Componentizing D's garbage collector

[Dmitry Olshansky]

13-Jan-2014 13:20, Rainer Schuetze пишет:
> On Sunday, 12 January 2014 at 10:40:50 UTC, Benjamin Thaut wrote:
>> Am 12.01.2014 11:27, schrieb Rainer Schuetze:
>>>
>>> I think a moving collector is currently not feasible without restricting
>>> the language a lot, probably similar to safe D and more. I'm not sure we
>>> want that in general.
>>>
>>
>> Could you give an example which part of the language would not be
>> doable with a moving collector? The only thing that comes to my mind
>> is unions and that problem can be solved by allowing the user to
>> specify manual scanning functions for structs or classes containing
>> unions.
>
> Maybe I'm too pessimistic ;-) I guess moving in general could be ok, I
> was thinking about segregating heaps by type (shared/immutable/mutable)
> and moving data between them adds restrictions. I'd like to be proven
> wrong.
>
> Some thoughts regarding a moving collector:
>

> Having to explicitely pin every pointer passed to C functions would be
> very expensive.

How would it be expensive? I don't see a need to do anything to "pin" a 
memory block, at the time of scanning there will be a potential pointer 
to it (in the stack space of C function or registers).

-- 
Dmitry Olshansky