Bump play services to latest versions

2 files changed, 1324 insertions, 0 deletions

diff --git a/library/cpp/actors/util/thread_load_log.h b/library/cpp/actors/util/thread_load_log.h
new file mode 100644
index 0000000000..26b32492d2
--- /dev/null
+++ b/library/cpp/actors/util/thread_load_log.h
@@ -0,0 +1,358 @@
+#pragma once
+
+#include "defs.h"
+
+#include <util/system/types.h>
+
+#include <algorithm>
+#include <atomic>
+#include <limits>
+#include <queue>
+
+template <ui64 TIME_SLOT_COUNT, ui64 TIME_SLOT_LENGTH_NS = 131'072, typename Type = std::uint8_t>
+class TThreadLoad {
+public:
+    using TimeSlotType = Type;
+
+private:
+    static constexpr auto TIME_SLOT_MAX_VALUE = std::numeric_limits<TimeSlotType>::max();
+    static constexpr ui64 TIME_SLOT_PART_COUNT = TIME_SLOT_MAX_VALUE + 1;
+    static constexpr auto TIME_SLOT_PART_LENGTH_NS = TIME_SLOT_LENGTH_NS / TIME_SLOT_PART_COUNT;
+
+    template <int MAX_VALUE, typename T>
+    static void AtomicAddBound(std::atomic<T>& val, int inc) {
+        if (inc == 0) {
+            return;
+        }
+
+        auto newVal = val.load();
+        auto oldVal = newVal;
+
+        do {
+            if (oldVal > MAX_VALUE) {
+                return;
+            }
+            newVal = std::min<int>(MAX_VALUE, oldVal + inc);
+        } while (!val.compare_exchange_weak(oldVal, newVal));
+    }
+
+    template <typename T>
+    static void AtomicSubBound(std::atomic<T>& val, int sub) {
+        if (sub == 0) {
+            return;
+        }
+
+        auto newVal = val.load();
+        auto oldVal = val.load();
+
+        do {
+            if (oldVal == 0) {
+                return;
+            }
+            newVal = std::max<int>(0, static_cast<int>(oldVal) - sub);
+        } while (!val.compare_exchange_weak(oldVal, newVal));
+    }
+
+    void UpdateCompleteTimeSlots(ui64 firstSlotNumber, ui64 lastSlotNumber, TimeSlotType timeSlotValue) {
+        ui32 firstSlotIndex = firstSlotNumber % TIME_SLOT_COUNT;
+        ui32 lastSlotIndex = lastSlotNumber % TIME_SLOT_COUNT;
+
+        const ui64 firstTimeSlotsPass = firstSlotNumber / TIME_SLOT_COUNT;
+        const ui64 lastTimeSlotsPass = lastSlotNumber / TIME_SLOT_COUNT;
+
+        if (firstTimeSlotsPass == lastTimeSlotsPass) {
+            // first and last time slots are in the same pass
+            for (auto slotNumber = firstSlotNumber + 1; slotNumber < lastSlotNumber; ++slotNumber) {
+                auto slotIndex = slotNumber % TIME_SLOT_COUNT;
+                TimeSlots[slotIndex] = timeSlotValue;
+            }
+        } else if (firstTimeSlotsPass + 1 == lastTimeSlotsPass) {
+            for (auto slotIndex = (firstSlotNumber + 1) % TIME_SLOT_COUNT; firstSlotIndex < slotIndex && slotIndex < TIME_SLOT_COUNT; ++slotIndex) {
+                TimeSlots[slotIndex] = timeSlotValue;
+            }
+            for (auto slotIndex = 0u; slotIndex < lastSlotIndex; ++slotIndex) {
+                TimeSlots[slotIndex] = timeSlotValue;
+            }
+        } else {
+            for (auto slotIndex = 0u; slotIndex < TIME_SLOT_COUNT; ++slotIndex) {
+                TimeSlots[slotIndex] = timeSlotValue;
+            }
+        }
+    }
+
+public:
+    std::atomic<ui64> LastTimeNs;
+    std::atomic<TimeSlotType> TimeSlots[TIME_SLOT_COUNT];
+    std::atomic<bool> LastRegisteredPeriodIsBusy = false;
+
+    explicit TThreadLoad(ui64 timeNs = 0) {
+        LastTimeNs = timeNs;
+        for (size_t i = 0; i < TIME_SLOT_COUNT; ++i) {
+            TimeSlots[i] = 0;
+        }
+    }
+
+    static constexpr auto GetTimeSlotCount() {
+        return TIME_SLOT_COUNT;
+    }
+
+    static constexpr auto GetTimeSlotLengthNs() {
+        return TIME_SLOT_LENGTH_NS;
+    }
+
+    static constexpr auto GetTimeSlotPartLengthNs() {
+        return TIME_SLOT_PART_LENGTH_NS;
+    }
+
+    static constexpr auto GetTimeSlotPartCount() {
+        return TIME_SLOT_PART_COUNT;
+    }
+
+    static constexpr auto GetTimeSlotMaxValue() {
+        return TIME_SLOT_MAX_VALUE;
+    }
+
+    static constexpr auto GetTimeWindowLengthNs() {
+        return TIME_SLOT_COUNT * TIME_SLOT_LENGTH_NS;
+    }
+
+    void RegisterBusyPeriod(ui64 timeNs) {
+        RegisterBusyPeriod<true>(timeNs, LastTimeNs.load());
+    }
+
+    template <bool ModifyLastTime>
+    void RegisterBusyPeriod(ui64 timeNs, ui64 lastTimeNs) {
+        LastRegisteredPeriodIsBusy = true;
+
+        if (timeNs < lastTimeNs) {
+            // when time goes back, mark all time slots as 'free'
+            for (size_t i = 0u; i < TIME_SLOT_COUNT; ++i) {
+                TimeSlots[i] = 0;
+            }
+
+            if (ModifyLastTime) {
+                LastTimeNs = timeNs;
+            }
+
+            return;
+        }
+
+        // lastTimeNs <= timeNs
+        ui64 firstSlotNumber = lastTimeNs / TIME_SLOT_LENGTH_NS;
+        ui32 firstSlotIndex = firstSlotNumber % TIME_SLOT_COUNT;
+        ui64 lastSlotNumber = timeNs / TIME_SLOT_LENGTH_NS;
+        ui32 lastSlotIndex = lastSlotNumber % TIME_SLOT_COUNT;
+
+        if (firstSlotNumber == lastSlotNumber) {
+            ui32 slotLengthNs = timeNs - lastTimeNs;
+            ui32 slotPartsCount = (slotLengthNs + TIME_SLOT_PART_LENGTH_NS - 1) / TIME_SLOT_PART_LENGTH_NS;
+            AtomicAddBound<TIME_SLOT_MAX_VALUE>(TimeSlots[firstSlotIndex], slotPartsCount);
+
+            if (ModifyLastTime) {
+                LastTimeNs = timeNs;
+            }
+            return;
+        }
+
+        ui32 firstSlotLengthNs = TIME_SLOT_LENGTH_NS - (lastTimeNs % TIME_SLOT_LENGTH_NS);
+        ui32 firstSlotPartsCount = (firstSlotLengthNs + TIME_SLOT_PART_LENGTH_NS - 1) / TIME_SLOT_PART_LENGTH_NS;
+        ui32 lastSlotLengthNs = timeNs % TIME_SLOT_LENGTH_NS;
+        ui32 lastSlotPartsCount = (lastSlotLengthNs + TIME_SLOT_PART_LENGTH_NS - 1) / TIME_SLOT_PART_LENGTH_NS;
+
+        // process first time slot
+        AtomicAddBound<TIME_SLOT_MAX_VALUE>(TimeSlots[firstSlotIndex], firstSlotPartsCount);
+
+        // process complete time slots
+        UpdateCompleteTimeSlots(firstSlotNumber, lastSlotNumber, TIME_SLOT_MAX_VALUE);
+
+        // process last time slot
+        AtomicAddBound<TIME_SLOT_MAX_VALUE>(TimeSlots[lastSlotIndex], lastSlotPartsCount);
+
+        if (ModifyLastTime) {
+            LastTimeNs = timeNs;
+        }
+    }
+
