TipcSrvGmdMsgStatus

TRUE if the poll for GMD status was successfully initiated, FALSE otherwise.

Diagnostics

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

Description

TipcSrvGmdMsgStatus polls for the GMD status of msg by sending a GMD_STATUS_CALL message to RTserver. RTserver responds by sending back a GMD_STATUS_RESULT message. The response should come back very quickly. The polling RTclient can use functions such as TipcSrvMsgSearchType to get the response.

When RTserver routes a message for GMD, it keeps track of which RTclients should receive the message and the status of GMD to each of these RTclients. TipcSrvGmdMsgStatus is intended to be used from a GMD_FAILURE connection process callback to query GMD status for the message.

If RTserver does not have an in-memory GMD record of msg, RTserver silently ignores the GMD_STATUS_CALL message and no GMD_STATUS_RESULT message is returned. This indicates that one of these has happened:

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

Caution

TipcSrvGmdMsgStatus is usually only used from a GMD_FAILURE process callback, but it can be called at any time by advanced applications which wish to poll for GMD status.

TipcSrvGmdMsgStatus sends a GMD_STATUS_CALL message to RTserver, but does not explicitly flush the message. See TipcSrvGetAutoFlushSize for more information on message buffering.

See Also

Examples

This example creates a connection process callback for GMD_FAILURE messages which uses TipcSrvGmdMsgStatus to poll RTserver for GMD status. (This example callback simply prints the GMD status information. A real callback would take some corrective actions to recover from the GMD failure.)

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; 
  T_IPC_MT mt; 
  T_IPC_MSG result_msg; 
  T_INT4 seq_num; 
  T_STR *success_client_names; 
  T_INT4 num_success_client_names; 
  T_STR *failure_client_names; 
  T_INT4 num_failure_client_names; 
  T_STR *pending_client_names; 
  T_INT4 num_pending_client_names; 
  T_INT4 counter; /* loop counter */ 
 
  /* 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 */ 
  } 
 
  /* poll RTserver for GMD status information */ 
  if (!TipcSrvGmdMsgStatus(failed_msg)) { 
    return;  /* error */ 
  } 
 
  mt = TipcMtLookupByNum(T_MT_GMD_STATUS_RESULT); 
  if (mt == NULL) { 
    return;  /* error */ 
  } 
 
  /* wait a short time for the GMD status result */ 
  result_msg = TipcSrvMsgSearchType(10.0, mt); 
  if (result_msg == NULL) { 
    return;  /* error */ 
  } 
 
  /* must set current field first */ 
  if (!TipcMsgSetCurrent(result_msg, 0)) { 
    return;  /* error */ 
  } 
 
  /* get the fields from the message */ 
  if (!TipcMsgRead(result_msg, 
                   T_IPC_FT_INT4, &seq_num, 
                   T_IPC_FT_STR_ARRAY, &success_client_names, 
                     &num_success_client_names, 
                   T_IPC_FT_STR_ARRAY, &failure_client_names, 
                     &num_failure_client_names, 
                   T_IPC_FT_STR_ARRAY, &pending_client_names, 
                     &num_pending_client_names, 
                   NULL)) { 
    return;  /* error */ 
  } 
 
  TutOut("Got GMD_STATUS poll result.\n"); 
  TutOut("seq_num = %d\n", seq_num); 
  TutOut("success_client_names\n"); 
  for (counter = 0; counter < num_success_client_names; counter++) 
{ 
    TutOut(" %s\n", success_client_names[counter]); 
  } 
  TutOut("failure_client_names\n"); 
  for (counter = 0; counter < num_failure_client_names; counter++) 
{ 
    TutOut(" %s\n", failure_client_names[counter]); 
  } 
  TutOut("pending_client_names\n"); 
  for (counter = 0; counter < num_pending_client_names; counter++) 
{ 
    TutOut(" %s\n", pending_client_names[counter]); 
  } 
 
  if (!TipcMsgDestroy(result_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 */ 
cb = TipcSrvProcessCbCreate(mt, my_gmd_failure_cb, NULL); 
if (cb == NULL) { 
  return;  /* error */ 
} 
 
/* raise priority of callback so it is called before */ 
/* TipcCbSrvProcessGmdFailure, which uses */ 
/* TipcSrvGmdMsgServerDelete to tell RTserver to forget */ 
/* the message */ 
if (!TutCbSetPriority(cb, 2)) { 
  return;  /* error */ 
}