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From "Xiao-Feng Li" <xiaofeng...@gmail.com>
Subject Re: Need info on copy-on-write support on Harmony
Date Sun, 06 Apr 2008 14:45:24 GMT
Yes, I think COW is not mandatory for Parrot. Thanks, -xiaofeng

On Sun, Apr 6, 2008 at 10:32 PM, Senaka Fernando <senakafdo@gmail.com> wrote:
> Hi Xiao-Feng, Alexei,
>
>  Thanks for the update. I'm not 100% aware of the usefulness of COW beyond
>  the scope of the Parrot VM, since this is a VM, the usefulness of COW would
>  depend on the upper layers that use it. Thus, perhaps when thinking about
>  uses of Parrot, and as we are interested in plugging the Harmony GC_Gen to
>  Parrot, we might need to support COW at least at an intermediate layer.
>
>  Most probably as it seems I believe that this can be handled in the
>  interfacing (porting) layer between Harmony and Parrot, which seems a bit
>  required in terms of interface aligning, as it seems. But, the approach
>  shouldn't need a 1-1 wrapper. This can rather be tailored to address
>  problems that may arise when aligning the interfaces.
>
>  Regards,
>  Senaka
>
>
>
>  On Sun, Apr 6, 2008 at 7:18 PM, Xiao-Feng Li <xiaofeng.li@gmail.com> wrote:
>
>  > Harmony GC doesn't have COW support (at the moment). COW can help to
>  > reduce the footprint when multiple processes are forked sharing data.
>  > It's not useful for Java (at the moment) because Java uses threads
>  > mostly.  Before we have real needs (workloads) for COW, we are not
>  > able to give an appropriate design.
>  >
>  > Thanks,
>  > xiaofeng
>  >
>  > On Sun, Apr 6, 2008 at 7:27 PM, Senaka Fernando <senakafdo@gmail.com>
>  > wrote:
>  > > Hi Alexei,
>  > >
>  > >  This issue came up when I was trying to match interfaces of Harmony
>  > GC_Gen
>  > >  and Parrot. It seems that the Parrot GC is aware on whether COW is
>  > used.
>  > >
>  > >  ex:- clear_cow, used_cow in dod.h
>  > >
>  > >  It seems that it maintains a COW ref count etc.
>  > >
>  > >  Regards,
>  > >  Senaka
>  > >
>  > >  On Sun, Apr 6, 2008 at 4:39 PM, Alexei Fedotov <
>  > alexei.fedotov@gmail.com>
>  > >  wrote:
>  > >
>  > >
>  > >
>  > >  > Hello Senaka,
>  > >  >
>  > >  > Copy-on-write semantics is used for native strings, see unistr.h If
>  > GC
>  > >  > would use copy-on-write, this would be rather implementation than
>  > >  > interface. Why do you need this info?
>  > >  >
>  > >  > Thanks.
>  > >  >
>  > >  > On Sun, Apr 6, 2008 at 12:36 PM, Senaka Fernando <senakafdo@gmail.com
>  > >
>  > >  > wrote:
>  > >  > > Hi all,
>  > >  > >
>  > >  > >  Need info on copy-on-write support on Harmony. I tried grepping
>  > the
>  > >  > source
>  > >  > >  but didn't uncover any related info. I also tried googling which
>  > was
>  > >  > not
>  > >  > >  that helpful. I would like to know whether Harmony has this
>  > feature?
>  > >  > and a
>  > >  > >  possible hint on where I should be looking would be really
>  > helpful.
>  > >  > >
>  > >  > >  Regards,
>  > >  > >  Senaka
>  > >  > >
>  > >  >
>  > >  >
>  > >  >
>  > >  > --
>  > >  > With best regards,
>  > >  > Alexei
>  > >  >
>  > >
>  >
>  >
>  >
>  > --
>  > http://xiao-feng.blogspot.com
>  >
>



-- 
http://xiao-feng.blogspot.com

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