Is shared ownership of objects a sign of bad design?

Question

Background: When reading Dr. Stroustrup\'s papers and FAQs, I notice some strong \"opinions\" and great advices from legendary CS scientist and programmer. One

Answer 1

Is Garbage Collection a Design Pattern? I don't know.

The big advantage of shared ownership, is its inherent predictability. With GC the reclamation of resources is out of your hands. Thats the point. When, and how it happens is usually not on the mind of the developer using it. With shared ownership, you are in control (beware, sometimes too much control is a bad thing). Lets say your app spawns off a million shared_ptr's to X. All of those are your doing, you are responsible for them and you have total control over when those references are created and destroyed. So a determined and careful programmer should know exaclty who references what and for how long. If you want an object to be destroyed, you have to destroy all the shared references to it, and viola, it's gone.

This carries some profound consequences for people who make realtime software, which MUST be totally predictable. This also means you can fudge up in ways that look an awful lot like memory leaks. I personally don't want to be a determined and careful programmer when I don't have to be (go ahead and laugh, I want to go on picnics and bike rides, not count my references), so where appropriate GC is my prefered route. I have written a little bit of realtime sound software, and used shared references to manage resources predictably.

Your question: When does RAII fail? (In the context of shared references) My Answer: When you can't answer the question: who may have a reference to this? When vicious insipid circles of ownership develop.

My question: When does GC fail? My answer: When you want total control and predictability. When the GC is the written by Sun Microsystems in a last minute dash to deadline and has ridiculous behaviors which could only have been designed and implemented by severely drunk protohuman code monkeys borrowed from Microsoft.

My opinion: I think BS is just really serious about clear design. It seems obvious that having one place where resources are destroyed is usually a clearer design than having many places where they might destroyed.