C# 奇怪的性能测试行为
作为我昨天发布的问题的后续,我决定继续编写一个简单的C# 奇怪的性能测试行为,c#,performance,C#,Performance,作为我昨天发布的问题的后续,我决定继续编写一个简单的RealNumberclass wrappingdecimal,以启用通用数学,并进行一些简单的测试以查看性能比较(请不要评论为什么、为什么或如何实现十进制包装器,这不是本问题的目的) 我决定比较以下两种实现: RealNumberStruct:接口选项 RealNumberClass:抽象基类选项 RealNumberStruct的代码如下: internal interface IArithmetic : IEquatable<IAr
RealNumber
class wrappingdecimal
,以启用通用数学,并进行一些简单的测试以查看性能比较(请不要评论为什么、为什么或如何实现十进制包装器,这不是本问题的目的)
我决定比较以下两种实现:
RealNumberStruct
:接口选项RealNumberClass
:抽象基类选项RealNumberStruct
的代码如下:
internal interface IArithmetic : IEquatable<IArithmetic>
{
IArithmetic Add(IArithmetic right);
IArithmetic Subtract(IArithmetic right);
IArithmetic Multiply(IArithmetic right);
IArithmetic Divide(IArithmetic right);
IArithmetic Negate();
}
public struct RealNumberStruct : IArithmetic
{
private readonly decimal value;
private RealNumberStruct(decimal d)
{
this.value = d;
}
public static implicit operator decimal(RealNumberStruct value)
{
return value.value;
}
public static implicit operator RealNumberStruct(decimal value)
{
return new RealNumberStruct(value);
}
public static RealNumberStruct operator +(RealNumberStruct left, RealNumberStruct right)
{
return new RealNumberStruct(left.value + right.value);
}
public static RealNumberStruct operator -(RealNumberStruct value)
{
return new RealNumberStruct(-value.value);
}
public static RealNumberStruct operator -(RealNumberStruct left, RealNumberStruct right)
{
return new RealNumberStruct(left.value - right.value);
}
public static RealNumberStruct operator *(RealNumberStruct left, RealNumberStruct right)
{
return new RealNumberStruct(left.value * right.value);
}
public static RealNumberStruct operator /(RealNumberStruct left, RealNumberStruct right)
{
return new RealNumberStruct(left.value / right.value);
}
IArithmetic IArithmetic.Add(IArithmetic right)
{
if (!(right is RealNumberStruct))
throw new ArgumentException();
return this + (RealNumberStruct)right;
}
IArithmetic IArithmetic.Subtract(IArithmetic right)
{
if (!(right is RealNumberStruct))
throw new ArgumentException();
return this - (RealNumberStruct)right;
}
IArithmetic IArithmetic.Multiply(IArithmetic right)
{
if (!(right is RealNumberStruct))
throw new ArgumentException();
return this * (RealNumberStruct)right;
}
IArithmetic IArithmetic.Divide(IArithmetic right)
{
if (!(right is RealNumberStruct))
throw new ArgumentException();
return this / (RealNumberStruct)right;
}
IArithmetic IArithmetic.Negate()
{
return -this;
}
bool IEquatable<IArithmetic>.Equals(IArithmetic other)
{
throw new NotImplementedException();
}
}
public abstract class Arithmetic: IEquatable<Arithmetic>
{
protected abstract Arithmetic _Add(Arithmetic right);
protected abstract Arithmetic _Subtract(Arithmetic right);
protected abstract Arithmetic _Multiply(Arithmetic right);
protected abstract Arithmetic _Divide(Arithmetic right);
protected abstract Arithmetic _Negate();
internal Arithmetic Add(Arithmetic right) { return _Add(right); }
internal Arithmetic Subtract(Arithmetic right) { return _Subtract(right); }
internal Arithmetic Multiply(Arithmetic right) { return _Multiply(right); }
internal Arithmetic Divide(Arithmetic right) { return _Divide(right); }
internal Arithmetic Negate() { return _Negate(); }
public abstract bool Equals(Arithmetic other);
}
public class RealNumberClass : Arithmetic
{
private readonly decimal value;
private RealNumberClass(decimal d)
{
this.value = d;
}
public static implicit operator decimal(RealNumberClass value)
{
return value.value;
}
public static implicit operator RealNumberClass(decimal value)
{
return new RealNumberClass(value);
}
public static RealNumberClass operator +(RealNumberClass left, RealNumberClass right)
{
return new RealNumberClass(left.value + right.value);
}
public static RealNumberClass operator -(RealNumberClass value)
{
return new RealNumberClass(-value.value);
}
public static RealNumberClass operator -(RealNumberClass left, RealNumberClass right)
{
return new RealNumberClass(left.value - right.value);
}
public static RealNumberClass operator *(RealNumberClass left, RealNumberClass right)
{
return new RealNumberClass(left.value * right.value);
