RFR: 7248: JMC7/8 Automated Analysis taking very long time to produce results for Class Leak Rule. [v2]

[Brice Dutheil]

On Tue, 27 Jul 2021 14:37:52 GMT, Suchita Chaturvedi <schaturvedi at openjdk.org> wrote:

>> This PR addresses the optimization of Class Leak Rule.
>> 
>> Please refer the JBS for the sample JFR which was taking ~90 minutes to generate results for Class Leak Rule. After the optimization time is reduced to ~10-15 minutes.
>> 
>> Please review the change and let me the know if there are any comments / suggestions.
>
> Suchita Chaturvedi has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Calculation maximum timeout is set via preference and hardcoding removed.

core/org.openjdk.jmc.flightrecorder.rules.jdk/src/main/java/org/openjdk/jmc/flightrecorder/rules/jdk/util/DefaultIItemResultSet.java line 135:

> 133: 				}
> 134: 				// Timeout can be configured in prefrences (default value is set to 5 minutes)
> 135: 				exec.awaitTermination(ClassLeakingRule.CONFIGURED_TIMEOUT, TimeUnit.MINUTES);

After re-reading this code I don't think `awaitTermination` is enough to terminate the ongoing tasks ; i.e. this call will block until either all tasks are finished or until the given time-out. This means that JMC may still have hanging threads doing some work in this anonymous thread pool.

I believe this statement should be followed by `exec.shutdownNow()` and making the runnables cooperate in this shutdown by checking the thread interrupt status in the for loops. E.g.


if (Thread.currentThread().isInterrupted()) return;

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PR: https://git.openjdk.java.net/jmc/pull/248