Question

I have a method that looks like this:

public void SomeMethodThatLoadsUserData()
{
   Method1();
   Method2();
   Method3();
   .....
   Method12();
}

These get executed when the user logs on and each method fetches some data related to the user. I was wondering if making these run in parallel would have any performance benefit because each method ends up calling a query to the same database file. And, if there would be a performance benefit, how would I rewrite this code?

Thanks for your suggestions.

Answer 1

The following code demonstrates a parallel test using a list of Thread and Stopwatch objects. I think this is pretty good method to test with because it guarantees a parallel execution attempt (unlike Parallel.Invoke) and it’s easier to set up than using the ThreadPool IMO.

public static void SomeMethodThatLoadsUserData()
{
    Stopwatch s = new Stopwatch();
    s.Start();

    List<Thread> threads = new List<Thread> {new Thread(Method1), new Thread(Method2)};

    foreach (Thread thread in threads)
    {
        thread.Start();
    }

    foreach (Thread thread in threads)
    {
        thread.Join();
    }

    s.Stop();
    Console.WriteLine("Total: {0} ms", s.ElapsedMilliseconds);

    Console.ReadKey();
}

private static void Method1()
{
    Stopwatch s = new Stopwatch();
    s.Start();
    // do work
    Thread.Sleep(1000);
    s.Stop();
    Console.WriteLine("Method 1: {0} ms", s.ElapsedMilliseconds);
}

private static void Method2()
{
    Stopwatch s = new Stopwatch();
    s.Start();
    // do work
    Thread.Sleep(1000);
    s.Stop();
    Console.WriteLine("Method 2: {0} ms", s.ElapsedMilliseconds);
}

Output:

Method 1: 999 ms
Method 2: 999 ms
Total: 1051 ms

Any time saving will show up when (hopefully) Total is less than the sum of each method.