- 1 year ago
Measuring generic delegates / wrapping GetDelegateForFunctionPointer
When measuring the performance of generic delegates or wrapping function pointers using the GetDelegateForFunctionPointer
method in C#, you can use the Stopwatch
class from the System.Diagnostics
namespace. The Stopwatch
class provides a convenient way to measure elapsed time with high precision.
Here's an example that demonstrates how you can measure the performance:
csharpusing System;
using System.Diagnostics;
using System.Runtime.InteropServices;
class Program
{
// Define the function signature for the target method
delegate int MyFunctionDelegate(int a, int b);
// Native method to be wrapped
[DllImport("user32.dll")]
static extern int MessageBox(int hWnd, string text, string caption, int options);
static void Main()
{
// Create a delegate for the native method using GetDelegateForFunctionPointer
MyFunctionDelegate myFunction = Marshal.GetDelegateForFunctionPointer<MyFunctionDelegate>(
Marshal.GetFunctionPointerForDelegate(new MyFunctionDelegate(MessageBox))
);
// Measure the performance of the delegate
Stopwatch stopwatch = Stopwatch.StartNew();
for (int i = 0; i < 1000000; i++)
{
// Call the delegate method
myFunction(0, 0);
}
stopwatch.Stop();
// Print the elapsed time
Console.WriteLine("Elapsed Time: " + stopwatch.Elapsed);
}
}
In the example above, the MessageBox
function from the user32.dll
library is wrapped in a generic delegate MyFunctionDelegate
using the GetDelegateForFunctionPointer
method.
The Stopwatch
class is used to measure the elapsed time for executing the delegate. The loop runs the delegate method 1,000,000 times, and the elapsed time is printed at the end.
By using the Stopwatch
class, you can accurately measure the performance of generic delegates or wrapped function pointers in C#. Adjust the code according to your specific scenario and the target methods you want to measure.