TcpClose

Use the procedure shown in Figure 1 to begin the TCP one-way closing sequence. During this closing sequence, you, the local client, cannot send any more data. Data might be delivered to you until the foreign application also closes. TcpClose also causes all data sent on that connection by your application, and buffered by TCPIP, to be sent to the foreign application immediately.

Figure 1. TcpClose example

   procedure TcpClose
            (
                 Connection: ConnectionType;
        var    ReturnCode: integer
            );
            external;

Parameter

Description

Connection

The connection number, as returned by TcpOpen or TcpWaitOpen in the Connection field of the StatusInfoType record.

ReturnCode

Indicates success or failure of call. Possible return values are:

OK
ABNORMALcondition
ALREADYclosing
NOsuchCONNECTION
NOTyetBEGUN
TCPipSHUTDOWN
SOFTWARError
REMOTEreset

For a description of Pascal return codes, see Table 1.

Notes:

If you receive the notification CONNECTIONstateCHANGED with a NewState of SENDINGonly, the remote application has done TcpClose (or an equivalent function) and is receiving only. Respond with TcpClose when you finish sending data on the connection.
The connection is fully closed when you receive the notification CONNECTIONstateCHANGED, with a NewState field set to NONEXISTENT.