这是一个可以 ping 多个端点的异步工作者。您可以 Start() 或 Stop() 心跳工作者并订阅以下事件：
- PingUp（当端点关闭时边缘触发）
- PingDown（当端点启动时边缘触发）
- PulseStarted
- 脉冲结束
- Ping 错误
-
public class NetworkHeartbeat
{
private static object lockObj = new object();
public bool Running { get; private set; }
public int PingTimeout { get; private set; }
public int HeartbeatDelay { get; private set; }
public IPAddress[] EndPoints { get; private set; }
public int Count => EndPoints.Length;
public PingReply[] PingResults { get; private set; }
private Ping[] Pings { get; set; }
public NetworkHeartbeat(IEnumerable<IPAddress> hosts, int pingTimeout, int heartbeatDelay)
{
PingTimeout = pingTimeout;
HeartbeatDelay = heartbeatDelay;
EndPoints = hosts.ToArray();
PingResults = new PingReply[EndPoints.Length];
Pings = EndPoints.Select(h => new Ping()).ToArray();
}
public async void Start()
{
if (!Running)
{
try
{
Debug.WriteLine("Heartbeat : starting ...");
// set up the tasks
var chrono = new Stopwatch();
var tasks = new Task<PingReply>[Count];
Running = true;
while (Running)
{
// set up and run async ping tasks
OnPulseStarted(DateTime.Now, chrono.Elapsed);
chrono.Restart();
for (int i = 0; i < Count; i++)
{
tasks[i] = PingAndUpdateAsync(Pings[i], EndPoints[i], i);
}
await Task.WhenAll(tasks);
for (int i = 0; i < tasks.Length; i++)
{
var pingResult = tasks[i].Result;
if (pingResult != null)
{
if (PingResults[i] == null)
{
if (pingResult.Status == IPStatus.Success)
OnPingUp(i);
}
else if (pingResult.Status != PingResults[i].Status)
{
if (pingResult.Status == IPStatus.Success)
OnPingUp(i);
else if (PingResults[i].Status == IPStatus.Success)
OnPingDown(i);
}
}
else
{
if (PingResults[i] != null && PingResults[i].Status == IPStatus.Success)
OnPingUp(i);
}
PingResults[i] = tasks[i].Result;
Debug.WriteLine("> Ping [" + PingResults[i].Status.ToString().ToUpper() + "] at " + EndPoints[i] + " in " + PingResults[i].RoundtripTime + " ms");
}
OnPulseEnded(DateTime.Now, chrono.Elapsed);
// heartbeat delay
var delay = Math.Max(0, HeartbeatDelay - (int)chrono.ElapsedMilliseconds);
await Task.Delay(delay);
}
Debug.Write("Heartbeat : stopped");
}
catch (Exception)
{
Debug.Write("Heartbeat : stopped after error");
Running = false;
throw;
}
}
else
{
Debug.WriteLine("Heartbeat : already started ...");
}
}
public void Stop()
{
Debug.WriteLine("Heartbeat : stopping ...");
Running = false;
}
private async Task<PingReply> PingAndUpdateAsync(Ping ping, IPAddress epIP, int epIndex)
{
try
{
return await ping.SendPingAsync(epIP, PingTimeout);
}
catch (Exception ex)
{
Debug.Write("-[" + epIP + "] : error in SendPing()");
OnPingError(epIndex, ex);
return null;
}
}
// Event on ping errors
public event EventHandler<PingErrorEventArgs> PingError;
public class PingErrorEventArgs : EventArgs
{
public int EndPointIndex { get; private set; }
public Exception InnerException { get; private set; }
public PingErrorEventArgs(int epIndex, Exception ex)
{
EndPointIndex = epIndex;
InnerException = ex;
}
}
private void OnPingError(int epIndex, Exception ex) => PingError?.Invoke(this, new PingErrorEventArgs(epIndex, ex));
// Event on ping Down
public event EventHandler<int> PingDown;
private void OnPingDown(int epIndex)
{
Debug.WriteLine("# Ping [DOWN] at " + EndPoints[epIndex]);
PingDown?.Invoke(this, epIndex);
}
// Event on ping Up
public event EventHandler<int> PingUp;
private void OnPingUp(int epIndex)
{
Debug.WriteLine("# Ping [UP] at " + EndPoints[epIndex] );
PingUp?.Invoke(this, epIndex);
}
// Event on pulse started
public event EventHandler<PulseEventArgs> PulseStarted;
public class PulseEventArgs : EventArgs
{
public DateTime TimeStamp { get; private set; }
public TimeSpan Delay { get; private set; }
public PulseEventArgs(DateTime date, TimeSpan delay)
{
TimeStamp = date;
Delay = delay;
}
}
private void OnPulseStarted(DateTime date, TimeSpan delay)
{
Debug.WriteLine("# Heartbeat [PULSE START] after " + (int)delay.TotalMilliseconds + " ms");
PulseStarted?.Invoke(this, new PulseEventArgs(date, delay));
}
// Event on pulse ended
public event EventHandler<PulseEventArgs> PulseEnded;
private void OnPulseEnded(DateTime date, TimeSpan delay)
{
PulseEnded?.Invoke(this, new PulseEventArgs(date, delay));
Debug.WriteLine("# Heartbeat [PULSE END] after " + (int)delay.TotalMilliseconds + " ms");
}
}