Implement bn::base::{mutex, recursive_mutex} for Windows and Linux - #8479
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Implement bn::base::{mutex, recursive_mutex} for Windows and Linux#8479bdash wants to merge 2 commits into
bdash wants to merge 2 commits into
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On Windows, `mutex` wraps a `std::shared_mutex`, which unlike `std::mutex` is a thin wrapper around `SRWLOCK`, so it is both fast and compact. On Linux, it is modeled after `mutex3` from Drepper's "Futexes are Tricky". A `std::atomic<int>` holds the state, and blocking is handled via `platform_wait`, a thin abstraction over futex wait/wake that also has `__ulock` and `WaitOnAddress` backends for macOS and Windows. `recursive_mutex` is a wrapper around `mutex` that tracks the owning thread and recursion count. These are comparable in performance to the equivalent standard library types, but they're significantly smaller (on Windows 8 bytes vs 80, on Linux 4 bytes vs 40).
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On Windows,
mutexwraps astd::shared_mutex, which unlikestd::mutexis a thin wrapper aroundSRWLOCK, so it is both fast and compact.On Linux, it is modeled after
mutex3from Drepper's "Futexes are Tricky". Astd::atomic<int>holds the state, and blocking is handled viaplatform_wait, a thin abstraction over futex wait/wake that also has__ulockandWaitOnAddressbackends for macOS and Windows.recursive_mutexis a wrapper aroundmutexthat tracks the owning thread and recursion count.These are comparable in performance to the equivalent standard library types, but they're significantly smaller (on Windows 8 bytes vs 80, on Linux 4 bytes vs 40).