8323552: AbstractMemorySegmentImpl#mismatch returns -1 when comparing distinct areas of the same instance of MemorySegment

[minborg]

This PR proposes to remove an old optimization check that was incorrect making AbstractMemorySegmentImpl::mismatch always return -1 if the source and destination segment are the same (disregarding offsets).

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Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
• Change must not contain extraneous whitespace
• Commit message must refer to an issue

Issue

• JDK-8323552: AbstractMemorySegmentImpl#mismatch returns -1 when comparing distinct areas of the same instance of MemorySegment (Bug - P4)

Reviewers

• Maurizio Cimadamore (@mcimadamore - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/18426/head:pull/18426
$ git checkout pull/18426

Update a local copy of the PR:
$ git checkout pull/18426
$ git pull https://git.openjdk.org/jdk.git pull/18426/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 18426

View PR using the GUI difftool:
$ git pr show -t 18426

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/18426.diff

Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back pminborg! 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]

@minborg 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:

8323552: AbstractMemorySegmentImpl#mismatch returns -1 when comparing distinct areas of the same instance of MemorySegment

Reviewed-by: mcimadamore

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 9 new commits pushed to the master branch:

• 684678f: 8328633: s390x: Improve vectorization of Match.sqrt() on floats
• 93d1700: 8328589: unify os::breakpoint among posix platforms
• a5a2eca: 8327683: Crash with primitive type pattern and generic expression in instanceof
• 65d9f11: 8328328: Convert javax/swing/JTabbedPane/4666224/bug4666224.java applet test to main
• 481473e: 8328035: Convert javax/swing/text/html/TableView/7030332/bug7030332.java applet test to main
• dea94f4: 8328300: Convert PrintDialogsTest.java from Applet to main program
• d32746e: 8296244: Alternate implementation of user-based authorization Subject APIs that doesn’t depend on Security Manager APIs
• 000f4d8: 8319251: [REDO] Change LockingMode default from LM_LEGACY to LM_LIGHTWEIGHT
• fbeac98: 8328379: Convert URLDragTest.html applet test to main

Please see this link for an up-to-date comparison between the source branch of this pull request and the master branch.
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.

[openjdk]

@minborg The following label will be automatically applied to this pull request:

• core-libs

When this pull request is ready to be reviewed, an "RFR" email will be sent to the corresponding mailing list. If you would like to change these labels, use the /label pull request command.

[mlbridge]

Webrevs

• 00: Full (e850fba8)

[minborg]

/integrate

[openjdk]

Going to push as commit 93579c2.
Since your change was applied there have been 72 commits pushed to the master branch:

• b235682: 8328709: AIX os::get_summary_cpu_info support Power 10
• 19a0151: 8328700: Unused import and variable should be deleted in regex package
• cf9b5a7: 8328776: [AIX] remove checked_vmgetinfo, use vmgetinfo directly
• acc4a82: 8328862: Remove unused GrowableArrayFilterIterator
• 9f920b9: 8324655: Identify integer minimum and maximum patterns created with if statements
• c7b9dc4: 8328404: RISC-V: Fix potential crash in C2_MacroAssembler::arrays_equals
• bc73963: 8328303: 3 JDI tests timed out with UT enabled
• 476421e: 8328370: Convert java/awt/print/Dialog/PrintApplet.java applet test to main
• c013fa1: 8328194: Add a test to check default rendering engine
• f33a844: 8325536: JVM crash during CDS archive creation with -XX:+AllowArchivingWithJavaAgent
• ... and 62 more: https://git.openjdk.org/jdk/compare/96530bcc07514c3eda40fd6ffa74f197fe541dea...master

Your commit was automatically rebased without conflicts.

[openjdk]

@minborg Pushed as commit 93579c2.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.

[minborg]

/backport jdk21u

[openjdk]

@minborg Could not automatically backport 93579c29 to openjdk/jdk21u due to conflicts in the following files:

• test/jdk/java/foreign/TestMismatch.java

Please fetch the appropriate branch/commit and manually resolve these conflicts by using the following commands in your personal fork of openjdk/jdk21u. Note: these commands are just some suggestions and you can use other equivalent commands you know.

# Fetch the up-to-date version of the target branch
$ git fetch --no-tags https://git.openjdk.org/jdk21u.git master:master

# Check out the target branch and create your own branch to backport
$ git checkout master
$ git checkout -b backport-minborg-93579c29

# Fetch the commit you want to backport
$ git fetch --no-tags https://git.openjdk.org/jdk.git 93579c29e3ba60a8bc16d712e7ffc733f324a223

# Backport the commit
$ git cherry-pick --no-commit 93579c29e3ba60a8bc16d712e7ffc733f324a223
# Resolve conflicts now

# Commit the files you have modified
$ git add files/with/resolved/conflicts
$ git commit -m 'Backport 93579c29e3ba60a8bc16d712e7ffc733f324a223'

Once you have resolved the conflicts as explained above continue with creating a pull request towards the openjdk/jdk21u with the title Backport 93579c29e3ba60a8bc16d712e7ffc733f324a223.

Below you can find a suggestion for the pull request body:

Hi all,

This pull request contains a backport of commit 93579c29 from the openjdk/jdk repository.

The commit being backported was authored by Per Minborg on 25 Mar 2024 and was reviewed by Maurizio Cimadamore.

Thanks!

[minborg]

/backport jdk22u

[openjdk]

@minborg the backport was successfully created on the branch backport-minborg-93579c29 in my personal fork of openjdk/jdk22u. To create a pull request with this backport targeting openjdk/jdk22u:master, just click the following link:

➡️ Create pull request

The title of the pull request is automatically filled in correctly and below you find a suggestion for the pull request body:

Hi all,

This pull request contains a backport of commit 93579c29 from the openjdk/jdk repository.

The commit being backported was authored by Per Minborg on 25 Mar 2024 and was reviewed by Maurizio Cimadamore.

Thanks!

If you need to update the source branch of the pull then run the following commands in a local clone of your personal fork of openjdk/jdk22u:

$ git fetch https://github.com/openjdk-bots/jdk22u.git backport-minborg-93579c29:backport-minborg-93579c29
$ git checkout backport-minborg-93579c29
# make changes
$ git add paths/to/changed/files
$ git commit --message 'Describe additional changes made'
$ git push https://github.com/openjdk-bots/jdk22u.git backport-minborg-93579c29