Possible approaches to JDK-8185886: Improve scrolling performance of TableView and TreeTableView

Kevin Rushforth kevin.rushforth at oracle.com
Tue Sep 8 20:12:17 UTC 2020


Thanks for filing it, Jose.

I think it's better not to use JDK-8185886 for any of these PRs, since 
it's too generic a description, and was meant as an umbrella issue 
anyway, so I closed it as a duplicate of the 4 issues that are split out 
from it.

I filed a new issue for each of PR #108 and PR #185.

There is already an issue about the lack of virtualization in the 
horizontal direction, JDK-8185887, so we can use that for PR #125.

Here is the list of the 4 PRs under review:

PR #108 [1] : JDK-8252936 [2] : Optimize removal of listeners from 
ExpressionHelper.Generic
PR #125 [3] : JDK-8185887 [4] : TableRowSkinBase fails to correctly 
virtualize cells in horizontal direction
PR #185 [5] : JDK-8252935 [6] : Add treeShowing listener only when needed
PR #298 [7] : JDK-8252811 [8] : The list of cells in a VirtualFlow is 
cleared every time the number of items changes

For the first three PRs, I ask the author of the PR to update the title 
of their PR to match their associated JBS issue.

We can proceed to discuss each fix in their respective PRs.

-- Kevin

[1] https://github.com/openjdk/jfx/pull/108
[2] https://bugs.openjdk.java.net/browse/JDK-8252936

[3] https://github.com/openjdk/jfx/pull/125
[4] https://bugs.openjdk.java.net/browse/JDK-8185887

[5] https://github.com/openjdk/jfx/pull/185
[6] https://bugs.openjdk.java.net/browse/JDK-8252935

[7] https://github.com/openjdk/jfx/pull/298
[8] https://bugs.openjdk.java.net/browse/JDK-8252811


