8281412: MemorySegment::map should live in FileChannel

[FrauBoes]

This change moves the factory for mapped memory segments to FileChannel, as a new instance method map, which moves it closer to the existing FileChannel::map that returns a MappedByteBuffer.

Tests are adjusted accordingly and a new test for custom file channels (that do/don't override the method) is added.

---

Progress

• Change must not contain extraneous whitespace
• Change must be properly reviewed

Issue

• JDK-8281412: MemorySegment::map should live in FileChannel

Reviewers

• Maurizio Cimadamore (@mcimadamore - Committer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.java.net/panama-foreign pull/668/head:pull/668
$ git checkout pull/668

Update a local copy of the PR:
$ git checkout pull/668
$ git pull https://git.openjdk.java.net/panama-foreign pull/668/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 668

View PR using the GUI difftool:
$ git pr show -t 668

Using diff file

Download this PR as a diff file:
https://git.openjdk.java.net/panama-foreign/pull/668.diff

[bridgekeeper]

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

[openjdk]

@FrauBoes this pull request can not be integrated into foreign-preview due to one or more merge conflicts. To resolve these merge conflicts and update this pull request you can run the following commands in the local repository for your personal fork:

git checkout filechannel-mapAsMemorySegment
git fetch https://git.openjdk.java.net/panama-foreign foreign-preview
git merge FETCH_HEAD
# resolve conflicts and follow the instructions given by git merge
git commit -m "Merge foreign-preview"
git push

[mlbridge]

Webrevs

• 04: Full - Incremental (6f102df2)
• 03: Full - Incremental (737add2c)
• 02: Full - Incremental (16895b36)
• 01: Full (5e002def)
• 00: Full (7a58b741)

[mcimadamore]

Some javadoc tweaks are probably required.

[mcimadamore]

Looks good!

[openjdk]

@FrauBoes 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:

8281412: MemorySegment::map should live in FileChannel

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 80 new commits pushed to the foreign-preview branch:

• cad5d16: Automatic merge of master into foreign-preview
• 53c5268: Automatic merge of jdk:master into master
• 95ca944: 8282354: Remove dependancy of TestHttpServer, HttpTransaction, HttpCallback from open/test/jdk/ tests
• f99193a: 8282811: Typo in IAE details message of RecordedObject.getValueDescriptor
• cab9def: 8282700: Properly handle several --without options during configure
• 1a5a496: 8282763: G1: G1CardSetContainer remove intrusive-list details.
• 88f0938: 8272493: Suboptimal code generation around Preconditions.checkIndex intrinsic with AVX2
• a5a1a32: 8282883: Use JVM_LEAF to avoid ThreadStateTransition for some simple JVM entries
• bb7ee5a: 8282314: nsk/jvmti/SuspendThread/suspendthrd003 may leak memory
• f5217b4: 8282852: Debug agent asserts in classTrack_addPreparedClass()
• ... and 70 more: https://git.openjdk.java.net/panama-foreign/compare/b1020d11b933935410e5e62f4023ab27853b85c7...foreign-preview

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 foreign-preview branch, type /integrate in a new comment.

[FrauBoes]

/integrate

[openjdk]

Going to push as commit c28366d.
Since your change was applied there have been 80 commits pushed to the foreign-preview branch:

• cad5d16: Automatic merge of master into foreign-preview
• 53c5268: Automatic merge of jdk:master into master
• 95ca944: 8282354: Remove dependancy of TestHttpServer, HttpTransaction, HttpCallback from open/test/jdk/ tests
• f99193a: 8282811: Typo in IAE details message of RecordedObject.getValueDescriptor
• cab9def: 8282700: Properly handle several --without options during configure
• 1a5a496: 8282763: G1: G1CardSetContainer remove intrusive-list details.
• 88f0938: 8272493: Suboptimal code generation around Preconditions.checkIndex intrinsic with AVX2
• a5a1a32: 8282883: Use JVM_LEAF to avoid ThreadStateTransition for some simple JVM entries
• bb7ee5a: 8282314: nsk/jvmti/SuspendThread/suspendthrd003 may leak memory
• f5217b4: 8282852: Debug agent asserts in classTrack_addPreparedClass()
• ... and 70 more: https://git.openjdk.java.net/panama-foreign/compare/b1020d11b933935410e5e62f4023ab27853b85c7...foreign-preview

Your commit was automatically rebased without conflicts.

[openjdk]

@FrauBoes Pushed as commit c28366d.

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