Remove pinning from StringBuilder #64405

stephentoub · 2022-01-27T21:40:24Z

Switch from pointers to refs to avoid pinning the inputs.

As part of this, I also consolidated the fast-path that was there specifically for string inputs to also apply to span inputs, char arrays, pointers, etc.

Method	Toolchain	Value	Mean	Ratio	Code Size
String	\main\corerun.exe	a	2.958 ns	1.00	719 B
String	\pr\corerun.exe	a	2.127 ns	0.72	684 B

Span	\main\corerun.exe	a	7.652 ns	1.00	1,170 B
Span	\pr\corerun.exe	a	2.516 ns	0.33	693 B

CharArray	\main\corerun.exe	a	6.631 ns	1.00	1,171 B
CharArray	\pr\corerun.exe	a	2.133 ns	0.32	684 B

AppendJoin	\main\corerun.exe	a	33.384 ns	1.00	821 B
AppendJoin	\pr\corerun.exe	a	22.326 ns	0.67	811 B

String	\main\corerun.exe	ab	3.432 ns	1.00	719 B
String	\pr\corerun.exe	ab	2.391 ns	0.70	684 B

Span	\main\corerun.exe	ab	7.274 ns	1.00	1,170 B
Span	\pr\corerun.exe	ab	2.932 ns	0.40	693 B

CharArray	\main\corerun.exe	ab	6.384 ns	1.00	1,171 B
CharArray	\pr\corerun.exe	ab	2.374 ns	0.37	684 B

AppendJoin	\main\corerun.exe	ab	36.239 ns	1.00	821 B
AppendJoin	\pr\corerun.exe	ab	22.674 ns	0.63	811 B

String	\main\corerun.exe	abc	4.760 ns	1.00	719 B
String	\pr\corerun.exe	abc	4.348 ns	0.91	684 B

Span	\main\corerun.exe	abc	7.354 ns	1.00	1,170 B
Span	\pr\corerun.exe	abc	4.811 ns	0.66	693 B

CharArray	\main\corerun.exe	abc	6.372 ns	1.00	1,171 B
CharArray	\pr\corerun.exe	abc	4.330 ns	0.68	684 B

AppendJoin	\main\corerun.exe	abc	38.682 ns	1.00	821 B
AppendJoin	\pr\corerun.exe	abc	31.658 ns	0.82	811 B

String	\main\corerun.exe	abcd	4.699 ns	1.00	719 B
String	\pr\corerun.exe	abcd	4.599 ns	0.98	684 B

Span	\main\corerun.exe	abcd	7.296 ns	1.00	1,170 B
Span	\pr\corerun.exe	abcd	4.950 ns	0.68	693 B

CharArray	\main\corerun.exe	abcd	6.390 ns	1.00	1,171 B
CharArray	\pr\corerun.exe	abcd	4.469 ns	0.70	684 B

AppendJoin	\main\corerun.exe	abcd	39.048 ns	1.00	821 B
AppendJoin	\pr\corerun.exe	abcd	30.638 ns	0.78	811 B

String	\main\corerun.exe	abcdefgh	4.698 ns	1.00	719 B
String	\pr\corerun.exe	abcdefgh	4.504 ns	0.96	684 B

Span	\main\corerun.exe	abcdefgh	7.366 ns	1.00	1,170 B
Span	\pr\corerun.exe	abcdefgh	5.057 ns	0.69	693 B

CharArray	\main\corerun.exe	abcdefgh	6.353 ns	1.00	1,171 B
CharArray	\pr\corerun.exe	abcdefgh	4.546 ns	0.72	684 B

AppendJoin	\main\corerun.exe	abcdefgh	39.165 ns	1.00	821 B
AppendJoin	\pr\corerun.exe	abcdefgh	30.765 ns	0.79	811 B

using System;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using System.Text.RegularExpressions;
using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Running;

[DisassemblyDiagnoser]
public class Program
{
    public static void Main(string[] args) => BenchmarkSwitcher.FromAssembly(typeof(Program).Assembly).Run(args);

    private const int Iterations = 1000;

    private StringBuilder _sb = new StringBuilder(100_000);
    private char[] _chars;
    private string[] _strings;

    [Params("a", "ab", "abc", "abcd", "abcdefgh")]
    public string Value { get; set; }

    [GlobalSetup]
    public void Setup()
    {
        _chars = Value.ToCharArray();
        _strings = Enumerable.Repeat(Value, 4).ToArray();
    }

    [Benchmark(OperationsPerInvoke = Iterations)]
    public void String()
    {
        _sb.Clear();
        for (int i = 0; i < Iterations; i++) _sb.Append(Value);
    }

