Abstract
We present the CB tree, a counting-based self-adjusting binary search tree in which, as in splay trees, more-frequently accessed items move closer to the root. In a sequential execution, after m operations of which c(v) access itema v access of v traverses a path of length O(1+log m/c(v)) while doing few if any rotations. Unlike the original splay tree, in which each access moves the accessed item all the way to the root via a sequence of rotations, accesses in a CB tree do very few rotations, specifically O(n+nlog(m/n), during a sequence of operations of which n are insertions. This is o(1)(subconstant) amortized per operation if m ≫ n. We adapt the CB tree into a scalable concurrent self-adjusting BST. We show experimentally that the concurrent CB tree scales well because it, too, performs few rotations, and therefore self-adjusts without having rotations create a bottleneck. Our evaluation shows that the concurrent CB tree performs better than existing concurrent search trees on non-uniform access sequences derived from real workloads.
Original language | English (US) |
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Pages (from-to) | 393-417 |
Number of pages | 25 |
Journal | Distributed Computing |
Volume | 27 |
Issue number | 6 |
DOIs | |
State | Published - Nov 23 2014 |
All Science Journal Classification (ASJC) codes
- Theoretical Computer Science
- Hardware and Architecture
- Computer Networks and Communications
- Computational Theory and Mathematics
Keywords
- Optimistic concurrency control
- Self-adjusting tree
- Splay tree