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Re: mt allocator documentation (draft)


On Tue, Feb 03, 2004 at 03:33:56PM +0100, Stefan Olsson wrote:
> >I'd just like to register the fact that I greatly appreciate time
> >taken to ensure that single-threaded performance is still "as good as
> >possible".  
> >
> Bad choice of words...
> ...the goal is of course to get as good performance as possible in 
> single threaded applications as well - my mind is just so set on multi 
> threading right now =)

I meant it as a compliment, not a complaint ;)  I meant I was glad to
see that ST had been an important factor.

> You are quite right, when __GTHREADS is undefined we could also remove 
> the thread_id var from the block_record struct.
> 
> The reason - which at the time when I am writing this I am no longer 
> sure that it actually is a reason - was to keep the memory layout the 
> same if a ST and a MT program somehow shared containers via some obscure 
> IPC mechanism...
> ...not very likely huh? This should probably be changed to save memory.

I agree.  I doubt any real-word application would boldly assume that
one could allocate and deallocate STL memory across such a conduit.  I
definitely would never rely on it since, clearly, libstdc++ is free to
change its underlying allocation scheme from release to release, so it
would be a compatibility nightmare. :)

-- 
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