}
public static RealNumberClass operator /(RealNumberClass left, RealNumberClass right)
{
return new RealNumberClass(left.value / right.value);
}
protected override Arithmetic _Add(Arithmetic right)
{
if (!(right is RealNumberClass))
throw new ArgumentException();
return this + (RealNumberClass)right;
}
protected override Arithmetic _Subtract(Arithmetic right)
{
if (!(right is RealNumberClass))
throw new ArgumentException();
return this - (RealNumberClass)right;
}
protected override Arithmetic _Multiply(Arithmetic right)
{
if (!(right is RealNumberClass))
throw new ArgumentException();
return this * (RealNumberClass)right;
}
protected override Arithmetic _Divide(Arithmetic right)
{
if (!(right is RealNumberClass))
throw new ArgumentException();
return this / (RealNumberClass)right;
}
protected override Arithmetic _Negate()
{
return -this;
}
public override bool Equals(Arithmetic other)
{
throw new NotImplementedException();
}
}
现在,如果我继续使用以下代码测试此代码:
static void TestPerformance(int outerCount)
{
int count = 0;
do
{
var stopWatch = new Stopwatch();
int repetitions = 100000;
testRealNumberStruct(1);
testRealNumberClass(1);
testDecimal(1);
double structAverage = 0, classAverage = 0, decimalAverage = 0;
for (int i = 0; i < outerCount; i++)
{
Console.WriteLine();
stopWatch.Start();
testRealNumberStruct(repetitions);
stopWatch.Stop();
structAverage += stopWatch.ElapsedMilliseconds;
Console.WriteLine("RealNumber struct test: {0} ms", stopWatch.ElapsedMilliseconds);
stopWatch = new Stopwatch();
stopWatch.Start();
testRealNumberClass(repetitions);
stopWatch.Stop();
classAverage += stopWatch.ElapsedMilliseconds;
Console.WriteLine("RealNumber class test: {0} ms", stopWatch.ElapsedMilliseconds);
stopWatch.Reset();
stopWatch = new Stopwatch();
stopWatch.Start();
testDecimal(repetitions);
stopWatch.Stop();
decimalAverage += stopWatch.ElapsedMilliseconds;
Console.WriteLine("Decimal test: {0} ms", stopWatch.ElapsedMilliseconds);
Console.WriteLine();
}
Console.WriteLine();
Console.WriteLine("Test #{0} results----------------------------------", ++count);
Console.WriteLine("RealNumber struct average: {0:F0} ms", structAverage / outerCount);
Console.WriteLine("RealNumber class average: {0:F0} ms", classAverage / outerCount);
Console.WriteLine("Decimal average: {0:F0} ms", decimalAverage / outerCount);
} while (Console.ReadKey().Key != ConsoleKey.Q);
}
private static void testRealNumberStruct(int repetitions)
{
for (int i = 0; i < repetitions; ++i)
{
IArithmetic d1 = (RealNumberStruct)1.25m;
IArithmetic d2 = (RealNumberStruct)(-0.25m);
var d = d1.Multiply(d2);
d = d.Add(d1);
d = d2.Divide(d);
d = d1.Subtract(d);
}
}
private static void testRealNumberClass(int repetitions)
{
for (int i = 0; i < repetitions; ++i)
{
Arithmetic d1 = (RealNumberClass)1.25m;
Arithmetic d2 = (RealNumberClass)(-0.25m);
var d = d1.Multiply(d2);
d = d.Add(d1);
d = d2.Divide(d);
d = d1.Subtract(d);
}
}
private static void testDecimal(int repetitions)
{
for (int i = 0; i < repetitions; ++i)
{
var d1 = 1.25m;
var d2 = -0.25m;
var d = d1 * d2;
d = d + d1;
d = d2 / d;
d = d1 - d;
}
}
静态无效测试性能(int-outerCount)
{
整数计数=0;
做
{
var stopWatch=新秒表();
重复整数=100000;
testRealNumberStruct(1);
testRealNumberClass(1);
testDecimal(1);
双结构平均值=0,类平均值=0,小数平均值=0;
对于(int i=0;i
<>我总是得到我认为奇怪的行为。测试的输出(<代码> OutTeCube=3 )如下:
RealNumber结构测试:40ms
RealNumber类测试:35毫秒
十进制测试:29毫秒
RealNumber结构测试:64毫秒
RealNumber类测试:32毫秒
十进制测试:27毫秒
RealNumber结构测试:62毫秒
RealNumber类测试:33毫秒
十进制测试:27毫秒
测试#1结果-----------------------------------
RealNumber结构平均值:55毫秒
RealNumber类平均值:33毫秒
十进制平均值:28毫秒
请注意,在第一次运行中,realmumberstruct
和realmumberclass
的性能相似(40 ms vs 35 ms),但在运行2和3realmumberstruct
时性能下降(62和52 ms)而RealNumberClass
和decimal
的性能保持不变。无论我运行多少次,这似乎都是一个一致的行为;第一次运行总是要快得多。有人能告诉我为什么会发生这种情况吗?是GC在某种程度上妨碍了我吗
测试在调试器外部的发布版本中运行。其他人是否可以复制此行为
编辑:修复了代码中的一些输入错误。您没有在
realmount struct
之前重建秒表,因此realmount struct
的后续运行包括之前的Decimal
测试的时间。我不能肯定,但只要看一眼,IArithmetic d1=(realmounterstruct)1.25m;
将其分配给类型为IArithmetic
的本地时会导致装箱,这可能会影响性能。请尝试完全删除结构上的接口。@vcsjones但为什么第一次运行与外部循环的其他两次之间有差异?很难说。您发布的代码无法编译。@vcs琼斯:是的,很抱歉有一些打字错误。代码现在应该可以编译了。哈哈,我讨厌我自己。@在这两者之间,容易出现的错误是最难看到的。:)