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

[Paul Hohensee]

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.

https://github.com/openjdk/jdk21u-dev/pull/1906 appears to include the [JDK-8344253](https://bugs.openjdk.org/browse/JDK-8344253) backport. You can use "/issue add JDK-8344253" to update 1906 to include the 8344253 backport, then close this one in favor of 1906.

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PR Comment: https://git.openjdk.org/jdk21u-dev/pull/1895#issuecomment-2992020392