Re: [webkit-dev] Parallel CSS styling
Eric, You're right that in flickr.com main page, Webkit spends very little time in StyleForElement. However, if you visit http://www.flickr.com/photos/tags/sanfrancisco/ , WebKit spends most of its CSS time in StyleForElement. For example, in our test machine (an 8-core Intel Xeon, 2.8GHz) StyleForElement takes 6450ms out of 9748 ms spent on CSS (66%). Our algorithm focuses on that 66%, and makes it scale linearly. The version of Webkit that we tested includes this patch: Bug 49876 - Optimize matching of descendant selectors Other websites that would benefit: amazon (68% in SFE) Google search (57%) Yahoo sports (56%) Apple (58%) Wikipedia article (65%) -Kulanthaivel Do you have statistics on how much total time rendering flickr.com is in CSS/Style code at all? I believe it to be very low. -eric On Mon, Jun 6, 2011 at 1:16 PM, Kulanthaivel Palanichamy kulanthai...@codeaurora.org wrote: Hi All, At Qualcomm Innovation Center we have been working on a parallel algorithm for CSS styling and wanted to see if there is any interest in the community to see it implemented in WebKit. The overall idea is that we replace CSS matching and styling with a parallel implementation assuming there is a barrier before and after the computation. CSS style application will be performed by the main thread, such that we avoid the need to make thread safe data structures accessed in other passes. The algorithm is task-based, so we would need to implement a thread pool and a simple task scheduler (or maybe use an existing one). In particular, our algorithm requires modifying Element::recalcStyle() and some of the methods it invokes. Code that calls Element::recalcStyle() will not have to be changed. By the time Element::recalStyle() returns, all threads involved on the parallel CSS styling have completed their execution. Effectively, there is a barrier when Element::recalcStyle() begins and another before it returns. Our experiments show that our CSS computation for complex websites scales rather well. For example, we observed that, for flickr.com, Webkit spends 75% of its time in CSS doing CSS matching. Thus, our algorithm would give a maximum speedup of 1.6X on 2 cores and 2.3X on 4 cores. Please let us know whether this would be of interest to the community. -Kulanthaivel ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
[webkit-dev] WebKit Layout test failures on Windows
Hi, Recently I downloaded WebKit revision 42567 and built it on windows. When I tried to run run-webkit-tests script, many of the css tests are failed. css1/basic/class_as_selector.html - failed. css1/basic/comments.html - failed. css1/basic/containment.html - failed. css1/basic/contextual_selectors.html - failed. css1/basic/grouping.html - failed. css1/basic/id_as_selector.html - failed. css1/basic/inheritance.html - failed css1/box_properties . css1/box_properties/acid_test.html - failed. css1/box_properties/border.html - failed. css1/box_properties/border_bottom.html - failed. css1/box_properties/border_bottom_inline.html - failed. css1/box_properties/border_bottom_width.html - failed. css1/box_properties/border_bottom_width_inline.html - failed. css1/box_properties/border_color.html - failed. css1/box_properties/border_color_inline.html - failed. css1/box_properties/border_inline.html - failed. css1/box_properties/border_left.html - failed. css1/box_properties/border_left_inline.html - failed. css1/box_properties/border_left_width.html - failed. css1/box_properties/border_left_width_inline.html - failed.. css1/box_properties/border_right.html - failedml - failed. css1/box_properties/border_right_inline.html - failed failed. css1/box_properties/border_right_width.html - failed- failed . . . I guess all these failures are related to incompatible fonts in Windows (The fonts that are listed in DumpRenderTree.cpp are not available in Windows). If these are font problems then please suggest me how to get these fonts to pass the layout tests in Windows. Thanks Regards Kvel ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
Re: [webkit-dev] How to handle error response on the browser when the HTTP request fails
Hi, If you are using CURL then check the implementation of WebCore\platform\network\curl\ResourceHandleManager.cpp. You can check the callbacks headerCallback() writeCallback() which are used to pass the header and data information from CURL to WebCore. The ResourceHandleManager::downloadTimerCallback() will get called whenever the download timer gets fired. Inside this function each CURL session is processed and the result is passed back to WebCore whenever a particular session is completed successfully or failed. Regards Kvel On Mon, Feb 16, 2009 at 7:26 PM, Nitin Walke nitwa...@gmail.com wrote: Hi All, Thanks for your reply.I am totally new for the GtkWebkit.I tried to follow your suggestion but I am unable to achive my target. I get response in FrameLoaderClient::setMainDocumentError and FrameLoaderClient::shouldFallBack for the HTTP errorbut how to get actual error message from ResourceError that I don't know.Can I get exact steps to get the error like changes in the files and build the webkit,gtk etc. Thanks Regards, Nitin On Fri, Feb 13, 2009 at 10:50 AM, zaheer ahmad zaheer@gmail.comwrote: I think you need to set CURLOPT_FAILONERROR on the curl handle for the curl to report http errors. Also in general you would want to diffferentiate how you handle errors on mainresource vs subresources regards, Zaheer On Thu, Feb 12, 2009 at 9:04 PM, Nitin Walke nitwa...