TipcConnErrorCbCreate

T_CB TipcConnErrorCbCreate(conn, func, arg) 
T_IPC_CONN conn; 
T_IPC_CONN_ERROR_CB_FUNC func; 
T_CB_ARG arg;

Arguments

Return Values

Diagnostics

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

T_ERR_NULL_PTR — conn was null or func was null

T_ERR_ALREADY_EXISTS — a callback with func and arg already exists

Description

TipcConnErrorCbCreate creates an error callback in a connection. These callbacks are called when an unrecoverable error occurs on a connection. The possible errors are:

the other end of the connection’s socket is closed, which may occur in TipcConnRead (when the socket function recv returns 0) or TipcConnFlush (when the socket function send returns -1)

the connection read timeout has elapsed without any data being read from the connection’s socket, and then the keep alive failed

the connection write timeout has elapsed without any data being able to be written to the connection’s socket

Connection error callbacks usually take measures to re-establish the connection. See TIBCO SmartSockets Utilities for more information on callbacks.

Caution

A connection error callback function should not destroy the connection with TipcConnDestroy.

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

See Also

TipcConnErrorCbLookup; see the TIBCO SmartSockets Utilities for information on TutCbDestroy.

Examples

This example creates a connection error callback which prints a warning and sets a global flag to indicate that an error has occurred:

T_BOOL my_conn_error_happened = FALSE; 
 
/* =========================================================== */ 
/*..my_conn_error_cb -- connection error callback */ 
void T_ENTRY my_conn_error_cb(conn, data, arg) 
T_IPC_CONN conn; 
T_IPC_CONN_ERROR_CB_DATA data; 
T_CB_ARG arg; /* not used */ 
{ 
  TutWarning("Error <%s> occurred on my connection.\n", 
             TutErrNumToStr(data->err_num)); 
  my_conn_error_happened = TRUE; 
} /* my_conn_error_cb */ 
 
/* =========================================================== */ 
/*...code from calling fragment is below */ 
 
if (TipcConnErrorCbCreate(conn, my_conn_error_cb, NULL) == NULL) { 
  return;  /* error */ 
} 
 
/* Now use the global flag to check for errors. */ 
msg = TipcConnMsgNext(conn, T_TIMEOUT_FOREVER); 
if (msg == NULL && my_conn_error_happened) { 
  return;  /* error */ 
}