How to check dll's reference count? How to know where the dll was loaded?

Question

As you know, if the call to LoadLibrary specifies a DLL module already mapped into the address space of the calling process, the function simply returns a handle of the DLL and increments the module's reference count.

Somewhere, I need to get the reference count of a dll. How to get the dll's reference count? How to know where the dll was loaded? Thanks.

Answer 1

This information isn't available via a public API afaik. What's your scenario? Running AppVerifier will catch any mistakes you've made with module (or any other) handles.

Answer 2

I googled it, and found this article which claims to provide the answer. Sorry I couldn't be more helpful:

Answer 3

If it is a non programmatic way (thanks to C.Johnson for giving that perspective), WinDBG could be helpful

http://windbg.info/doc/1-common-cmds.html#10_modules

Look at !dlls and it's variants.

!dll - all loaded modules with load count

EDIT 2:

If you want to know from where all the DLL is being loaded from the process, there are two ways:

a. Look at the command

"bu kernel32!LoadLibraryExW ";as /mu ${/v:MyAlias} poi(@esp+4); .if ( $spat( \"${MyAlias}\", \"MYDLL\" ) != 0 ) { kn; } .else { g }" "

in the above URL

b. Run the process under WinDBG. Debug->Even Filter and select "Load Module" and set it to "Enabled" under "Execution". Under "Continue" set it to "Not Handled".

One of these should help you definitely.

Answer 4

I'm not certain you fully understand how LoadLibrary/FreeLibrary is meant to work. You call FreeLibrary when you're finished with it and that decrements the reference count that was incremented when you loaded it. If some other part of your process is still using it, it's probably not your concern.

The reference count may tell you how many times it's been "loaded" but won't help in figuring out who loaded it.