1216939 - Don't import IndexedDBHelper.jsm and SettingsDB.jsm in preload.js

Status: RESOLVED WONTFIX

(Firefox OS Graveyard :: Performance, defect, P2)

Description

[Cervantes Yu [:cyu] [:cervantes]]

IndexedDB is used through IPC in content processes. There's no need to load IndexedDBHelper.jsm and SettingsDB.jsm in preload.js.

Comment 1

[Cervantes Yu [:cyu] [:cervantes]]

Oops! Accidentally marked as security-sensitive. Need help to make this bug public.

Comment 2

[Cervantes Yu [:cyu] [:cervantes]]

Paul, would you help uncheck the security-sensitive flag? Thanks :)

Comment 3

[Cervantes Yu [:cyu] [:cervantes]]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=806d118836da

Comment 4

[Cervantes Yu [:cyu] [:cervantes]]

Attachment: dont-preload-indexeddb-jsms.patch

Comment 5

[[:fabrice] Fabrice Desré]

SettingsDB.jsm is used by SettingsRequestManager.jsm which is then used by SettingsService.js
And this service can be used in child process unless I missed something, so we still benefit from preloading SettingsDB.jsm no?

Comment 6

[Cervantes Yu [:cyu] [:cervantes]]

(In reply to [:fabrice] Fabrice Desré from comment #5)
> SettingsDB.jsm is used by SettingsRequestManager.jsm which is then used by
> SettingsService.js
> And this service can be used in child process unless I missed something, so
> we still benefit from preloading SettingsDB.jsm no?

SettingsRequestManager states that it only lives in the parent process:
https://dxr.mozilla.org/mozilla-central/source/dom/settings/SettingsRequestManager.jsm#1219
so I don't think i has any benefit in loading it in child processes.

Comment 7

[[:fabrice] Fabrice Desré]

Hm, yes - but we still load it when using the SettingsService in child processes. Maybe we should not do that instead?

Comment 8

[Cervantes Yu [:cyu] [:cervantes]]

(In reply to [:fabrice] Fabrice Desré from comment #7)
> Hm, yes - but we still load it when using the SettingsService in child
> processes. Maybe we should not do that instead?

We shouldn't. I think we should also have a check in SettingsService that don't import SettingsRequestManager.jsm in the child process. The JSM is loaded only to throw an exception.

Comment 9

[Cervantes Yu [:cyu] [:cervantes]]

After checking SettingsServiceLock, I think it only resides in the parent process because it has direct calls to SettingsRequestManager.