Concurrency in C++20: A Deep Dive
summary
C++20 actually adds concrete primitives and shows measured tradeoffs: atomic_flag stays the only guaranteed lockfree atomic, compare_exchange_strong underpins lockfree algorithms, and atomics gain wait/notify that block when the value matches a predicate. The library adds atomic_ref, atomic shared/weak pointer wrappers (currently locking), counting and binary semaphore, latch and barrier for one‑shot and reusable joins, cooperative interruption with stop_token/stop_source, jthread that auto‑joins, and synchronized output; benchmarks show condition_variable is slow while semaphores match atomics for a 1M ping‑pong.
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chapters (12)
- 0:00Introduction
- 1:12Atomic operations
- 9:49Atomic waiting and notification
- 11:55Atomic smart pointers
- 15:00Atomic reference
- 19:18Semaphores
- 23:54Condition variables
- 34:02Ping pong game comparison
- 41:30Latches and barriers
- 47:33Cooperative interruption
- 55:41Jthread and synchronization
- 57:07Summary and conclusions
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