synchronizers: CountDownLatch vs CyclicBarrier vs Phaser vs Semaphore

One three-round worker pipeline implemented with CountDownLatch (one latch
per round), CyclicBarrier (reusable, with a barrier action), and Phaser
(reusable, plus dynamic mid-run registration), alongside Semaphore solving
the genuinely different problem of bounding concurrent access. Covers
timeout behavior (CyclicBarrier permanently breaks on one timeout, Phaser
doesn't) and virtual-thread compatibility, including the corrected finding
that Object.wait() releases its monitor and never pinned, unlike
Thread.sleep() inside synchronized.

Co-Authored-By: Claude Sonnet 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01FhzLY5p6okFva3qsnsRyvM
This commit is contained in:
2026-09-30 06:43:52 +00:00
co-authored by Claude Sonnet 5
parent 0819993c51
commit 55ee850a75
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$ java CyclicBarrierPipeline
worker-0: finished round 1
worker-1: finished round 1
worker-2: finished round 1
worker-3: finished round 1
barrier action: round 1 complete, all 4 workers arrived
worker-0: finished round 2
worker-1: finished round 2
worker-2: finished round 2
worker-3: finished round 2
barrier action: round 2 complete, all 4 workers arrived
worker-0: finished round 3
worker-1: finished round 3
worker-2: finished round 3
worker-3: finished round 3
barrier action: round 3 complete, all 4 workers arrived
done