On Sun, Feb 17, 2013 at 9:20 PM, Paul Coccoli <[email protected]> wrote:
> This scheme sounds error prone. In general, copying C++ objects via > memcpy (or writing them 1 byte at a time into the ringbuffer, which is > what I think you're proposing) is a bad idea. Nope, write them one sizeof( event->size() ) at a time. I'm very interested in why copying C++ objects like this is a bad idea. Its been discussed on list before ( http://linux-audio.4202.n7.nabble.com/Inter-thread-Communication-Design-Approach-td68710.html ). This seemed to be the best simple RT safe solution. If you have suggestions / improvements I'd love to hear them. JACK ringbuffers are > ideally suited to passing simple types (like floats), and not vairable > sized things (like different derived Event classes). Your enum for > event types is a bit of a red flag, too. While its perfectly valid, > "type flags" like this more often than not accompany inflexible, > tightly coupled code (which may be fine in a small audio app, but few > apps stay small). > > What about passing pointers via the ringbuffer? Pointers to an Event? Just makes it more hassle to send an Event from the RT thread. Involves taking X memory from a mem-pool, and then using placement new to construct the EventPlay(), and then send the pointer trough the ringbuffer. More complicated IMO. > To free the event objects, you could pass them back via a second > ringbuffer so the RT > threads aren't responsible for deleting them. > Indeed, that would be necessary. Again, more complications. That said, it can be done, and would involve less "traffic" trough the ringbuffer, and also "fixed size" traffic": pointers to EventBase.
_______________________________________________ Linux-audio-dev mailing list [email protected] http://lists.linuxaudio.org/listinfo/linux-audio-dev