    [Benchmark(OperationsPerInvoke = Iterations)]
    public void Span()
    {
        _sb.Clear();
        for (int i = 0; i < Iterations; i++) _sb.Append((ReadOnlySpan<char>)Value);
    }

    [Benchmark(OperationsPerInvoke = Iterations)]
    public void CharArray()
    {
        _sb.Clear();
        for (int i = 0; i < Iterations; i++) _sb.Append(_chars);
    }

    [Benchmark(OperationsPerInvoke = Iterations)]
    public void AppendJoin()
    {
        _sb.Clear();
        for (int i = 0; i < Iterations; i++)
        {
            _sb.AppendJoin(", ", _strings);
        }
    }
}

dotnet-issue-labeler · 2022-01-27T21:40:28Z

I couldn't figure out the best area label to add to this PR. If you have write-permissions please help me learn by adding exactly one area label.

ghost · 2022-01-27T21:40:58Z

Tagging subscribers to this area: @dotnet/area-system-runtime
See info in area-owners.md if you want to be subscribed.

Issue Details

Switch from pointers to refs to avoid pinning the inputs.

As part of this, I also consolidated the fast-path that was there specifically for string inputs to also apply to span inputs, char arrays, pointers, etc.

Method	Toolchain	Value	Mean	Ratio	Code Size
String	\main\corerun.exe	a	2.958 ns	1.00	719 B
String	\pr\corerun.exe	a	2.127 ns	0.72	684 B

Span	\main\corerun.exe	a	7.652 ns	1.00	1,170 B
Span	\pr\corerun.exe	a	2.516 ns	0.33	693 B

CharArray	\main\corerun.exe	a	6.631 ns	1.00	1,171 B
CharArray	\pr\corerun.exe	a	2.133 ns	0.32	684 B

AppendJoin	\main\corerun.exe	a	33.384 ns	1.00	821 B
AppendJoin	\pr\corerun.exe	a	22.326 ns	0.67	811 B

String	\main\corerun.exe	ab	3.432 ns	1.00	719 B
String	\pr\corerun.exe	ab	2.391 ns	0.70	684 B

Span	\main\corerun.exe	ab	7.274 ns	1.00	1,170 B
Span	\pr\corerun.exe	ab	2.932 ns	0.40	693 B

CharArray	\main\corerun.exe	ab	6.384 ns	1.00	1,171 B
CharArray	\pr\corerun.exe	ab	2.374 ns	0.37	684 B

AppendJoin	\main\corerun.exe	ab	36.239 ns	1.00	821 B
AppendJoin	\pr\corerun.exe	ab	22.674 ns	0.63	811 B

String	\main\corerun.exe	abc	4.760 ns	1.00	719 B
String	\pr\corerun.exe	abc	4.348 ns	0.91	684 B

Span	\main\corerun.exe	abc	7.354 ns	1.00	1,170 B
Span	\pr\corerun.exe	abc	4.811 ns	0.66	693 B

CharArray	\main\corerun.exe	abc	6.372 ns	1.00	1,171 B
CharArray	\pr\corerun.exe	abc	4.330 ns	0.68	684 B

AppendJoin	\main\corerun.exe	abc	38.682 ns	1.00	821 B
AppendJoin	\pr\corerun.exe	abc	31.658 ns	0.82	811 B

String	\main\corerun.exe	abcd	4.699 ns	1.00	719 B
String	\pr\corerun.exe	abcd	4.599 ns	0.98	684 B

Span	\main\corerun.exe	abcd	7.296 ns	1.00	1,170 B
Span	\pr\corerun.exe	abcd	4.950 ns	0.68	693 B

CharArray	\main\corerun.exe	abcd	6.390 ns	1.00	1,171 B
CharArray	\pr\corerun.exe	abcd	4.469 ns	0.70	684 B

AppendJoin	\main\corerun.exe	abcd	39.048 ns	1.00	821 B
AppendJoin	\pr\corerun.exe	abcd	30.638 ns	0.78	811 B

String	\main\corerun.exe	abcdefgh	4.698 ns	1.00	719 B
String	\pr\corerun.exe	abcdefgh	4.504 ns	0.96	684 B

Span	\main\corerun.exe	abcdefgh	7.366 ns	1.00	1,170 B
Span	\pr\corerun.exe	abcdefgh	5.057 ns	0.69	693 B

CharArray	\main\corerun.exe	abcdefgh	6.353 ns	1.00	1,171 B
CharArray	\pr\corerun.exe	abcdefgh	4.546 ns	0.72	684 B

AppendJoin	\main\corerun.exe	abcdefgh	39.165 ns	1.00	821 B
AppendJoin	\pr\corerun.exe	abcdefgh	30.765 ns	0.79	811 B

using System;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using System.Text.RegularExpressions;
using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Running;

