Re: new-ing an exported class
On 14 Nov 2006 05:09:21 -0800, "ben" <brm@morrisb.fsnet.co.uk> wrote:
Hi,
If I create an object on the heap by calling new() in an .exe then the
.exe's heap manager creates the object. If I call new() in a DLL then
the DLL's heap manager creates the object for me. What happens if I
create an object on the heap in an exe then pass an object reference to
a DLL that calls a method on the object that calls new(). Which heap
manager creates the object, i.e. the exe's or the dll's? I think it's
the .exe's because the object's code is in the exe
You lost me there. Per your subject line, the class is exported from a DLL,
so the "method" is a member function, and so the "object's code" is in the
DLL.
and so the function
that is invoked by the DLL on the object will run inside the exe. Does
this sound right?
The heap manager belonging to the module (EXE or DLL) invoking new is the
one that will be used. If it is an exported function calling new, the only
way it escapes its module is if it is an inline function actually expanded
inline in another module. So if you new an exported class in an EXE, the
EXE's heap will be used. If you call a member function implemented by the
DLL on the object, that member function will use the DLL's heap when it
invokes new.
More subtle is the determination of the operator delete function to call;
it depends on whether or not you used __declspec(dllimport) on the class,
and whether or not the class has a virtual destructor. See this message for
more:
http://groups.google.com/group/microsoft.public.vc.language/msg/55cdcefeaf770212
--
Doug Harrison
Visual C++ MVP