Cryptomator: Lock & Reveal Drive buttons do nothing on click

[rorygsales]

Description

Slightly related to https://github.com/cryptomator/cryptomator/issues/984 but moved to new issue as requested by "Sebastian Stenzel - overheadhunter" as in this case after a upgrade to latest BETA version it "seems" that the GUI blank problem has stopped but the locking and revealing buttons don't work.

Usually after sleeping or putting the laptop into standby for the night, on wake-up the next morning one of the 3 cases below took place
1) All was working fine
2) The GUI was as follows - https://github.com/cryptomator/cryptomator/issues/984
3) The GUI was fine but the Reveal Drive and Lock buttons did nothing when clicked.

A side effect of this is usually that one cannot close Cryptomator gracefully as upon closing it offers to lock the open drives which its not able to do and either hangs or stays open.

System Setup

• Operating system and version: Windows 10 Pro
• Cryptomator version: 1.5.0-beta2
• Drive: Dokany - Dokan Library 1.3.0.1000 (x64)

Steps to Reproduce

As above its intermittent and usually requires a sleep / system standby for a period of time from what I experience. That said it has happened in the past a few minutes after closing the Cryptomator window and reopening it shortly after.

Expected Behavior

To be able to lock and reveal the drive by clicking the buttons

Actual Behavior

Nothing....

Reproducibility

Intermittent

Additional Information

Before the upgrade from version 1.4 to this latest 1.5 Beta if you clicked lock drive sometimes the drive (letter - e.g. a:\ b:\ etc.) would actually be removed from "Explorer / My computer / This PC". This latest version 1.5 beta leaves the drive letter and keeps the vault open even after clicking the lock button, and I can still browse the open vault.

Cryptomator 2020-01-15 08-40-55.zip

[overheadhunter]

At least in your video you have three vaults unlocked at the same time. Three might be a magical number here in order to reproduce this issue.

Both, "Reveal" and "Lock" spawn tasks that are scheduled for background execution:

https://github.com/cryptomator/cryptomator/blob/eb047e29a0f5f31e973aa3373f1e5ffcbca3d9bc/main/ui/src/main/java/org/cryptomator/ui/common/VaultService.java#L32-L34

https://github.com/cryptomator/cryptomator/blob/eb047e29a0f5f31e973aa3373f1e5ffcbca3d9bc/main/ui/src/main/java/org/cryptomator/ui/common/VaultService.java#L54-L56

The used executorService is injected via Dagger and created here:

https://github.com/cryptomator/cryptomator/blob/eb047e29a0f5f31e973aa3373f1e5ffcbca3d9bc/main/commons/src/main/java/org/cryptomator/common/CommonsModule.java#L69-L79

The issue might be that we have a fixed number of NUM_SCHEDULER_THREADS = 4 background thread. If all of these are currently blocked, no further long-running tasks can be executed, including locking, unlocking or revealing vaults.

If my assumption is true it should therefore also not be possible to create a new vault or unlock a fourth vault.

[rorygsales]

Got distracted on another topic - work related.

Sounds like you are onto something here.

I recall ... this problem ( and the GUI issue #984 ) also before when only 1 vault was opened/unlocked, but I had others registered not yet opened/unlocked.
Lets see how your investigation of the code goes and I will try and do some more testing asap.

Time to get back to java programming this side (for work).

[overheadhunter]

I'm able to reproduce this on Windows with Dokany.

[rorygsales]

Well done / found Sebastian. Thanks for the update.