Reduce the amount of slicing in GetMemory/GetSpan/Advance by davidfowl · Pull Request #35216 · dotnet/corefx (original) (raw)

• Avoid setting End on the writing segment until commit or until
  we're moving to the next segment.
• This ends up making the pipe a little bigger but makes writing faster.

PS: This is another take on what I was trying to do with #33948 (inspired by dotnet/aspnetcore#7432)

This is the benchmark https://github.com/aspnet/AspNetCore/blob/c1ce7b9a7764f7ee742da7abb29c1b498f1e2594/src/Servers/Kestrel/perf/Kestrel.Performance/PipeThroughputBenchmark.cs but using the default pool instead of the Kestrel memory pool.

Released version

                  Method |     Mean |     Error |    StdDev |   Median |      Op/s | Gen 0/1k Op | Gen 1/1k Op | Gen 2/1k Op | Allocated Memory/Op |
------------------------ |---------:|----------:|----------:|---------:|----------:|------------:|------------:|------------:|--------------------:|
 ParseLiveAspNetTwoTasks | 1.002 us | 0.0815 us | 0.2379 us | 1.077 us | 998,447.5 |           - |           - |           - |                 1 B |
   ParseLiveAspNetInline | 1.113 us | 0.0839 us | 0.2448 us | 1.060 us | 898,460.3 |           - |           - |           - |                24 B |

Before changes

                  Method |       Mean |     Error |   StdDev |        Op/s | Gen 0/1k Op | Gen 1/1k Op | Gen 2/1k Op | Allocated Memory/Op |
------------------------ |-----------:|----------:|---------:|------------:|------------:|------------:|------------:|--------------------:|
 ParseLiveAspNetTwoTasks |   951.5 ns |  90.71 ns | 263.2 ns | 1,050,924.4 |           - |           - |           - |                 1 B |
   ParseLiveAspNetInline | 1,060.2 ns | 109.24 ns | 315.2 ns |   943,226.1 |           - |           - |           - |                   - |

After changes

                  Method |     Mean |    Error |   StdDev |        Op/s | Gen 0/1k Op | Gen 1/1k Op | Gen 2/1k Op | Allocated Memory/Op |
------------------------ |---------:|---------:|---------:|------------:|------------:|------------:|------------:|--------------------:|
 ParseLiveAspNetTwoTasks | 894.1 ns | 87.71 ns | 255.8 ns | 1,118,447.7 |           - |           - |           - |                 1 B |
   ParseLiveAspNetInline | 991.6 ns | 67.47 ns | 190.3 ns | 1,008,508.4 |           - |           - |           - |                   - |