The lock-free k-LSM relaxed priority queue
Paper i proceeding, 2015

We present a new, concurrent, lock-free priority queue that relaxes the delete-min operation to allow deletion of any of the ρ+1 smallest keys instead of only a minimal one, where ρ is a parameter that can be configured at runtime. It is built from a logarithmic number of sorted arrays, similar to log-structured merge-trees (LSM). For keys added and removed by the same thread the behavior is identical to a non-relaxed priority queue. We compare to state-of-the-art lock-free priority queues with both relaxed and non-relaxed semantics, showing high performance and good scalability of our approach.

Concurrent data structure relaxation


Shared memory

Task-parallel programming


M. Wimmer

Technische Universitat Wien

J. Gruber

Technische Universitat Wien

J.L. Träff

Technische Universitat Wien

Philippas Tsigas

Chalmers, Data- och informationsteknik, Nätverk och system

SIGPLAN Notices (ACM Special Interest Group on Programming Languages)

0362-1340 (ISSN)

Vol. 50 277-278