C# 异步专题（async/await）

  private static async Task<long> SumAsync()
        {
            Console.WriteLine($"SumAsync 111 start ManagedThreadId={Thread.CurrentThread.ManagedThreadId}");
            long result = 0;

            await Task.Run(() =>
            {
                for (int k = 0; k < 10; k++)
                {
                    Console.WriteLine($"SumAsync {k} await Task.Run ManagedThreadId={Thread.CurrentThread.ManagedThreadId}");
                    Thread.Sleep(1000);
                }
                for (long i = 0; i < 999_999_999; i++)
                {
                    result += i;
                }
            });

            Console.WriteLine($"SumFactory 111   end ManagedThreadId={Thread.CurrentThread.ManagedThreadId}");
            await Task.Run(() =>
            {
                for (int k = 0; k < 10; k++)
                {
                    Console.WriteLine($"SumAsync {k} await Task.Run ManagedThreadId={Thread.CurrentThread.ManagedThreadId}");
                    Thread.Sleep(1000);
                }
                for (long i = 0; i < 999999999; i++)
                {
                    result += i;
                }
            });
            Console.WriteLine($"SumFactory 111   end ManagedThreadId={Thread.CurrentThread.ManagedThreadId}");

            await Task.Run(() =>
            {
                for (int k = 0; k < 10; k++)
                {
                    Console.WriteLine($"SumAsync {k} await Task.Run ManagedThreadId={Thread.CurrentThread.ManagedThreadId}");
                    Thread.Sleep(1000);
                }

                for (long i = 0; i < 999999999; i++)
                {
                    result += i;
                }
            });

            Console.WriteLine($"SumFactory 111   end ManagedThreadId={Thread.CurrentThread.ManagedThreadId}");

            return result;
        }