+    void RegisterIdlePeriod(ui64 timeNs) {
+        LastRegisteredPeriodIsBusy = false;
+
+        ui64 lastTimeNs = LastTimeNs.load();
+        if (timeNs < lastTimeNs) {
+            // when time goes back, mark all time slots as 'busy'
+            for (size_t i = 0u; i < TIME_SLOT_COUNT; ++i) {
+                TimeSlots[i] = TIME_SLOT_MAX_VALUE;
+            }
+            LastTimeNs = timeNs;
+            return;
+        }
+
+        // lastTimeNs <= timeNs
+        ui64 firstSlotNumber = lastTimeNs / TIME_SLOT_LENGTH_NS;
+        ui32 firstSlotIndex = firstSlotNumber % TIME_SLOT_COUNT;
+        ui64 lastSlotNumber = timeNs / TIME_SLOT_LENGTH_NS;
+        ui32 lastSlotIndex = lastSlotNumber % TIME_SLOT_COUNT;
+
+        if (firstSlotNumber == lastSlotNumber) {
+            ui32 slotLengthNs = timeNs - lastTimeNs;
+            ui32 slotPartsCount = slotLengthNs / TIME_SLOT_PART_LENGTH_NS;
+
+            AtomicSubBound(TimeSlots[firstSlotIndex], slotPartsCount);
+
+            LastTimeNs = timeNs;
+            return;
+        }
+
+        ui32 firstSlotLengthNs = TIME_SLOT_LENGTH_NS - (lastTimeNs % TIME_SLOT_LENGTH_NS);
+        ui32 firstSlotPartsCount = (firstSlotLengthNs + TIME_SLOT_PART_LENGTH_NS - 1) / TIME_SLOT_PART_LENGTH_NS;
+        ui32 lastSlotLengthNs = timeNs % TIME_SLOT_LENGTH_NS;
+        ui32 lastSlotPartsCount = (lastSlotLengthNs + TIME_SLOT_PART_LENGTH_NS - 1) / TIME_SLOT_PART_LENGTH_NS;
+
+        // process first time slot
+        AtomicSubBound(TimeSlots[firstSlotIndex], firstSlotPartsCount);
+
+        // process complete time slots
+        UpdateCompleteTimeSlots(firstSlotNumber, lastSlotNumber, 0);
+
+        // process last time slot
+        AtomicSubBound(TimeSlots[lastSlotIndex], lastSlotPartsCount);
+
+        LastTimeNs = timeNs;
+    }
+};
+
+class TMinusOneThreadEstimator {
+private:
+    template <typename T, int MaxSize>
+    class TArrayQueue {
+    public:
+        bool empty() const {
+            return FrontIndex == -1;
+        }
+
+        bool full() const {
+            return (RearIndex + 1) % MaxSize == FrontIndex;
+        }
+
+        T& front() {
+            return Data[FrontIndex];
+        }
+
+        bool push(T &&t) {
+            if (full()) {
+                return false;
+            }
+
+            if (FrontIndex == -1) {
+                FrontIndex = 0;
+            }
+
+            RearIndex = (RearIndex + 1) % MaxSize;
+            Data[RearIndex] = std::move(t);
+            return true;
+        }
+
+        bool pop() {
+            if (empty()) {
+                return false;
+            }
+
+            if (FrontIndex == RearIndex) {
+                FrontIndex = RearIndex = -1;
+            } else {
+                FrontIndex = (FrontIndex + 1) % MaxSize;
+            }
+
+            return true;
+        }
+
+    private:
+        int FrontIndex = -1;
+        int RearIndex = -1;
+        T Data[MaxSize];
+    };
+
+public:
+    template <typename T>
+    ui64 MaxLatencyIncreaseWithOneLessCpu(T **threadLoads, ui32 threadCount, ui64 timeNs, ui64 periodNs) {
+        Y_VERIFY(threadCount > 0);
+
+        struct TTimeSlotData {
+            typename T::TimeSlotType Load;
+            ui64 Index;
+        };
+
+        ui64 lastTimeNs = timeNs;
+        for (auto threadIndex = 0u; threadIndex < threadCount; ++threadIndex) {
+            if (threadLoads[threadIndex]->LastRegisteredPeriodIsBusy.load()) {
+                lastTimeNs = std::min(lastTimeNs, threadLoads[threadIndex]->LastTimeNs.load());
+            } else {
+                // make interval [lastTimeNs, timeNs] 'busy'
+                threadLoads[threadIndex]->template RegisterBusyPeriod<false>(timeNs, threadLoads[threadIndex]->LastTimeNs.load());
+            }
+        }
+
+        periodNs = std::min(T::GetTimeWindowLengthNs(), periodNs);
+
+        ui64 beginTimeNs = periodNs < timeNs ? timeNs - periodNs : 0;
+
+        ui64 firstSlotNumber = beginTimeNs / T::GetTimeSlotLengthNs();
+        ui64 lastSlotNumber = (lastTimeNs + T::GetTimeSlotLengthNs() - 1) / T::GetTimeSlotLengthNs();
+
+        ui64 maxTimeSlotShiftCount = 0u;
+        TArrayQueue<TTimeSlotData, T::GetTimeSlotCount()> firstThreadLoadDataQueue;
+
+        for (auto slotNumber = firstSlotNumber; slotNumber < lastSlotNumber; ++slotNumber) {
+            ui64 slotIndex = slotNumber % T::GetTimeSlotCount();
+
+            typename T::TimeSlotType firstThreadTimeSlotValue = threadLoads[0]->TimeSlots[slotIndex].load();
+
+            // distribute previous load of the first thread by other threads
+            auto foundIdleThread = false;
+
+            for (auto threadIndex = 1u; threadIndex < threadCount; ++threadIndex) {
+                typename T::TimeSlotType thisThreadAvailableTimeSlotLoad = threadLoads[threadIndex]->GetTimeSlotMaxValue() - threadLoads[threadIndex]->TimeSlots[slotIndex].load();
+
+                while (!firstThreadLoadDataQueue.empty() && thisThreadAvailableTimeSlotLoad > 0) {
+                    auto& firstThreadLoadData = firstThreadLoadDataQueue.front();
+
+                    auto distributedLoad = std::min(thisThreadAvailableTimeSlotLoad, firstThreadLoadData.Load);
+
+                    thisThreadAvailableTimeSlotLoad -= distributedLoad;
+                    firstThreadLoadData.Load -= distributedLoad;
+
+                    if (firstThreadLoadData.Load == 0) {
+                        auto timeSlotShiftCount = slotIndex - firstThreadLoadData.Index;
+                        maxTimeSlotShiftCount = std::max(maxTimeSlotShiftCount, timeSlotShiftCount);
+                        auto res = firstThreadLoadDataQueue.pop();
+                        Y_VERIFY(res);
+                    }
+                }
+
+                if (thisThreadAvailableTimeSlotLoad == threadLoads[threadIndex]->GetTimeSlotMaxValue()) {
+                    foundIdleThread = true;
+                }
+            }
+
+            // distribute current load of the first thread by other threads
+            if (firstThreadTimeSlotValue > 0) {
+                if (foundIdleThread) {
+                    // The current load of the first thead can be
+                    // moved to the idle thread so there is nothing to do
+                } else {
+                    // The current load of the first thread can be later
