What is the mutator?

[Bulat Ziganshin]

Hello Jason,

Thursday, August 6, 2009, 11:38:08 AM, you wrote:

>     One solution to the GC synchronisation problem would be to
>     implement a concurrent garbage collector. Typically,
>     however, concurrent GC adds some overhead to the mutator,
>     since it must synchronise with the collector.some thunks are
>     never “black-holed”, so giving a potential performance win.
>     Unfortunately, in the parallel setting, it substantially
>     enlarges the time window in which two or more duplicate
>     threads might evaluate the same think, and thus

i'm not an expert, but: lazy haskell value is some expression to
comupte. when this value started to evaluate, it's replaced by "black
hole" - special value. attempt to compute black-holed value (in the
same thread) means that we have cyclic computation dependency -
exception triggered. once value of thunk is evaluated, it's written
back by code called mutator


-- 
Best regards,
 Bulat                            mailto:Bulat.Ziganshin at gmail.com