Mac Apps That Use Garbage Collection Must Move to ARC

[Martin Nowak via Digitalmars-d]

On Tuesday, 3 March 2015 at 02:05:08 UTC, Walter Bright wrote:
> On 3/2/2015 11:38 AM, Martin Nowak wrote:
>> Compacting is indeed easy once we have a precise GC, and can 
>> be done
>> partially, i.e. objects pointed to by the stack/register are 
>> pinned.
>
> Also unions.

Compacting doesn't solve the inherent performance problem of a 
conservative GC though. It's the capability to run small 
incremental collections that make modern GCs fast. With a 
conservative GC you always have to mark the complete heap to even 
free a single object. Shoveling a 1GB heap from main memory 
through your CPU already takes 250ms, and on top of that comes 
memory latency for non-sequential traversing and the actual 
marking.