[ruby-core:36436] Re: GC thought

In order to have a multi-threading marking-phrase everything needs to
be thread-safe.

However, a multi-threaded sweeping-phrase does *not* require thread
safety. The sweeper will only release objects that's garbage (not
being marked) and nothing can go from garbage to alive. It doesn't
matter if code is run in parallell: if it's garbage once it's garbage
forever.

// Magnus Holm

On Tue, May 24, 2011 at 19:51, Asher <[e-mail]> wrote:
> My understanding was that there are relatively major thread-safe issues all around?
>
> I believe that doing this would require locking/unlocking every heap slot every time it's accessed— at that point, why stop the first thread at all?
>
> From what little I know from having looked into the GC before, I thought that multi-threaded GC is a fairly standard option but not feasible here.
>
> But I'm also interested to hear more from those in the know.
>
> Asher
>
> On May 24, 2011, at 10:57 AM, Roger Pack wrote:
>
>> Hello all.
>> Had a thought for improving ruby's GC the other day.
>>
>> Currently it's
>>
>> *stop world*
>> mark
>> sweep
>> *start world*
>>
>> suggestion:
>>
>> *stop world*
>> mark
>> sweep a little bit
>> *start world*
>> finish sweep in another thread.
>>
>> (Obviously there's be some ramifications, like having to add some
>> locks here or there, and doing some thread joins, but hopefully that
>> wouldn't cost too much cpu-wise).
>> Thoughts?
>> -roger-
>>
>
>
>