[linux-audio-dev] Lock Free Ringbuffer in C ?

[Ingo Oeser]

On Fri, Apr 04, 2003 at 07:43:40AM -0500, Paul Davis wrote:
> there are several solutions, none of them particularly good. the best
> is to wait on a FIFO. these provide a fast, 99% non-blocking way to
> get 1 process to wake up another. the "real" solution needs to be
> provided by the kernel, and futexes in 2.5/2.6 will be fairly
> close. they are still not completely correct for our purposes, but
> they will probably work OK.

The futexes are the solution. You can basically wait, until a
long at a specified address is changed, if you tell the kernel
that it might be changed, after you did. So the kernel just does
the sleep/wakeup for you, nothing else.

But you can also just do what you want and use the NPTL of RH9,
which uses futexes transparently, if available.

That way you get a performance gain on machines you recommend
while still being correct on every other machine with POSIX
threading implemented.

Regards

Ingo Oeser
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