8313882: Fix -Wconversion warnings in runtime code

[coleenp]

Here are fixes to silence -Wconversion warnings in runtime code. Use direct cast for 64 bit int to double, otherwise default to checked_cast<>. I changed the declaration of _held_monitor_count and _jni_monitor count to intx to fix cascade of warnings coming from this.

src/hotspot/share/runtime/synchronizer.cpp:1802:41: warning: conversion from 'intx' {aka 'long int'} to 'int' may change value [-Wconversion]
1802 | _thread->dec_held_monitor_count(rec + 1);
| ~~~~^~~

Tested with tier1-4 on linux-x64-debug and windows-x64-debug and tier1 on Oracle supported platforms.

---

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Issue

• JDK-8313882: Fix -Wconversion warnings in runtime code (Bug - P4)

Reviewers

• Patricio Chilano Mateo (@pchilano - Reviewer) ⚠️ Review applies to 17eaec50
• Dean Long (@dean-long - Reviewer)
• David Holmes (@dholmes-ora - Reviewer)

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👋 Welcome back coleenp! 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]

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Webrevs

• 07: Full - Incremental (0e21a929)
• 06: Full - Incremental (e254b2df)
• 05: Full - Incremental (17eaec50)
• 04: Full - Incremental (43665637)
• 03: Full - Incremental (f4961655)
• 02: Full - Incremental (1af1cfe5)
• 01: Full - Incremental (a77884e4)
• 00: Full (4eeeb165)

[coleenp]

Thank you Dean and Patricio for your comments on this change.

[openjdk]

@coleenp this pull request can not be integrated into master 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 runtime-conversion
git fetch https://git.openjdk.org/jdk.git master
git merge FETCH_HEAD
# resolve conflicts and follow the instructions given by git merge
git commit -m "Merge master"
git push

[pchilano]

Thanks for the fixes. Looks good to me.

[openjdk]

@coleenp 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:

8313882: Fix -Wconversion warnings in runtime code

Reviewed-by: pchilanomate, dlong, dholmes

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 6 new commits pushed to the master branch:

• c822183: 8313768: Reduce interaction with volatile field in j.u.l.StreamHandler
• cd16158: 8314075: Update JCov version for JDK 22
• c307391: 8307184: Incorrect/inconsistent specification and implementation for Elements.getDocComment
• 593ba2f: 8313693: Introduce an internal utility for the Damerau–Levenshtein distance calculation
• 360f65d: 8314022: Problem-list tests failing with jtreg 7.3
• 0eb0997: 8288936: Wrong lock ordering writing G1HeapRegionTypeChange JFR event

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.

[dholmes-ora]

Overall seems okay. A couple of minor comments.

Thanks.

[dholmes-ora]

Clicked wrong button :)

[coleenp]

Thanks for the reviews, Patricio, Dean and David. I believe I addressed all the comments.
/integrate

[openjdk]

Going to push as commit f47767f.
Since your change was applied there have been 14 commits pushed to the master branch:

• 0cb9ab0: 8313239: InetAddress.getCanonicalHostName may return ip address if reverse lookup fails
• 028b3ae: 8313874: JNI NewWeakGlobalRef throws exception for null arg
• 83adaf5: 8313421: [JVMCI] avoid locking class loader in CompilerToVM.lookupType
• 35b60f9: 8298095: Refine implSpec for SegmentAllocator
• 6dba202: 8313670: Simplify shared lib name handling code in some tests
• 8f28809: 8299790: os::print_hex_dump is racy
• e080a0b: 8311508: ZGC: RAII use of IntelJccErratumAlignment
• 242a2e6: 8308843: Generational ZGC: Remove gc/z/TestHighUsage.java
• c822183: 8313768: Reduce interaction with volatile field in j.u.l.StreamHandler
• cd16158: 8314075: Update JCov version for JDK 22
• ... and 4 more: https://git.openjdk.org/jdk/compare/19ae62ae2cd2bbb436924b296151021864a3fcd9...master

Your commit was automatically rebased without conflicts.

[openjdk]

@coleenp Pushed as commit f47767f.

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