Re: [Boost-users] [Intrusive] unordered_set and thread safety

Subject: Re: [Boost-users] [Intrusive] unordered_set and thread safety
From: Dmitriy Matison (matison.d_at_[hidden])
Date: 2012-11-22 04:01:01

Hi Alexandre,

Please, notify us if you will find one that meets your requirements.

Thanks,
Dmitriy.

С уважением,
Матисон Дмитрий.

On 22 November 2012 12:41, Alexandre Hamez <alexandre.hamez_at_[hidden]>wrote:

> On 21 nov. 2012, at 22:14, Ion Gaztañaga <igaztanaga_at_[hidden]> wrote:
>
> > El 18/11/2012 8:56, Alexandre Hamez escribió:
> >> Hello,
> >>
> >>      I'm currently using intrusive:: unordered_set in a single threaded
> application. But now, I need to switch to a multi threaded application. As
> such, the unordered_set must be protected.
> >>      I don't want to block the whole table with a single mutex. Thus,
> it would be fine to have a lock per bucket. Furthermore, intrusive::
> unordered_set provides a bucket_traits mechanism to enable some
> customization.
> >>      So, my question: is it possible to use bucket_traits to have a
> lock per bucket?
> >
> > I don't think so. We can obtain the bucket from the value but there is
> no insert function taking a bucket as argument. That would be an easy way
> to get some paralelism, at least for insertions. Intrusive could guarantee
> that the bucket search can be done in parallel and the insert_in_bucket
> function could be called with a locked mutex.
> >
> > We would need an erase_from_bucket function that does not return an
> iterator to the next remaining object, as that could provoke race
> conditions (the next remaining object can be in a different bucket).
> >
> > It's an interesting optimization for Intrusive, but I'm afraid it's not
> trivial.
>         Thanks for your answer. I thought so that it was no feasible in
> the current state of Intrusive. I have then no other choice than to find a
> (intrusive) concurrent hash map implementation, or worst, to write my own
> :-).
>
> Best regards,
>
> > Best,
> >
> > Ion
> >
> > _______________________________________________
> > Boost-users mailing list
> > Boost-users_at_[hidden]
> > http://lists.boost.org/mailman/listinfo.cgi/boost-users
>
> --
> Alexandre Hamez
>
>
>
>
>
>
>
>
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