Persistent list

[Andrei Alexandrescu via Digitalmars-d]

On 11/15/2015 03:23 PM, Dicebot wrote:
> On Friday, 13 November 2015 at 23:10:04 UTC, Andrei Alexandrescu wrote:
>> I created a simple persistent list with reference counting and custom
>> allocation at http://dpaste.dzfl.pl/0981640c2835.
>
>
> There is also another thing I wanted to mention on topic of persistent
> containers. Right now for me the most intriguing topic is trying to
> define immutable (and actually thread shared) cache data structure than
> can be efficiently and safely used without GC. There is whole class of
> tasks where you can get best performance by building new copy of cache
> in memory instead of modifying separate elements, trading increased
> memory concsumption for fast no lock parallel access. However in absence
> of GC task of deleting memory for older generations of cache becomes
> rather challenging. I have been thinking about approach with external
> two-level reference counting + dedicated allocator - quick thread-local
> RC comes first and once it goes to 0, shared RC in allocator gets
> decremented (being effetively user thread counter). Do you think it can
> work?

I don't think we can make that work with current language semantics. 
I'll post more about that soonish. -- Andrei