C# Stopwatch 使用

 static IEnumerable<int> SampleData()
    {
      const int arraySize = 100000000;
      var r = new Random();
      return Enumerable.Range(0, arraySize).Select(x => r.Next(140)).ToList();
    }

    static void IntroParallel()
    {
      var data = SampleData();

      var watch = new Stopwatch();

      watch.Start();
      var q1 = (from x in data
                where Math.Log(x) < 4
                select x).Average();
      watch.Stop();
      Console.WriteLine("sync {0}, result: {1}", watch.ElapsedMilliseconds, q1);

      watch.Reset();
      watch.Start();
      var q2 = (from x in Partitioner.Create(data).AsParallel()
                where Math.Log(x) < 4
                select x).Average();
      watch.Stop();
      Console.WriteLine("async {0}, result: {1}", watch.ElapsedMilliseconds, q2);
    }