[LAD] memory allocation for the real time thread, opinions wanted

[Paul Coccoli]

On Mon, Feb 27, 2012 at 8:43 PM, James Morris <james at jwm-art.net> wrote:
> On Mon, 27 Feb 2012 20:01:18 -0500
> Paul Coccoli <pcoccoli at gmail.com> wrote:
[Mass snippage]
>> Why not just use 2 ringbuffers: one to send pointers to the RT thread,
>> and a second to send them back to the low prio thread (so it can free
>> them).  You probably need a semaphore for the return ringbuffer, but
>> that should be RT-safe.
>
> That's what I thought... would be better for someone who is new to real
> time threads and memory allocation... and is what I decided on... minus
> the semaphore.
>
> So why is a semaphore needed? If the RT thread only sends an item back
> when it absolutely no longer will use it?

I suppose the semaphore isn't strictly necessary, but I think it's an
easy way to tell the main thread that it has a message to process.
Although one that probably doesn't integrate well with most
main/non-RT threads.