Re: [boost] [lockfree] Review

Subject: Re: [boost] [lockfree] Review
From: Gottlob Frege (gottlobfrege_at_[hidden])
Date: 2011-08-06 02:30:05

On Wed, Aug 3, 2011 at 7:06 AM, Helge Bahmann <hcb_at_[hidden]> wrote:
>>
>> > - if the data is changing (through a writable mapping by someone else
>> > to the
>> > page), then you have some sort of producer-/consumer-problem and that
>> > is
>> > trivialley solvable with word-sized atomic operations
>>
>> Really?
>
> yes, really
>
> keep an "even" and an "odd" copy of your data structure, keep an atomically
> readable "generation counter" -- on access, read the generation counter, read
> the data (depending on parity of generation counter), read the generation
> counter again
>
> if it changed, start over. if it didn't change, you have your data; on
> modification, update generation counter as appropriate (if you are paranoid
> about counter overflows, you can repeat a similar trick with the counter
> itself)
>

This is single producer / single consumer?  (probably works for spmc
too).  But not multi-producer.  Right?
Or do misunderstand?

Tony