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Subject: Re: [boost] [pool2] Requests for comment
From: Jeffrey Lee Hellrung, Jr. (jeffrey.hellrung_at_[hidden])
Date: 2012-10-16 22:39:00

On Tue, Oct 16, 2012 at 1:02 PM, Ion Gaztañaga <igaztanaga_at_[hidden]> wrote:

> El 16/10/2012 15:06, Klaim - Joël Lamotte escribió:
> Stable vector don't guarantee contiguity but it apparently does keep bloc
>> of objects contiguous as much as it can.
>> If you reserve your optionals at first, then a lot of contiguous memory is
>> allocated for your future objects, which is basically a pool.
>> I'd say the main difference with boost::pool for example is that you can't
>> have any input on the memory blocks boost::stable_vector will allocate.
> stable_vector allocs nodes even when just reserving (and of course when
> resizing). It keeps then in an internal pool as it offers better exception
> guarantees than vector: it does not throw a memory error exception (as
> memory was already reserved) and of course, it does not have potentially
> throwing move operations when inserting in the middle.
> I might be wrong on the boost::stable_vector behaviour but my current
>> tests
>> shows that it's a win win scenario in my case.
> If you reserve, then stable vector will call the allocator several times
> to reserve memory and fill the internal pool. That memory is probably
> contiguous (it depends on the allocator).
> In the near future I hope to improve the performance of stable_vector and
> other node containers adding "burst-allocation" extensions to a general
> purpose heap allocator, an improved version of:
> Current experiments are very encouraging.

Ah, I didn't know there were these additional optimizations behind the
scenes :)

- Jeff

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