question: synchronized void sendRoleRequest ( OFControllerRole role , long xid ) throws IOException { Boolean supportsNxRole = ( Boolean ) sw . getAttribute ( IOFSwitch . SWITCH_SUPPORTS_NX_ROLE ) ; if ( ( supportsNxRole != null ) && ! supportsNxRole ) { setSwitchRole ( role , RoleRecvStatus . UNSUPPORTED ) ; } else { pendingXid = sendNiciraRoleRequest ( role , xid ) ; pendingRole = role ; this . roleSubmitTimeNs = System . nanoTime ( ) ; requestPending = true ; } }
target:  Send a role request with the given role to the switch. Send a role request with the given role to the switch and update the pending request and timestamp.