avoid race condition

TransitTunnel.cpp

@@ -48,6 +48,7 @@ namespace tunnel
 		TunnelMessageBlock block;
 		block.deliveryType = eDeliveryTypeLocal;
 		block.data = msg;
+		std::unique_lock<std::mutex> l(m_SendMutex);
 		m_Gateway.SendTunnelDataMsg (block);
 	}		
 
@@ -81,4 +82,4 @@ namespace tunnel
 		}	
 	}		
 }
-}
+}

TransitTunnel.h

@@ -2,6 +2,7 @@
 #define TRANSIT_TUNNEL_H__
 
 #include <inttypes.h>
+#include <mutex>
 #include "aes.h"
 #include "I2NPProtocol.h"
 #include "TunnelEndpoint.h"
@@ -55,6 +56,7 @@ namespace tunnel
 			
 		private:
 
+			std::mutex m_SendMutex;
 			TunnelGateway m_Gateway;
 	};