+                    // processed by the following time slots of other threads
+                    auto res = firstThreadLoadDataQueue.push({firstThreadTimeSlotValue, slotIndex});
+                    Y_VERIFY(res);
+                }
+            }
+        }
+
+        if (!firstThreadLoadDataQueue.empty()) {
+            const auto& timeSlotData = firstThreadLoadDataQueue.front();
+            auto timeSlotShiftCount = T::GetTimeSlotCount() - timeSlotData.Index;
+            maxTimeSlotShiftCount = std::max(maxTimeSlotShiftCount, timeSlotShiftCount);
+        }
+
+        return maxTimeSlotShiftCount * T::GetTimeSlotLengthNs();
+    }
+};
diff --git a/library/cpp/actors/util/thread_load_log_ut.cpp b/library/cpp/actors/util/thread_load_log_ut.cpp
new file mode 100644
index 0000000000..20e776cff6
--- /dev/null
+++ b/library/cpp/actors/util/thread_load_log_ut.cpp
@@ -0,0 +1,966 @@
+#include "thread_load_log.h"
+
+#include <library/cpp/testing/unittest/registar.h>
+
+#include <util/random/random.h>
+#include <util/system/hp_timer.h>
+#include <util/system/thread.h>
+#include <util/system/types.h>
+#include <util/system/sanitizers.h>
+
+#include <limits>
+
+Y_UNIT_TEST_SUITE(ThreadLoadLog) {
+
+    Y_UNIT_TEST(TThreadLoad8BitSlotType) {
+        constexpr auto timeWindowLengthNs = 5368709120ull; // 5 * 2 ^ 30 ~5 sec
+        constexpr auto timeSlotLengthNs = 524288ull; // 2 ^ 19 ns ~ 512 usec
+        constexpr auto timeSlotCount = timeWindowLengthNs / timeSlotLengthNs;
+
+        using TSlotType = std::uint8_t;
+        using T = TThreadLoad<timeSlotCount, timeSlotLengthNs, TSlotType>;
+
+        UNIT_ASSERT_VALUES_EQUAL(T::GetTimeWindowLengthNs(), timeWindowLengthNs);
+        UNIT_ASSERT_VALUES_EQUAL(T::GetTimeSlotLengthNs(), timeSlotLengthNs);
+        UNIT_ASSERT_VALUES_EQUAL(T::GetTimeSlotCount(), timeSlotCount);
+        UNIT_ASSERT_VALUES_EQUAL(T::GetTimeSlotMaxValue(), std::numeric_limits<TSlotType>::max());
+        UNIT_ASSERT_VALUES_EQUAL(T::GetTimeSlotPartCount(), (ui64)std::numeric_limits<TSlotType>::max() + 1);
+        UNIT_ASSERT_VALUES_EQUAL(T::GetTimeSlotPartLengthNs(), T::GetTimeSlotLengthNs() / T::GetTimeSlotPartCount());
+    }
+
+    Y_UNIT_TEST(TThreadLoad16BitSlotType) {
+        constexpr auto timeWindowLengthNs = 5368709120ull; // 5 * 2 ^ 30 ~5 sec
+        constexpr auto timeSlotLengthNs = 524288ull; // 2 ^ 19 ns ~ 512 usec
+        constexpr auto timeSlotCount = timeWindowLengthNs / timeSlotLengthNs;
+
+        using TSlotType = std::uint16_t;
+        using T = TThreadLoad<timeSlotCount, timeSlotLengthNs, TSlotType>;
+
+        UNIT_ASSERT_VALUES_EQUAL(T::GetTimeWindowLengthNs(), timeWindowLengthNs);
+        UNIT_ASSERT_VALUES_EQUAL(T::GetTimeSlotLengthNs(), timeSlotLengthNs);
+        UNIT_ASSERT_VALUES_EQUAL(T::GetTimeSlotCount(), timeSlotCount);
+        UNIT_ASSERT_VALUES_EQUAL(T::GetTimeSlotMaxValue(), std::numeric_limits<TSlotType>::max());
+        UNIT_ASSERT_VALUES_EQUAL(T::GetTimeSlotPartCount(), (ui64)std::numeric_limits<TSlotType>::max() + 1);
+        UNIT_ASSERT_VALUES_EQUAL(T::GetTimeSlotPartLengthNs(), T::GetTimeSlotLengthNs() / T::GetTimeSlotPartCount());
+    }
+
+    Y_UNIT_TEST(TThreadLoad8BitSlotTypeWindowBusy) {
+        constexpr auto timeWindowLengthNs = 5368709120ull; // 5 * 2 ^ 30 ~5 sec
+        constexpr auto timeSlotLengthNs = 524288ull; // 2 ^ 19 ns ~ 512 usec
+        constexpr auto timeSlotCount = timeWindowLengthNs / timeSlotLengthNs;
+
+        using TSlotType = std::uint8_t;
+        using T = TThreadLoad<timeSlotCount, timeSlotLengthNs, TSlotType>;
+
+        T threadLoad;
+        threadLoad.RegisterBusyPeriod(T::GetTimeWindowLengthNs());
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), T::GetTimeWindowLengthNs());
+        for (auto slotIndex = 0u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), T::GetTimeSlotMaxValue());
+        }
+    }
+
+    Y_UNIT_TEST(TThreadLoad16BitSlotTypeWindowBusy) {
+        constexpr auto timeWindowLengthNs = 5368709120ull; // 5 * 2 ^ 30 ~5 sec
+        constexpr auto timeSlotLengthNs = 524288ull; // 2 ^ 19 ns ~ 512 usec
+        constexpr auto timeSlotCount = timeWindowLengthNs / timeSlotLengthNs;
+
+        using TSlotType = std::uint16_t;
+        using T = TThreadLoad<timeSlotCount, timeSlotLengthNs, TSlotType>;
+
+        T threadLoad;
+        threadLoad.RegisterBusyPeriod(T::GetTimeWindowLengthNs());
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), T::GetTimeWindowLengthNs());
+        for (auto slotIndex = 0u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), T::GetTimeSlotMaxValue());
+        }
+    }
+
+    Y_UNIT_TEST(TThreadLoadRegisterBusyPeriodFirstTimeSlot1) {
+        TThreadLoad<38400> threadLoad;
+
+        for (auto slotIndex = 0u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        ui64 timeNs = threadLoad.GetTimeSlotLengthNs() - 1;
+        threadLoad.RegisterBusyPeriod(timeNs);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[0].load(), threadLoad.GetTimeSlotMaxValue());
+
+        for (auto slotIndex = 1u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+    }
+
+    Y_UNIT_TEST(TThreadLoadRegisterBusyPeriodFirstTimeSlot2) {
+        using T = TThreadLoad<38400>;
+
+        ui32 startNs = 2 * T::GetTimeSlotPartLengthNs();
+        T threadLoad(startNs);
+
+        for (auto slotIndex = 0u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        ui64 timeNs = 3 * T::GetTimeSlotPartLengthNs() - 1;
+        threadLoad.RegisterBusyPeriod(timeNs);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[0].load(), 1);
+
+        for (auto slotIndex = 1u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+    }
+
+    Y_UNIT_TEST(TThreadLoadRegisterBusyPeriodFirstTimeSlot3) {
+        TThreadLoad<38400> threadLoad;
+
+        for (auto slotIndex = 0u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        ui64 timeNs = threadLoad.GetTimeSlotLengthNs();
+        threadLoad.RegisterBusyPeriod(timeNs);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[0].load(), threadLoad.GetTimeSlotMaxValue());
+
+        for (auto slotIndex = 1u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+    }
+
+    Y_UNIT_TEST(TThreadLoadRegisterBusyPeriodFirstTimeSlot4) {
+        using T = TThreadLoad<38400>;
+
+        ui32 startNs = 2 * T::GetTimeSlotPartLengthNs();
