定时器可以提前吗？

Question

显然，System.Threading.Timer回调应该会延迟一点。但是，它可以提早召唤吗？

例如，如果您启动秒表并安排计时器在1000毫秒内运行回调，秒表是否可能在回调中显示999？或者我们可以依靠它必须显示1000或更多的事实？

public sealed class EarlyTiming : IDisposable
{
    public EarlyTiming()
    {
        stopwatch = new Stopwatch();
        stopwatch.Start();

        timer = new Timer(TimerCallback, null, 1000, Timeout.Infinite);
    }

    public void Dispose()
    {
        timer.Dispose();
    }

    private readonly Timer timer;
    private readonly Stopwatch stopwatch;

    private void TimerCallback(object state)
    {
        var elapsedMs = stopwatch.ElapsedMilliseconds;

        if (elapsedMs < 1000)
            Console.WriteLine("It was early! (" + elapsedMs + " ms)");

        try
        {
            stopwatch.Restart();
            timer.Change(1000, Timeout.Infinite);
        }
        catch (ObjectDisposedException) { }
    }
}