I need a slow C# function

Question

For some testing I\'m doing I need a C# function that takes around 10 seconds to execute. It will be called from an ASPX page, but I need the function to eat up CPU time on

Answer 1

For maxing out multiple cores I adjusted @Motti's answer a bit, and got the following:

Enumerable
  .Range(1, Environment.ProcessorCount) // replace with lesser number if 100% usage is not what you are after.
  .AsParallel()
  .Select(i => {
    var end = DateTime.Now + TimeSpan.FromSeconds(10);
    while (DateTime.Now < end)
      /*nothing here */ ;
    return i;
  })
  .ToList(); // ToList makes the query execute.