mcs/class/test-helpers/NetworkHelpers.cs

   1 using System;
   2 using System.Net;
   3 using System.Net.Sockets;
   4 using System.Collections.Generic;
   5
   6 namespace MonoTests.Helpers {
   7
   8         public static class NetworkHelpers
   9         {
  10                 static Random rndPort = new Random ();
  11                 static HashSet<int> portsTable = new HashSet<int> ();
  12
  13                 public static int FindFreePort ()
  14                 {
  15                         return LocalEphemeralEndPoint ().Port;
  16                 }
  17
  18                 public static IPEndPoint LocalEphemeralEndPoint ()
  19                 {
  20                         int counter = 0;
  21
  22                         while (counter < 1000) {
  23                                 var testingPort = rndPort.Next (10000, 60000);
  24
  25                                 var ep = new IPEndPoint (IPAddress.Loopback, testingPort);
  26
  27                                 lock (portsTable) {
  28                                         if (portsTable.Contains (testingPort))
  29                                                 continue;
  30
  31                                         ++counter;
  32
  33                                         try {
  34                                                 using (var socket = new Socket (ep.AddressFamily, SocketType.Stream, ProtocolType.Tcp)) {
  35                                                         socket.Bind (ep);
  36                                                         socket.Close ();
  37                                                 }
  38
  39                                                 portsTable.Add (testingPort);
  40                                                 return ep;
  41                                         } catch (SocketException) { }
  42                                 }
  43                         }
  44
  45                         throw new ApplicationException ($"Could not find available local port after {counter} retries");
  46                 }
  47         }
  48 }