1452917 - Clean up budget throttling "active" tracking and unused Quantum Scheduling TabGroup::{IndexedDBTransactionCounter, IndexedDBDatabaseCounter} if they're still around.

Status: NEW

(Core :: Storage: IndexedDB, enhancement, P3)

Description

[Andrew Sutherland [:asuth] (he/him)]

Bug 1352401 added tracking of active databases and active transactions for the benefit of a) opting out of budget throttling blockage due to IDB semantics and b) for Quantum Scheduling.  :bkelly is currently cleaning up 'a' in bug 1451913 but the cleanup as-is is going to result in a small amount of excess coverage.  It also doesn't entirely remove the 'b' stuff, which is the IndexedDB state tracking on TabGroup (which may go away when Quantum Scheduling is removed on its own).

For 'a', for efficiency we could drop the IDBTransaction implementation.  Or we could keep it, but maybe add some comments that provide context and hand-wave that there's no harm in the extra tracking.

Comment 1

[Andrew Sutherland [:asuth] (he/him)]

So bug 1451913 is changing to not do the cleanup it was going to do, but I think :bkelly demonstrated well that the IDB implementation could be simpler.  In particular, the logic relating to transactions is entirely un-needed now that Quantum Scheduling is being removed, including the extra runnable it uses when noting an inactive transaction; Bevis was concerned about pre-emption points, but those are no longer a thing without Quantum Scheduling.

Bumping down to P3 too.