Method try_dequeue_bulk

include/dmlc/concurrentqueue.h:1153–1163

  // Never allocates. Thread-safe.
  template<typename It>
  size_t try_dequeue_bulk(It itemFirst, size_t max) {
    size_t count = 0;
    for (auto ptr = producerListTail.load(std::memory_order_acquire);
         ptr != nullptr; ptr = ptr->next_prod()) {
      count += ptr->dequeue_bulk(itemFirst, max - count);
      if (count == max) {
        break;
      }
    }
    return count;
  }

  // Attempts to dequeue several elements from the queue using an explicit consumer token.
  // Returns the number of items actually dequeued.