721105 - A lot of calling document.title can hang Fennec

Status: RESOLVED INCOMPLETE

(Firefox for Android Graveyard :: General, defect)

Description

[Martijn Wargers (dead)]

Attachment: testcase

See testcase, the testcase consists of a bunch of iframes, which have a script that sets top.document.title repeatedly. 
This causes Fennec to slow down considerably.

Tapping on the button should bring up an alert, but that doesn't happen on that page.
Opening a new tab and loading a page and after a while, I get the "Force quit" dialog from Android.

Tested on the LG Optimus Black, Android 2.2.2.

Comment 1

[Martijn Wargers (dead)]

Attachment: logcat of testcase

This is a logcat of the testcase.

Comment 2

[Doug Turner (:dougt)]

martijn, can you test again?  I checked in a fix that reduces the length of the title.  I am wondering if your title string length was just really long and this is a dupe of that bug.

Comment 3

[Martijn Wargers (dead)]

No, this testcase is just setting Math.random() in the title a lot of times, which seem to cause the hang.

Comment 4

[Naoki Hirata :nhirata (please use needinfo instead of cc)]

Can cause OOM on Maple 1331046734 on LG Revolution

Comment 5

[Mark Finkle (:mfinkle) (use needinfo?)]

Even though we trim the title length, we send the message. We could cache the title in browser.js Tab and not send it if the same. Maybe sending the message is causing the OOM.

Comment 6

[Mark Finkle (:mfinkle) (use needinfo?)]

We can't cache the title either. The testcase uses random numbers as title, changing the title as fast as possible (setTimeout with 0ms). It's no wonder the app gets slow and either hangs or OOMs.

I don't think we can fix this without multi-process. I am tempted to close the bug as WONTFIX.

Comment 7

[BMO Automation]

We have completed our launch of our new Firefox on Android. The development of the new versions use GitHub for issue tracking. If the bug report still reproduces in a current version of [Firefox on Android nightly](https://play.google.com/store/apps/details?id=org.mozilla.fenix) an issue can be reported at the [Fenix GitHub project](https://github.com/mozilla-mobile/fenix/). If you want to discuss your report please use [Mozilla's chat](https://wiki.mozilla.org/Matrix#Connect_to_Matrix) server https://chat.mozilla.org and join the [#fenix](https://chat.mozilla.org/#/room/#fenix:mozilla.org) channel.