Bug 42135 – [Qt] Declarative demo webbrowser crashes on Symbian^3 when scrolling website http://www.nytimes.com

• Status: RESOLVED
• Resolution: INVALID
• Component: WebKit Qt

[Joona Petrell]

Open website www.nytimes.com with webbrowser demo (found in demos/declarative/webbrowser). Double click to zoom to 1:1 aspect ratio. Pan or flick the page around by dragging your finger. After just few seconds of scrolling the QML Viewer crashes. Seems to happen also on other websites. 

From src/3rdparty/webkit
"This is a snapshot of the Qt port of WebKit from
       git://gitorious.org/qtwebkit/qtwebkit.git
and has the sha1 checksum
        ad96ca2f9b57271da4ea7432022ac686ee0981c2

[Joona Petrell]

The crash reproduces on fairly high number of websites (try www.ourbrisbane.com for example). Makes WebView unusable on Symbian^3. Increased priority to P1 to get it fixed for Qt 4.7.0.

[Joona Petrell]

Seems to be caused by maximum heap size of 2MB in QML Viewer (TARGET.EPOCHEAPSIZE = 0x20000 0x8000000) not being enough for running both the QML UI and Webkit at the same application process. If I raise the heap size to 8MB the New York Times website no longer crashes.

[Joona Petrell]

Ok so the maximum EPOCHEAPSIZE 0x2000000 that QML Viewer specificies is in hexadecimals, which means 33.6MB and not 2MB like I stated above. And while Symbian default maximum heap size is 1MB, the Qt applications will have EPOCHEAPSIZE by default set of 8.4MB (0x800000). 8 megs may sound like a lot and often is enough for normal Qt applications, but QML uses JavaScriptCore that apparently requires 2MB of extra heap on it's own. If you load webkit using WebView element that means another 2MB of being reserved as webkit uses different JavaScriptCore.

So this is not a bug to Webkit but to Declarative team. We need to decide whether we want to increase the maximum heap size of QML Viewer or document it clearly that if you want to load complex websites in your QML application you need to assign more heap.

[Alexis Menard (darktears)]

Hello Joona,

Jason from the S60 port, Simon from WebKit agree that we should actually put 64mb to be safe. It's not a plain allocation so the memory is still free for other programs. We should definitively increase the heap size and solve the problem for ever.

Would you mind talking to QML team and increase it? Thanks. The patch is straightforward but I want to be sure you guys agree.

[Joona Petrell]

QML team agrees, we will double the maximum heap size of QML Viewer from 0x2000000 to 0x4000000, that is from 33.6MB to 67.1MB. I re-opened the original bug on the Qt Bug Tracker side, this bug can be closed.

[Antonio Gomes]

Marked as INVALID, based on comment #5.