如何将突发事件缓冲为较少的结果操作

时间:2015-07-02 10:20:01

标签: c# async-await

我想将多个事件简化为单个延迟操作。在发生一些触发后,我预计会出现更多类似的触发器,但我不想重复产生的延迟动作。行动等待,以便有机会完​​成爆发 问题:如何以优雅的可重复使用方式进行?
直到现在我使用了一个属性来标记事件并触发延迟操作,如下所示:

public  void SomeMethod()
    {
        SomeFlag = true; //this will intentionally return to the caller before completing the resulting buffered actions.
    }
    private bool someFlag;
    public bool SomeFlag
    {
        get { return someFlag; }
        set
        {
            if (someFlag != value)
            {
                someFlag = value;
                if (value)
                    SomeDelayedMethod(5000);
            }
        }
    }

    public async void SomeDelayedMethod(int delay)
    {
        //some bufferred work.
        await Task.Delay(delay);
        SomeFlag = false;
    }

下面是一个较短的方法,但仍然不是通用的或可重用的...我想要一些简洁的包装动作和标志,并保持功能(在执行完成之前返回调用者(如今))。 我还需要能够将对象引用传递给此操作)

 public void SerializeAccountsToConfig()
    {
        if (!alreadyFlagged)
        {
            alreadyFlagged = true;
            SerializeDelayed(5000, Serialize);
        }
    }
    public async void SerializeDelayed(int delay, Action whatToDo)
    {
        await Task.Delay(delay);
        whatToDo();
    }

    private bool alreadyFlagged;
    private void Serialize()
    {
        //some buferred work.
        //string json = JsonConvert.SerializeObject(Accounts, Formatting.Indented);
        //Settings1.Default.Accounts = json;
        //Settings1.Default.Save();
        alreadyFlagged = false;
    }

3 个答案:

答案 0 :(得分:4)

这是一个线程安全且可重复使用的解决方案。

您可以创建DelayedSingleAction的实例,并在构造函数中传递您想要执行的操作。我相信这是线程安全的,尽管在启动操作之前它会重新启动计时器的风险很小,但我认为无论解决方案是什么,风险都会存在。

public class DelayedSingleAction
{
    private readonly Action _action;
    private readonly long _millisecondsDelay;
    private long _syncValue = 1;
    public DelayedSingleAction(Action action, long millisecondsDelay)
    {
        _action = action;
        _millisecondsDelay = millisecondsDelay;
    }

    private Task _waitingTask = null;
    private void DoActionAndClearTask(Task _)
    {
        Interlocked.Exchange(ref _syncValue, 1);
        _action();
    }

    public void PerformAction()
    {
        if (Interlocked.Exchange(ref _syncValue, 0) == 1)
        {
            _waitingTask = Task.Delay(TimeSpan.FromMilliseconds(_millisecondsDelay))
                               .ContinueWith(DoActionAndClearTask);
        }
    }

    public Task Complete()
    {
        return _waitingTask ?? Task.FromResult(0);
    }
}

请参阅此dotnetfiddle以获取从多个线程连续调用一个操作的示例。

https://dotnetfiddle.net/el14wZ

答案 1 :(得分:2)

由于您对RX这里的简单控制台应用示例感兴趣:

javac -sourcepath . path/to/Main.java

答案 2 :(得分:0)

基于Andrew提出的解决方案,这是一个更通用的解决方案 延迟行动的声明和实例创建:

public DelayedSingleAction<Account> SendMailD;

在函数内或构造函数中创建实例(这可以是每个处理不同对象的此类操作的集合):

SendMailD = new DelayedSingleAction<Account>(SendMail, AccountRef, 5000);

反复调用此操作

SendMailD.PerformAction();

发送邮件是您将要执行的操作&#34;爆发控制&#34;。它的签名匹配:

public int SendMail(Account A)
    {}

这是更新的课程

    public class DelayedSingleAction<T>
{
    private readonly Func<T, int> actionOnObj;
    private T tInstance;
    private readonly long millisecondsDelay;
    private long _syncValue = 1;

    public DelayedSingleAction(Func<T, int> ActionOnObj, T TInstance, long MillisecondsDelay)
    {
        actionOnObj = ActionOnObj;
        tInstance = TInstance;
        millisecondsDelay = MillisecondsDelay;
    }

    private Task _waitingTask = null;

    private void DoActionAndClearTask(Task _)
    {
        Console.WriteLine(string.Format("{0:h:mm:ss.fff} DelayedSingleAction Resetting SyncObject: Thread {1} for {2}", DateTime.Now, System.Threading.Thread.CurrentThread.ManagedThreadId, tInstance));
        Interlocked.Exchange(ref _syncValue, 1);
        actionOnObj(tInstance);
    }

    public void PerformAction()
    {
        if (Interlocked.Exchange(ref _syncValue, 0) == 1)
        {
            Console.WriteLine(string.Format("{0:h:mm:ss.fff} DelayedSingleAction Starting the timer: Thread {1} for {2}", DateTime.Now, System.Threading.Thread.CurrentThread.ManagedThreadId, tInstance));
            _waitingTask = Task.Delay(TimeSpan.FromMilliseconds(millisecondsDelay)).ContinueWith(DoActionAndClearTask);
        }
    }

    public Task Complete()
    {
        return _waitingTask ?? Task.FromResult(0);
    }
}