Fix Autosave threading issue

[Ka0o0]

This PR fixes #5658
Please see my comment in the associated issue.

• Change in CHANGELOG.md described (if applicable)
• Manually tested changed features in running JabRef (always required)

[tobiasdiez]

Thanks for your PR. I guess this works, but has the disadvantage that now the complete save operation is run on the javafx thread and thus JabRef gets inresponsible for large databases. Would prefer if you find a solution that only certain parts (the ones that are needed) run on the javafx thread.

Either way, merging should be postponed until 5.0 stable is released to be on the safe side.

[tobiasdiez]

@Ka0o0 did you already had the chance to investigate this further?

[Ka0o0]

@tobiasdiez yes. So I found that the exception happened in the updateAllTabTitles method in JabRefFrame. So by just putting this into a foreground thread, I think the performance issues should be resolved. However, I'm not sure if that jumping between threads isn't making development a bit more complicated. Are there any rules whether or not it is okay to call UI methods classes from classes that operate on a background thread?

[koppor]

@Ka0o0 Without thinking deeper, UI should never be called from the background. For instance the integrity check, we just call the logic from the UI: org.jabref.gui.integrity.IntegrityCheckAction#execute

[tobiasdiez]

@Ka0o0 sorry for the late answer. The general principle is that every background process is not allowed do change anything in the UI. Using the BackgroundWorker the strategy is the following:

BackgroundWorker.wrap(do the operation that takes long, return result of calculation)
                .success(update ui)

Right now the auto-save operation triggers also UI updates, which shouldn't be the case. The code needs to be refactored so that only the actual save operation is on the background thread, while the rest should be on the UI thread.

I fear this might be more work. Could you please investigate if you find a solution along these lines. If it is indeed too complicated, we can go with your fix as well for the moment.

[koppor]

JabCon decision: We did not see the issue appearing. Reading #5658 (comment), we should really go for a clean fix. Thus, closing this out.