in spectator/stateful_meters.h [54:66]
void Measure(std::vector<Measurement>* measurements) override {
auto cnt = count_.exchange(0);
if (cnt == 0) {
return;
}
auto total = total_.exchange(0);
auto t_sq = totalSq_.exchange(0);
auto mx = max_.exchange(0);
measurements->emplace_back(id_->WithStat(DistType::total_name), total);
measurements->emplace_back(id_->WithStat("totalOfSquares"), t_sq);
measurements->emplace_back(id_->WithStat("max"), mx);
measurements->emplace_back(id_->WithStat("count"), cnt);
}