[jdk21u-dev] RFR: 8343426: ConcurrentSkipListMap.spliterator() can no longer split the stream

[Goetz Lindenmaier]

On Tue, 17 Jun 2025 17:28:11 GMT, Satyen Subramaniam <ssubramaniam at openjdk.org> wrote:

> Backporting JDK-8343426: ConcurrentSkipListMap.spliterator() can no longer split the stream. Since Java 10, the trySplit() method for spliterators for the ConcurrentSkipListMap always returned null, causing parallel streams to be broken for ConcurrentSkipListMap and ConcurrentSkipListSet since. This change fixes the logic for considering the head.node.next field in addition to head.node. Ran GHA Sanity Checks, local Tier 1 and 2, and new test directly. Patch is clean.

Hi @satyenme 
can you please
  * annotate the change that broke this issue in JBS (caused by link)
  * do a dependent pull request for the follow-up  bug fix?
  * mention the dependent pull request in your fix request message
 Thanks for the good risk assessment.

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PR Comment: https://git.openjdk.org/jdk21u-dev/pull/1895#issuecomment-2982774203