[Submitted on 7 Feb 2021 (v1), last revised 26 Jul 2026 (this version, v5)]

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Abstract:We present Hemlock, a novel mutual exclusion locking algorithm that is extremely compact, requiring just one word per thread plus one word per lock, but which still provides local spinning in most circumstances, high throughput under contention, and low latency in the uncontended case. Hemlock is context-free -- not requiring any information to be passed from a lock operation to the corresponding unlock -- and FIFO. The performance of Hemlock is competitive with and often better than the best scalable spin locks.

Submission history

From: David Dice [view email]
[v1] Sun, 7 Feb 2021 17:46:25 UTC (161 KB)
[v2] Thu, 18 Feb 2021 16:35:09 UTC (169 KB)
[v3] Thu, 13 May 2021 20:02:13 UTC (184 KB)
[v4] Wed, 5 Jan 2022 23:57:48 UTC (184 KB)
[v5] Sun, 26 Jul 2026 20:17:05 UTC (236 KB)