Re: [Denemo-devel] Showstopper bug?

[Dominic Sacré]

Hi Richard,

On Thursday 10 May 2012 10:44:20 Richard Shann wrote:
> Dominic Sacre came on irc #denemo to report problems with playback. He
> pointed out that the page_for_time() is not thread-safe.
> I felt torn about declaring this a showstopper for the release, as we
> have been so long in getting this release out, but threading bugs are
> so pernicious that I think we have to put in a fix for this and make
> another release candidate.

I noticed more playback issues. Some of these may be specific to certain 
backends (or combinations thereof), I'll have to do more testing and 
debugging to be sure.

- Sometimes playback just doesn't start. The "playback only works once" 
issue I mentioned before seems to be a common case of this problem, but 
somehow this has become harder for me to (intentionally) reproduce.

- Occasionally playback stops after a few seconds, always at the same 
position in the score.

- The JACK backends cause an xrun every time I stop playback. Every now 
and then, Denemo gets zombified by JACK.

- PortMidi output is completely disabled, due to an unconditional return 
statement in the process_midi() function. If, as the comment in that 
function suggests, the PortAudio backend supports some feature that the 
PortMidi backend doesn't, doesn't this apply to the ALSA and JACK backends 
as well?

All in all, I don't think Denemo in its current state is quite ready for 
release yet. The chance of users stumbling upon one or more of these 
issues is just too high.
If that's ok for you, I'd like to try and fix as many of these bugs before 
the next release candidate. As far as I can tell none of these issues 
existed half a year ago, so it shouldn't be too hard to figure out what 
changed since then, and hopefully I'll have some time to do that this 
weekend.


Dominic