"Open in file browser" produces buffer underflow

[ronso0]

Reproduce 1
* select file in tracks table
* right click > "Open in file browser"
= audible buffer underflow
(occurs only the first time during a session)

Reproduce 2
* Preferences > Controllers > Your Controller > Scripts tab
* select a file, click "Open selected file"
= audible buffer underflow
(occurs every time)

Before this was never an issue, also I didn't change my latency setting (10ms).

Only a latency of 80ms solves this, which makes my controller interaction very sluggish.

linux 64bit rt-kernel
2.1.0-alpha-pre (build master r6411)

[Uwe Klotz (uklotzde-deactivatedaccount)]

Maybe related to https://bugs.launchpad.net/mixxx/+bug/1738227

I'm already working on this issue and will publish a first patch soon.

[Uwe Klotz (uklotzde-deactivatedaccount)]

It turned out that both issues are not directly related. The main reason for the sluggish behaviour during batch analysis seems to be a dependency inversion between the analysis and the UI thread.

PR will follow soon.

[Uwe Klotz (uklotzde-deactivatedaccount)]

https://github.com/mixxxdj/mixxx/pull/1415

[Uwe Klotz (uklotzde-deactivatedaccount)]

Edit: Thread "priority" and not "dependency" inversion, of course ;)

[Uwe Klotz (uklotzde-deactivatedaccount)]

The underflows and drop outs doesn't seem to be caused by track or source related changes. We need to keep an eye on this issue during the beta.

[Be (be.ing)]

I can reproduce this. Does anyone have an idea what is going on? If we cannot fix this issue very soon, then I propose removing "Open in File Browser" from the track context menu. It is not an essential feature, just a nice thing to have.

[ronso0 (ronso0)]

@be does it happen with a regular kernel or did you try a PREEMPT RT one?

anyways, "Open in File Browser" shouldn't be removed, I find it very useful for library maintenance. therefore it doesn't matter IMO where the button is located.

[Be (be.ing)]

This is with the realtime patched version of Linux from PlanetCCRMA (4.14.12-300.rt10.1.fc27.ccrma.x86_64+rt).

Do you have any idea when this became an issue?

[Uwe Klotz (uklotzde-deactivatedaccount)]

This happens with any kind of disk io activity. I often notice buffer underflows when using Mixxx to play background music while executing an rsync backup. Even when mirroring disks that neither contain the OS nor any music files or the library database.

[Sean M. Pappalardo (pegasus-renegadetech)]

Has anyone tried with a stock kernel? In any case, this sounds like a job for valgrind or something.

[Uwe Klotz (uklotzde-deactivatedaccount)]

Tested on 4.15.12-301.fc27.x86_64 (and various other Fedora non-RT kernels)

[ronso0 (ronso0)]

> Do you have any idea when this became an issue?
IIRC it appeared 2017-11/12.

> This happens with any kind of disk io activity.
Here it only happens when opening the track's folder from within Mixxx. I do pretty much everything while Mixxx is running. Like compiling, copying music from flashdrives to harddisk, deleting/moving tracks within my music partition.

[ronso0 (ronso0)]

still happens with Bionic and 4.16.18-rt12
2.3.0-alpha-pre (build master r6553)

[RJ Skerry-Ryan (rryan)]

Does it matter if the file you open is playing / loaded in a deck, or can it be any file?

[ronso0 (ronso0)]

play/load state doesn't matter, or if a file in that folder is loaded/playing.

with 2.3.0-alpha-pre it's happening only the first time in the mixxx session

[ronso0 (ronso0)]

Edit
also happens when I open controller scripts in MyController > Scripts

[Daniel Schürmann (daschuer)]

Is there something logged in mixxx.log when the buffer underflow happens?

[ronso0 (ronso0)]

when I run with --developer I only see this when opening a controller script:
Warning [Engine]: underflowHappened code: 6
Warning [Engine]: underflowHappened code: 24

side note:
when I assign .js files to 'mousepad' editor it fails to open the files every second time. with 'scribes' it works always. underflow happens with both.

[Daniel Schürmann (daschuer)]

By chance this is fixed with the latest changes. In the 2.2 branch?
Can you restart?

[ronso0 (ronso0)]

I built 2.2 and with a moderate latency setting there's no underflow anymore with "Open file in browser" but it still happens when I attempt to open loaded script files from within Mixxx for the first time in a Mixxx session.

2.2 at 70e7ce90d9
Merge pull request #2326 from goddisignz/ddj-sx-reduce-messages

[Swiftb0y (swiftb0y)]

Mixxx now uses GitHub for bug tracking. This bug has been migrated to:
https://github.com/mixxxdj/mixxx/issues/9006