From 65df583f0c7407df22fd722052f9815eed516456 Mon Sep 17 00:00:00 2001
From: Bruce Wayne <admin@bige0.com>
Date: Sat, 25 Apr 2020 12:27:07 +0800
Subject: [PATCH] Refine TCPing

---
 Netch/Models/Server.cs | 25 +++----------------------
 Netch/Utils/Utils.cs   | 26 +++++++++++++++++++++++++-
 2 files changed, 28 insertions(+), 23 deletions(-)

diff --git a/Netch/Models/Server.cs b/Netch/Models/Server.cs
index b60deb88..9bef4847 100644
--- a/Netch/Models/Server.cs
+++ b/Netch/Models/Server.cs
@@ -1,7 +1,4 @@
 using System;
-using System.Diagnostics;
-using System.Net;
-using System.Net.Sockets;
 using System.Threading.Tasks;
 
 namespace Netch.Models
@@ -181,27 +178,11 @@ namespace Netch.Models
                 var list = new Task<int>[3];
                 for (var i = 0; i < 3; i++)
                 {
-                    list[i] = Task.Run(() =>
+                    list[i] = Task.Run(async () =>
                     {
                         try
                         {
-                            using (var client = new Socket(SocketType.Stream, ProtocolType.Tcp))
-                            {
-                                var watch = new Stopwatch();
-                                watch.Start();
-
-                                var task = client.BeginConnect(new IPEndPoint(destination, Port), result =>
-                                {
-                                    watch.Stop();
-                                }, 0);
-
-                                if (task.AsyncWaitHandle.WaitOne(1000))
-                                {
-                                    return (int)watch.ElapsedMilliseconds;
-                                }
-
-                                return 1000;
-                            }
+                            return await Utils.Utils.TCPingAsync(destination, Port);
                         }
                         catch (Exception)
                         {
@@ -210,7 +191,7 @@ namespace Netch.Models
                     });
                 }
 
-                Task.WaitAll(list);
+                Task.WaitAll(list[0], list[1], list[2]);
 
                 var min = Math.Min(list[0].Result, list[1].Result);
                 min = Math.Min(min, list[2].Result);
diff --git a/Netch/Utils/Utils.cs b/Netch/Utils/Utils.cs
index f4bb0d65..efe0f693 100644
--- a/Netch/Utils/Utils.cs
+++ b/Netch/Utils/Utils.cs
@@ -1,5 +1,10 @@
-using System.Diagnostics;
+using System;
+using System.Diagnostics;
 using System.IO;
+using System.Net;
+using System.Net.Sockets;
+using System.Threading;
+using System.Threading.Tasks;
 
 namespace Netch.Utils
 {
@@ -40,5 +45,24 @@ namespace Netch.Utils
 
             return false;
         }
+
+        public static async Task<int> TCPingAsync(IPAddress ip, int port, int timeout = 1000, CancellationToken ct = default)
+        {
+            using var client = new TcpClient(ip.AddressFamily);
+            var task = client.ConnectAsync(ip, port);
+
+            var stopwatch = new Stopwatch();
+            stopwatch.Start();
+
+            var resTask = await Task.WhenAny(Task.Delay(timeout, ct), task);
+
+            stopwatch.Stop();
+            if (resTask == task && client.Connected)
+            {
+                var t = Convert.ToInt32(stopwatch.Elapsed.TotalMilliseconds);
+                return t;
+            }
+            return timeout;
+        }
     }
 }