TipcConnGmdFileDelete

Name

TipcConnGmdFileDelete — delete guaranteed message delivery files for a connection

Synopsis

T_BOOL TipcConnGmdFileDelete(conn) 
T_IPC_CONN conn;

Arguments

conn — connection for which to remove GMD files

Return Values

TRUE if the connection GMD files were successfully deleted from disk, FALSE otherwise.

Diagnostics

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

T_ERR_NULL_PTR — conn was null

T_ERR_IN_USE — the connection GMD files are already open by this process and cannot be removed

T_ERR_C — a C error has occurred. Call the function TutErrNumGetC to obtain the related C-specific error value.

any error number from TipcGetGmdDir

Description

TipcConnGmdFileDelete deletes from disk guaranteed message delivery (GMD) files for a connection. TipcConnGmdFileDelete is useful for processes that wish to completely delete any obsolete GMD information. See TipcConnGmdFileCreate for more information on GMD areas.

When a process using GMD creates a connection, one of two scenarios is possible:

the process does not care about GMD information from a previous connection with the same GMD configuration and should thus call TipcConnGmdFileDelete to delete the old files

the process is recreating the connection after a network failure and should thus call TipcConnGmdResend to resend all previously sent messages that may have been lost when the connection was destroyed

TipcConnGmdFileDelete should be used carefully, as deleting GMD files removes all record of old messages that were supposed to be delivered.

Caution

Old GMD files must be removed before any messages with guaranteed delivery are sent or received on the connection. TipcConnGmdFileDelete does not delete the GMD files if they are already open by this process and in use for the connection. The GMD files are opened by TipcConnGmdFileCreate.

Examples

This example creates a client connection to a server process, calls TipcConnGmdFileDelete to remove any existing GMD files for the connection, and then sends a NUMERIC_DATA message with guaranteed delivery to the server process:

T_IPC_CONN conn; 
T_IPC_MT mt; 
T_IPC_MSG msg; 
 
/* have to set the Unique_Subject option to use file-based GMD */ 
TutCommandParseStr("setopt unique_subject example_client"); 
 
conn = TipcConnCreateClient("tcp:_node:4242"); 
if (conn == NULL) { 
  return;  /* error */ 
}  
 
/* Clear out old GMD files before sending/receiving any messages. Use TipcConnGmdResend 
instead of TipcConnGmdFileDelete here if you wish to resend any previously sent messages with 
GMD. */ 
if (!TipcConnGmdFileDelete(conn)) { 
  return;  /* error */ 
} 
 
mt = TipcMtLookupByNum(T_MT_NUMERIC_DATA); 
if (mt == NULL) { 
  return;  /* error */ 
}  
 
if (!TipcConnMsgWrite(conn, mt, 
                      T_IPC_PROP_DELIVERY_MODE, T_IPC_DELIVERY_ALL, 
                      T_IPC_FT_STR, "test_value", 
                      T_IPC_FT_REAL8, 10.0, 
                      NULL)) { 
  return;  /* error */ 
}