Re: C++ Memory Management Innovation: GC Allocator

"xu****wei" <xu****weizh@[EMAIL PROTECTED]
> wrote in message
news:52ee8318-2611-4883-bbef-33c9a566bb75@[EMAIL PROTECTED]
> On 4ÔÂ22ÈÕ, ÉÏÎç9ʱ52·Ö, "Chris Thomasson" <cris...@[EMAIL PROTECTED]
> wrote:
>> "Chris Thomasson" <cris...@[EMAIL PROTECTED]
> wrote in message
>>
>> If I am correct, well, "perhaps" I have something that just might be
able 
>> to
>> help your allocator. There is an invention that can transform most
>> single-threaded memory allocators into scaleable multi-threaded ones; 
>> here
>> is my initial post:
>>
>>
http://groups.google.com/group/comp.arch/browse_frm/thread/6dc825ec99...
>>
>> basically, you create single-threaded allocator and plug it into the 
>> system,
>> then, boom, its multi-threaded. If you have any questions, feel free to

>> fire
>> away...
>
>
> I'm sorry but I think you misunderstand my points. I don't want to
> create single-threaded allocator.
>
> Why? Sharing GC Allocator in multi threads is not recommended. It
> means that sharing memory between threads is also not recommended. If
> you REALLY want to share memory, use new/delete or anything else.
>
> For users of GC Allocator, we suggest that only use ONE BlockPool
> instance in ONE thread, and ONE thread may use multiple PRIVATE
> "ScopeAlloc" instances (depend on your requirement) to allocate
> memory.
[...]

You did create a purely single-threaded allocator. Your saying that I need
to create an allocator instance per-thread, but I cannot do cross thread
deallocations using them because they provide no sup****t for
synchronization. Did you know that there are multi-threaded allocators
that
are based on per-thread heaps? Check StreamFlow or Hoard do***entation. If
I
use those allocators I can allocate memory in Thread A and deallocate in
Thread A without any synchronization whatsoever, however, if I deallocate
in
Thread B then there is an interlocked RMW instruction. This aspect makes
them more flexible. For your own words, I cannot create a simple
producer/consumer pattern using your algorithm because they are not
thread-safe.


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