+        T threadLoad(startNs);
+
+        for (auto slotIndex = 0u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        ui64 timeNs = 3 * T::GetTimeSlotPartLengthNs();
+        threadLoad.RegisterBusyPeriod(timeNs);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[0].load(), (timeNs - startNs) / T::GetTimeSlotPartLengthNs());
+
+        for (auto slotIndex = 1u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+    }
+
+    Y_UNIT_TEST(TThreadLoadRegisterBusyPeriodFirstTwoTimeSlots1) { 
+        TThreadLoad<38400> threadLoad;
+
+        for (auto slotIndex = 0u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        ui64 timeNs = 2 * threadLoad.GetTimeSlotLengthNs() - 1;
+        threadLoad.RegisterBusyPeriod(timeNs);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[0].load(), threadLoad.GetTimeSlotMaxValue());
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[1].load(), threadLoad.GetTimeSlotMaxValue());
+
+        for (auto slotIndex = 2u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+    }
+
+    Y_UNIT_TEST(TThreadLoadRegisterBusyPeriodFirstTwoTimeSlots2) { 
+        TThreadLoad<38400> threadLoad;
+
+        for (auto slotIndex = 0u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        ui64 timeNs = 2 * threadLoad.GetTimeSlotLengthNs();
+        threadLoad.RegisterBusyPeriod(timeNs);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[0].load(), threadLoad.GetTimeSlotMaxValue());
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[0].load(), threadLoad.GetTimeSlotMaxValue());
+
+        for (auto slotIndex = 2u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+    }
+
+    Y_UNIT_TEST(TThreadLoadRegisterBusyPeriodFirstThreeTimeSlots1) { 
+        TThreadLoad<38400> threadLoad;
+
+        for (auto slotIndex = 0u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        ui64 timeNs = 3 * threadLoad.GetTimeSlotLengthNs() - 1;
+        threadLoad.RegisterBusyPeriod(timeNs);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[0].load(), threadLoad.GetTimeSlotMaxValue());
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[1].load(), threadLoad.GetTimeSlotMaxValue());
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[2].load(), threadLoad.GetTimeSlotMaxValue());
+
+        for (auto slotIndex = 3u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+    }
+
+    Y_UNIT_TEST(TThreadLoadRegisterBusyPeriodFirstThreeTimeSlots2) { 
+        TThreadLoad<38400> threadLoad;
+
+        for (auto slotIndex = 0u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        ui64 timeNs = 3 * threadLoad.GetTimeSlotLengthNs();
+        threadLoad.RegisterBusyPeriod(timeNs);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[0].load(), threadLoad.GetTimeSlotMaxValue());
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[0].load(), threadLoad.GetTimeSlotMaxValue());
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[2].load(), threadLoad.GetTimeSlotMaxValue());
+
+        for (auto slotIndex = 3u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+    }
+
+    Y_UNIT_TEST(TThreadLoadRegisterBusyPeriodFirstThreeTimeSlots3) { 
+        using T = TThreadLoad<38400>;
+
+        ui32 startNs = 3 * T::GetTimeSlotPartLengthNs();
+        T threadLoad(startNs);
+
+        for (auto slotIndex = 0u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        ui64 timeNs = 0;
+        threadLoad.RegisterBusyPeriod(timeNs);
+        for (auto slotIndex = 0u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+    }
+
+    Y_UNIT_TEST(TThreadLoadRegisterIdlePeriodFirstTimeSlot1) {
+        using T = TThreadLoad<38400>;
+
+        ui64 timeNs = T::GetTimeSlotPartLengthNs();
+        T threadLoad(timeNs);
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+        for (auto slotIndex = 0u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        timeNs = 2 * T::GetTimeSlotPartLengthNs();
+        threadLoad.RegisterBusyPeriod(timeNs);
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[0].load(), 1);
+        for (auto slotIndex = 1u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        timeNs = 3 * T::GetTimeSlotPartLengthNs();
+        threadLoad.RegisterIdlePeriod(timeNs);
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[0].load(), 0);
+        for (auto slotIndex = 1u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        timeNs = 4 * T::GetTimeSlotPartLengthNs();
+        threadLoad.RegisterBusyPeriod(timeNs);
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[0].load(), 1);
+        for (auto slotIndex = 1u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+    }
+
+    Y_UNIT_TEST(TThreadLoadRegisterIdlePeriodFirstTimeSlot2) {
+        using T = TThreadLoad<38400>;
+
+        ui64 timeNs = T::GetTimeSlotPartLengthNs();
+        T threadLoad(timeNs);
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+        for (auto slotIndex = 0u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        timeNs = 2 * T::GetTimeSlotPartLengthNs();
+        threadLoad.RegisterBusyPeriod(timeNs);
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[0].load(), 1);
+        for (auto slotIndex = 1u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        timeNs = 3 * T::GetTimeSlotPartLengthNs() - 1;
+        threadLoad.RegisterIdlePeriod(timeNs);
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[0].load(), 1);
+        for (auto slotIndex = 1u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        timeNs = 4 * T::GetTimeSlotPartLengthNs();
+        threadLoad.RegisterBusyPeriod(timeNs);
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[0].load(), 3);
+        for (auto slotIndex = 1u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+    }
+
+    Y_UNIT_TEST(TThreadLoadRegisterIdlePeriodFirstTimeSlot3) {
+        using T = TThreadLoad<38400>;
+
+        ui64 timeNs = T::GetTimeSlotPartLengthNs();
+        T threadLoad(timeNs);
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+        for (auto slotIndex = 0u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        timeNs = 2 * T::GetTimeSlotPartLengthNs();
+        threadLoad.RegisterBusyPeriod(timeNs);
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[0].load(), 1);
+        for (auto slotIndex = 1u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        timeNs = 3 * T::GetTimeSlotPartLengthNs() - 1;
