[Boost-users] [ptr_container]delete_clone and shared libraries

Subject: [Boost-users] [ptr_container]delete_clone and shared libraries
From: Robert Dailey (rcdailey_at_[hidden])
Date: 2009-06-24 11:51:46

On Windows, I plan to create a ptr_vector in a separate DLL and propagate it
to the executable for ownership (Factory-style). The executable will be
responsible for the lifetime of this ptr_vector, and will eventually result
in "delete" being called on each element in the ptr_vector. However, this
'delete' will be from the executable's memory manager, when the memory was
originally allocated in the shared library's memory manager, causing serious
issues.
It would be ideal to specify a delete_clone class that ptr_vector would use
(via ADL) and would force those objects in the ptr_vector to use the
'delete' call from the DLL's memory manager, and not the executable's.

I don't see that this is going to be possible, or at least able to be done
easily. Since the delete_clone's operator will have to be implemented in a
CPP file, so it will be included into the shared library. This also implies
that I'll have to import the delete_clone's interface, since this DLL will
be loaded dynamically with LoadLibrary() in Windows. I just don't see this
happening.

Now, if ptr_vector had a function like so:

ptr_vector::set_deleter()

I could give it a pointer to a global function in my DLL, and the deleter
becomes fully transparent to my executable. It just has to keep the
ptr_vector around and let it fall out of scope and the deleter from the DLL
will be used to delete each object in the ptr_vector. However, it isn't this
simple and I need advice on how I can make this work.

Thanks.