Method set_empty

include/dmlc/concurrentqueue.h:1527–1543

    // Returns true if the block is now empty (does not apply in explicit context)
    template<InnerQueueContext context>
    inline bool set_empty(index_t i) {
      if (context == explicit_context && BLOCK_SIZE <= EXPLICIT_BLOCK_EMPTY_COUNTER_THRESHOLD) {
        // Set flag
        assert(!emptyFlags[BLOCK_SIZE - 1 -
                           static_cast<size_t>(i & static_cast<index_t>(BLOCK_SIZE - 1))].load(
          std::memory_order_relaxed));
        emptyFlags[BLOCK_SIZE - 1 -
                   static_cast<size_t>(i & static_cast<index_t>(BLOCK_SIZE - 1))].store(true,
                                                                                        std::memory_order_release);
        return false;
      } else {
        // Increment counter
        auto prevVal = elementsCompletelyDequeued.fetch_add(1, std::memory_order_release);
        assert(prevVal < BLOCK_SIZE);
        return prevVal == BLOCK_SIZE - 1;
      }
    }

    // Sets multiple contiguous item statuses to 'empty' (assumes no wrapping and count > 0).
    // Returns true if the block is now empty (does not apply in explicit context).