memory optimization for each task

[ankur-anand]

This PR improve the memory usage across the board for the taskwheel timer.

benchstat old.txt new.txt | grep TimingWheel
TimingWheelAfterTimeout/1K_timers_100ms-10              110.1m ± ∞ ¹     110.0m ± ∞ ¹       ~ (p=1.000 n=1) ²
TimingWheelAfterTimeout/10K_timers_100ms-10             111.1m ± ∞ ¹     110.0m ± ∞ ¹       ~ (p=1.000 n=1) ²
TimingWheelAfterTimeout/100K_timers_100ms-10            122.7m ± ∞ ¹     121.2m ± ∞ ¹       ~ (p=1.000 n=1) ²
MemoryComparison/TimingWheel_10K_timers-10              110.2m ± ∞ ¹     110.0m ± ∞ ¹       ~ (p=1.000 n=1) ²
ExpirationOverhead_N/TimingWheel_Expiration_1000-10     51.26m ± ∞ ¹     51.14m ± ∞ ¹       ~ (p=1.000 n=1) ²
ExpirationOverhead_N/TimingWheel_Expiration_10000-10    54.12m ± ∞ ¹     53.48m ± ∞ ¹       ~ (p=1.000 n=1) ²
ExpirationOverhead_N/TimingWheel_Expiration_100000-10   61.03m ± ∞ ¹     59.90m ± ∞ ¹       ~ (p=1.000 n=1) ²
TimingWheel_AddRemove-10                                9.341n ± ∞ ¹   110.700n ± ∞ ¹       ~ (p=1.000 n=1) ²
TimingWheel_FireBatch-10                                6.682n ± ∞ ¹     4.984n ± ∞ ¹       ~ (p=1.000 n=1) ²
TimingWheel_Memory/Timers_100000-10                     24.43m ± ∞ ¹     19.54m ± ∞ ¹       ~ (p=1.000 n=1) ²
TimingWheel_Memory/Timers_1000000-10                    255.6m ± ∞ ¹     199.8m ± ∞ ¹       ~ (p=1.000 n=1) ²
TimingWheel_Memory/Timers_10000000-10                    2.718 ± ∞ ¹      1.807 ± ∞ ¹       ~ (p=1.000 n=1) ²
TimingWheelPeriodic-10                                  212.8m ± ∞ ¹     206.1m ± ∞ ¹       ~ (p=1.000 n=1) ²
TimingWheelAfterTimeout/1K_timers_100ms-10              308.2Ki ± ∞ ¹   209.5Ki ± ∞ ¹        ~ (p=1.000 n=1) ²
TimingWheelAfterTimeout/10K_timers_100ms-10             2.725Mi ± ∞ ¹   1.882Mi ± ∞ ¹        ~ (p=1.000 n=1) ²
TimingWheelAfterTimeout/100K_timers_100ms-10            25.25Mi ± ∞ ¹   17.89Mi ± ∞ ¹        ~ (p=1.000 n=1) ²
MemoryComparison/TimingWheel_10K_timers-10              2.725Mi ± ∞ ¹   1.882Mi ± ∞ ¹        ~ (p=1.000 n=1) ²
ExpirationOverhead_N/TimingWheel_Expiration_1000-10     17.19Ki ± ∞ ¹   17.19Ki ± ∞ ¹        ~ (p=1.000 n=1) ³
ExpirationOverhead_N/TimingWheel_Expiration_10000-10    303.2Ki ± ∞ ¹   303.3Ki ± ∞ ¹        ~ (p=1.000 n=1) ²
ExpirationOverhead_N/TimingWheel_Expiration_100000-10   4.288Mi ± ∞ ¹   4.288Mi ± ∞ ¹        ~ (p=1.000 n=1) ²
TimingWheel_AddRemove-10                                  0.000 ± ∞ ¹     0.000 ± ∞ ¹        ~ (p=1.000 n=1) ³
TimingWheel_FireBatch-10                                  0.000 ± ∞ ¹     0.000 ± ∞ ¹        ~ (p=1.000 n=1) ³
TimingWheel_Memory/Timers_100000-10                     9.218Mi ± ∞ ¹   9.218Mi ± ∞ ¹        ~ (p=1.000 n=1) ²
TimingWheel_Memory/Timers_1000000-10                    91.62Mi ± ∞ ¹   91.62Mi ± ∞ ¹        ~ (p=1.000 n=1) ³
TimingWheel_Memory/Timers_10000000-10                   915.6Mi ± ∞ ¹   915.6Mi ± ∞ ¹        ~ (p=1.000 n=1) ²
TimingWheelPeriodic-10                                  60.45Mi ± ∞ ¹   46.30Mi ± ∞ ¹        ~ (p=1.000 n=1) ²
TimingWheelAfterTimeout/1K_timers_100ms-10              1.056k ± ∞ ¹   1.056k ± ∞ ¹       ~ (p=1.000 n=1) ³
TimingWheelAfterTimeout/10K_timers_100ms-10             10.18k ± ∞ ¹   10.18k ± ∞ ¹       ~ (p=1.000 n=1) ³
TimingWheelAfterTimeout/100K_timers_100ms-10            101.1k ± ∞ ¹   101.1k ± ∞ ¹       ~ (p=1.000 n=1) ²
MemoryComparison/TimingWheel_10K_timers-10              10.18k ± ∞ ¹   10.18k ± ∞ ¹       ~ (p=1.000 n=1) ³
ExpirationOverhead_N/TimingWheel_Expiration_1000-10      11.00 ± ∞ ¹    11.00 ± ∞ ¹       ~ (p=1.000 n=1) ³
ExpirationOverhead_N/TimingWheel_Expiration_10000-10     18.00 ± ∞ ¹    19.00 ± ∞ ¹       ~ (p=1.000 n=1) ²
ExpirationOverhead_N/TimingWheel_Expiration_100000-10    28.00 ± ∞ ¹    29.00 ± ∞ ¹       ~ (p=1.000 n=1) ²
TimingWheel_AddRemove-10                                 0.000 ± ∞ ¹    0.000 ± ∞ ¹       ~ (p=1.000 n=1) ³
TimingWheel_FireBatch-10                                 0.000 ± ∞ ¹    0.000 ± ∞ ¹       ~ (p=1.000 n=1) ³
TimingWheel_Memory/Timers_100000-10                     700.0k ± ∞ ¹   600.0k ± ∞ ¹       ~ (p=1.000 n=1) ²
TimingWheel_Memory/Timers_1000000-10                    7.000M ± ∞ ¹   6.000M ± ∞ ¹       ~ (p=1.000 n=1) ²
TimingWheel_Memory/Timers_10000000-10                   70.00M ± ∞ ¹   60.00M ± ∞ ¹       ~ (p=1.000 n=1) ²
TimingWheelPeriodic-10                                  481.0k ± ∞ ¹   401.1k ± ∞ ¹       ~ (p=1.000 n=1)