RFR: 8362289: [macOS] Remove finalize method in JRSUIControls.java [v4]

[Sergey Bylokhov]

On Wed, 16 Jul 2025 22:45:21 GMT, Phil Race <prr at openjdk.org> wrote:

>> Eliminate a finalize() method in the Swing macOS implementation.
>> 
>> I tested that the dispose method is being called by running this small test in combination with some 'println' statements in the source code (now removed)
>> 
>> import javax.swing.JTabbedPane;
>> import javax.swing.plaf.TabbedPaneUI;
>> 
>> public class CreateTabbedPaneUIStressTest {
>> 
>>    public static void main(String[] args) {
>>        for (int i=0; i<1000000000; i++) {
>>            JTabbedPane jtp = new JTabbedPane();
>>            TabbedPaneUI tpui = jtp.getUI();
>>        }
>>    }
>> }
>> 
>> 
>> I also monitored the process size using 'top'.
>> And when I commented out the native call that did the free and re-tested I saw process size grow.
>> 
>> Turning the above into a useful regression test doesn't seem possible to me.
>> Limiting Java heap is pointless (and I did use -Xmx20m) since it is a native resource that is to be freed and failure to dispose won't show up as a problem without taking down the machine.
>
> Phil Race has updated the pull request incrementally with one additional commit since the last revision:
> 
>   JRSUIControl.java

Marked as reviewed by serb (Reviewer).

>Synchronized methods might be OK without, but the following methods are not synchronized, and access cfDictionaryPtr:

Unfortunately this is actually true, in awt we even have a special class [CFRetainedResource](https://github.com/openjdk/jdk/blob/04c0b130f09c093797895cc928fe020d7e584cb9/src/java.desktop/macosx/classes/sun/lwawt/macosx/CFRetainedResource.java#L36) which maintains a locks around the native pointer and prevents its usage after de-allocation(intentional or via finalize). It was implemented as part of JDK-8164143.

I can migrate the current API of DIsposer to the something similar to CFRetainedResource as a follow up bug. The current one did not introduce the new issues, since implementation via finalize has the same bug.

-------------

PR Review: https://git.openjdk.org/jdk/pull/26331#pullrequestreview-3031678484
PR Comment: https://git.openjdk.org/jdk/pull/26331#issuecomment-3086587833