Re: [boost] [Review] Shmem

From: Fred Bertsch (fred.bertsch_at_[hidden])
Date: 2006-02-07 15:38:00

On 2/7/06, Fred Bertsch <fred.bertsch_at_[hidden]> wrote:
> Second, there isn't as much type safety as there could be in a lot of
> these classes. For example, shared_message_queue does not have a
> template parameter to determine what is stored in the queue. Instead,
> its send and receive member functions take void*'s. Is there a good
> reason for this? I suppose another process could use the same
> shared_message_queue with another type, but I'd really like to see
> some type safety within the same process.

After rereading the documentation and reading the code, I think I was
confused when I wrote this. It appears that the shared_message_queue
cannot be used for objects created with the
named_shared_object::construct member function. A memcpy is done on
the buffer passed into send, so objects cannot be sent. Thus, a void*
is correct.

I do think that the documentation should be improved on that. I wasn't
sure until I dug into the source code. If there are other places in
the shmem library that don't support objects, I'd like to see those
documented as well.

Shmem is the first library I've seen that tries to support passing a
C++ object through shared memory to another process. It seems like a
really good idea, and I'd be happier if it were supported throughout
the library. Maybe the shared_message_queue should support only
offset_ptr's to objects that are created elsewhere in the
named_shared_object?