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Subject: Re: [boost] [xint] Third release is ready, requesting preliminary review
From: Chad Nelson (chad.thecomfychair_at_[hidden])
Date: 2010-05-02 10:58:34

Hash: SHA1

On 05/02/2010 02:44 AM, joel falcou wrote:

>> If you're saying that people often write multithreaded programs, then I
>> have to disagree. In my experience, it's rare, and most programmers
>> actively avoid them.
> Plural of anedocte is not data.
> In genral, not taking multithreading seriously now is likely to be a
> problem in the upcoming years.

I thought I *was* taking it seriously. I'm providing a way to support
it, after all. :-)

>>> Then it means you did somethign wrong or the code doesn't lend itself
>>> to trivial multithreading ...
> Sorry for the tone of that, I wasn't implying anything wrong with
> yourself, just that this kind of result (multithreaded version being
> slower) is usually because soemthing don't lend itself to be
> multithreaded. Do you have this MT code somewhere still, i may have
> a look if needed.

All of the code is available in the Boost Sandbox
<> and Vault

There are only two (well, three now) things that change when switching
to the thread-safe version: integers aren't allowed to use
copy-on-write, access to the random number generator is serialized, and
(now) Boost.Move semantics are enabled.

I've been assuming that the copy-on-write was responsible for the major
part of the speed difference, but after thinking about it, that doesn't
make a lot of sense. The serialized access to the random number
generator could be responsible for a good part of it. The tests I based
that assumption on used it heavily. I'll run some further tests when I
have a chance today to see how they turn out.
- --
Chad Nelson
Oak Circle Software, Inc.
Version: GnuPG v1.4.10 (GNU/Linux)
Comment: Using GnuPG with Mozilla -


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