1644260 - Xulstore writing can still occur during late shutdown

Status: RESOLVED FIXED

(Core :: SQLite and Embedded Database Bindings, defect)

Description

[Alex Thayer [:alexical] (she/her)]

Bug 1638166 sought to eliminate late writes during shutdown by the xulstore by flushing writes on the main thread. However, we still see writes due to get_database itself performing a write, resulting in a call to mdb_env_setup_locks which writes to disk in order to set up locking on the db. We should not call get_database if there are no changes to persist.

Comment 1

[Alex Thayer [:alexical] (she/her)]

Attachment: Bug 1644260 - Do not get xulstore db if no changes r?lina

In bug 1638166 we added a call to persist xulstore changes on the main thread
during shutdown, to ensure that all changes were flushed if we were about to do
an _exit(0). Unfortunately I neglected to notice that get_database does a write
inside mdb_env_setup_locks, which trips our late write checking, and is also
just generally unnecessary / inefficient if there are no changes. This ensures
that we don't do any disk-level locking if there aren't any changes to commit.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/76de3ec91992
Do not get xulstore db if no changes r=lina

Comment 3

[Bogdan Tara[:bogdan_tara | bogdant]]

https://hg.mozilla.org/mozilla-central/rev/76de3ec91992