try/catch send in TryPingAsync. fixes #150

src/MySqlConnector/Serialization/MySqlSession.cs

@@ -138,9 +138,14 @@ public async Task ResetConnectionAsync(ConnectionSettings cs, IOBehavior ioBehav
 
 		public async Task<bool> TryPingAsync(IOBehavior ioBehavior, CancellationToken cancellationToken)
 		{
-			await SendAsync(PingPayload.Create(), ioBehavior, cancellationToken).ConfigureAwait(false);
+			// check if client socket is still connected
+			// http://stackoverflow.com/questions/2661764/how-to-check-if-a-socket-is-connected-disconnected-in-c
+			if (m_socket.Poll(1, SelectMode.SelectRead) && m_socket.Available == 0)
+				return false;
+			// client socket is still connected, send ping payload to verify server socket is still connected
 			try
 			{
+				await SendAsync(PingPayload.Create(), ioBehavior, cancellationToken).ConfigureAwait(false);
 				var payload = await ReceiveReplyAsync(ioBehavior, cancellationToken).ConfigureAwait(false);
 				OkPayload.Create(payload);
 				return true;

tests/SideBySide.New/ConnectionPool.cs

@@ -1,6 +1,5 @@
 using System;
 using System.Collections.Generic;
-using System.Data.Common;
 using System.Diagnostics;
 using System.Linq;
 using System.Threading;
@@ -131,6 +130,35 @@ public async Task ExhaustConnectionPoolWithTimeout()
 				connection.Dispose();
 		}
 
+		[Fact]
+		public async Task WaitTimeout()
+		{
+			var csb = AppConfig.CreateConnectionStringBuilder();
+			csb.Pooling = true;
+			csb.MinimumPoolSize = 0;
+			csb.MaximumPoolSize = 1;
+			int serverThread;
+
+			using (var connection = new MySqlConnection(csb.ConnectionString))
+			{
+				await connection.OpenAsync();
+				using (var cmd = connection.CreateCommand())
+				{
+					cmd.CommandText = "SET @@session.wait_timeout=3";
+					await cmd.ExecuteNonQueryAsync();
+				}
+				serverThread = connection.ServerThread;
+			}
+
+			await Task.Delay(TimeSpan.FromSeconds(5));
+
+			using (var connection = new MySqlConnection(csb.ConnectionString))
+			{
+				await connection.OpenAsync();
+				Assert.NotEqual(serverThread, connection.ServerThread);
+			}
+		}
+
 		[Fact]
 		public async Task CharacterSet()
 		{