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8280844: Epoch shift synchronization point for Compiler threads is inadequate#8724

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8280844: Epoch shift synchronization point for Compiler threads is inadequate#8724
mgronlun wants to merge 2 commits intoopenjdk:masterfrom
mgronlun:8280844

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@mgronlun mgronlun commented May 16, 2022 •
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Greetings,

JDK-8233111 attempted to address artefact tagging for Compiler threads, letting threads run _thread_in_native to avoid the transition. Unfortunately, that attempt proved inadequate.

The epoch race is avoided only by performing the transition to _thread_in_vm.

Testing: jdk_jfr

Thanks
Markus

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  • JDK-8280844: Epoch shift synchronization point for Compiler threads is inadequate

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bridgekeeper bot commented May 16, 2022

👋 Welcome back mgronlun! 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 openjdk bot added the rfr Pull request is ready for review label May 16, 2022
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openjdk bot commented May 16, 2022

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

  • build
  • hotspot

When this pull request is ready to be reviewed, an "RFR" email will be sent to the corresponding mailing lists. If you would like to change these labels, use the /label pull request command.

@openjdk openjdk bot added build build-dev@openjdk.org hotspot hotspot-dev@openjdk.org labels May 16, 2022
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mlbridge bot commented May 16, 2022 •
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mgronlun commented May 16, 2022

/label hotspot-jfr

@openjdk openjdk bot added the hotspot-jfr hotspot-jfr-dev@openjdk.org label May 16, 2022
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mgronlun commented May 16, 2022

/label remove hotspot

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mgronlun commented May 16, 2022

/label add hotspot-compiler

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The hotspot-compiler label was successfully added.

dholmes-ora
dholmes-ora reviewed May 16, 2022
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src/hotspot/share/compiler/compilerEvent.cpp Outdated
template <typename EventType>
static inline void commit(EventType& event) {
JavaThread* thread = JavaThread::current();
assert(thread->thread_state() == _thread_in_native, "invariant");
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You don't need this assert as ThreadInVMfromNative already has it.

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openjdk bot commented May 16, 2022 •
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@mgronlun 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:

8280844: Epoch shift synchronization point for Compiler threads is inadequate

Reviewed-by: egahlin

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 34 new commits pushed to the master branch:

  • a31130f: 7131823: bug in GIFImageReader
  • 4bc7b7d: 8286760: Update citation of "Effective Java" second edition to third edition
  • c044cb8: 8286399: Address possibly lossy conversions in JDK Build Tools
  • b884db8: 8285844: TimeZone.getTimeZone(ZoneOffset) does not work for all ZoneOffsets and returns GMT unexpected
  • dbd3737: 8286200: SequenceInputStream::read(b, off, 0) returns -1 at EOF
  • 743c779: 8286390: Address possibly lossy conversions in jdk.incubator.foreign moved to java.base
  • 22139c3: 8286704: G1: Call offset_of directly in subclasses of G1CardSetContainer
  • 77dfbb4: 8178701: Compile error with switch statement on protected enum defined in parent inner class
  • f4258a5: 8209137: Add ability to bind to specific local address to HTTP client
  • 65da38d: 8284585: PushPromiseContinuation test fails intermittently in timeout
  • ... and 24 more: https://git.openjdk.java.net/jdk/compare/8daf08dbc438f5c1b53b52f86ed6b1c5884280c4...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 openjdk bot added the ready Pull request is ready to be integrated label May 16, 2022
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magicus commented May 16, 2022

/label -build

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mgronlun commented May 18, 2022

/integrate

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openjdk bot commented May 18, 2022

Going to push as commit d936c30.
Since your change was applied there have been 68 commits pushed to the master branch:

Your commit was automatically rebased without conflicts.

@openjdk openjdk bot added the integrated Pull request has been integrated label May 18, 2022
@openjdk openjdk bot closed this May 18, 2022
@openjdk openjdk bot removed ready Pull request is ready to be integrated rfr Pull request is ready for review labels May 18, 2022
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@mgronlun Pushed as commit d936c30.

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

dougxc
dougxc reviewed Feb 28, 2023
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src/hotspot/share/compiler/compilerEvent.cpp
return index;
}

// As part of event commit, a Method* is tagged as a function of an epoch.
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This transition is not necessary for JVMCI compiler threads: #12787

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@dougxc dougxc dougxc left review comments

@dholmes-ora dholmes-ora dholmes-ora left review comments

@egahlin egahlin egahlin approved these changes

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