Function SuggestSleepDelay

library/cpp/yt/threading/spin_wait.cpp:17–35

namespace {

TDuration SuggestSleepDelay(int iteration)
{
    static std::atomic<ui64> Rand;
    auto rand = Rand.load(std::memory_order::relaxed);
    rand = 0x5deece66dLL * rand + 0xb;   // numbers from nrand48()
    Rand.store(rand, std::memory_order::relaxed);

    constexpr ui64 MinDelayUs = 128;

    // Double delay every 8 iterations, up to 16x (2ms).
    if (iteration > 32) {
        iteration = 32;
    }
    ui64 delayUs = MinDelayUs << (iteration / 8);

    // Randomize in delay..2*delay range, for resulting 128us..4ms range.
    delayUs = delayUs | ((delayUs - 1) & rand);
    return TDuration::MicroSeconds(delayUs);
}

} // namespace