C#: Make a method to return Execution Time of another Method

Question

I'm trying to come up with a method which will measure and return the execution time of another method. Basically something like this:

public void DoSomething(Int32 aNumber)
{ /* Stuff happens */ }

//
// Somewhere else in code:
TimeSpan executionTime = MyDiag.MeasureExecTime(DoSomething(5));

// Now executionTime contains how long DoSomething(5) took to execute,
// e.g. 2.55463 seconds.

How can I do this (the MeasureExecTime method)?

Answer 1

I've just created such a method to test performance in this SO question:

private static TimeSpan MeasureExecTime(Action action, int iterations)
{
    action(); // warm up
    var sw = Stopwatch.StartNew();
    for (int i = 0; i < iterations; i++)
    {
        action();
    }
    return sw.Elapsed;
}

Usage:

MeasureExecTime(() => DoSomething(5), 100000);

See 280Z28's answer if you don't want to test more than one iteration :-)

Answer 2

public static TimeSpan MeasureExecTime(Action action)
{
    Stopwatch stopwatch = Stopwatch.StartNew();
    action();
    return stopwatch.Elapsed;
}

Answer 3

See this thread for a long discussion on this topic, the accepted answers has quite a few flaws.

Benchmarking small code samples in C#, can this implementation be improved?