8357179: Deprecate VFORK launch mechanism from Process implementation (linux)

[tstuefe]

For the ratio behind this please see the companion CSR: https://bugs.openjdk.org/browse/JDK-8357180.

We plan to deprecate this in JDK 25 and to remove it in JDK 26.

This patch just writes a deprecation message to stderr:

08:46:38 thomas@starfish java -Djdk.lang.Process.launchMechanism=VFORK SimpleSpawn ls
VFORK MODE DEPRECATED
The VFORK launch mechanism has been deprecated for being dangerous.
It will be removed in a future java version. Either remove the
jdk.lang.Process.launchMechanism property (preferred) or use FORK mode
instead (-Djdk.lang.Process.launchMechanism=FORK).
...

---

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
• Change requires CSR request JDK-8357180 to be approved

Issues

• JDK-8357179: Deprecate VFORK launch mechanism from Process implementation (linux) (Enhancement - P3)
• JDK-8357180: Deprecate VFORK launch mechanism from Process implementation (linux) (CSR)

Reviewers

• Roger Riggs (@RogerRiggs - Reviewer)

Reviewing

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[bridgekeeper]

👋 Welcome back stuefe! 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]

@tstuefe 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:

8357179: Deprecate VFORK launch mechanism from Process implementation (linux)

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 54 new commits pushed to the master branch:

• 972f2eb: 8351412: Add AVX-512 intrinsics for ML-KEM
• e9d1d87: 8357013: HttpURLConnection#getResponseCode can avoid substring call when parsing to int
• bcf5cd6: 8355954: File.delete removes read-only files (win)
• ... and 51 more: https://git.openjdk.org/jdk/compare/f6b0f016f6da5d9c96b21c74d3b906ed8e6ae4b4...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.

[openjdk]

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

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[mlbridge]

Webrevs

• 01: Full - Incremental (ec3197f9)
• 00: Full (8bd4a36e)

[RogerRiggs]

lgtm; thanks

[AlanBateman]

This is okay although I could imagine someone wanting to replace this with a text block.

[tstuefe]

okay, changed to string block

[RogerRiggs]

Looks good, also reviewed the CSR, it can be finalized.

[tstuefe]

Thanks all
/integrate

[openjdk]

Going to push as commit 74fc4e4.
Since your change was applied there have been 55 commits pushed to the master branch:

• cedd1a5: 8357250: assert(shift >= 0 && shift < 4) failed: unexpected compressd klass shift!
• 972f2eb: 8351412: Add AVX-512 intrinsics for ML-KEM
• e9d1d87: 8357013: HttpURLConnection#getResponseCode can avoid substring call when parsing to int
• ... and 52 more: https://git.openjdk.org/jdk/compare/f6b0f016f6da5d9c96b21c74d3b906ed8e6ae4b4...master

Your commit was automatically rebased without conflicts.

[openjdk]

@tstuefe Pushed as commit 74fc4e4.

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

[shipilev]

VFORK deprecation sneaked up on me. I filed JDK-8357436 to amend jspawnhelper warning message.