explicite producer inner call set_many_empty lead to assert(false)

	inline bool set_many_empty(MOODYCAMEL_MAYBE_UNUSED index_t i, size_t count)
	{
		MOODYCAMEL_CONSTEXPR_IF (context == explicit_context && BLOCK_SIZE <= EXPLICIT_BLOCK_EMPTY_COUNTER_THRESHOLD) {
			// Set flags
			std::atomic_thread_fence(std::memory_order_release);
			i = BLOCK_SIZE - 1 - static_cast<size_t>(i & static_cast<index_t>(BLOCK_SIZE - 1)) - count + 1;
			for (size_t j = 0; j != count; ++j) {
				assert(!emptyFlags[i + j].load(std::memory_order_relaxed));  @marked 1
				emptyFlags[i + j].store(true, std::memory_order_relaxed);
			}
			return false;
		}
		else {
			// Increment counter
			auto prevVal = elementsCompletelyDequeued.fetch_add(count, std::memory_order_release);
			assert(prevVal + count <= BLOCK_SIZE);
			return prevVal + count == BLOCK_SIZE;
		}
	}

code at @marked 1, if the block has been marked true, it will trigger assert(false) and coredump the program. i wonder:

1. how can it be?
2. can comment such code, actually, the block just marked rue once more

Start by tracing set_many_empty and the emptyFlags assertion at the marked line, then inspect how explicit producers mark and reuse blocks. Reproduce the reported assertion if possible and determine whether repeated marking is valid before deciding whether the assertion or surrounding state transition needs changing.