再探C 类与结构体究竟谁快——考虑栈变量、栈分配、位整数、密封类

1、再探C#类与结构体究竟谁快考虑栈变量、栈分配、64位整数、密封类 上次我对C#类与结构体做了一次速度评测（/zyl910/article/details/6788417）。经过一段时间思索，发现还可以进一步探讨第一、栈变量。上次的“硬编码”，是访问类中的静态变量的。若改为访问函数中的栈变量，性能会不会有所提高？第二、栈分配（stackalloc）。既然要测试栈变量，我们还可以顺便测试一下在栈上分配的内存块的访问性能。第三、64位整数。由于32位系统的成功，我们已经习惯了使用32位整数（int）。现在64位系统逐渐普及，我们得为此做好准备。对于指针操作时经常

2、要用到的偏移量增减运算来说，是使用32位整数，还是使用64位整数，或写两套代码？这需要测试后才能决定。第四、密封类（sealed）。听说密封类能提高性能，我们可以测试一下。有两种测试方式，一是为原来的派生类增加sealed关键字，二是专门另外写一个密封类。我决定同时使用这两种方法，分别测试其性能。一、测试代码测试代码如下?123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737

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7、483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525using System; using System.Collections.Generic; using System.Text; using System.Diagnostics; namespace TryPointerCall / / 指针操作接口 / public interface IPointerCall / / 指针操作 /

8、 / 源指针 / 修改后指针 unsafe byte* Ptr(byte* p); #region 非泛型 / / 非泛型 指针操作基类 / public abstract class PointerCall : IPointerCall public abstract unsafe byte* Ptr(byte* p); / / 非泛型 指针操作派生类: 指针+偏移 / public sealed class PointerCallAdd : PointerCall / / 偏移值 / public int Offset = 0; public override unsafe byte* P

9、tr(byte* p) return unchecked(p + Offset); / / 非泛型 指针操作密封类: 指针+偏移 / public sealed class SldPointerCallAdd : IPointerCall / / 偏移值 / public int Offset = 0; public unsafe byte* Ptr(byte* p) return unchecked(p + Offset); / / 非泛型 指针操作结构体: 指针+偏移 / public struct SPointerCallAdd : IPointerCall / / 偏移值 / publ

10、ic int Offset; public unsafe byte* Ptr(byte* p) return unchecked(p + Offset); #endregion #region 泛型 / ! C#不支持将整数类型作为泛型约束 ! /public abstract class GenPointerCall : IPointerCall where T: int, long / / public abstract unsafe byte* Ptr(byte* p); / void d() / / / #endregion #region 全部测试 / / 指针操作的一些常用函数 /

11、 public static class PointerCallTool #if DEBUG private const int CountLoop = 10000000; / 循环次数 #else private const int CountLoop = 200000000; / 循环次数 #endif / / 调用指针操作 / / 具有IPointerCall接口的类型。 / 调用者 / 源指针 / 修改后指针 public static unsafe byte* CallPtr(T ptrcall, byte* p) where T : IPointerCall return ptrc

12、all.Ptr(p); public static unsafe byte* CallClassPtr(T ptrcall, byte* p) where T : PointerCall return ptrcall.Ptr(p); public static unsafe byte* CallRefPtr(ref T ptrcall, byte* p) where T : IPointerCall return ptrcall.Ptr(p); / C#不允许将特定的结构体作为泛型约束。所以对于结构体只能采用上面那个方法，通过IPointerCall接口进行约束，可能会造成性能下降。 /pub

13、lic static unsafe byte* SCallPtr(T ptrcall, byte* p) where T : SPointerCallAdd / / return ptrcall.Ptr(p); / private static int TryIt_Static_Offset; private static unsafe byte* TryIt_Static_Ptr(byte* p) return unchecked(p + TryIt_Static_Offset); / / 执行测试 - 静态调用 / / 文本输出 private static unsafe void Try

