[linux-audio-dev] Lock Free Ringbuffer in C ?

[David Olofson]

On Friday 04 April 2003 17.15, torbenh at gmx.de wrote:
[...]
> 	res = sfifo_write(sf, &buf, j);
> 	if(res != j)
> 	{

DOH! Sorry, I'm in a hurry and misread your code.

Well, we're talking about a basic lock free FIFO here, based on atomic 
reads and writes of two indices. Proper blocking read() and write() 
would require talking to the OS scheduler one way or another (block + 
wake up functionality), and that's not even possible on some of the 
platforms this code is used on.

That said, I do have a version with busy-waiting versions, meant for 
use with IRQs in environments without threads. I wouldn't recommend 
using this on any multitasking OS, though, except possibly for IPC 
across CPUs in SMP systems in some special cases.


//David Olofson - Programmer, Composer, Open Source Advocate

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