std.container.BinaryHeap + refCounted = WTF???

[Steven Schveighoffer]

On Mon, 29 Nov 2010 10:58:05 -0500, dsimcha <dsimcha at yahoo.com> wrote:

> == Quote from Steven Schveighoffer (schveiguy at yahoo.com)'s article
>> On Wed, 17 Nov 2010 12:09:11 -0500, dsimcha <dsimcha at yahoo.com> wrote:
>> > == Quote from Steven Schveighoffer (schveiguy at yahoo.com)'s article
>> >> The issue is that if you append to such an array and it adds more  
>> pages
>> >> in
>> >> place, the block length location will move.  Since each thread caches
>> >> its
>> >> own copy of the block info, one will be wrong and look at array data
>> >> thinking it's a length field.
>> >> Even if you surround the appends with a lock, it will still cause
>> >> problems
>> >> because of the cache.  I'm not sure there's any way to reliably  
>> append
>> >> to
>> >> such data from multiple threads.
>> >> -Steve
>> >
>> > Would assumeSafeAppend() do the trick?
>> >
>> No, that does not affect your cache.  I probably should add a function  
>> to
>> append without using the cache.
>> -Steve
>
> How about using std.array.Appender?  This looks safe as far as I can  
> tell, but I
> want to make sure there aren't any obscure implementation details that  
> would
> prevent this from working, too.

That should be fine, std.array.Appender does not affect the LRU cache.  In  
fact, if you try to do normal appending to an array built with Appender,  
it will automatically reallocate because the memory does not have the  
APPENDABLE bit set (new GC bit I added to avoid misinterpretations).

This is a good solution.

-Steve