[dmd-concurrency] Smoke test

[Walter Bright]

Sean Kelly wrote:
> On Jan 7, 2010, at 1:18 PM, Michel Fortin wrote:
>   
>> I'm not against promoting memory blocks to the shared GC, but I'd like this to be just a feature of the GC in the runtime, not a requirement for the concurrency model to make sense. In a way, it shouldn't be done implicitly.
>>     
>
> That's a good point.  And it's certainly what I was going for until this shared reference issue threw a wrench in the works and I panicked :-).  I agree that this should be a part of the rule because I'd consider the model broken otherwise.
> _______________________________________________
>   

Having a per-thread gc is an optimization, not a fundamental feature of 
the concurrency model. For one thing, it precludes casting data to 
immutable. For another, it may result in excessive memory consumption as 
one thread may have a lot of unused data in its pool that is not 
available for allocation by another thread.