[Ffmpeg-devel] alsa input / output

Michael Niedermayer michaelni
Sun Mar 25 14:18:30 CEST 2007


Hi

On Sun, Mar 25, 2007 at 11:48:19AM +0200, Reimar D?ffinger wrote:
> Hello,
> On Sun, Mar 25, 2007 at 05:26:16AM +0200, Michael Niedermayer wrote:
> > > I should also note that such a lock-free implementation depends on
> > > volatile keyword working "well enough" and pointer reads and writes being
> > > atomic on the architecture...
> > 
> > could you show one example where volatile makes a difference in practice?
> 
> In practice maybe not, but in theory you could do
> while (av_fifo_size(f) <= 0) sleep();
> and the compiler might inline av_fifo_size (not gcc though unless we

NO!!!
no compiler can do this, it breaks the seperation of implementation and API
no way to relink with a lavu with different fifo implementation ...

any inlining must be limited to within lavu ...

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Those who are too smart to engage in politics are punished by being
governed by those who are dumber. -- Plato 
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