Various GUI components make blocking Admin API calls on the main thread

[DemiMarie]

How to file a helpful issue

Qubes OS release

R4.2

Brief summary

Various GUI components make Admin API calls on the main thread. This is a very bad idea, because this blocks the UI until qubesd responds. This takes far too long for the UI to be responsive.

Once this issue is fixed, I would like for using the Admin API on the main thread to throw an exception, to ensure that future calls to it are caught.

Steps to reproduce

Use the updater when many VMs are running.

Expected behavior

UI is constantly responsive.

Actual behavior

UI becomes unresponsive at various points.

[DemiMarie]

@marmarta: I think this is the source of most “XYZ becomes temporarily unresponsive” issues.

[marmarek]

Alternative solution (although probably more work) is to make core-admin-client provide async API (via asyncio), similar to its backend counterpart (core-admin). This is something I would want anyway, but what I don't know is how to make it compatible (to not break all users of core-admin-client, including 3rd-party ones). Maybe implement alternative Qubes() class (QubesAsync()?) ?

[DemiMarie]

QubesAsync() seems like a good option, unless there are ordering requirements that make a callback-based solution more attractive.