我对计时器有一些问题。
这是我的代码:
_uploadHelper = new DataProcessorUploadHelper((sender, args) => Start())
public void Start()
{
Task.Factory.StartNew(() =>
{
if (UploadHelper.UploadState == UploadState.UploadOn)
{
UploadHelper.IncrementSavingRequestCounter();
}
else
{
UploadHelper.StopTimer();
lock (_lock)
{
UploadHelper.UploadState = UploadState.UploadOn;
UploadData();
UploadHelper.UploadState = UploadState.UploadOff;
}
UploadHelper.StartTimer();
}
});
}
上传状态以这种方式实现
private int _uploadState;
public UploadState UploadState
{
get { return (UploadState)_uploadState; }
set { Interlocked.Exchange(ref _uploadState, (int)value); }
}
我正在使用System.Timers.Timer 它应该以 10 分钟的间隔调用 Start 方法(在我的帮助程序类中实现)。
private Timer _intervalTimer;
private long _savingRequestsCounter;
public DataProcessorUploadHelper(ElapsedEventHandler callback)
{
UploadState = UploadState.UploadOff;;
_intervalTimer = new Timer();
_intervalTimer.Interval = UploadIntervalTimeSpan.TotalMilliseconds;
_intervalTimer.Elapsed += callback;
_intervalTimer.Start();
_intervalTimer.Enabled = true;
}
public void StartTimer()
{
_intervalTimer.Start();
}
public void ResetTimer()
{
_intervalTimer.Start();
_intervalTimer.Stop();
}
public void StopTimer()
{
_intervalTimer.Stop();
}
public void IncrementSavingRequestCounter()
{
Interlocked.Increment(ref _savingRequestsCounter);
}
public void DecrementSavingRequestCounter()
{
Interlocked.Decrement(ref _savingRequestsCounter);
}
此外,当用户单击特定按钮时,也会调用此方法。
还有我的麻烦。
计时器调用 Start 方法 => UploadHelper.UploadState = UploadState.UploadOn。
此外,应由_lock锁定。
但是当用户在上传数据()期间单击时我看到 UploadState = UploadState.UploadOff并且未锁定。
这段代码有什么问题?
为什么计时器调用此方法时状态不同?
-
"...而且应该被_lock锁定"
是的,如果在您的情况下_lock被声明为静态。
由于计时器的经过事件导致在单独的线程中调用 UploadData(),因此_lock(如果不是静态)每次都不是同一个_lock并且不用作同步对象。
- 如果您的计时器来自 System.Timers,则还有另一种同步方法:请参阅同步对象