Imported Upstream version 4.2.0.179

Former-commit-id: 4610231f55806d2a05ed69e5ff3faa7336cc1479

mcs/class/test-helpers/NetworkHelpers.cs

@@ -0,0 +1,22 @@
+using System;
+using System.Net;
+using System.Net.Sockets;
+
+namespace MonoTests.Helpers {
+
+	public static class NetworkHelpers
+	{
+		public static int FindFreePort ()
+		{
+			TcpListener l = new TcpListener(IPAddress.Loopback, 0);
+			l.Start();
+			int port = ((IPEndPoint)l.LocalEndpoint).Port;
+			l.Stop();
+			return port;
+		}
+		public static IPEndPoint LocalEphemeralEndPoint ()
+		{
+			return new IPEndPoint (IPAddress.Loopback, FindFreePort());
+		}
+	}
+}