8267990: Revisit some uses of synchronized in the HttpClient API

[dfuch]

The Utils.remaining(List list) method assumes that it can and should synchronize on the given list to prevent concurrent modification. In 99% of the cases this assumption is wrong. There's only one such list (the SSLFlowDelegate writeList) that requires this synchronization.

Also the SequentialScheduler.synchronizedScheduler uses synchronized, it could use a Lock instead and this would make it possible to assert that there is no contention (since the logic of the SequentialScheduler is supposed to prevent contention from occurring at this place).

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Issue

• JDK-8267990: Revisit some uses of synchronized in the HttpClient API

Reviewers

• Chris Hegarty (@ChrisHegarty - Reviewer) ⚠️ Review applies to c2f49a5

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• 01: Full - Incremental (7d92e7bd)
• 00: Full (c2f49a5f)

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8267990: Revisit some uses of `synchronized` in the HttpClient API

Reviewed-by: chegar

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At the time when this comment was updated there had been 2 new commits pushed to the master branch:

• 382e7ec: 8246351: elements in headings are of incorrect size
• 5df25dc088cfc3069e451b48c4f013d1d0491aa2: 8266807: Windows os_windows-gtest broken for UseLargePages

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[dfuch]

/integrate

[openjdk]

@dfuch Since your change was applied there have been 14 commits pushed to the master branch:

• 36dc268: 8268036: ProblemList gtest/AsyncLogGtest.java
• 74b70a5: 8036580: CHA: improve default method support
• 20479c3: 8065760: CHA: Improve abstract method support
• 68f3b3a: 8267807: C2: Downcast receiver to target holder during inlining
• 1c7c0e1: 8267937: Wrong indentation in G1 gc+phases log for free cset subphases
• ffd28c4: 8267947: CI: Preserve consistency between has_subklass() and is_subclass_of()
• 229a6e2: 8267095: Miscellaneous cleanups in vm.runtime.defmeth tests
• 6149b9a: 8267914: Remove DeferredObjectToKlass workaround
• 4eb2168: 8267670: Update java.io, java.math, and java.text to use switch expressions
• f5634fe: 8267979: C2: Fix verification code in SubTypeCheckNode::Ideal()
• ... and 4 more: https://git.openjdk.java.net/jdk/compare/ce44cd6881bcbef81a840d7961a951ba586c0eae...master

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