Mixer A sometimes does not show all tracks

[spamatica]

Posting a ticket here while I remember it, was meaning to have a look at this.

Sometimes I have found that Mixer A is missing a lot of tracks. In this case the mixer also gets very crashy if I try to reorganize it or similar.
Mixer B for some reason always seem to show all tracks.
No clue if this is just a coincidence or if there is some relevant difference between A and B that could cause this.

[terminator356]

Just to bump up: Any problems still even after all the recent fixes and my
"fix blank mixers after auto-restart" of 04/06?

[spamatica]

I think I have still seen problems (both completely empty mixer and missing tracks) after updating to that fix, but I haven't done enough museing after that to say for sure.

The missing track scenario feels very related to when you are in a high cpu-load scenario. E.g. working on a song that already has lots of tracks and effects. Added tracks then often do not end up in the mixer.

The difference between mixer A and B is probably due to B often not being initialized so there is a different mechanism when it is populated upon open. Though I have seen issues with B too when trying to provoke it.

[MyLoFy]

I can reproduce this on Mixer B (Archlinux, MusE 4.0.0-pre1-127-g381f20da) with only audio tracks (all synths deactivated). Workaround: Create a new empty wave track and all missing tracks pop up.

[kybos]

It there any way to reproduce this problem reliably? I'm not able to, even with audio only. For me it occurs quite randomly, which makes a fix pretty impossible...

[MyLoFy]

I can reliably reproduce this on the attached session. When playing the session my DSP load gets to 100%.
mixertest.zip

Steps to reproduce:

• Open session (do not open the mixer. If the mixer is opened before adding a track the bug won't occur)
• Add any track type
• Open Mixer A or B: New track is missing
• Add any track type
• All missing tracks pop up

Interestingly this only happens on a mixer that hasn't been opened before. So if you open Mixer A before those steps the bug will only appear in Mixer B and vice versa.

MusE_Mixertest.mp4

[kybos]

I could reproduce the problem in debugger. The mixer strip output it not based on the track list (any more), but on another list which is apparently out of sync - it doesn't contain the newly added track (amixer.cpp, line 785):

 // NOTE: stripConfigList is the replacement for obsolete stripOrder string list.
  else if (!cfg->stripConfigList.empty()) {
    const int sz = cfg->stripConfigList.size();
    for (int i=0; i < sz; i++) {
      const MusEGlobal::StripConfig& sc = cfg->stripConfigList.at(i);
      DEBUG_MIXER(stderr, "processing strip #:%d [%d][%d]\n", i, sc._serial, sc._visible);
      if(!sc._deleted && !sc.isNull()) {
        const MusECore::Track* t = tl->findSerial(sc._serial);
        if(t)
          addStrip(t, sc);
        }
    }
  }

@terminator356
Tim, it seems to be quite a recent addition of yours (acc.to git), so I guess you will know better how to fix it quickly.

[kybos]

I noticed another problem (apart from 2 of 5 track being missing in my case): The strips in the mixers are not selected on first display (the yellow border is not shown):

[kybos]

Fix is now in master.