1771168 - Some recurring events still missing from agenda on first load

Status: RESOLVED FIXED

(Calendar :: Provider: Local Storage, defect, P1)

Description

[[e-mail]]

+++ This bug was initially created as a clone of Bug #1738867 +++

I have some recurring events in one of my calendars that don't appear on the Agenda. I've discovered that this is because of a race condition. We load the events, including recurrence info, into a cache and retrieve them from there, assuming (because we have just done it) the recurrence info is there. Meanwhile another operation comes along and throws away the cache to refill it (I don't really understand why and that code path has the word HACK in a comment, so not a good sign). So when the event retrieval code goes to use the recurrence info, it is missing and we get the wrong result.

+++ Additional information +++

I encountered this with Thunderbird 91, and crafted something similar to the patch in that bug, but it wasn't enough to resolve it. It turns out that there was a third caller racing with the other two, so although they avoided stepping on the first caller's toes, they still stepped on each other's toes.

Comment 1

[[e-mail]]

Attachment: Proposed patch

I didn't need an extra idle dispatch to solve the race with the third caller but it shouldn't affect the fix so I've left it in.

Comment 2

[Geoff Lankow (:darktrojan)]

Comment on attachment 9278159 [details] [diff] [review]
Proposed patch

Okay, sure. Sorry that this patch disappeared into the void that is my to-do list.

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/comm-central/rev/cff4e6caac16
[CalStorageCalendar] Empty recurring item caches even more carefully r=darktrojan

Comment 4

[Wayne Mery (:wsmwk)]

Good for uplifting to 102?

Comment 5

[Lasana Murray]

Let's ask Geoff.

Comment 6

[Geoff Lankow (:darktrojan)]

Comment on attachment 9278159 [details] [diff] [review]
Proposed patch

I have no objection.

Comment 7

[Wayne Mery (:wsmwk)]

Comment on attachment 9278159 [details] [diff] [review]
Proposed patch

[Triage Comment]
Approved for esr102

Comment 8

[Rob Lemley [:rjl]]

Thunderbird 102.4.1:
https://hg.mozilla.org/releases/comm-esr102/rev/929d913e1763