8264279: Shenandoah: Missing handshake after JDK-8263427

[zhengyu123]

JDK-8263427 mistakenly removed handshake after concurrent weak roots, which is needed to flush out stale oops before we can safely recycle trash regions. Otherwise, those stale oops are suddenly resurrected, because they are above TAMS after regions are recycled.

Test:

• hotspot_gc_shenandoah

---

Progress

• Change must not contain extraneous whitespace
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Issue

• JDK-8264279: Shenandoah: Missing handshake after JDK-8263427

Reviewers

• Aleksey Shipilev (@shipilev - Reviewer)

Reviewing

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$ git pr checkout 3248

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https://git.openjdk.java.net/jdk/pull/3248.diff

[bridgekeeper]

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[openjdk]

@zhengyu123 The following labels will be automatically applied to this pull request:

• hotspot-gc
• shenandoah

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[mlbridge]

Webrevs

• 00: Full (db0862e)

[shipilev]

D'oh. Looks good.

[openjdk]

@zhengyu123 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:

8264279: Shenandoah: Missing handshake after JDK-8263427

Reviewed-by: shade

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 8 new commits pushed to the master branch:

• 1a681fa: 8263560: Remove needless wrapping with BufferedInputStream
• 182b11c: 8264016: [JVMCI] add some thread local fields for use by JVMCI
• 8cf1c62: 8263754: HexFormat 'fromHex' methods should be static
• a5d7de2: 8263404: RsaPrivateKeySpec is always recognized as RSAPrivateCrtKeySpec in RSAKeyFactory.engineGetKeySpec
• 128c0c9: 8248418: jpackage fails to extract main class and version from app module linked in external runtime
• fd45694: 8264344: Outdated links in JavaComponentAccessibility.m
• f17ea9e: 8262899: TestRedirectLinks fails
• 963f1fc: 8264309: JFR: Improve .jfc parser

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.

[zhengyu123]

/integrate

[openjdk]

@zhengyu123 Since your change was applied there have been 16 commits pushed to the master branch:

• ac604a1: 8264374: Shenandoah: Remove leftover parallel reference processing argument
• f3726a8: 8264020: Optimize double negation elimination
• 4ffa41c: 8263615: Cleanup tightly_coupled_allocation
• 4ea6abf: 8264324: Simplify allocation list management in OopStorage::reduce_deferred_updates
• 8735259: 8264333: Use the blessed modifier order in jdk.jshell
• d2a63f2: 8264360: Loop strip mining verification fails with "should be on the backedge"
• 8100a20: 8263971: C2 crashes with SIGFPE with -XX:+StressGCM and -XX:+StressIGVN
• bcdf469: 8264337: VM crashed when -XX:+VerifySharedSpaces
• 1a681fa: 8263560: Remove needless wrapping with BufferedInputStream
• 182b11c: 8264016: [JVMCI] add some thread local fields for use by JVMCI
• ... and 6 more: https://git.openjdk.java.net/jdk/compare/364cce1485aad9a870fefda38017301e481a31d9...master

Your commit was automatically rebased without conflicts.

Pushed as commit ee5e00b.

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