Immutable and Transient Objects and GC?

[Dimonax <dimonax@nospam.net>]

I'm researching the use of Immutable and Transient data structures in 
regards to Concurrent Garbage collection in Ada.

While my focus for the moment is on Garbage Collection, these kinds of 
data structures look useful for solving a lot of Concurrent programming 
issues.

An Immutable Object, conceptually, is pretty clear. I'm curious as to 
what methods you guys might have used to handle them.

Transient Objects, as a formal data type, might be a bit more 
challenging. I'd like a Transient Object to behave thusly....
It's created once. It exists until it is accessed one time and one time 
only, at which point it's storage is either re-initialized or reclaimed 
by the system.

I have some ideas on how this might work. But I'm still dancing around, 
trying to figure out how to do it well.

Tips and pointers?

Freejack
aka
Diogenese