static void Main(string[] args)
        {
            //Task启动等待对象
            object taskStartSyncRoot = new object();

            //多线程等待对象
            object syncRoot = new object();

            //多线程全部进入等待状态对象
            object parallelStartSyncRoot = new object();

            lock (taskStartSyncRoot)
            {
                Task.Factory.StartNew(() =>
                {
                    lock (parallelStartSyncRoot)
                    {
                        lock (taskStartSyncRoot)
                        {
                            //通知Task已经启动完毕
                            Monitor.Pulse(taskStartSyncRoot);
                        }

                        Console.WriteLine("Wait all parallel task started.");

                        //等待所有并行任务已经进行等待状态,并释放parallelStartSyncRoot锁
                        Monitor.Wait(parallelStartSyncRoot);

                        lock (syncRoot)
                        {
                            //通知所有并行任务syncRoot已经释放
                            Monitor.PulseAll(syncRoot);
                            Console.WriteLine("All syncRoot waiter notified.");
                        }
                    }
                });

                //等待Task启动完毕,并释放taskStartSyncRoot对象锁
                Monitor.Wait(taskStartSyncRoot);
            }

            //并行等待任务计数器，当该计数器为10时，则通知所有并行任务已经进入等待状态
            int counter = 0;

            Parallel.For(0, 10, (i) =>
            {
                lock (syncRoot)
                {
                    //使用原子锁增加counter,当计数器为10时代表所有并行任务已经启动
                    if (Interlocked.Increment(ref counter) == 10)
                    {
                        lock (parallelStartSyncRoot)
                        {
                            //通知并行任务已经全部启动，并释放parallelStartSyncRoot锁
                            Monitor.Pulse(parallelStartSyncRoot);
                        }
                    }

                    Console.WriteLine(string.Format("[{0}] Waiting For syncRoot notify.", i));

                    //等待syncRoot通知，并释放syncRoot锁
                    Monitor.Wait(syncRoot);
                    Console.WriteLine(string.Format("[{0}] syncRoot notify received.", i));
                }
            });

            Console.Read();
        }