[LAD] Fwd: [LAU] Simple, easy multithreaded circular buffer library for Linux?

From: Sean Bolton Date: October 22, 2008 11:45:31 AM PDT To: Olivier Guilyardi Cc: linux-audio-dev(a)lists.linuxaudio.org Subject: Re: [LAD] [LAU] Simple, easy multithreaded circular buffer library for Linux? On Oct 20, 2008, at 3:18 PM, Olivier Guilyardi wrote: They all pass on my uniprocessor G4, but that doesn't really tell us much. Anybody got a multiprocessor PPC? This stuff makes my head hurt, too, but as best I can figure out, I believe the jack code needs memory barriers on several non-x86 architectures with weak memory ordering, PPC probably being the most common. It appears to me that without barriers, there's a small chance reordered writes on one processor could result in another processor reading invalid data: CPU1: CPU2: write index --- write data2 read index write data3 read data1 <- invalid write data1 read data2 --- read data3 x Paul E. McKenney Memory Ordering in Modern Microprocessors, Part I http://www.linuxjournal.com/article/8211 Memory Ordering in Modern Microprocessors, Part II http://www.linuxjournal.com/article/8212 Linus Torvalds Re: Memory barriers and spin_unlock safety http://lkml.org/lkml/2006/3/3/142 Parts of this *thread* Re: Re: [liblf-dev] Possible lock-free ring buffer: msg#00152 http://techweb.rfa.org/pipermail/portaudio/2006-May/005661.html