14、It_Static(StringBuilder sOut, int CountLoop) TryIt_Static_Offset = 1; / = 性能测试 = byte* p = null; Stopwatch sw = new Stopwatch(); int i; unchecked #region 测试 / 硬编码.栈变量 int iOffset = 1; sw.Reset(); sw.Start(); for (i = 0; i CountLoop; +i) p = p + iOffset; sw.Stop(); sOut.AppendLine(string.Format(硬编码.栈

15、变量:t0, sw.ElapsedMilliseconds); / 硬编码.栈分配 int* pOffset = stackalloc int1; pOffset0 = 1; sw.Reset(); sw.Start(); for (i = 0; i CountLoop; +i) p = p + pOffset0; sw.Stop(); sOut.AppendLine(string.Format(硬编码.栈分配:t0, sw.ElapsedMilliseconds); / 硬编码.静态 sw.Reset(); sw.Start(); for (i = 0; i CountLoop; +i) p

16、 = p + TryIt_Static_Offset; sw.Stop(); sOut.AppendLine(string.Format(硬编码.静态:t0, sw.ElapsedMilliseconds); / 静态调用 sw.Reset(); sw.Start(); for (i = 0; i CountLoop; +i) p = TryIt_Static_Ptr(p); sw.Stop(); sOut.AppendLine(string.Format(静态调用:t0, sw.ElapsedMilliseconds); #endregion / 测试 private static long

17、 TryIt_Static64_Offset; private static unsafe byte* TryIt_Static64_Ptr(byte* p) return unchecked(p + TryIt_Static64_Offset); / / 执行测试 - 静态调用 / / 文本输出 private static unsafe void TryIt_Static64(StringBuilder sOut, int CountLoop) TryIt_Static64_Offset = 1; / = 性能测试 = byte* p = null; Stopwatch sw = new

18、Stopwatch(); int i; unchecked #region 测试 / 硬编码.栈变量 long iOffset = 1; sw.Reset(); sw.Start(); for (i = 0; i CountLoop; +i) p = p + iOffset; sw.Stop(); sOut.AppendLine(string.Format(64硬编码.栈变量:t0, sw.ElapsedMilliseconds); / 硬编码.栈分配 long* pOffset = stackalloc long1; pOffset0 = 1; sw.Reset(); sw.Start();

19、 for (i = 0; i CountLoop; +i) p = p + pOffset0; sw.Stop(); sOut.AppendLine(string.Format(64硬编码.栈分配:t0, sw.ElapsedMilliseconds); / 硬编码.静态 sw.Reset(); sw.Start(); for (i = 0; i CountLoop; +i) p = p + TryIt_Static64_Offset; sw.Stop(); sOut.AppendLine(string.Format(64硬编码.静态:t0, sw.ElapsedMilliseconds);

20、/ 静态调用 sw.Reset(); sw.Start(); for (i = 0; i CountLoop; +i) p = TryIt_Static64_Ptr(p); sw.Stop(); sOut.AppendLine(string.Format(64静态调用:t0, sw.ElapsedMilliseconds); #endregion / 测试 / / 执行测试 - 非泛型 / / 文本输出 private static unsafe void TryIt_NoGen(StringBuilder sOut, int CountLoop) / 创建 PointerCallAdd pc

21、a = new PointerCallAdd(); SldPointerCallAdd dpca = new SldPointerCallAdd(); SPointerCallAdd spca; pca.Offset = 1; spca.Offset = 1; / 转型 PointerCall pca_base = pca; IPointerCall pca_itf = pca; IPointerCall dpca_itf = dpca; IPointerCall spca_itf = spca; / = 性能测试 = byte* p = null; Stopwatch sw = new St

22、opwatch(); int i; unchecked #region 调用 #region 直接调用 / 调用派生类 sw.Reset(); sw.Start(); for (i = 0; i CountLoop; +i) p = pca.Ptr(p); sw.Stop(); sOut.AppendLine(string.Format(调用派生类:t0, sw.ElapsedMilliseconds); / 调用密封类 sw.Reset(); sw.Start(); for (i = 0; i CountLoop; +i) p = dpca.Ptr(p); sw.Stop(); sOut.A

