Relaxed semantics have been introduced to increase the achievable parallelism of concurrent data structures in exchange for weakening their ordering semantics. In this paper, we revisit the balanced allocations $d$-choice load balancing scheme in the context of relaxed FIFO queues. Our novel load balancing approach distributes operations evenly across $n$ sub-queues based on operation counts, achieving low relaxation errors independent on the queues size, as opposed to similar earlier designs. We prove its relaxation errors to be of $\mathcal{O}(\frac{n \log\log n}{\log d})$ with high probability for a collection of possible executions. Furthermore, our scheme, contrary to previous ones, manages to interface and integrate the most performant linearizable queue designs from the literature as components. Our resulting relaxed FIFO queue is experimentally shown to outperform the previously best design using balanced allocations by more than four times in throughput, while simultaneously incurring less than a thousandth of its relaxation errors. In a concurrent breadth-first-search benchmark, our queue consistently outperforms both relaxed and strict state-of-the-art FIFO queues.

Tue 4 Mar

Displayed time zone: Pacific Time (US & Canada) change

15:40 - 17:00
Session 9: Concurrent Data Structures and Synchronization II (Session Chair: Pengfei Su)Main Conference at Acacia D
15:40
20m
Talk
PANNS: Enhancing Graph-based Approximate Nearest Neighbor Search through Recency-aware Construction and Parameterized Search
Main Conference
Xizhe Yin University of California, Riverside, Chao Gao University of California Riverside, Zhijia Zhao University of California at Riverside, Rajiv Gupta University of California at Riverside (UCR)
16:00
20m
Talk
Balanced Allocations over Efficient Queues: A Fast Relaxed FIFO Queue
Main Conference
Kåre von Geijer Chalmers University of Technology, Philippas Tsigas Chalmers University of Technology, Elias Johansson Chalmers University of Technology, Sebastian Hermansson Chalmers University of Technology
16:20
20m
Talk
LibRTS: A Spatial Indexing Library by Ray Tracing
Main Conference
Liang Geng The Ohio State University, USA, Rubao Lee , Xiaodong Zhang The Ohio State University
16:40
20m
Talk
Crystality: A Programming Model for Smart Contracts on Parallel EVMs
Main Conference
Hao Wang International Digital Economy Academy (IDEA), Shenzhen, China; and Fullnodes Labs, Minghao Pan International Digital Economy Academy (IDEA), Shenzhen, China; and Fullnodes Labs, Jiaping Wang International Digital Economy Academy (IDEA), Shenzhen, China; and Fullnodes Labs