+        threadLoad.RegisterIdlePeriod(timeNs);
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[0].load(), 1);
+        for (auto slotIndex = 1u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        timeNs = 4 * T::GetTimeSlotPartLengthNs() - 2;
+        threadLoad.RegisterIdlePeriod(timeNs);
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[0].load(), 1);
+        for (auto slotIndex = 1u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        timeNs = 5 * T::GetTimeSlotPartLengthNs();
+        threadLoad.RegisterBusyPeriod(timeNs);
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[0].load(), 3);
+        for (auto slotIndex = 1u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+    }
+
+    Y_UNIT_TEST(TThreadLoadRegisterIdlePeriodFirstTwoTimeSlots1) {
+        using T = TThreadLoad<38400>;
+
+        T threadLoad;
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), 0);
+        for (auto slotIndex = 0u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        ui64 timeNs = threadLoad.GetTimeSlotLengthNs();
+        threadLoad.RegisterIdlePeriod(timeNs);
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+        for (auto slotIndex = 0u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        timeNs = 2 * threadLoad.GetTimeSlotLengthNs();
+        threadLoad.RegisterBusyPeriod(timeNs);
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[0].load(), 0);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[1].load(), threadLoad.GetTimeSlotMaxValue());
+        for (auto slotIndex = 2u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+    }
+
+    Y_UNIT_TEST(TThreadLoadRegisterIdlePeriodFirstTwoTimeSlots2) {
+        using T = TThreadLoad<38400>;
+
+        T threadLoad;
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), 0);
+        for (auto slotIndex = 0u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        ui64 timeNs = threadLoad.GetTimeSlotLengthNs() - 1;
+        threadLoad.RegisterIdlePeriod(timeNs);
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+        for (auto slotIndex = 0u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        timeNs = 2 * threadLoad.GetTimeSlotLengthNs();
+        threadLoad.RegisterBusyPeriod(timeNs);
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[0].load(), 1);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[1].load(), threadLoad.GetTimeSlotMaxValue());
+        for (auto slotIndex = 2u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+    }
+
+    Y_UNIT_TEST(TThreadLoadRegisterIdlePeriodFirstTwoTimeSlots3) {
+        using T = TThreadLoad<38400>;
+
+        T threadLoad;
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), 0);
+        for (auto slotIndex = 0u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        ui64 timeNs = threadLoad.GetTimeSlotLengthNs() - 1;
+        threadLoad.RegisterIdlePeriod(timeNs);
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+        for (auto slotIndex = 0u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        timeNs = 2 * threadLoad.GetTimeSlotLengthNs() - 1;
+        threadLoad.RegisterBusyPeriod(timeNs);
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[0].load(), 1);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[1].load(), threadLoad.GetTimeSlotMaxValue());
+        for (auto slotIndex = 2u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+    }
+
+    Y_UNIT_TEST(TThreadLoadRegisterIdlePeriodFirstThreeTimeSlots1) {
+        using T = TThreadLoad<38400>;
+
+        T threadLoad;
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), 0);
+        for (auto slotIndex = 0u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        ui64 timeNs = threadLoad.GetTimeSlotLengthNs();
+        threadLoad.RegisterBusyPeriod(timeNs);
+
+        timeNs = 2 * threadLoad.GetTimeSlotLengthNs();
+        threadLoad.RegisterIdlePeriod(timeNs);
+
+        timeNs = 3 * threadLoad.GetTimeSlotLengthNs();
+        threadLoad.RegisterBusyPeriod(timeNs);
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[0].load(), threadLoad.GetTimeSlotMaxValue());
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[1].load(), 0);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[2].load(), threadLoad.GetTimeSlotMaxValue());
+        for (auto slotIndex = 3u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+    }
+
+    Y_UNIT_TEST(TThreadLoadRegisterIdlePeriodFirstThreeTimeSlots2) {
+        using T = TThreadLoad<38400>;
+
+        T threadLoad;
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), 0);
+        for (auto slotIndex = 0u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        ui64 timeNs = threadLoad.GetTimeSlotLengthNs();
+        threadLoad.RegisterBusyPeriod(timeNs);
+
+        timeNs = 3 * threadLoad.GetTimeSlotLengthNs();
+        threadLoad.RegisterIdlePeriod(timeNs);
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[0].load(), threadLoad.GetTimeSlotMaxValue());
+        for (auto slotIndex = 1u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+    }
+
+    Y_UNIT_TEST(TThreadLoadRegisterIdlePeriodFirstThreeTimeSlots3) {
+        using T = TThreadLoad<38400>;
+
+        T threadLoad;
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), 0);
+        for (auto slotIndex = 0u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        ui64 timeNs = threadLoad.GetTimeSlotLengthNs();
+        threadLoad.RegisterIdlePeriod(timeNs);
+
+        timeNs = 3 * threadLoad.GetTimeSlotLengthNs();
+        threadLoad.RegisterBusyPeriod(timeNs);
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[0].load(), 0);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[1].load(), threadLoad.GetTimeSlotMaxValue());
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[2].load(), threadLoad.GetTimeSlotMaxValue());
+        for (auto slotIndex = 3u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+    }
+
+    Y_UNIT_TEST(TThreadLoadRegisterIdlePeriodFirstThreeTimeSlots4) {
+        using T = TThreadLoad<38400>;
+
+        T threadLoad;
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), 0);
+        for (auto slotIndex = 0u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        ui64 timeNs = threadLoad.GetTimeSlotLengthNs() + 2 * threadLoad.GetTimeSlotPartLengthNs();
+        threadLoad.RegisterIdlePeriod(timeNs);