@gmail.com wrote: Hi, Thanks for your suggestion. I added delegate method in FrameloaderClient::dispatchDidFailLoading for GTK, however, noticed that the control flow never reached there - either in case of successful response or for http error like server not found etc. Then I added some debug code in FrameloaderClient::dispatchDidFailLoading for GTK; and found that the control flow does not reach there. Am I missing something here? Your inputs will be appreciated. Regards, Nitin On Thu, Feb 12, 2009 at 11:55 AM, zaheer ahmad zaheer@gmail.comwrote: If you are using curl backend, network errors are already reported back but ignored. you need to implement FrameloaderClient::dispatchDidFailLoading delegate to pass it back to the application. regards, Zaheer On Wed, Feb 11, 2009 at 7:03 PM, Nitin Walke nitwa...@gmail.comwrote: Hi, I am new to Webkit and have developed a basic browser using Webkit GTK port on linux. I want to show error response on the browser when the HTTP request fails for some reason like bad gateway or Server error etc. Currently the browser does not show any response in case of any error. Please advise how to go about implementing the same. Thanks ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
Re: [webkit-dev] Out-of-memory handling
You can check the Nokia's S60WebKit MemoryManager implementation. They have developed a method to handle out of memory situations in WebKit On Tue, Dec 9, 2008 at 12:07 AM, Darin Adler da...@apple.com wrote: On Dec 8, 2008, at 8:21 AM, Kelemen Balázs wrote: A tempting approach would be using exception handling. E.g., what if we could catch a bad_alloc exception? To use exception handling you'd probably have to change all the WebKit code to do cleanup when an exception is propagating. Otherwise, exiting an arbitrary function half way through could leave data structures in an inconsistent state. Fixing this is a large project, almost certainly impractical. Would there be any way to simply force WebKit from the browser to shutdown itself? When I say shutdown, I mean exiting in an elegant way, e.g., we could save history and other important information to disk (so that when the browser restarts, some info does not get lost). Sure, you could do that if you make sure that the important information is stored in data structures that have some sort of integrity guarantee, which are not manipulated directly by the WebCore/WebKit code. And make sure the code that writes those data structures can function without allocating additional memory. But I don't think there's any real advantage to using exception handling for this. You could have a function called when out of memory that does this work. Another approach is to save history and other important information as you go. So if you run out of memory there's nothing that needs to be done. -- Darin ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
Re: [webkit-dev] Out-of-memory handling
Yes I do. Nokia's Memory manager has a memory collector which goes and collects memory if the available application memory goes below certain threshold. It collects memory from WebCore cache. If the collected memory is not enough then it goes ahead and stops all the browser loads and notifies the browser application about the out of memory situation. In WebKit they have added OOM (Out Of Memory) conditions in various places (javascript parsing/execution, html tokenizer, text encoding, image decoding etc..) and if there is not enough memory then it gracefully fails. Regards Kulanthaivel On Fri, Dec 19, 2008 at 12:58 PM, Paul Pedriana ppedri...@gmail.com wrote: You don't happen to know anything about the approach Nokia took, do you? Thanks Paul You can check the Nokia's S60WebKit MemoryManager implementation. They have developed a method to handle out of memory situations in WebKit On Tue, Dec 9, 2008 at 12:07 AM, Darin Adler da...@apple.com wrote: On Dec 8, 2008, at 8:21 AM, Kelemen Balázs wrote: A tempting approach would be using exception handling. E.g., what if we could catch a bad_alloc exception? To use exception handling you'd probably have to change all the WebKit code to do cleanup when an exception is propagating. Otherwise, exiting an arbitrary function half way through could leave data structures in an inconsistent state. Fixing this is a large project, almost certainly impractical. Would there be any way to simply force WebKit from the browser to shutdown itself? When I say shutdown, I mean exiting in an elegant way, e.g., we could save history and other important information to disk (so that when the browser restarts, some info does not get lost). Sure, you could do that if you make sure that the important information is stored in data structures that have some sort of integrity guarantee, which are not manipulated directly by the WebCore/WebKit code. And make sure the code that writes those data structures can function without allocating additional memory. But I don't think there's any real advantage to using exception handling for this. You could have a function called when out of memory that does this work. Another approach is to save history and other important information as you go. So if you run out of memory there's nothing that needs to be done. -- Darin ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev -- ___ webkit-dev mailing listwebkit-...@lists.webkit.orghttp://lists.webkit.org/mailman/listinfo.cgi/webkit-dev ___ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
