MMCore: simplify notificationQueueMutex_#908
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marktsuchida merged 1 commit intomicro-manager:mainfrom Apr 7, 2026
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- Switch from std::shared_mutex to plain std::mutex, because this
uncontended and briefly held mutex is unlikely to benefit from a
read-write lock (if anything, shared_mutex may have more overhead)
- In postNotification(), only hold notificationQueueMutex_ while making
a copy of the shared_ptr to the queue, and perform the push outside
it. This is safe because:
- If the queue doesn't exist, no behavior change (no push)
- If the queue exists and a callback swap is happening concurrently,
the queue is not swapped so no notifications are lost
- If the queue exists and a callback unregister is happening
concurrently, we have a slight increase in concurrency but no
behavioral change because the queue is dropped after joining the
delivery thread; the concurrently posted notifications are dropped
in either case and this is not a problem
(Assisted by Claude Code; any errors are mine.)
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Minor cleanup/simplification.
Switch from std::shared_mutex to plain std::mutex, because this uncontended and briefly held mutex is unlikely to benefit from a read-write lock (if anything, shared_mutex may have more overhead)
In postNotification(), only hold notificationQueueMutex_ while making a copy of the shared_ptr to the queue, and perform the push outside it. This is safe because: