8356698: JFR: @Contextual

[egahlin]

Could I have a review of a new annotation that can be used to annotate a field as contextual.

Testing: jdk/jdk/jfr + tier1

Thanks
Erik

---

Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
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• Commit message must refer to an issue
• Change requires CSR request JDK-8356699 to be approved

Issues

• JDK-8356698: JFR: @Contextual (Enhancement - P3)
• JDK-8356699: JFR: @Contextual (CSR)

Reviewers

• Markus Grönlund (@mgronlun - Reviewer)

Reviewing

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8356698: JFR: @Contextual

Reviewed-by: mgronlun

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At the time when this comment was updated there had been 30 new commits pushed to the master branch:

• a3f9e22: 8358218: Problemlist jdk/incubator/vector/PreferredSpeciesTest.java#id0
• 84002d1: 8228773: URLClassLoader constructors should include API note warning that the parent should not be null
• 3a3ea7e: 8357598: Toolkit.removeAWTEventListener should handle null listener in AWTEventListenerProxy
• ... and 27 more: https://git.openjdk.org/jdk/compare/e33eeeea04fc7899bf66b0a2fdaccc30060854b4...master

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[mgronlun]

A very nice addition and an excellent demo example for showcasing the capabilities is provided in the test: TestPrintContextual.java

[mgronlun]

Should the MethodTraceEvent's method field really have this annotation? Or is it a remnant from testing?

[egahlin]

I think it can be useful if a contextual GUI is created where users can drill down into tables and see all events that occur during a method call. For example, if you want to troubleshoot a slow login:

$ java -XX:StartFlightRecording:method-trace=LoginService::login ...

Context Types
Order::id
MethodTrace::method (selected)
Trace::id
Trace::name

Start Time	Duration	Context Values
20:05:02.10	5.0 s	LoginService::login(String, String) (selected)
20:05:08.10	80 ms	LoginService::login(String, String)
20:05:10.10	75 ms	LoginService::login(String, String)

Start Time	Event Name	Duration
20:05:02.45	Java Monitor Enter	25 ms
20:05:03.12	JDBC Execute Query	4.7 s

or some other known aspect of the program that has been problematic in the past and now have been annotated, for example:

$ java -XX:StartFlightRecording:method-trace=@com.example.UpdateOrder ...

[mgronlun]

I think it can be useful if a contextual GUI is created where users can drill down into tables and see all events that occur during a method call. For example, if you want to troubleshoot a slow login:

$ java -XX:StartFlightRecording:method-trace=LoginService::login ...

Context Types
Order::id
MethodTrace::method (selected)
Trace::id
Trace::name
Start Time Duration Context Values
20:05:02.10 5.0 s LoginService::login(String, String) (selected)
20:05:08.10 80 ms LoginService::login(String, String)
20:05:10.10 75 ms LoginService::login(String, String)
Start Time Event Name Duration
20:05:02.45 Java Monitor Enter 25 ms
20:05:03.12 JDBC Execute Query 4.7 s

or some other known aspect of the program that has been problematic in the past and now have been annotated, for example:

$ java -XX:StartFlightRecording:method-trace=@com.example.UpdateOrder ...

I could not agree more.

A GUI picking up these innovations, making them conveniently accessible and easily understandable to the end user would be fantastic.

[egahlin]

/integrate

[openjdk]

Going to push as commit 1373ceb.
Since your change was applied there have been 60 commits pushed to the master branch:

• ec02a87: 8345745: Update mode of the Attach API communication pipe.
• a7671e7: 8358337: JDK-8357991 was committed with incorrect indentation
• bce2bd2: 8356308: Assert with -Xlog:class+path when classpath has an empty element
• ... and 57 more: https://git.openjdk.org/jdk/compare/e33eeeea04fc7899bf66b0a2fdaccc30060854b4...master

Your commit was automatically rebased without conflicts.

[openjdk]

@egahlin Pushed as commit 1373ceb.

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