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Register a new userAnalysis and Evaluation of Non-Blocking Interpolation Search Trees
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Aleksandar Prokopec
Publication date
2020
fields
Informatics Engineering
and research's language is
English
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We start by summarizing the recently proposed implementation of the first non-blocking concurrent interpolation search tree (C-IST) data structure. We then analyze the individual operations of the C-IST, and show that they are correct and linearizable. We furthermore show that lookup (and several other non-destructive operations) are wait-free, and that the insert and delete operations are lock-free. We continue by showing that the C-IST has the following properties. For arbitrary key distributions, this data structure ensures worst-case $O(log n + p)$ amortized time for search, insertion and deletion traversals. When the input key distributions are smooth, lookups run in expected $O(log log n + p)$ time, and insertion and deletion run in expected amortized $O(log log n + p)$ time, where $p$ is a bound on the number of threads. Finally, we present an extended experimental evaluation of the non-blocking IST performance.
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This paper presents the first implementation of a search tree data structure in an asynchronous shared-memory system that provides a wait-free algorithm for executing range queries on the tree, in addition to non-blocking algorithms for Insert, Delete and Find, using single-word Compare-and-Swap (CAS). The implementation is linearizable and tolerates any number of crash failures. Insert and Delete operations that operate on different parts of the tree run fully in parallel (without any interference with one another). We employ a lightweight helping mechanism, where each Insert, Delete and Find operation helps only update operations that affect the local neighbourhood of the leaf it arrives at. Similarly, a Scan helps only those updates taking place on nodes of the part of the tree it traverses, and therefore Scans operating on different parts of the tree do not interfere with one another. Our implementation works in a dynamic system where the number of processes may change over time. The implementation builds upon the non-blocking binary search tree implementation presented by Ellen et al. (in PODC 2010) by applying a simple mechanism to make the tree persistent.
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