+
+        timeNs = 3 * threadLoad.GetTimeSlotLengthNs();
+        threadLoad.RegisterBusyPeriod(timeNs);
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[0].load(), 0);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[1].load(), threadLoad.GetTimeSlotPartCount() - 2);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[2].load(), threadLoad.GetTimeSlotMaxValue());
+        for (auto slotIndex = 3u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+    }
+
+    Y_UNIT_TEST(TThreadLoadRegisterIdlePeriodFirstThreeTimeSlots5) {
+        using T = TThreadLoad<38400>;
+
+        T threadLoad;
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), 0);
+        for (auto slotIndex = 0u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        ui64 timeNs = 2 * threadLoad.GetTimeSlotLengthNs();
+        threadLoad.RegisterBusyPeriod(timeNs);
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[0].load(), threadLoad.GetTimeSlotMaxValue());
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[1].load(), threadLoad.GetTimeSlotMaxValue());
+        for (auto slotIndex = 2u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        timeNs = timeNs + threadLoad.GetTimeWindowLengthNs() + threadLoad.GetTimeSlotLengthNs();
+        threadLoad.RegisterIdlePeriod(timeNs);
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+        for (auto slotIndex = 0u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+    }
+
+    Y_UNIT_TEST(TThreadLoadRegisterIdlePeriodOverTimeWindow) {
+        constexpr auto timeWindowLengthNs = 5368709120ull; // 5 * 2 ^ 30 ~5 sec
+        constexpr auto timeSlotLengthNs = 524288ull; // 2 ^ 19 ns ~ 512 usec
+        constexpr auto timeSlotCount = timeWindowLengthNs / timeSlotLengthNs;
+
+        using T = TThreadLoad<timeSlotCount, timeSlotLengthNs, std::uint8_t>;
+
+        T threadLoad;
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), 0);
+        for (auto slotIndex = 0u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        ui64 timeNs = 5 * threadLoad.GetTimeSlotLengthNs();
+        threadLoad.RegisterBusyPeriod(timeNs);
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[0].load(), threadLoad.GetTimeSlotMaxValue());
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[1].load(), threadLoad.GetTimeSlotMaxValue());
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[2].load(), threadLoad.GetTimeSlotMaxValue());
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[3].load(), threadLoad.GetTimeSlotMaxValue());
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[4].load(), threadLoad.GetTimeSlotMaxValue());
+        for (auto slotIndex = 5u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+
+        timeNs = timeNs + threadLoad.GetTimeWindowLengthNs() - 3 * threadLoad.GetTimeSlotLengthNs();
+        threadLoad.RegisterIdlePeriod(timeNs);
+
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.LastTimeNs.load(), timeNs);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[0].load(), 0);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[1].load(), 0);
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[2].load(), threadLoad.GetTimeSlotMaxValue());
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[3].load(), threadLoad.GetTimeSlotMaxValue());
+        UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[4].load(), threadLoad.GetTimeSlotMaxValue());
+        for (auto slotIndex = 5u; slotIndex < threadLoad.GetTimeSlotCount(); ++slotIndex) {
+            UNIT_ASSERT_VALUES_EQUAL(threadLoad.TimeSlots[slotIndex].load(), 0);
+        }
+    }
+
+    Y_UNIT_TEST(MinusOneThreadEstimatorTwoThreadLoadsZeroShiftNs) {
+        constexpr auto timeWindowLengthNs = 5368709120ull; // 5 * 2 ^ 30 ~5 sec
+        constexpr auto timeSlotLengthNs = 524288ull; // 2 ^ 19 ns ~ 512 usec
+        constexpr auto timeSlotCount = timeWindowLengthNs / timeSlotLengthNs;
+
+        using T = TThreadLoad<timeSlotCount, timeSlotLengthNs, std::uint16_t>;
+
+        UNIT_ASSERT_VALUES_EQUAL(T::GetTimeSlotPartCount(), (ui64)std::numeric_limits<std::uint16_t>::max() + 1);
+
+        T *threadLoads[2];
+        threadLoads[0] = new T;
+        threadLoads[1] = new T;
+
+        for (ui64 i = 1; i < timeSlotCount; i += 2) {
+            threadLoads[0]->RegisterIdlePeriod(i * T::GetTimeSlotLengthNs());
+            threadLoads[0]->RegisterBusyPeriod((i + 1) * T::GetTimeSlotLengthNs());
+        }
+
+        for (ui64 i = 1; i < timeSlotCount; i += 2) {
+            threadLoads[1]->RegisterBusyPeriod(i * T::GetTimeSlotLengthNs());
+            threadLoads[1]->RegisterIdlePeriod((i + 1) * T::GetTimeSlotLengthNs());
+        }
+
+        TMinusOneThreadEstimator estimator;
+        ui64 value = estimator.MaxLatencyIncreaseWithOneLessCpu(threadLoads, 2, T::GetTimeWindowLengthNs(), T::GetTimeWindowLengthNs());
+        UNIT_ASSERT_VALUES_EQUAL(value, 0);
+
+        delete threadLoads[0];
+        delete threadLoads[1];
+    }
+
+    Y_UNIT_TEST(MinusOneThreadEstimatorTwoThreadLoadsOneTimeSlotShift1) {
+        constexpr auto timeWindowLengthNs = 5368709120ull; // 5 * 2 ^ 30 ~5 sec
+        constexpr auto timeSlotLengthNs = 524288ull; // 2 ^ 19 ns ~ 512 usec
+        constexpr auto timeSlotCount = timeWindowLengthNs / timeSlotLengthNs;
+        constexpr auto threadCount = 2;
+
+        using T = TThreadLoad<timeSlotCount, timeSlotLengthNs, std::uint16_t>;
+
+        T *threadLoads[threadCount];
+
+        for (auto t = 0u; t < threadCount; ++t) {
+            threadLoads[t] = new T;
+
+            for (ui64 i = 2; i < threadLoads[t]->GetTimeSlotCount(); i += 2) {
+                threadLoads[t]->RegisterIdlePeriod((i - 1) * T::GetTimeSlotLengthNs());
+                threadLoads[t]->RegisterBusyPeriod(i * T::GetTimeSlotLengthNs());
+            }
+
+            threadLoads[t]->RegisterIdlePeriod((threadLoads[t]->GetTimeSlotCount() - 1) * T::GetTimeSlotLengthNs());
+            threadLoads[t]->RegisterBusyPeriod(threadLoads[t]->GetTimeSlotCount() * T::GetTimeSlotLengthNs());
+
+            for (ui64 s = 0; s < threadLoads[t]->GetTimeSlotCount(); ++s) {
+                if (s % 2 == 1) {
+                    UNIT_ASSERT_VALUES_EQUAL_C(threadLoads[t]->TimeSlots[s].load(), T::GetTimeSlotMaxValue(), ToString(s).c_str());
+                } else {
