I have a single-consumer, multiple-producer lock-free queue (MPSCQueue) combined with a std::counting_semaphore to notify the consumer when new items are enqueued. The consumer uses dequeue() to attempt fetching an item; if it succeeds, it calls sema.try_acquire() which I expect to succeed every time there’s actually an item in the queue. However, under very rare circumstances, I get an assertion failure indicating try_acquire() returned false even though the queue returned a valid item.

I have a single-consumer, multiple-producer lock-free queue (MPSCQueue) combined with a std::counting_semaphore to notify the consumer when new items are enqueued. The consumer uses dequeue() to attempt fetching an item; if it succeeds, it calls sema.try_acquire() which I expect to succeed every time there’s actually an item in the queue. However, under very rare circumstances, I get an assertion failure indicating try_acquire() returned false even though the queue returned a valid item.

I have a single-consumer, multiple-producer lock-free queue (MPSCQueue) combined with a std::counting_semaphore to notify the consumer when new items are enqueued. The consumer uses dequeue() to attempt fetching an item; if it succeeds, it calls sema.try_acquire() which I expect to succeed every time there’s actually an item in the queue. However, under very rare circumstances, I get an assertion failure indicating try_acquire() returned false even though the queue returned a valid item.