8268855: Cleanup name handling in the Thread class and subclasses

[dholmes-ora]

Please review this small cleanup item.

We can simplify and cleanup up name() management:

• make name() return "const char *" and only cast away constness at API boundaries when essential
• add type_name() so that we can avoid code like "if (t->is_VM_Thread()) print("VMThread");
• Rename JavaThread::get_thread_name() to name() (no need for the extra indirection)

There are a couple of minor changes to the appearance of some internal threads in the hs_err log e.g.

0x000055af03e5b1b0 WatcherThread [stack: 0x00007f685df00000,0x00007f685e000000] [id=15952]

is now:

0x000055af03e5b1b0 WatcherThread "VM Periodic Task Thread" [stack: 0x00007f685df00000,0x00007f685e000000] [id=15952]

but this shouldn't affect anything and makes things more consistent.

Notes:

1. While "override" is the ideal style when declaring overriding methods it has to be applied to all virtual methods in a class. So unless "override" is already used in a class, I did not start using it. I have filed a separate RFE to convert the Thread classes to use "override" consistently.
2. While there is no need to redeclare a virtual method as "virtual" I kept to the existing style in those classes where changes were made.
3. I did not override type_name() for all the JavaThread subclasses as it seemed unnecessary, but happy to hear other views on this.

Testing (in progress):

• All builds in tiers 1-5
• GHA
• tiers 1-3 as a sanity test

Thanks,
David

---

Progress

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Issue

• JDK-8268855: Cleanup name handling in the Thread class and subclasses

Reviewers

• Lois Foltan (@lfoltan - Reviewer)
• Coleen Phillimore (@coleenp - Reviewer)

Reviewing

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Webrevs

• 00: Full (cc322f41)

[lfoltan]

Looks good!
Lois

[openjdk]

@dholmes-ora 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:

8268855: Cleanup name handling in the Thread class and subclasses

Reviewed-by: lfoltan, coleenp

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At the time when this comment was updated there had been 11 new commits pushed to the master branch:

• f375916: 8269186: [REDO] Remove CodeCache::mark_for_evol_deoptimization() method
• 7621fa3: 8268464: Remove dependancy of TestHttpsServer, HttpTransaction, HttpCallback from open/test/jdk/sun/net/www/protocol/https/ tests
• f3ba269: 8256306: ObjectMonitor::_contentions field should not be 'jint'
• 52d5d1b: 8269188: [BACKOUT] Remove CodeCache::mark_for_evol_deoptimization() method
• f2e690e: 8268720: Unspecified checks on NameAndType constants should not be performed
• 2c29d79: 8269206: A small typo in comment in test/lib/sun/hotspot/WhiteBox.java
• 6237630: 8269120: Build failure with GCC 6.3.0 after JDK-8017163
• a5e4307: 8269134: Remove sparsePRT.inline.hpp after JDK-8017163
• 17daf32: 8269138: Move typeArrayOop.inline.hpp include to vectorSupport.cpp
• 36d82b6: 8268858: Determine register pressure automatically by the number of available registers for allocation
• ... and 1 more: https://git.openjdk.java.net/jdk/compare/cd678a383f7b23ea40132b207ddfc041394ba4c1...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.

[navyxliu]

LGTM.

[coleenp]

This looks good.

[dholmes-ora]

Thanks for the reviews.

/integrate

[openjdk]

Going to push as commit 08ee7ae.
Since your change was applied there have been 19 commits pushed to the master branch:

• c79034e: 8269303: Remove unnecessary forward declaration of PSPromotionManager in cpCache.hpp
• 42968db: 8269293: ObjectMonitor thread id fields should be 64 bits.
• 2fd7943: 8256425: Obsolete Biased Locking in JDK 18
• 595446b: 8269087: CheckSegmentedCodeCache test fails in an emulated-client VM
• 7c31903: 8267075: jcmd VM.cds should print directory of the output files
• e515873: 8269216: Useless initialization in com/sun/crypto/provider/PBES2Parameters.java
• 51d9159: 8236212: CompiledMethodLoad and CompiledMethodUnload events can be posted in START phase
• 280f2d5: 8268433: serviceability/dcmd/framework/VMVersionTest.java fails with Unable to send object throw not established PipeIO Listener Thread connection
• f375916: 8269186: [REDO] Remove CodeCache::mark_for_evol_deoptimization() method
• 7621fa3: 8268464: Remove dependancy of TestHttpsServer, HttpTransaction, HttpCallback from open/test/jdk/sun/net/www/protocol/https/ tests
• ... and 9 more: https://git.openjdk.java.net/jdk/compare/cd678a383f7b23ea40132b207ddfc041394ba4c1...master

Your commit was automatically rebased without conflicts.

[openjdk]

@dholmes-ora Pushed as commit 08ee7ae.

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