8314157: G1: "yielded" is not initialized on some paths after JDK-8140326

[tschatzl]

Hi all,

can I have reviews for this change that fixes a bug with with some variable not being initialized, leading to (minor) unnecessary work.

The use of the yielded variable is an optimization to not re-check TARSes again if there has been no yielding (safepoint) while processing. Maybe it is useful to remove it because the re-echeck for TARS isn't that expensive anyway.

Testing: tier1-3

Thanks,
Thomas

Note: this has been edited to only cover the uninitialized variables after after @albertnetymk pointed out that the original error analysis has been wrong. There is some more information in the CR about the original analysis.

---

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Issue

• JDK-8314157: G1: "yielded" is not initialized on some paths after JDK-8140326 (Bug - P4)

Reviewers

• Albert Mingkun Yang (@albertnetymk - Reviewer)
• Ivan Walulya (@walulyai - Reviewer)

Reviewing

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@tschatzl This change now passes all automated pre-integration checks.

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After integration, the commit message for the final commit will be:

8314157: G1: "yielded" is not initialized on some paths after JDK-8140326

Reviewed-by: ayang, iwalulya

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At the time when this comment was updated there had been 22 new commits pushed to the master branch:

• 7e843c2: 8284772: GHA: Use GCC Major Version Dependencies Only
• ba6cdbe: 8309214: sun/security/pkcs11/KeyStore/CertChainRemoval.java fails after 8301154
• 9f4a9fe: 8312434: SPECjvm2008/xml.transform with CDS fails with "can't seal package nu.xom"
• 7c169a4: 8312232: Remove sun.jvm.hotspot.runtime.VM.buildLongFromIntsPD()
• 2eae13c: 8214248: (fs) Files:mismatch spec clarifications
• ce1ded1: 8314749: Remove unimplemented _Copy_conjoint_oops_atomic
• 32bf468: 8314274: G1: Fix -Wconversion warnings around G1CardSetArray::_data
• eb06572: 8313408: Use SVG for BoxLayout example
• 20e9478: 8314426: runtime/os/TestTrimNative.java is failing on slow machines
• 69d900d: 8314730: GHA: Drop libfreetype6-dev transitional package in favor of libfreetype-dev
• ... and 12 more: https://git.openjdk.org/jdk/compare/8939d15d92982300f090bc1c51f59550529eaaf3...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.

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[tschatzl]

Thanks @albertnetymk @walulyai for your reviews

/integrate

[openjdk]

Going to push as commit 742e319.
Since your change was applied there have been 28 commits pushed to the master branch:

• 1cee3b9: 8313262: C2: Sinking node may cause required cast to be dropped
• f8203cb: 8313626: C2 crash due to unexpected exception control flow
• 2be469f: 8314743: Use of uninitialized local in SR_initialize after JDK-8314114
• 571c435: 8313374: --enable-ccache's CCACHE_BASEDIR breaks builds
• d1de3d0: 8313901: [TESTBUG] test/hotspot/jtreg/compiler/codecache/CodeCacheFullCountTest.java fails with java.lang.VirtualMachineError
• a0d0f21: 8314752: Use google test string comparison macros
• 7e843c2: 8284772: GHA: Use GCC Major Version Dependencies Only
• ba6cdbe: 8309214: sun/security/pkcs11/KeyStore/CertChainRemoval.java fails after 8301154
• 9f4a9fe: 8312434: SPECjvm2008/xml.transform with CDS fails with "can't seal package nu.xom"
• 7c169a4: 8312232: Remove sun.jvm.hotspot.runtime.VM.buildLongFromIntsPD()
• ... and 18 more: https://git.openjdk.org/jdk/compare/8939d15d92982300f090bc1c51f59550529eaaf3...master

Your commit was automatically rebased without conflicts.

[openjdk]

@tschatzl Pushed as commit 742e319.

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