Hello Anthony
If so I'll approve this one
;-)
I already got your approval in your message on 10/06/2009 08:23 PM. The
only "if" was about whether the tests pass, and they do! ;)
What?! already approved...
Okay, you got this time
:-)
Thanks
alexp
--
best regards,
Anthony
Thanks
alexp
--
best regards,
Anthony
Moreover your variant is even more risky:
any field that is going to be accessed via different threads
must always be used under the lock,
otherwise it is possible that one thread
will see the field in an invalid state
However in your fix the descendUnconditionallyWhenValidating field
is mutated under the treeLock and then accessed in the validate()
method
outside the synchronization block which is unsafe
The following comment: /* Avoid grabbing lock unless really
necessary.*/
is obsolete, the modern JVM do a great job to optimize synchronization
so there is no need to invent tricky patterns to avoid synchronization
I see two options here:
1) Refactor Container.validate to alway get the treeLock and
do everything inside it. This is the most preferable choice.
2) Define descendUnconditionallyWhenValidating as volatile,
this is better than nothing but less safe than #1
Thanks
alexp
--
best regards,
Anthony
On 10/01/2009 12:24 PM, Artem Ananiev wrote:
I've quickly looked through the changes, the fix looks fine with
the exception of using double-check idiom in
Container.validate() - I told you about that the other day.
To make sure we don't get messed up when discovering potential
regressions, I've just filed a separate CR 6887249 (Get rid of
double-check for isValid() idiom in validate() methods) to fix
the issue later. Thanks for the suggestion.
--
best regards,
Anthony
Thanks,
Artem
Anthony Petrov wrote:
It's been a long time since we discussed the issue. Now is the
time for revival.
Last time we came across a failing test [1] that had a JApplet
embedded in a JFrame. The frame was expected to be validated
upon showing. However, the components in the JApplet were not
validated, since the JApplet itself was marked valid, but the
invalidate() requests from the children of the applet stopped
on the RootPane of the JApplet because it was a validate root.
Later we found out a possible solution for that problem [2]:
the show() (as well as the pack()) should validate the whole
component hierarchy unconditionally.
So, here's the fix with this solution implemented. Please review:
http://cr.openjdk.java.net/~anthony/7-23-invalidate-6852592.3/
The fix has been tested quite thoroughly: all sort of related
automatic tests for both Swing and AWT areas have been run
(including layout-related tests, bare (J)Component and
Container-related tests, and some other.) All manual
layout-related tests from AWT and Swing have also been run and
passed. Mixing-related regression tests pass as well.
Please note that I've also changed the synopsis of the change
request by replacing revalidate() with invalidate() because the
fix actually affects the invalidate() method only.
[1]
http://mail.openjdk.java.net/pipermail/awt-dev/2009-August/000831.html
[2]
http://mail.openjdk.java.net/pipermail/awt-dev/2009-August/000835.html
--
best regards,
Anthony
