A couple of the guys here at work were talking about passing around large objects with the nodelets when we realised there was no thread safety attached to the objects that were getting passed around. Is there any plans to add this functionality to them? i.e. either via something like a Mutex.msg you could include with your other msg's (aka Time.msg) or perhaps via a thread safe shared pointer that you could use when publishing.

I'm not really sure what you mean -- boost::shared_ptr is atomically reference counted, so it the object won't be deleted out from under you if you have multiple subscribers to the same topic. If you need to modify the object in the subscriber you can subscribe to a non-const version of the message, and it will make a copy for you if there are multiple subscribers. Do you mean you want to be able to modify the object on the publisher side after you've sent it?

Josh