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

Olivier Guilyardi ml at xung.org
Tue Oct 14 07:38:40 EDT 2008


Hi Ken,

Ken Restivo wrote:
> It has been over 7 years since I last messed around with writing Pthreads applications.
> 
> I recall it as a painful, ugly, brain-numbing task. I located an exercise I did back then to address the consumer/producer problem in Pthreads, and just the sight of it is giving me a headache.
> 
> I'm being lazy, so instead of researching everything that's out there, I'll ask here: can anyone recommend a relatively simple and painless abstraction library (GPL or LGPL of course) that will give me functions to create a thread in which I can stuff things into a ring buffer, and another thread in which I can pull stuff out of it?
> 
> By the way, I know that JACK has a very nice event buffer which is insanely easy to use (and I have), and makes multithreading almost transparent, but this isn't a JACK app.

I don't know of any abstraction library, but creating/terminating a normal
thread with pthread is really an easy task IMO. It's about 10 lines in C.

For inter-thread communication there's Portaudio's ring buffer:
http://portaudio.com/trac/browser/portaudio/trunk/src/common/pa_ringbuffer.h

It can easily be used out of Portaudio (I'm currently doing that), and it
features memory barriers [1] which AFAIK Jack's ringbuffer doesn't.

One problem with everything Portaudio is this heavy naming scheme. For a simpler
API, you might like my little wrapper:
http://jackbeat.samalyse.org/browser/jackbeat/trunk/src/core/ringbuffer.h

Portaudio actually also offers a callback mechanism (with hidden thread
creation), so if you're coding an non-JACK audio app, you might want to check it
out.

For thread synchronization, semaphores (man semaphore.h) are really easy to use.
However, if you need a lock-free equivalent (for realtime, ...) phtread mutex
and especially pthread_mutex_trylock are your friends.

[1] http://www.audiomulch.com/~rossb/code/lockfree/

Cheers,

-- 
  Olivier Guilyardi / Samalyse



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