+                    UNIT_ASSERT_VALUES_EQUAL_C(threadLoads[t]->TimeSlots[s].load(), 0, ToString(s).c_str());
+                }
+            }
+        }
+
+        TMinusOneThreadEstimator estimator;
+        auto result = estimator.MaxLatencyIncreaseWithOneLessCpu(threadLoads, threadCount, T::GetTimeWindowLengthNs(), T::GetTimeWindowLengthNs());
+
+        for (ui64 t = 0; t < threadCount; ++t) {
+            for (ui64 s = 0; s < threadLoads[t]->GetTimeSlotCount(); ++s) {
+                if (s % 2 == 1) {
+                    UNIT_ASSERT_VALUES_EQUAL_C(threadLoads[t]->TimeSlots[s].load(), T::GetTimeSlotMaxValue(), ToString(s).c_str());
+                } else {
+                    UNIT_ASSERT_VALUES_EQUAL_C(threadLoads[t]->TimeSlots[s].load(), 0, ToString(s).c_str());
+                }
+            }
+        }
+
+        UNIT_ASSERT_VALUES_EQUAL(result, T::GetTimeSlotLengthNs());
+
+        for (auto t = 0u; t < threadCount; ++t) {
+            delete threadLoads[t];
+        }
+    }
+
+    Y_UNIT_TEST(MinusOneThreadEstimatorTwoThreadLoadsOneTimeSlotShift2) {
+        constexpr auto timeWindowLengthNs = 5368709120ull; // 5 * 2 ^ 30 ~5 sec
+        constexpr auto timeSlotLengthNs = 524288ull; // 2 ^ 19 ns ~ 512 usec
+        constexpr auto timeSlotCount = timeWindowLengthNs / timeSlotLengthNs;
+        constexpr auto threadCount = 2;
+
+        using T = TThreadLoad<timeSlotCount, timeSlotLengthNs, std::uint16_t>;
+
+        T *threadLoads[threadCount];
+
+        for (auto t = 0u; t < threadCount; ++t) {
+            threadLoads[t] = new T;
+
+            for (ui64 i = 2; i < threadLoads[t]->GetTimeSlotCount(); i += 2) {
+                threadLoads[t]->RegisterBusyPeriod((i - 1) * T::GetTimeSlotLengthNs());
+                threadLoads[t]->RegisterIdlePeriod(i * T::GetTimeSlotLengthNs());
+            }
+
+            threadLoads[t]->RegisterBusyPeriod((threadLoads[t]->GetTimeSlotCount() - 1) * T::GetTimeSlotLengthNs());
+            threadLoads[t]->RegisterIdlePeriod(threadLoads[t]->GetTimeSlotCount() * T::GetTimeSlotLengthNs());
+
+            for (ui64 s = 0; s < threadLoads[t]->GetTimeSlotCount(); ++s) {
+                if (s % 2 == 0) {
+                    UNIT_ASSERT_VALUES_EQUAL_C(threadLoads[t]->TimeSlots[s].load(), T::GetTimeSlotMaxValue(), ToString(s).c_str());
+                } else {
+                    UNIT_ASSERT_VALUES_EQUAL_C(threadLoads[t]->TimeSlots[s].load(), 0, ToString(s).c_str());
+                }
+            }
+        }
+
+        TMinusOneThreadEstimator estimator;
+        auto result = estimator.MaxLatencyIncreaseWithOneLessCpu(threadLoads, threadCount, T::GetTimeWindowLengthNs(), T::GetTimeWindowLengthNs());
+
+        for (ui64 t = 0; t < threadCount; ++t) {
+            for (ui64 s = 0; s < threadLoads[t]->GetTimeSlotCount(); ++s) {
+                if (s % 2 == 0) {
+                    UNIT_ASSERT_VALUES_EQUAL_C(threadLoads[t]->TimeSlots[s].load(), T::GetTimeSlotMaxValue(), ToString(s).c_str());
+                } else {
+                    UNIT_ASSERT_VALUES_EQUAL_C(threadLoads[t]->TimeSlots[s].load(), 0, ToString(s).c_str());
+                }
+            }
+        }
+
+        UNIT_ASSERT_VALUES_EQUAL(result, T::GetTimeSlotLengthNs());
+
+        for (auto t = 0u; t < threadCount; ++t) {
+            delete threadLoads[t];
+        }
+    }
+
+    Y_UNIT_TEST(MinusOneThreadEstimatorTwoThreadLoadsTwoTimeSlotsShift1) {
+        constexpr auto timeWindowLengthNs = 5368709120ull; // 5 * 2 ^ 30 ~5 sec
+        constexpr auto timeSlotLengthNs = 524288ull; // 2 ^ 19 ns ~ 512 usec
+        constexpr auto timeSlotCount = timeWindowLengthNs / timeSlotLengthNs;
+        constexpr auto threadCount = 2;
+
+        using T = TThreadLoad<timeSlotCount, timeSlotLengthNs, std::uint16_t>;
+
+        T *threadLoads[threadCount];
+
+        for (auto t = 0u; t < threadCount; ++t) {
+            threadLoads[t] = new T;
+
+            for (ui64 i = 4; i < threadLoads[t]->GetTimeSlotCount(); i += 4) {
+                threadLoads[t]->RegisterIdlePeriod((i - 2) * T::GetTimeSlotLengthNs());
+                threadLoads[t]->RegisterBusyPeriod(i * T::GetTimeSlotLengthNs());
+            }
+
+            threadLoads[t]->RegisterIdlePeriod((threadLoads[t]->GetTimeSlotCount() - 2) * T::GetTimeSlotLengthNs());
+            threadLoads[t]->RegisterBusyPeriod(threadLoads[t]->GetTimeSlotCount() * T::GetTimeSlotLengthNs());
+
+            for (ui64 s = 0; s < threadLoads[t]->GetTimeSlotCount(); ++s) {
+                if (s % 4 == 2 || s % 4 == 3) {
+                    UNIT_ASSERT_VALUES_EQUAL_C(threadLoads[t]->TimeSlots[s].load(), T::GetTimeSlotMaxValue(), ToString(s).c_str());
+                } else {
+                    UNIT_ASSERT_VALUES_EQUAL_C(threadLoads[t]->TimeSlots[s].load(), 0, ToString(s).c_str());
+                }
+            }
+        }
+
+        TMinusOneThreadEstimator estimator;
+        auto result = estimator.MaxLatencyIncreaseWithOneLessCpu(threadLoads, threadCount, T::GetTimeWindowLengthNs(), T::GetTimeWindowLengthNs());
+
+        for (ui64 t = 0; t < threadCount; ++t) {
+            for (ui64 s = 0; s < threadLoads[t]->GetTimeSlotCount(); ++s) {
+                if (s % 4 == 2 || s % 4 == 3) {
+                    UNIT_ASSERT_VALUES_EQUAL_C(threadLoads[t]->TimeSlots[s].load(), T::GetTimeSlotMaxValue(), ToString(s).c_str());
+                } else {
+                    UNIT_ASSERT_VALUES_EQUAL(threadLoads[t]->TimeSlots[s].load(), 0);
+                }
+            }
+        }
+
+        UNIT_ASSERT_VALUES_EQUAL(result, 2 * T::GetTimeSlotLengthNs());
+
+        for (auto t = 0u; t < threadCount; ++t) {
+            delete threadLoads[t];
+        }
+    }
+
+    Y_UNIT_TEST(MinusOneThreadEstimatorTwoThreadLoadsTwoTimeSlotsShift2) {
+        constexpr auto timeWindowLengthNs = 5368709120ull; // 5 * 2 ^ 30 ~5 sec
+        constexpr auto timeSlotLengthNs = 524288ull; // 2 ^ 19 ns ~ 512 usec
+        constexpr auto timeSlotCount = timeWindowLengthNs / timeSlotLengthNs;
+        constexpr auto threadCount = 2;
+
+        using T = TThreadLoad<timeSlotCount, timeSlotLengthNs, std::uint16_t>;
+
+        T *threadLoads[threadCount];
+
+        for (auto t = 0u; t < threadCount; ++t) {
+            threadLoads[t] = new T;
+
+            for (ui64 i = 4; i < threadLoads[t]->GetTimeSlotCount(); i += 4) {
