.Net

.Net performance Strut vs Class

In this article I am writing a simple test to compare the performance of ‘Struct’ and a ‘Class’. Yes, everyone knows thats a ‘Struct’ wins because it is a value type. No, Absolutely No. Use a ‘Struct’ wisely. It can be of huge benefit to performance if used properly. If it is not used properly, it can a bottleneck also. Lets see 2 simple examples which illustrate this.

The following code snippet is going to show the benefits of Struct, creating a value type, reading it and removing it on the stack is much easier than creating an object on the heap. So ‘Struct’ is faster.




using System;

namespace StructVsClass
{
public struct TempStruct
{
private int i;
public int I
{
get { return i; }
set { i = value; }
}
}

public class TempClass
{
private int i;
public int I
{
get { return i; }
set { i = value; }
}
}

class Program
{
static void Main(string[] args)
{
DateTime start = DateTime.Now;
for (int i = 0; i < 5000000; i++)
{
TempStruct ts = new TempStruct();
ts.I = i;
}

DateTime endOfStruct = DateTime.Now;
for (int i = 0; i < 5000000; i++)
{
TempClass tc = new TempClass();
tc.I = i;
}

DateTime endOfClass = DateTime.Now;

Console.WriteLine(endOfStruct.Subtract(start).Ticks);
Console.WriteLine(endOfClass.Subtract(endOfStruct).Ticks);
}
}
}

When I ran this code, I got the following result:

After that I made small changes to the code and within the for loop, I casted the struct to and object and casted the object back to a struct. Now as you guessed, the structs for loop ran slower because an value type is crested on stack and when we casted it an object was created on heap also, so it lost all of its performance benefits.

Here are the results.

The lesson is: use struct but use it wisely.

You can download the code used for this simple test here.
Uncomment the commented lines for the second test program i.e with the casting stuff.

Related Posts:
Profiling your .Net Applications Part - 1
Types in .Net - Part 1
Type in .Net - Part 2

PS:
Thanks to ‘Bart Czernicki’ for his valuable comment and for pointing my spelling mistake. And man its all over the post. As he suggested I will try to put in more useful information in a future article. Once again thank you very much Mr. Bart Czernicki.

.Net performance Strut vs Class

Tags: .Net, .Net 3.5, C#, Code, Code Snippet

This entry was posted on Monday, June 9th, 2008 at 4:12 am and is filed under .Net, C#, Code Snippet. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.