TipcConnGmdMsgDelete

TipcConnGmdMsgDelete — delete a message from GMD area after a GMD failure on a connection

Synopsis

T_BOOL TipcConnGmdMsgDelete(conn, msg) 
T_IPC_CONN conn; 
T_IPC_MSG msg;

Arguments

Return Values

TRUE if the guaranteed message was successfully deleted from the GMD area of the connection, FALSE otherwise.

Diagnostics

If TipcConnGmdMsgDelete fails, it returns FALSE and sets the global SmartSockets error number to one of:

T_ERR_NULL_PTR — conn was null or msg was null

T_ERR_MSG_INVALID — msg was not a valid message

T_ERR_VAL_INVALID — the connection is not set up for GMD (TipcConnGmdFileCreate must be called before TipcConnGmdMsgDelete) or the message was not previously sent with GMD

T_ERR_DOESNT_EXIST — msg could not be found in the GMD area for conn

T_ERR_C — a C error has occurred. Call the function TutErrNumGetC to obtain the related C-specific error value. This error number occurs if TipcConnGmdMsgDelete has a problem updating the GMD files.

Description

TipcConnGmdMsgDelete deletes a message after a GMD failure on a connection. TipcConnGmdMsgDelete is intended to be used from a GMD_FAILURE connection process callback to terminate GMD for the message.

When a GMD_FAILURE message is processed by a sender, one of two scenarios is possible:

The standard callback TipcCbConnProcessGmdFailure uses TipcConnGmdMsgDelete to delete failed messages. See TipcCbConnProcessGmdFailure and TipcCbSrvProcessGmdFailure for more information on processing GMD_FAILURE messages.

Caution

The T_ENTRY declaration specifier is required in the definition of all callback functions as well as their prototypes.

See Also

Examples

This example creates a connection process callback for GMD_FAILURE messages which silently deletes the message that failed (this callback is essentially a silent version of TipcCbConnProcessGmdFailure). The existing callback TipcCbConnProcessGmdFailure is destroyed to avoid interfering with the new callback:

void T_ENTRY my_gmd_failure_cb(conn, data, arg) 
T_IPC_CONN conn; 
T_IPC_CONN_PROCESS_CB_DATA data; 
T_CB_ARG arg; /* not used */ 
{ 
  T_IPC_MSG failed_msg; 
 
  /* go to the first field of the GMD_FAILURE message */ 
  if (!TipcMsgSetCurrent(data->msg, 0)) { 
    return;  /* error */ 
  } 
 
  /* read the first field of the GMD_FAILURE message, which is */ 
  /* the message where GMD failed */ 
  if (!TipcMsgNextMsg(data->msg, &failed_msg)) 
    return;  /* error */ 
  } 
 
  /* terminate the sender’s knowledge about the message for GMD */ 
  if (!TipcConnGmdMsgDelete(conn, failed_msg)) { 
    return;  /* error */ 
  } 
 
} /* my_gmd_failure_cb */ 
 
/* =========================================================== */ 
/*...code from calling function is below */ 
 
T_IPC_MT mt; 
T_CB cb; 
 
mt = TipcMtLookupByNum(T_MT_GMD_FAILURE); 
if (mt == NULL) { 
  return;  /* error */ 
} 
 
/* create connection process callback for GMD_FAILURE messages */ 
if (TipcConnProcessCbCreate(conn, mt, my_gmd_failure_cb, NULL) 
    == NULL) { 
  return;  /* error */ 
} 
 
/* destroy standard callback for GMD_FAILURE messages */ 
cb = TipcConnProcessCbLookup(conn, mt,  
                             TipcCbConnProcessGmdFailure, NULL); 
if (cb == NULL) { 
  return;  /* error */ 
} 
 
if (!TutCbDestroy(cb)) { 
  return;  /* error */ 
}