C#直接赋值和反射赋值(无GC)的性能比较

时间:2022-05-14 15:13:39
using System;
using System.Reflection;
using System.Diagnostics;
using System.Runtime.InteropServices; namespace Field
{
struct Test
{
public float X;
} class MainClass
{
const int loops = ; Stopwatch m_StopWatch = new Stopwatch();
Test m_Test;
object m_Target;
object m_Value;
FieldInfo m_Field;
public MainClass()
{
m_Target = m_Test;
Type t = typeof(Test);
m_Field = t.GetField("X");
m_Value = m_Field.GetValue(m_Test);
} public void Test1()
{
m_StopWatch.Reset();
m_StopWatch.Start();
for (int i = ; i < loops; ++i)
{
m_Test.X = (float)i;
}
m_StopWatch.Stop(); Console.WriteLine("Test1: " + m_StopWatch.ElapsedMilliseconds + " ms");
} public unsafe void Test2()
{
m_StopWatch.Reset();
m_StopWatch.Start();
for (int i = ; i < loops; ++i)
{
GCHandle gcHandle = GCHandle.Alloc(m_Value, GCHandleType.Pinned);
IntPtr rawPtr = gcHandle.AddrOfPinnedObject();
float* buffer = (float*)rawPtr.ToPointer();
*buffer = (float)i;
gcHandle.Free();
m_Field.SetValueDirect(__makeref(m_Test), m_Value);
}
m_StopWatch.Stop(); Console.WriteLine("Test2: " + m_StopWatch.ElapsedMilliseconds + " ms");
} public unsafe void Test3()
{
m_StopWatch.Reset();
m_StopWatch.Start();
for (int i = ; i < loops; ++i)
{
GCHandle gcHandle = GCHandle.Alloc(m_Value, GCHandleType.Pinned);
IntPtr rawPtr = gcHandle.AddrOfPinnedObject();
float* buffer = (float*)rawPtr.ToPointer();
*buffer = (float)i;
gcHandle.Free();
m_Field.SetValue(m_Target, m_Value);
m_Test = (Test)m_Target;
}
m_StopWatch.Stop(); Console.WriteLine("Test3: " + m_StopWatch.ElapsedMilliseconds + " ms");
} public static void Main(string[] args)
{
MainClass main = new MainClass();
main.Test1();
main.Test2();
main.Test3(); Console.ReadKey();
}
}
}

Xamarin - Release

Test1: 35 ms

Test2: 3237 ms

Test3: 5189 ms