On 12/9/14 3:18 PM, Ali Çehreli wrote:
On 12/09/2014 11:56 AM, Steven Schveighoffer wrote:
>> i checked attributes for GC block holding this array:
>>
>> ```
>> FINALIZE NO_SCAN NO_MOVE APPENDABLE NO_INTERIOR
>> ```
>>
>
> That does not sound right at all. No block should ever have both
> FINALIZE (reserved for objects only) and APPENDABLE (reserved for arrays
> only).
FINALIZE and APPENDABLE together sounds like "an array that holds class
objects."
I think I get it as I write this: Do we mean that the array should
always hold class references and the class objects should live on other
blocks? If so, the memory block for the objects can be marked as
FINALIZE?
Yes, that's exactly right. A class is never allocated "inline" inside
another object or an array.
What block should be APPENDABLE?
The array of class references can be APPENDABLE.
Of course, this may be all in the documentation but I can't understand
it. ;) Here is what is says for FINALIZE: "Finalize the data in this
block on collect." (I will study that part a little more. :p)
http://dlang.org/phobos/core_memory.html#.GC.BlkAttr.FINALIZE
In truth, the code expects the block then to have a ClassInfo pointer at
the beginning of the block.
See here:
https://github.com/D-Programming-Language/druntime/blob/master/src/rt/lifetime.d#L1225
-Steve
