in system?

i have a doubt in dlls loading &processing in memory ,normally dlls are shared library so dll should loads once is enough.if a process loads a dll (ex.advapi32.dll )into memory means ,after that another process how refers advapi32.dll to that process ...how开发者_运维问答 can share common location for each process...

I'm not entirely sure what your question is, but yes, if multiple processes import the same DLL, then the read-only sections of that DLL are typically mapped into all of those processes. On the other hand, section that can change, like the BSS (variable) segment, get a copy in each process so that the changes that one process makes are invisible to other processes. If you want certain changes to be shared between processes for your own DLL, you can mark a data section in the DLL as shared. Exactly how you do this depends on the development tools you're using.