619670 - onLowMemory may not work on Android

Status: RESOLVED FIXED

(Core Graveyard :: Widget: Android, defect)

Description

[Makoto Kato [:m_kato]]

Java_org_mozilla_gecko_GeckoAppShell_onLowMemory is called from DalvikVM thread. But NotifyObservers only works on XUL main thread (in other word, NS_IsMainThread() == TRUE).  So onLowMemory may not work on Android.

Comment 1

[Makoto Kato [:m_kato]]

Attachment: fix v1

Comment 2

[Doug Turner (:dougt)]

Comment on attachment 498970 [details] [diff] [review]
fix v1

The behavior of nsAppShell::NotifyObservers() is going to be different depending on if you are on the main thread or not.  If you are on the main thread, you will directly call nsIObserverService::NotifyObservers.  This call will enumerate all listeners and synchronously call Observe.  In the non-main-thread case, nsAppShell::NotifyObservers() will simple post an event and immediately return.

I think I would prefer that you make nsAppShell::NotifyObservers just post events regardless of which thread it is called on.

Otherwise looks fine.

Comment 3

[Doug Turner (:dougt)]

Attachment: minor clean up from last patch to address my concern.

Comment 4

[Doug Turner (:dougt)]

http://hg.mozilla.org/mozilla-central/rev/a31e58c375b6

Comment 5

[Benoit Jacob [:bjacob] (mostly away)]

onLowMemory still doesn't work on this test case:

   http://crazybugs.ivank.net/

See bug 736436

Comment 6

[Benoit Jacob [:bjacob] (mostly away)]

Hm, though, that is not our fault, it's android who fails to notify us. re-closing. will file a separate bug.