Some updates to TPCircularBuffer

I’ve recently made some updates to [TPCircularBuffer](http://atastypixel.com/circular-ring-buffer-plus-neat-virtual-memory-mapping-trick/) ([on GitHub](https://github.com/michaeltyson/TPCircularBuffer)), my C circular/ring buffer implementation, which add a memory barrier on read and write, inline the main functions for a potential performance boost, and add support for use within C++ projects.

If you’re using TPCircularBuffer at all, I recommend updating!

One Comment

Jean-François Brouil

February 14, 2012 at 11:08 pm

You might want to consider using NS_INLINE rather than static inline'. My experience is that the former, probably due to the "always_inline" attribute *does* inline my C++ header code, whereas barestatic inline’ doesn’t:

    #define NS_INLINE static inline attribute((always_inline))

Michael Tyson
February 15, 2012 at 8:29 am

Ah, thanks very much for the suggestion, Jean-François! I’ll try it out.

Shahzeb

March 14, 2012 at 4:03 pm

Hi Michael,

Thanks for this wonderful implementation.

I have seen TPCircularBuffer working absolutely fine in AudioGraph’s sample project, but when I add the .h and .c files of TPCircularBuffer to my project, and import the .h file in my RealTimeAudioController.mm, it gives me the ‘Apple Mach-o-linker error’ saying :

Undefined symbols for architecture armv7: “__Z20TPCircularBufferInitP22TPCircularBufferRecordi”, referenced from: -[RealtimeAudioController initDelayBuffer] in RealtimeAudioController.o ld: symbol(s) not found for architecture armv7 clang: error: linker command failed with exit code 1 (use -v to see invocation)

I have checked and all the required frameworks are added. No idea why that’s happening.

Any help in this regard will be highly appreciated.

Thanks.

Shahzeb
March 14, 2012 at 4:17 pm

In case somebody else is having the same problem as me, here is the solution that worked for me,

When you import the header, instead of writing, import TPCircularBuffer.h

Just write the following, extern “C” { include “TPCircularBuffer.h” };

Chamin Morikawa

February 8, 2013 at 1:55 am

Thanks a lot for sharing the circular buffer implementation; easy to use, and fast.

For the benefit of those who want to use the circular buffer for playing large audio files while processing PCM samples, I created a sample application:

https://github.com/iitotoro/BufferedAudioPlayer.git

Michael Tyson
February 8, 2013 at 2:54 am

My pleasure Chamin!

One thing you should know: You should never (ever) allocate or free memory, or perform Objective-C calls from within the Remote IO callback (or the Core Audio thread, generally). The result will be occasional (maybe even frequent) horrible audio glitches.

Here’s a decent article on this: http://www.rossbencina.com/code/real-time-audio-programming-101-time-waits-for-nothing
Michael Tyson
February 8, 2013 at 2:55 am

Incidentally, also check out the AudioBufferList stuff from TPCircularBuffer – that’s designed to make a lot of this stuff easier, and you might find yourself saving quite a few lines of code.
1. Chamin Morikawa
  February 8, 2013 at 4:56 am
  
  Thanks a lot! will check both and refine the code, too.

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