Use ThreadLocalRandom for thread selection in OrderedExecutor#4832
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merlimat wants to merge 1 commit into
Open
Use ThreadLocalRandom for thread selection in OrderedExecutor#4832merlimat wants to merge 1 commit into
merlimat wants to merge 1 commit into
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void-ptr974
approved these changes
Jul 11, 2026
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Motivation
OrderedExecutor.chooseThread()— the path behind the keylesssubmit()/execute()overloads andchooseThread(null)— picks a thread using a single sharedjava.util.Randominstance.Random.nextInt()is a CAS retry loop over one sharedAtomicLongseed, so when many threads submit keyless tasks to a shared executor they all contend on the same cache line, purely to produce a thread index.Changes
Use
ThreadLocalRandom.current().nextInt(...)for the random routing (no shared state, no CAS contention) and remove the now-unusedrandfield.Verified with
TestOrderedExecutorandTestOrderedExecutorDecorators(all pass) and module checkstyle.