TipcConnReadCbCreate

Name

TipcConnReadCbCreate — create a read callback in a connection

Synopsis

T_CB TipcConnReadCbCreate(conn, mt, func, arg) 
T_IPC_CONN conn; 
T_IPC_MT mt; 
T_IPC_CONN_READ_CB_FUNC func; 
T_CB_ARG arg; 

Arguments

conn — connection to create callback for

mt — message type to create callback for (null means global callback)

func — callback function

arg — user-defined argument to pass to func

Return Values

New callback if successful, NULL otherwise.

Diagnostics

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

Description

TipcConnReadCbCreate creates a read callback in a connection. These callbacks are called when a new message is received from the connection’s socket, which occurs in TipcConnRead. Connection read callbacks are useful for message file logging and preprocessing of messages before the normal processing with TipcConnMsgProcess. See the TIBCO SmartSockets Utilities for more information on callbacks.

A read callback is usually created for a specific message type and connection. If the message type is null, then a global read callback is created for all message types on that connection.

Caution

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

See Also

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

Examples

This example creates a global connection read callback that writes all received messages to a message file:

void T_ENTRY my_conn_read_cb(conn, data, arg) 
T_IPC_CONN conn; 
T_IPC_CONN_READ_CB_DATA data; 
T_CB_ARG arg; /* really (T_IPC_MSG_FILE) */ 
{ 
  T_IPC_MSG msg = data->msg; 
  T_IPC_MSG_FILE msg_file = arg; 
 
  if (!TipcMsgFileWrite(msg_file, msg)) { 
    return;  /* error */ 
  }  
} /* my_conn_read_cb */ 
 
/* =========================================================== */ 
/*...code from calling function is below */ 
 
T_IPC_MSG_FILE msg_file; 
 
msg_file = TipcMsgFileCreate("my_log.msg",  
                             T_IPC_MSG_FILE_CREATE_WRITE); 
if (msg_file == NULL) { 
  return;  /* error */ 
}  
 
/* global connection read callback */ 
if (TipcConnReadCbCreate(conn, NULL, my_conn_read_cb, msg_file) 
    == NULL) { 
  return;  /* error */ 
}