8277441: CompileQueue::add fails with assert(_last->next() == __null) failed: not last

[TobiHartmann]

In the rare case that the compiler threads fail during initialization or the code cache is full and flushing is disabled, we completely disable JIT compilation and shut down the compiler runtime:

jdk/src/hotspot/share/compiler/compileBroker.cpp

Lines 1813 to 1817 in 2f4b540

	if (comp->should_perform_shutdown()) {
	// There are two reasons for shutting down the compiler
	// 1) compiler runtime initialization failed
	// 2) The code cache is full and the following flag is set: -XX:-UseCodeCacheFlushing
	warning("%s initialization failed. Shutting down all compilers", comp->name());

In the process, we free all compiler queues and set CompileQueue::_first to NULL and put the CompileTasks on the free list:

jdk/src/hotspot/share/compiler/compileTask.cpp

Line 84 in 2f4b540

task->set_next(_task_free_list);

In rare cases, although compilation is disabled, another waiting thread might still call CompileQueue::add. That code then fails because _last != NULL and _last->next() is set to _task_free_list.

jdk/src/hotspot/share/compiler/compileBroker.cpp

Lines 362 to 369 in 2f4b540

	if (_last == NULL) {
	// The compile queue is empty.
	assert(_first == NULL, "queue is empty");
	_first = task;
	_last = task;
	} else {
	// Append the task to the queue.
	assert(_last->next() == NULL, "not last");

The fix is to set _last to NULL in CompileQueue::free_all. Adding to the compile queue then succeeds which is harmless because queues have only been freed to make the compiler threads exit faster:

jdk/src/hotspot/share/compiler/compileBroker.cpp

Line 1823 in 2f4b540

// Delete all queued compilation tasks to make compiler threads exit faster.

The test that triggered this will be added with PR 6364. I verified that it now passes.

Thanks,
Tobias

---

Progress

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Issue

• JDK-8277441: CompileQueue::add fails with assert(_last->next() == __null) failed: not last

Reviewers

• Christian Hagedorn (@chhagedorn - Reviewer)
• Nils Eliasson (@neliasso - Reviewer)

Reviewing

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[bridgekeeper]

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[openjdk]

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[mlbridge]

Webrevs

• 00: Full (c3c87d7c)

[chhagedorn]

Looks good!

[openjdk]

@TobiHartmann 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:

8277441: CompileQueue::add fails with assert(_last->next() == __null) failed: not last

Reviewed-by: chagedorn, neliasso

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 3 new commits pushed to the master branch:

• e529865: 8277239: SIGSEGV in vrshift_reg_maskedNode::emit
• 8683de5: 8274685: Documentation suggests there are ArbitrarilyJumpableGenerator when none
• 6b4fbae: 8273792: JumpableGenerator.rngs() documentation refers to wrong method

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.

[TobiHartmann]

Thanks for the review, Christian!

[neliasso]

Looks good!

[TobiHartmann]

Thanks for the review, Nils!

[TobiHartmann]

/integrate

[openjdk]

Going to push as commit 90f96fb.
Since your change was applied there have been 18 commits pushed to the master branch:

• 66eaf65: 8277413: Remove unused local variables in jdk.hotspot.agent
• 36b887a: 8277560: Remove WorkerDataArray::_is_serial
• 017df14: 8277556: Call ReferenceProcessorPhaseTimes::set_processing_is_mt once
• 79350b9: 8276216: Negated character classes performance regression in Pattern
• e3243ee: 8277087: ZipException: zip END header not found at ZipFile#Source.findEND
• 12f08ba: 8277507: Add jlink.debug system property while launching jpackage tests to help diagonize recent intermittent failures
• bb11c55: 8277542: G1: Move G1CardSetFreePool and related classes to separate files
• f62b81c: 8273095: vmTestbase/vm/mlvm/anonloader/stress/oome/heap/Test.java fails with "wrong OOME"
• 05a9a51: 8277423: ciReplay: hidden class with comment expected error
• 1049aba: 8277576: ProblemList runtime/ErrorHandling/CreateCoredumpOnCrash.java on macosx-X64
• ... and 8 more: https://git.openjdk.java.net/jdk/compare/d427c79d3bd6c80b67c10d15a461f13ae7e0f84b...master

Your commit was automatically rebased without conflicts.

[openjdk]

@TobiHartmann Pushed as commit 90f96fb.

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