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A self-balancing skip-list (a.k.a. "splay-list") library in C

A self-balancing skip-list (a.k.a. "splay-list") library in C

by gregburd·May 19, 2026·4 points·0 comments
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AI Analysis

●●SolidCozyNiche Gem

Header-only lock-free splay-list in C with MVCC snapshots and epoch-based reclaim.

Strengths
  • •Macro-generated type safety mimics C++ templates while staying pure C99/C11.
  • •Fraser/Harris algorithm + EBR ensures correct concurrent memory management without GC.
  • •Dual ISC/MIT licensing and zero external deps make it trivial to vendor into projects.
Weaknesses
  • •Splay rebalancing adds overhead—may underperform plain skip-lists for read-heavy workloads.
  • •No Windows support; relies on pthreads and C11 atomics unavailable on older toolchains.
Target Audience

Systems programmers, embedded developers, high-performance C application authors

Similar To

libcds · folly::ConcurrentSkipList · RCU-based lists in Linux kernel

Post Description

A header-only C library implementing a concurrent, lock-free skip-list (specifically, a splay-list: a skip-list with optional adaptive rebalancing). The entire implementation lives in preprocessor macros in include/sl.h that generate type-specific code at compile time, similar to C++ templates.

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