C# 任务、线程、同步（二）

取消架构

1、Parallel.For()方法的取消

 

 static void CancelParallelLoop()
        {
            var cts = new CancellationTokenSource();
            cts.Token.Register(() => Console.WriteLine("*** token canceled"));

            cts.CancelAfter(200);

            try
            {
                ParallelLoopResult result = Parallel.For(0, 100, new ParallelOptions() { CancellationToken = cts.Token },
                    x => {
                        Console.WriteLine("loop {0} started", x);
                        int sum = 0;
                        for (int i = 0; i < 100; i++)
                        {
                            Thread.Sleep(2);
                            sum += i;
                        }
                        Console.WriteLine("loop {0} finished", x);
                    });
            }
            catch (Exception ex) 
            {
                Console.WriteLine(ex.Message);
            }
        }

2、任务的取消

 static void CancelTask()
        {
            var cts = new CancellationTokenSource();
            cts.Token.Register(() => Console.WriteLine("*** task cancelled"));
            cts.CancelAfter(500);

            Task t1 = Task.Run(() => {
                Console.WriteLine("in task ");
                for (int i = 0; i < 20; i++)
                {
                    Thread.Sleep(50);
                    CancellationToken token = cts.Token;
                    if(token.IsCancellationRequested)
                    {
                        Console.WriteLine("cancelling was requested, cancelling from within the task");
                        token.ThrowIfCancellationRequested();
                        break;
                    }
                    Console.WriteLine("in loop");
                }
                Console.WriteLine("task finished without cancellation");
            },cts.Token);
            try
            {
                t1.Wait();
            }
            catch (AggregateException ex)
            {
                Console.WriteLine("exception: {0}, {1}", ex.GetType().Name, ex.Message);
                foreach (var innerException in ex.InnerExceptions)
                {
                    Console.WriteLine("inner excepion: {0}, {1}", ex.InnerException.GetType().Name, ex.InnerException.Message);
                }
            }
        }