| Platform SDK: Quality of Service |
The TcModifyFlow function modifies an existing flow. When calling TcModifyFlow, new flowspec parameters and any traffic control objects should be filled.
Traffic control clients that have registered a ModifyFlowComplete handler (a mechanism for allowing traffic control to call the ClModifyFlowComplete callback function in order to alert clients of completed flow modifications) can expect a return value of ERROR_SIGNAL_PENDING.
DWORD TcModifyFlow( HANDLE FlowHandle, PTC_GEN_FLOW pGenericFlow );
| Error codes | Description |
|---|---|
| NO_ERROR | The function executed without errors. |
| ERROR_SIGNAL_PENDING | The function is being executed asynchronously; the client will be called back through the client-exposed ClModifyFlowComplete function when the flow has been added, or when the process has been completed. |
| ERROR_INVALID_HANDLE | The interface handle is invalid. |
| ERROR_NOT_ENOUGH_MEMORY | The system is out of memory. |
| ERROR_INVALID_PARAMETER | A parameter is invalid. |
| ERROR_INVALID_SERVICE_TYPE | An unspecified or bad intserv service type has been provided. |
| ERROR_INVALID_TOKEN_RATE | An unspecified or bad TokenRate value has been provided. |
| ERROR_INVALID_PEAK_RATE | The PeakBandwidth value is invalid. |
| ERROR_INVALID_SD_MODE | The ShapeDiscardMode is invalid. |
| ERROR_INVALID_QOS_PRIORITY | The priority value is invalid. |
| ERROR_INVALID_TRAFFIC_CLASS | The traffic class value is invalid. |
| ERROR_NO_SYSTEM_RESOURCES | There are not enough resources to accommodate the requested flow. |
| ERROR_TC_OBJECT_LENGTH_INVALID | Bad length specified for the TC objects. |
| ERROR_INVALID_DIFFSERV_FLOW | Applies to Diffserv flows. Indicates that the QOS_DIFFSERV object was passed with an invalid parameter. |
| ERROR_DS_MAPPING_EXISTS | Applies to Diffserv flows. Indicates that the QOS_DIFFSERV_RULE specified in TC_GEN_FLOW already applies to an existing flow on the interface. |
| ERROR_INVALID_SHAPE_RATE | The QOS_OBJECT_SHAPING_RATE was passed with an invalid ShapeRate. |
| ERROR_INVALID_DS_CLASS | QOS_OBJECT_DS_CLASS is invalid. |
| ERROR_NETWORK_UNREACHABLE | The network cable is not plugged into the adapter. |
If the TcModifyFlow function returns ERROR_SIGNAL_PENDING, the ClModifyFlowComplete function will be called on a different thread than the thread that called the TcModifyFlow function.
Note Use of the TcModifyFlow function requires administrative privilege.
Windows NT/2000: Requires Windows 2000.
Windows 95/98: Unsupported.
Header: Declared in Traffic.h.
Library: Use Traffic.lib.