+                threadLoads[t]->RegisterBusyPeriod((i - 2) * T::GetTimeSlotLengthNs());
+                threadLoads[t]->RegisterIdlePeriod(i * T::GetTimeSlotLengthNs());
+            }
+
+            threadLoads[t]->RegisterBusyPeriod((threadLoads[t]->GetTimeSlotCount() - 2) * T::GetTimeSlotLengthNs());
+            threadLoads[t]->RegisterIdlePeriod(threadLoads[t]->GetTimeSlotCount() * T::GetTimeSlotLengthNs());
+
+            for (ui64 s = 0; s < threadLoads[t]->GetTimeSlotCount(); ++s) {
+                if (s % 4 == 0 || s % 4 == 1) {
+                    UNIT_ASSERT_VALUES_EQUAL_C(threadLoads[t]->TimeSlots[s].load(), T::GetTimeSlotMaxValue(), ToString(s).c_str());
+                } else {
+                    UNIT_ASSERT_VALUES_EQUAL_C(threadLoads[t]->TimeSlots[s].load(), 0, ToString(s).c_str());
+                }
+            }
+        }
+
+        TMinusOneThreadEstimator estimator;
+        auto result = estimator.MaxLatencyIncreaseWithOneLessCpu(threadLoads, threadCount, T::GetTimeWindowLengthNs(), T::GetTimeWindowLengthNs());
+
+        for (ui64 t = 0; t < threadCount; ++t) {
+            for (ui64 s = 0; s < threadLoads[t]->GetTimeSlotCount(); ++s) {
+                if (s % 4 == 0 || s % 4 == 1) {
+                    UNIT_ASSERT_VALUES_EQUAL_C(threadLoads[t]->TimeSlots[s].load(), T::GetTimeSlotMaxValue(), ToString(s).c_str());
+                } else {
+                    UNIT_ASSERT_VALUES_EQUAL_C(threadLoads[t]->TimeSlots[s].load(), 0, ToString(s).c_str());
+                }
+            }
+        }
+
+        UNIT_ASSERT_VALUES_EQUAL(result, 2 * T::GetTimeSlotLengthNs());
+
+        for (auto t = 0u; t < threadCount; ++t) {
+            delete threadLoads[t];
+        }
+    }
+
+    Y_UNIT_TEST(MinusOneThreadEstimatorTwoThreadLoadsTwoTimeSlotsShift3) {
+        constexpr auto timeWindowLengthNs = 5368709120ull; // 5 * 2 ^ 30 ~5 sec
+        constexpr auto timeSlotLengthNs = 524288ull; // 2 ^ 19 ns ~ 512 usec
+        constexpr auto timeSlotCount = timeWindowLengthNs / timeSlotLengthNs;
+        constexpr auto threadCount = 2;
+
+        using T = TThreadLoad<timeSlotCount, timeSlotLengthNs, std::uint16_t>;
+
+        T *threadLoads[threadCount];
+
+        for (auto t = 0u; t < threadCount; ++t) {
+            threadLoads[t] = new T;
+
+            auto timeNs = T::GetTimeWindowLengthNs() - 1.5 * T::GetTimeSlotLengthNs();
+            threadLoads[t]->RegisterIdlePeriod(timeNs);
+            UNIT_ASSERT_VALUES_EQUAL(threadLoads[t]->LastTimeNs.load(), timeNs);
+
+            timeNs = T::GetTimeWindowLengthNs();
+            threadLoads[t]->RegisterBusyPeriod(timeNs);
+            UNIT_ASSERT_VALUES_EQUAL(threadLoads[t]->LastTimeNs.load(), timeNs);
+
+            for (ui64 s = 0; s + 2 < threadLoads[t]->GetTimeSlotCount(); ++s) {
+                UNIT_ASSERT_VALUES_EQUAL_C(threadLoads[t]->TimeSlots[s].load(), 0, ToString(s).c_str());
+            }
+
+            UNIT_ASSERT_VALUES_EQUAL(threadLoads[t]->TimeSlots[timeSlotCount - 2].load(), T::GetTimeSlotPartCount() / 2);
+            UNIT_ASSERT_VALUES_EQUAL(threadLoads[t]->TimeSlots[timeSlotCount - 1].load(), T::GetTimeSlotMaxValue());
+        }
+
+        TMinusOneThreadEstimator estimator;
+        auto result = estimator.MaxLatencyIncreaseWithOneLessCpu(threadLoads, threadCount, T::GetTimeWindowLengthNs(), T::GetTimeWindowLengthNs());
+
+        for (auto t = 0u; t < threadCount; ++t) {
+            for (ui64 s = 0; s + 2 < threadLoads[t]->GetTimeSlotCount(); ++s) {
+                UNIT_ASSERT_VALUES_EQUAL_C(threadLoads[t]->TimeSlots[s].load(), 0, ToString(s).c_str());
+            }
+
+            UNIT_ASSERT_VALUES_EQUAL(threadLoads[t]->TimeSlots[timeSlotCount - 2].load(), T::GetTimeSlotPartCount() / 2);
+            UNIT_ASSERT_VALUES_EQUAL(threadLoads[t]->TimeSlots[timeSlotCount - 1].load(), T::GetTimeSlotMaxValue());
+        }
+
+        UNIT_ASSERT_VALUES_EQUAL(result, 2 * T::GetTimeSlotLengthNs());
+
+        for (auto t = 0u; t < threadCount; ++t) {
+            delete threadLoads[t];
+        }
+    }
+
+    Y_UNIT_TEST(MinusOneThreadEstimator16ThreadLoadsAllTimeSlots) {
+        constexpr auto timeWindowLengthNs = 5368709120ull; // 5 * 2 ^ 30 ~5 sec
+        constexpr auto timeSlotLengthNs = 524288ull; // 2 ^ 19 ns ~ 512 usec
+        constexpr auto timeSlotCount = timeWindowLengthNs / timeSlotLengthNs;
+        constexpr auto threadCount = 16;
+        constexpr auto estimatesCount = 16;
+
+        using T = TThreadLoad<timeSlotCount, timeSlotLengthNs, std::uint16_t>;
+
+        for (auto e = 0u; e < estimatesCount; ++e) {
+            T *threadLoads[threadCount];
+
+            for (auto t = 0u; t < threadCount; ++t) {
+                threadLoads[t] = new T;
+                auto timeNs = threadLoads[t]->GetTimeWindowLengthNs();
+                threadLoads[t]->RegisterBusyPeriod(timeNs);
+
+                UNIT_ASSERT_VALUES_EQUAL(threadLoads[t]->LastTimeNs.load(), timeNs);
+                for (ui64 s = 0; s < threadLoads[t]->GetTimeSlotCount(); ++s) {
+                    UNIT_ASSERT_VALUES_EQUAL_C(threadLoads[t]->TimeSlots[s].load(), T::GetTimeSlotMaxValue(), ToString(s).c_str());
+                }
+            }
+
+            ui64 result = 0;
+            {
+                THPTimer timer;
+                TMinusOneThreadEstimator estimator;
+                result = estimator.MaxLatencyIncreaseWithOneLessCpu(threadLoads, threadCount, T::GetTimeWindowLengthNs(), T::GetTimeWindowLengthNs());
+                // output in microseconds
+                auto passed = timer.Passed() * 1000000;
+                Y_UNUSED(passed);
+                // Cerr << "timer : " << passed << " " << __LINE__ << Endl;
+            }
+
+            for (ui64 t = 0; t < threadCount; ++t) {
+                UNIT_ASSERT_VALUES_EQUAL(threadLoads[t]->LastTimeNs.load(), T::GetTimeWindowLengthNs());
+                for (ui64 s = 0; s < threadLoads[t]->GetTimeSlotCount(); ++s) {
+                    UNIT_ASSERT_VALUES_EQUAL_C(threadLoads[t]->TimeSlots[s].load(), T::GetTimeSlotMaxValue(), ToString(s).c_str());
+                }
+            }
+
+            UNIT_ASSERT_VALUES_EQUAL(result, T::GetTimeWindowLengthNs());
+
+            for (auto t = 0u; t < threadCount; ++t) {
+                delete threadLoads[t];
+            }
+        }
+    }
+}