Synchronous Reclamation Beyond Concurrency TS2 – Maged Michael • A call to hazard_pointer_clean_up guarantees that all objects that were • retired to the domain • and not protected by hazard pointers • before • A retired object can belong to at most one cohort. • The completion of a cohort’s destructor guarantees the completion of all deleters of objects that belong/belonged to the cohort. Hazard Pointer

 std::system_clock: wall clock time from system-wide real-time clock  std::steady_clock: guarantees it never goes backwards  std::high_resolution_clock: has shortest possible tick period  C++20

Atomic Smart Pointers  Is shared_ptr thread safe?  Yes: control block manipulation thread safe  guarantees object is deleted exactly once  No: accessing pointer not thread-safe, one thread could be reading