What exactly shared means?

[via Digitalmars-d-learn]

On Friday, 2 January 2015 at 23:10:46 UTC, John Colvin wrote:
> What significant optimisations does SC-DRF actually prevent?

By "SC-DRF" I assume you mean the Java memory model. AFAIK SCDRF 
just means that if you syncronize correctly (manually) then you 
will get sequential consistency (restriction on the compiler).

Getting rid of the restrictions on the compiler and eliding 
programmer-provided syncronization allows for more optimizations 
on loads, writes, reordering, syncronization/refcounting...?