npgsql · glenebob · Dec 4, 2013 · Dec 3, 2013 · Dec 3, 2013
diff --git a/src/Npgsql/NpgsqlError.cs b/src/Npgsql/NpgsqlError.cs
@@ -287,6 +287,11 @@ internal NpgsqlError(ProtocolVersion protocolVersion, Stream stream)
 									_routine = PGUtil.ReadString(stream);
 									;
 									break;
+								default:
+									// Unknown error field; consume and discard.
+									PGUtil.ReadString(stream);
+									;
+									break;
 
 							}
 						}

diff --git a/src/Npgsql/NpgsqlState.cs b/src/Npgsql/NpgsqlState.cs
@@ -357,9 +357,9 @@ internal IEnumerable<IServerResponseObject> ProcessBackendResponsesEnum(NpgsqlCo
             {
             // Process commandTimeout behavior.
 
-            if ((context.Mediator.CommandTimeout > 0) &&
-                (!context.Socket.Poll(1000000*context.Mediator.CommandTimeout, SelectMode.SelectRead)))
-            {
+            if ((context.Mediator.CommandTimeout > 0) &&
+                    (!CheckForContextSocketAvailability(context, SelectMode.SelectRead)))
+            {
                 // If timeout occurs when establishing the session with server then
                 // throw an exception instead of trying to cancel query. This helps to prevent loop as CancelRequest will also try to stablish a connection and sends commands.
                 if (!((this is NpgsqlStartupState || this is NpgsqlConnectedState || context.CancelRequestCalled)))
@@ -596,6 +596,46 @@ protected IEnumerable<IServerResponseObject> ProcessBackendResponses_Ver_2(Npgsq
             }
         }
 
+        /// <summary>
+        /// Checks for context socket availability.
+        /// Socket.Poll supports integer as microseconds parameter.
+        /// This limits the usable command timeout value
+        /// to 2,147 seconds: (2,147 x 1,000,000 less than  max_int).
+        /// In order to bypass this limit, the availability of
+        /// the socket is checked in 2,147 seconds cycles
+        /// </summary>
+        /// <returns><c>true</c>, if for context socket availability was checked, <c>false</c> otherwise.</returns>
+        /// <param name="context">Context.</param>
+        /// <param name="selectMode">Select mode.</param>
+        internal bool CheckForContextSocketAvailability (NpgsqlConnector context, SelectMode selectMode)
+        {
+            /* Socket.Poll supports integer as microseconds parameter.
+             * This limits the usable command timeout value
+             * to 2,147 seconds: (2,147 x 1,000,000 < max_int).
+             */
+            const int limitOfSeconds = 2147;
+
+            bool socketPoolResponse = false;
+
+            // Because the backend's statement_timeout parameter has been set to context.Mediator.CommandTimeout,
+            // we will give an extra 5 seconds because we'd prefer to receive a timeout error from PG
+            // than to be forced to start a new connection and send a cancel request.
+            // The result is that a timeout could take 5 seconds too long to occur, but if everything
+            // is healthy, that shouldn't happen.
+            int secondsToWait = context.Mediator.CommandTimeout + 5;
+
+            /* In order to bypass this limit, the availability of
+             * the socket is checked in 2,147 seconds cycles
+             */
+            while ((secondsToWait > limitOfSeconds) && (!socketPoolResponse))
+            {
+                socketPoolResponse = context.Socket.Poll (1000000 * limitOfSeconds, selectMode);
+                secondsToWait -= limitOfSeconds;
+            }
+
+            return socketPoolResponse || context.Socket.Poll (1000000 * secondsToWait, selectMode);
+        }
+
         private enum BackEndMessageCode
         {
             IO_ERROR = -1, // Connection broken. Mono returns -1 instead of throwing an exception as ms.net does.