23、ppendLine(string.Format(调用密封类:t0, sw.ElapsedMilliseconds); / 调用结构体 sw.Reset(); sw.Start(); for (i = 0; i CountLoop; +i) p = spca.Ptr(p); sw.Stop(); sOut.AppendLine(string.Format(调用结构体:t0, sw.ElapsedMilliseconds); #endregion / 直接调用 #region 间接调用 / 调用基类 sw.Reset(); sw.Start(); for (i = 0; i CountLoop;

24、+i) p = pca_base.Ptr(p); sw.Stop(); sOut.AppendLine(string.Format(调用基类:t0, sw.ElapsedMilliseconds); / 调用派生类的接口 sw.Reset(); sw.Start(); for (i = 0; i CountLoop; +i) p = pca_itf.Ptr(p); sw.Stop(); sOut.AppendLine(string.Format(调用派生类的接口:t0, sw.ElapsedMilliseconds); / 调用密封类的接口 sw.Reset(); sw.Start(); fo

25、r (i = 0; i CountLoop; +i) p = dpca_itf.Ptr(p); sw.Stop(); sOut.AppendLine(string.Format(调用密封类的接口:t0, sw.ElapsedMilliseconds); / 调用结构体的接口 sw.Reset(); sw.Start(); for (i = 0; i CountLoop; +i) p = spca_itf.Ptr(p); sw.Stop(); sOut.AppendLine(string.Format(调用结构体的接口:t0, sw.ElapsedMilliseconds); #endregio

26、n / 间接调用 #endregion / 调用 #region 泛型调用 #region 泛型基类约束 / 基类泛型调用派生类 sw.Reset(); sw.Start(); for (i = 0; i CountLoop; +i) p = CallClassPtr(pca, p); sw.Stop(); sOut.AppendLine(string.Format(基类泛型调用派生类:t0, sw.ElapsedMilliseconds); / 基类泛型调用基类 sw.Reset(); sw.Start(); for (i = 0; i CountLoop; +i) p = CallClas

27、sPtr(pca_base, p); sw.Stop(); sOut.AppendLine(string.Format(基类泛型调用基类:t0, sw.ElapsedMilliseconds); #endregion / 泛型基类约束 #region 泛型接口约束 - 直接调用 / 接口泛型调用派生类 sw.Reset(); sw.Start(); for (i = 0; i CountLoop; +i) p = CallPtr(pca, p); sw.Stop(); sOut.AppendLine(string.Format(接口泛型调用派生类:t0, sw.ElapsedMilliseco

28、nds); / 接口泛型调用密封类 sw.Reset(); sw.Start(); for (i = 0; i CountLoop; +i) p = CallPtr(dpca, p); sw.Stop(); sOut.AppendLine(string.Format(接口泛型调用密封类:t0, sw.ElapsedMilliseconds); / 接口泛型调用结构体 sw.Reset(); sw.Start(); for (i = 0; i CountLoop; +i) p = CallPtr(spca, p); sw.Stop(); sOut.AppendLine(string.Format

29、(接口泛型调用结构体:t0, sw.ElapsedMilliseconds); / 接口泛型调用结构体引用 sw.Reset(); sw.Start(); for (i = 0; i CountLoop; +i) p = CallRefPtr(ref spca, p); sw.Stop(); sOut.AppendLine(string.Format(接口泛型调用结构体引用:t0, sw.ElapsedMilliseconds); #endregion / 直接调用 #region 间接调用 / 接口泛型调用基类 sw.Reset(); sw.Start(); for (i = 0; i CountLoop; +i) p = CallPtr(pca_base, p); sw.Stop(); sOut.AppendLine(string.Format(接口泛型调用基类:t0, sw.ElapsedMilliseconds); / 接口泛型调用派生类的接口 sw.Reset(); sw.Start(); for (i = 0; i CountLoop; +i) p = CallPtr(pca_itf, p); sw.Stop(); sOut.AppendLine(string.Format(接口泛型调用派生类的接口:t0, sw.E