added mutex lock for "get config"

ndb/include/transporter/TransporterRegistry.hpp:
  added comment

ndb/include/transporter/TransporterRegistry.hpp

@@ -101,6 +101,11 @@ public:
 		      unsigned maxTransporters = MAX_NTRANSPORTERS, 
 		      unsigned sizeOfLongSignalMemory = 100);
 
+  /**
+   * this handle will be used in the client connect thread
+   * to fetch information on dynamic ports.  The old handle
+   * id destroyed, and this is destroyed by the destructor
+   */
   void set_mgm_handle(NdbMgmHandle h);
   NdbMgmHandle get_mgm_handle(void) { return m_mgm_handle; };
 

ndb/src/mgmsrv/Services.cpp

@@ -572,11 +572,13 @@ MgmApiSession::getConfig_common(Parser_t::Context &,
     }
   }  
   
+  NdbMutex_Lock(m_mgmsrv.m_configMutex);
   const ConfigValues * cfg = &conf->m_configValues->m_config;
   const Uint32 size = cfg->getPackedSize();
   
   UtilBuffer src;
   cfg->pack(src);
+  NdbMutex_Unlock(m_mgmsrv.m_configMutex);
   
   BaseString str;
   int res = base64_encode(src, str);