*TEST* send udp sync. Stop uncontroled and hidden use of IO threads.

Testing this may require several people.

OpenSim/Region/ClientStack/Linden/UDP/LLUDPServer.cs

@@ -1305,7 +1305,8 @@ namespace OpenSim.Region.ClientStack.LindenUDP
             PacketsSentCount++;
 
             // Put the UDP payload on the wire
-            AsyncBeginSend(buffer);
+            //AsyncBeginSend(buffer);
+            SyncSend(buffer);
 
             // Keep track of when this packet was sent out (right now)
             outgoingPacket.TickCount = Environment.TickCount & Int32.MaxValue;

OpenSim/Region/ClientStack/Linden/UDP/OpenSimUDPBase.cs

@@ -375,12 +375,28 @@ namespace OpenMetaverse
 
                     // Synchronous mode waits until the packet callback completes
                     // before starting the receive to fetch another packet
-                    if (!m_asyncPacketHandling)
+//                    if (!m_asyncPacketHandling)
                         AsyncBeginReceive();
                 }
             }
         }
 
+        public void SyncSend(UDPPacketBuffer buf)
+        {
+            try
+            {
+                m_udpSocket.SendTo(
+                    buf.Data,
+                    0,
+                    buf.DataLength,
+                    SocketFlags.None,
+                    buf.RemoteEndPoint
+                    );
+            }
+            catch (SocketException) { }
+            catch (ObjectDisposedException) { }
+        }
+
         public void AsyncBeginSend(UDPPacketBuffer buf)
         {
 //            if (IsRunningOutbound)