MATLAB: DLL loaded by mex would not unload?

I have a mex module called p.mexw64 which uses another dll called p.dll

The mex module loads p.dll when it is loaded since it is linking to it's lib file.

Normally, when I want to recompile p.dll I do clear p;. This unloads p.mexw64 and then in turn also unloads p.dll.

Except when it doesn't. In some scenario which I can't really quantify p.mexw64 is unloaded (I see that it is 开发者_如何学JAVAin Process Explorer) but p.dll remain loaded and is not freed.

Then I'm forced to close matlab in order to recompile d.dll which is a pain.

What could possibly make this dll remain loaded after the mex which used it is gone?

try clear all. Otherwise as a general solution, I find Unlocker an invaluable tool for Windows.