Re: [webkit-dev] freeing static variables
Hi Adam, thank you for your suggestions. I have something similar in my mind. I have opened a bugzilla entry and submited an early patch draft about my concept: https://bugs.webkit.org/show_bug.cgi?id=27980 The patch frees memory objects in a reversed creation order, and seemed working well with QtLauncher (although only a subset of static variables are freed right now). Do you know about special cases when this approach is not enough? Actually it is hard to find real memory leaks in the output of valgrind because many of them are related to static variables. I hope this feature will help to the leak hunters in the future. Cheers, Zoltan On Thursday 30 July 2009 02:55:18 am Zoltan Herczeg wrote: Hi, any thoughts on this? I hope my qestion was clear :) I would like to pack the static declarations into wrapper classes, so we can add platform and/or compilation mode (debug/release) dependent functionality to all static variables (i.e: freeing them on exit). Zoltan I've tried this before and it didn't work out so well. The order in which you free them becomes very important and error prone. And, of course, whatever solution you make has to be optional and easy to maintain as the default policy in WebKit is to not care - by design - about cleaning up after static globals on exit as that is left to the OS. Another strategy for the embedded case where you want to free everything on exit is to create a custom memory handler that will do this for you. Cheers, Adam ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
Re: [webkit-dev] freeing static variables
Hi, any thoughts on this? I hope my qestion was clear :) I would like to pack the static declarations into wrapper classes, so we can add platform and/or compilation mode (debug/release) dependent functionality to all static variables (i.e: freeing them on exit). Zoltan Hi all, Valgrind reports a lot of memory leaks when QtLauncher quits, because many static local variables are not freed. I did a little research and realized there is no consistent way to define static variables in webkit: WebCore/css/CSSSelector.cpp: CSSSelector::extractPseudoType() using a DEFINE_STATIC_LOCAL() macro WebCore/bindings/js/JSDOMWindowBase.cpp: JSDOMWindowBase::commonJSGlobalData() static JSGlobalData* globalData; WebCore/platform/qt/CursorQt.cpp: Cursors* Cursors::s_self = 0; (no static keyword) I belive it would be a good thing to define a template for static variables, which can (optionally) free static variables (enabled in debug mode, but sometimes it would be good to enable it in release mode as well) And I am wondering whether it would be worth to free (some) static variables if they are used in a given time period. This may help to reduce the memory consumption in the long run. This would be an optional feature, an extra flag (or timeout value) for the template, which can be enabled or disabled at compile time. If disabled, the value of this flag is not used at all. Regards Zoltan ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
Re: [webkit-dev] freeing static variables
Zoltan, I think it would be a great add from a embedder-dev point of view. Particularly, such leaks have been faced here in a soon past, when we were loading a webkit browser as a plugin, and not as an application by itself. So, we the webkit plugin was unloaded, it used to left behind lots of leaks affecting the (main) loader application, and as we you might imagine many of this leaks were from global vars (including in dependency libs , e.g. fontconfig =/) On Wed, Jul 29, 2009 at 4:05 AM, Zoltan Herczegzherc...@inf.u-szeged.hu wrote: Hi all, Valgrind reports a lot of memory leaks when QtLauncher quits, because many static local variables are not freed. I did a little research and realized there is no consistent way to define static variables in webkit: WebCore/css/CSSSelector.cpp: CSSSelector::extractPseudoType() using a DEFINE_STATIC_LOCAL() macro WebCore/bindings/js/JSDOMWindowBase.cpp: JSDOMWindowBase::commonJSGlobalData() static JSGlobalData* globalData; WebCore/platform/qt/CursorQt.cpp: Cursors* Cursors::s_self = 0; (no static keyword) I belive it would be a good thing to define a template for static variables, which can (optionally) free static variables (enabled in debug mode, but sometimes it would be good to enable it in release mode as well) And I am wondering whether it would be worth to free (some) static variables if they are used in a given time period. This may help to reduce the memory consumption in the long run. This would be an optional feature, an extra flag (or timeout value) for the template, which can be enabled or disabled at compile time. If disabled, the value of this flag is not used at all. Regards Zoltan ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev -- --Antonio Gomes ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
Re: [webkit-dev] freeing static variables
On Thursday 30 July 2009 02:55:18 am Zoltan Herczeg wrote: Hi, any thoughts on this? I hope my qestion was clear :) I would like to pack the static declarations into wrapper classes, so we can add platform and/or compilation mode (debug/release) dependent functionality to all static variables (i.e: freeing them on exit). Zoltan I've tried this before and it didn't work out so well. The order in which you free them becomes very important and error prone. And, of course, whatever solution you make has to be optional and easy to maintain as the default policy in WebKit is to not care - by design - about cleaning up after static globals on exit as that is left to the OS. Another strategy for the embedded case where you want to free everything on exit is to create a custom memory handler that will do this for you. Cheers, Adam ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
[webkit-dev] freeing static variables
Hi all, Valgrind reports a lot of memory leaks when QtLauncher quits, because many static local variables are not freed. I did a little research and realized there is no consistent way to define static variables in webkit: WebCore/css/CSSSelector.cpp: CSSSelector::extractPseudoType() using a DEFINE_STATIC_LOCAL() macro WebCore/bindings/js/JSDOMWindowBase.cpp: JSDOMWindowBase::commonJSGlobalData() static JSGlobalData* globalData; WebCore/platform/qt/CursorQt.cpp: Cursors* Cursors::s_self = 0; (no static keyword) I belive it would be a good thing to define a template for static variables, which can (optionally) free static variables (enabled in debug mode, but sometimes it would be good to enable it in release mode as well) And I am wondering whether it would be worth to free (some) static variables if they are used in a given time period. This may help to reduce the memory consumption in the long run. This would be an optional feature, an extra flag (or timeout value) for the template, which can be enabled or disabled at compile time. If disabled, the value of this flag is not used at all. Regards Zoltan ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