On 9/4/2020 9:04 AM, José Pereda wrote:
> I've filed https://bugs.openjdk.java.net/browse/JDK-8252811 (under 
> javafx/controls).
>
> I believe this is not an alternative to any of the other three 
> issues, but obviously a less invasive one, as it only implies changes 
> in VirtualFlow.
>
> Once tackled, it should directly increase performance and reduce CPU 
> usage of TableView/TreeTableView/ListView controls when their items 
> change frequently.
>
> But it will also benefit from the improvements of the other three 
> approaches.
>
> Jose
>
> On Fri, Sep 4, 2020 at 1:46 AM Kevin Rushforth 
> <kevin.rushforth at oracle.com <mailto:kevin.rushforth at oracle.com>> wrote:
>
>     It seems clear now that we will need 3 different JBS issues for these
>     proposed performance enhancements. It's a holiday weekend coming
>     up in
>     the US, so I can file the other two issues unless someone else
>     gets to
>     it first. Unless there is a good reason to do otherwise, I propose:
>
>     The JBS Issue associated with PR #108 should be filed against
>     javafx/base
>     The JBS Issue associated with PR #125 should be filed against
>     javafx/controls (or we can reuse JDK-8185886)
>     The JBS Issue associated with PR #185 should be filed against
>     javafx/scenegraph
>
>     Jose: Is you approach an alternative to one of the above or could
>     it be
>     considered a 4th approach? If the latter, can you file a new JBS
>     Issue
>     for that?
>
>     -- Kevin
>
>
>     On 9/2/2020 5:24 AM, Jeanette Winzenburg wrote:
>     >
>     > Hi John,
>     >
>     > thanks for the clarification :)
>     >
>     > Hmm .. but then it's not really a PR against JDK-8185886 (scrolling
>     > performance was always bad with many columns) but against - yet
>     to be
>     > reported - side-effect of JDK-8090322 which happens to detoriate
>     > tableView performance even further (there might be other
>     side-effects)?
>     >
>     > -- Jeanette
>     >
>     > Zitat von John Hendrikx <hjohn at xs4all.nl <mailto:hjohn at xs4all.nl>>:
>     >
>     >> The "dynamic update performance" performance issue we are
>     seeing is a
>     >> regression from JDK-8090322.  In this change the Node treeShowing
>     >> property was introduced.  The JDK-8090322 warns in its description
>     >> about:
>     >>
>     >> """    Considerations:
>     >> * This is too expensive to calculate for all nodes by default.
>     So the
>     >> simplest way to provide it would be a special binding
>     implementation
>     >> or a util class. Where you create a instance and pass in the
>     node you
>     >> are interested in. It can then register listeners all the way
>     up the
>     >> tree and listen to what it needs. """
>     >>
>     >> The above comment is warning against the fact that registering
>     >> listeners for EACH Node on Window and Scene is going to be a
>     >> performance issue. As nodes can number in the 1000's or 10.000's,
>     >> that's a lot of listeners to store in a List data structure.
>     >>
>     >> PR 185 targets this issue and implements the feature in
>     JDK-8090322 in
>     >> the way that was suggested in the above comment, instead of how it
>     >> currently is implemented (registering listeners for every Node,
>     just
>     >> in case someone needs the treeShowing property).
>     >>
>     >> It's scope is not as broad as it would seem (because of a
>     change in
>     >> Node).  It effectively only makes a small change in two controls
>     >> (PopupWindow and ProgressIndicatorSkin).
>     >>
>     >> --John
>     >>
>     >>
>     >>
>     >> On 31/08/2020 16:54, Jeanette Winzenburg wrote:
>     >>>
>     >>> Looking at the examples provided in 108/125: apart from both
>     having
>     >>> many
>     >>> columns (> 300 makes them really nasty) they differ in
>     >>>
>     >>> Table content:
>     >>> 125 - static data
>     >>> 108 - items are frequently modified (added)
>     >>>
>     >>> Perceived performance:
>     >>> 125 - vertical scrolling: thumb/content lags behind mouse
>     >>> 108 - with enough columns, all interaction is sluggish (mouse,
>     keys,
>     >>> ..), scrolling being just one of them
>     >>>
>     >>> Both have examples, running those against the suggested fixes
>     (with
>     >>> 108a
>     >>> for Jose's approach)
>     >>> 125 - fixes its own example, does nothing for the other
>     >>> 108, 108a, 185 - improves its own example, does nothing for other
>     >>>
>     >>> So we seem to have multiple issues that are (mostly)
>     orthogonal: one
>     >>> being the broken/missing horizontal virtualization (125), the
>     other
>     >>> related to dynamic update of table content (108, 108a, 185).
>     We need to
>     >>> solve both, the solution/s for one looks (mostly?) unrelated
>     to the
>     >>> solution to the other.
>     >>>
>     >>> 125 is the only one PR for its use-case, and it seems to do
>     its job.
>     >>> From those targeting the dynamic data update all except Jose's
>     (not yet
>     >>> formalized into a PR) approach feel too broad: table's
>     reaction to
>     >>> items
>     >>> modifications is .. suboptimal in more than one aspect. Changing
>     >>> overall
>     >>> notification implementation to improve that, sounds like
>     covering it
>     >>> up.
>     >>>
>     >>> -- Jeanette
>     >>>
>     >>> Zitat von Kevin Rushforth <kevin.rushforth at oracle.com
>     <mailto:kevin.rushforth at oracle.com>>:
>     >>>
>     >>>> Sorry for the badly formatted html. Here it is again.
>     >>>>
>     >>>> I see some progress being made on the {Tree}TableView performance
>     >>>> issue. To summarize where I think we are:
>     >>>>
>     >>>> There are currently 2 different approaches under review:
>     >>>>
>     >>>> 1. https://github.com/openjdk/jfx/pull/108
>     <https://urldefense.com/v3/__https://github.com/openjdk/jfx/pull/108__;!!GqivPVa7Brio!KKyin4SuSWheT-b4caAsZF_NoXktXLzN4u06UJjtC7VRkTGdedov8ZVfFVGL4ViqWALw$>
>     : optimization in
>     >>>> javafx.base to make removing listeners faster
>     >>>> 2. https://github.com/openjdk/jfx/pull/125
>     <https://urldefense.com/v3/__https://github.com/openjdk/jfx/pull/125__;!!GqivPVa7Brio!KKyin4SuSWheT-b4caAsZF_NoXktXLzN4u06UJjtC7VRkTGdedov8ZVfFVGL4S6OPoyp$>
>     : optimization in TableView
>     >>>> to reduce the number of add / removes
>     >>>>
>     >>>> In addition, the following is a WIP PR that the author thinks
>     could be
>     >>>> a 3rd approach:
>     >>>>
>     >>>> 3. https://github.com/openjdk/jfx/pull/185
>     <https://urldefense.com/v3/__https://github.com/openjdk/jfx/pull/185__;!!GqivPVa7Brio!KKyin4SuSWheT-b4caAsZF_NoXktXLzN4u06UJjtC7VRkTGdedov8ZVfFVGL4dXd0a_r$>
>     : optimization in scene
>     >>>> graph to avoid install treeShowing listeners on Window and
>     Scene for
>     >>>> all nodes
>     >>>>
>     >>>> Jose has proposed a 4th approach as a comment to PR #108, and
>     as I
>     >>>> understand it, he will propose a PR shortly.
>     >>>>
>     >>>> 4. Don't clear the list of children in a VirtualFlow when the
>     number
>     >>>> of items changes.
>     >>>>
>     >>>> So the first thing that is needed is to evaluate the
>     approaches and
>     >>>> decide which one to pursue.
>     >>>>
>     >>>> Options 1 and 3 are more broad in their scope, option #2 is more
>     >>>> targeted (to TableView), but within that area is a larger change.
>     >>>> Option #3 would remove the (internal) treeShowing property as a
>     >>>> generally available concept and only use it for controls like
>     >>>> ProgressIndicator that really need it. Option #4 affects only
>     controls
>     >>>> that use VirtualFlow (ListView, TableVIew, TreeTableView),
>     and seems
>     >>>> not to be a large change (presuming we can verify that no leak is
>     >>>> introduced).
>     >>>>
>     >>>> I note that these fixes are not mutually exclusive, but I do
>     think we
>     >>>> need to settle on a primary approach and use that to fix this
>     issue.
>     >>>> If there are still performance problems after that fix, we can
>     >>>> consider one (or more) of the others.
>     >>>>
>     >>>> Comments?
>     >>>>
>     >>>> -- Kevin
>     >>>
>     >>>
>     >>>
>     >
>     >
>     >
>
>
>
> -- 
>



More information about the openjfx-dev mailing list