Method getFor

include/dmlc/concurrentqueue.h:3120–3194

    private:
      static MemStats getFor(ConcurrentQueue* q)
      {
        MemStats stats = { 0 };

        stats.elementsEnqueued = q->size_approx();

        auto block = q->freeList.head_unsafe();
        while (block != nullptr) {
          ++stats.allocatedBlocks;
          ++stats.freeBlocks;
          block = block->freeListNext.load(std::memory_order_relaxed);
        }

        for (auto ptr = q->producerListTail.load(std::memory_order_acquire); ptr != nullptr; ptr = ptr->next_prod()) {
          bool implicit = dynamic_cast<ImplicitProducer*>(ptr) != nullptr;
          stats.implicitProducers += implicit ? 1 : 0;
          stats.explicitProducers += implicit ? 0 : 1;

          if (implicit) {
            auto prod = static_cast<ImplicitProducer*>(ptr);
            stats.queueClassBytes += sizeof(ImplicitProducer);
            auto head = prod->headIndex.load(std::memory_order_relaxed);
            auto tail = prod->tailIndex.load(std::memory_order_relaxed);
            auto hash = prod->blockIndex.load(std::memory_order_relaxed);
            if (hash != nullptr) {
              for (size_t i = 0; i != hash->capacity; ++i) {
                if (hash->index[i]->key.load(std::memory_order_relaxed) != ImplicitProducer::INVALID_BLOCK_BASE && hash->index[i]->value.load(std::memory_order_relaxed) != nullptr) {
                  ++stats.allocatedBlocks;
                  ++stats.ownedBlocksImplicit;
                }
              }
              stats.implicitBlockIndexBytes += hash->capacity * sizeof(typename ImplicitProducer::BlockIndexEntry);
              for (; hash != nullptr; hash = hash->prev) {
                stats.implicitBlockIndexBytes += sizeof(typename ImplicitProducer::BlockIndexHeader) + hash->capacity * sizeof(typename ImplicitProducer::BlockIndexEntry*);
              }
            }
            for (; details::circular_less_than<index_t>(head, tail); head += BLOCK_SIZE) {
              //auto block = prod->get_block_index_entry_for_index(head);
              ++stats.usedBlocks;
            }
          }
          else {
            auto prod = static_cast<ExplicitProducer*>(ptr);
            stats.queueClassBytes += sizeof(ExplicitProducer);
            auto tailBlock = prod->tailBlock;
            bool wasNonEmpty = false;
            if (tailBlock != nullptr) {
              auto block = tailBlock;
              do {
                ++stats.allocatedBlocks;
                if (!block->template is_empty<explicit_context>() || wasNonEmpty) {
                  ++stats.usedBlocks;
                  wasNonEmpty = wasNonEmpty || block != tailBlock;
                }
                ++stats.ownedBlocksExplicit;
                block = block->next;
              } while (block != tailBlock);
            }