Hello.
Please review the fix for a jdk9. I plan to backport it to jdk8u60.
Description.
An UIworks really slowly, when an application has a lot of components in
one container, and these components should be disabled one by one.
The reason is the next sequence of methods calls:
Component.setEnabled->updateCursorImmediately()-> some cursor related
staff->GlobalCursorManager._updateCursor->Container.findComponentAt()-iteration
over all components in the container.....-> twice....
You can imagine how it works in case of 10000 components in the container.
Note that in the bug report described difference jdk6 vs jdk8 -> 1sec vs
6 sec. This was caused by the two fixes, one of which adds
checkTreeLock() and in another one a simple array of components was
replaced by the ArrayList. Since code was added to the really hot method
we got so big slowdown.
To fix the problem I suggest two different approaches:
- Container.java: Fix a general case, by eliminating a second
iteration in the hot loop.
- Component.java: Totally eliminates cursor machinery, if component
cannot affect current cursor.
Some speedup measurements on my local system:
- Simple removing of checkTreeLock() will partly solve a regression
reported by the user(12 sec -> 5 sec).
- Changes in the loop will speedup the code in the worse case(5->2 sec)
- The changes in the Component.java will change the performance from 2
sec to 100< ms
Test case which was added was improved from 10 seconds to 80 ms.
JMH test:
http://cr.openjdk.java.net/~serb/8071306/SetEnabledPerformanceTest.java
Fixedversion:
Benchmark Mode Cnt Score
Error Units
SetEnabledPerformanceTest.testContains thrpt 5 301300,813 ±
17338,045 ops/ms
SetEnabledPerformanceTest.testFindComponentAt thrpt 5 20,521 ±
0,269 ops/ms
SetEnabledPerformanceTest.testGetComponentAt thrpt 5 22,297 ±
1,264 ops/ms
SetEnabledPerformanceTest.testSetEnabled thrpt 5 711,120 ±
19,837 ops/ms
Base version:
Benchmark Mode Cnt Score
Error Units
SetEnabledPerformanceTest.testContains thrpt 5 299145,642 ±
2120,183 ops/ms
SetEnabledPerformanceTest.testFindComponentAt thrpt 5 1,101 ±
0,012 ops/ms
SetEnabledPerformanceTest.testGetComponentAt thrpt 5 6,792 ±
0,097 ops/ms
SetEnabledPerformanceTest.testSetEnabled thrpt 5 0,464 ±
0,020 ops/ms
Bug: https://bugs.openjdk.java.net/browse/JDK-8071306
Webrev can be found at: http://cr.openjdk.java.net/~serb/8071306/webrev.03
--
Best regards, Sergey.
