8308694: Clarify reversed() default methods' implementation requirements

[stuart-marks]

Can I get a preliminary review of the wording for Deque.reversed()? If the text is good, I'll make corresponding changes to the implSpecs of the other reversed() default methods, namely those in List, SortedMap, and SortedSet and then file the CSR.

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Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
• Change must not contain extraneous whitespace
• Change requires CSR request JDK-8311845 to be approved
• Commit message must refer to an issue

Issues

• JDK-8308694: Clarify reversed() default methods' implementation requirements (Bug - P3)
• JDK-8311845: Clarify reversed() default methods' implementation requirements (CSR)

Reviewers

• Roger Riggs (@RogerRiggs - Reviewer) ⚠️ Review applies to c8a69ee7

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[bridgekeeper]

👋 Welcome back smarks! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[openjdk]

@stuart-marks The following label will be automatically applied to this pull request:

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[mlbridge]

Webrevs

• 03: Full - Incremental (b97e6022)
• 02: Full - Incremental (c8a69ee7)
• 01: Full - Incremental (0a8b769f)
• 00: Full (5981ca83)

[stuart-marks]

/csr

[openjdk]

@stuart-marks has indicated that a compatibility and specification (CSR) request is needed for this pull request.

@stuart-marks please create a CSR request for issue JDK-8308694 with the correct fix version. This pull request cannot be integrated until the CSR request is approved.

[bplb]

Reads well.

[stuart-marks]

@bplb OK thanks. But now that I've posted this, I'm having second thoughts. :-)

The problem is that this spec is trying to be more specific...and the more specific something is, the greater the possibility is of inaccuracy. What I had written is mostly true, but it isn't true for all operations. Some operations in particular such as addAll actually have to do rather more complex things than delegating operations to the backing Deque. See the implementation for other examples:

https://github.com/openjdk/jdk/blob/master/src/java.base/share/classes/java/util/ReverseOrderDequeView.java

I don't want to specify the exact behavior of every method. Issues of a similar magnitude occur with the other reversed views. For example, getting the iterator of a reversed SortedSet involves some heavy lifting:

https://github.com/openjdk/jdk/blob/master/src/java.base/share/classes/java/util/ReverseOrderSortedSetView.java#L206

and I certainly don't want to specify all of that.

So, while in fact the general sense is true that the operations of the reversed view are all implemented via calls to the backing collection, I need to be deliberately vague in certain respects.

[stuart-marks]

OK please take another look.

[RogerRiggs]

Looks good.

[stuart-marks]

CSR JDK-8311845 ready for review.

[openjdk]

@stuart-marks This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8308694: Clarify reversed() default methods' implementation requirements

Reviewed-by: rriggs

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 24 new commits pushed to the master branch:

• fd7fddb: 8295894: Remove SECOM certificate that is expiring in September 2023
• d82ade3: 8310683: Refactor StandardCharset/standard.java to use JUnit
• aac903d: 8311805: Clean up ScrollPane: drop redundant initialiser, mark scroller final
• 15195e6: 8310066: Improve test coverage for JVMTI GetThreadState on carrier and mounted vthread
• 6cb9ec3: 6960866: [Fmt-Ch] ChoiceFormat claims impossible and unimplemented functionality
• 401c3de: 8311645: Memory leak in jspawnhelper spawnChild after JDK-8307990
• e154b0d: 8311606: Change read_icc_profile() to static function in java.desktop/share/native/libjavajpeg/imageioJPEG.c
• a03a3a4: 8311178: JMH tests don't scale well when sharing output buffers
• 00c7f91: 8310047: Add UTF-32 based Charsets into StandardCharsets
• caadad4: 8303279: C2: crash in SubTypeCheckNode::sub() at IGVN split if
• ... and 14 more: https://git.openjdk.org/jdk/compare/5667afc36275b064c7700518f453fe8657e13636...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

[stuart-marks]

/integrate

[openjdk]

Going to push as commit f82c818.
Since your change was applied there have been 28 commits pushed to the master branch:

• 7304316: 8311926: java/lang/ScopedValue/StressStackOverflow.java takes 9mins in tier1
• aa7367f: 8311921: Inform about MaxExpectedDataSegmentSize in case of pthread_create failures on AIX
• 753bd56: 8311870: Split CompressedKlassPointers from compressedOops.hpp
• 0b0e064: 8311656: Shenandoah: Unused ShenandoahSATBAndRemarkThreadsClosure::_claim_token
• fd7fddb: 8295894: Remove SECOM certificate that is expiring in September 2023
• d82ade3: 8310683: Refactor StandardCharset/standard.java to use JUnit
• aac903d: 8311805: Clean up ScrollPane: drop redundant initialiser, mark scroller final
• 15195e6: 8310066: Improve test coverage for JVMTI GetThreadState on carrier and mounted vthread
• 6cb9ec3: 6960866: [Fmt-Ch] ChoiceFormat claims impossible and unimplemented functionality
• 401c3de: 8311645: Memory leak in jspawnhelper spawnChild after JDK-8307990
• ... and 18 more: https://git.openjdk.org/jdk/compare/5667afc36275b064c7700518f453fe8657e13636...master

Your commit was automatically rebased without conflicts.

[openjdk]

@stuart-marks Pushed as commit f82c818.

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