Investigate why SelectedMailboxImpl could be slow to process Added.

[chibenwa]

Possible deadlock?

I do not think writing data to the client takes that much time.

UID-MSN converter looks ok. Adding 40.000 randonm ints in it completed in 7.6 sec

[chibenwa]

Could be also caused by contention on the boundedElastic schedulers....

[vttranlina]

Tried some cases but the timeout exception was not thrown

• Tried to modify IdleProcessor#reactiveEvent take more time 600000ms (11 minutes),
• Tried to immediately stop client connection when idling new add message event

[vttranlina]

The concurrent test code for select inbox and IDLE (it works fine) https://github.com/apache/james-project/commit/477a30d182a4976881723210968a7e26026c1b4e // no idea now

[chibenwa]

I think some of the refactoring I did could help... (cross object locking is never a good idea)

[chibenwa]

Never happened again.

Recent refactoring should had fixed that.