“A lock-free concurrency toolkit for deferred reclamation and optimistic speculation"
summary
Proposes a C++ Concurrency Toolkit that standardizes two lock-free reclamation methods: hazard pointers (fixed per-thread pointer metadata, used to prevent ABA and unsafe reclamation in pointer-copy CAS patterns) and read-copy-update (RCU) (grace-period based reclamation with very fast reader paths but potentially large unreclaimed memory). Presents an experimental C++ API and GitHub implementation, shows a hand-over-hand linked-list traversal example, compares tradeoffs (memory vs traversal speed, forward progress), and surfaces a C++ call_rcu ABI issue across translation units.
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chapters (10)
- 0:00Introduction to concurrency
- 1:40Concurrency and uncertainty
- 4:39Four key approaches
- 7:48Reference counting details
- 13:18Performance trade-offs
- 17:42Hazard pointers overview
- 31:09Hazard pointer implementation
- 38:00RCU concepts and mechanisms
- 45:47RCU implementation details
- 50:14Final thoughts and Q&A
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