Cases of Benchmark Testing

cases from golang

golang std pkg log:

• commit c3b4c27: reduce lock contention by using atomics so that the header formatting can be moved out of the critical lock section.

  Performance:  
    name           old time/op  new time/op  delta
    Concurrent-24  19.9µs ± 2%   8.3µs ± 1%  -58.37%  (p=0.000 n=10+10)
  

• commit 2da8a55: reduce allocation by replacing fmt.Sprintf by fmt.Appendf

  Performance:
    name               old time/op    new time/op    delta
    Println            188ns ± 2%     172ns ± 4%    -8.39%  (p=0.000 n=10+10)
    PrintlnNoFlags     139ns ± 1%     116ns ± 1%   -16.71%  (p=0.000 n=9+9)
  
    name               old allocs/op  new allocs/op  delta
    Println             1.00 ± 0%      0.00       -100.00%  (p=0.000 n=10+10)
    PrintlnNoFlags      1.00 ± 0%      0.00       -100.00%  (p=0.000 n=10+10)