[FFmpeg-cvslog] avcodec/ff_init_vlc_sparse: use a spinlock for thread sync

[Carl Eugen Hoyos]

Reimar Döffinger <Reimar.Doeffinger <at> gmx.de> writes:

> >> avcodec/ff_init_vlc_sparse: use a spinlock for thread sync
> > 
> > This commit leads to many deadlocks when running fate 
> > on AIX PPC64, for example when reading the mp2 file 
> > produced by fate-acodec-mp2.
> 
> I don't know the exact code that was used, but spinlocks 
> in the traditional sense can only be used when you can 
> _guarantee_ that each thread runs on its own, fully 
> independent CPU.

Some observations:
It works fine on the same hardware, the same OS and the 
same compiler for 32bit. It also works fine on very 
similar hardware and a different OX for 64bit.

Carl Eugen