[DisassemblyDiagnoser]
public class Program
{
    public static void Main(string[] args) => BenchmarkSwitcher.FromAssembly(typeof(Program).Assembly).Run(args);

    private const int Iterations = 1000;

    private StringBuilder _sb = new StringBuilder(100_000);
    private char[] _chars;
    private string[] _strings;

    [Params("a", "ab", "abc", "abcd", "abcdefgh")]
    public string Value { get; set; }

    [GlobalSetup]
    public void Setup()
    {
        _chars = Value.ToCharArray();
        _strings = Enumerable.Repeat(Value, 4).ToArray();
    }

    [Benchmark(OperationsPerInvoke = Iterations)]
    public void String()
    {
        _sb.Clear();
        for (int i = 0; i < Iterations; i++) _sb.Append(Value);
    }

    [Benchmark(OperationsPerInvoke = Iterations)]
    public void Span()
    {
        _sb.Clear();
        for (int i = 0; i < Iterations; i++) _sb.Append((ReadOnlySpan<char>)Value);
    }

    [Benchmark(OperationsPerInvoke = Iterations)]
    public void CharArray()
    {
        _sb.Clear();
        for (int i = 0; i < Iterations; i++) _sb.Append(_chars);
    }

    [Benchmark(OperationsPerInvoke = Iterations)]
    public void AppendJoin()
    {
        _sb.Clear();
        for (int i = 0; i < Iterations; i++)
        {
            _sb.AppendJoin(", ", _strings);
        }
    }
}

Author:	stephentoub
Assignees:	stephentoub
Labels:	`area-System.Runtime`, `tenet-performance`
Milestone:	7.0.0

Switch from pointers to refs to avoid pinning the inputs. As part of this, I also consolidated the fast-path that was there specifically for string inputs to also apply to span inputs, char arrays, pointers, etc.

EgorBo · 2022-02-01T16:32:39Z

Improvements on Win-x64: dotnet/perf-autofiling-issues#3219

stephentoub · 2022-02-01T16:34:18Z

Improvements on Win-x64: dotnet/perf-autofiling-issues#3219

Nice, thanks.

EgorBo · 2022-02-01T16:37:49Z

Improvement for DateTimeOffset.ToString if it's related: dotnet/perf-autofiling-issues#3239

stephentoub · 2022-02-01T16:40:24Z

if it's related

Likely. That test uses ToString(null) which will end up formatting into a StringBuilder.

ghost assigned stephentoub Jan 27, 2022

stephentoub added this to the 7.0.0 milestone Jan 27, 2022

stephentoub added area-System.Runtime tenet-performance Performance related issue labels Jan 27, 2022

Remove pinning from StringBuilder

a2742f9

Switch from pointers to refs to avoid pinning the inputs. As part of this, I also consolidated the fast-path that was there specifically for string inputs to also apply to span inputs, char arrays, pointers, etc.

stephentoub force-pushed the sbpin branch from 8c240ef to a2742f9 Compare January 28, 2022 15:56

tannergooding approved these changes Jan 28, 2022

View reviewed changes

stephentoub merged commit 315fb41 into dotnet:main Jan 28, 2022

stephentoub deleted the sbpin branch January 28, 2022 20:04

This was referenced Feb 3, 2022

Add/use ArgumentException.ThrowIfNullOrEmpty #64357

Merged

Regressions in System.Text.Tests.Perf_StringBuilder #64751

Closed

stephentoub mentioned this pull request Feb 7, 2022

Optimize StringBuilder by embracing spans and ISpanFormattable more. #58907

Closed

kunalspathak mentioned this pull request Feb 24, 2022

[Perf] Changes at 1/28/2022 8:15:35 PM dotnet/perf-autofiling-issues#3231

Closed

ghost locked as resolved and limited conversation to collaborators Mar 3, 2022

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Remove pinning from StringBuilder #64405

Remove pinning from StringBuilder #64405

stephentoub commented Jan 27, 2022

dotnet-issue-labeler bot commented Jan 27, 2022

ghost commented Jan 27, 2022

EgorBo commented Feb 1, 2022

stephentoub commented Feb 1, 2022

EgorBo commented Feb 1, 2022

stephentoub commented Feb 1, 2022 •

edited

Loading

Remove pinning from StringBuilder #64405

Remove pinning from StringBuilder #64405

Conversation

stephentoub commented Jan 27, 2022

dotnet-issue-labeler bot commented Jan 27, 2022

ghost commented Jan 27, 2022

EgorBo commented Feb 1, 2022

stephentoub commented Feb 1, 2022

EgorBo commented Feb 1, 2022

stephentoub commented Feb 1, 2022 • edited Loading

stephentoub commented Feb 1, 2022 •

edited

Loading