ct_con_alloc

Description

Allocate a CS_CONNECTION structure.

Syntax

CS_RETCODE ct_con_alloc(context, con_pointer)
 
 CS_CONTEXT          *context;
 CS_CONNECTION     **con_pointer;

Parameters

Returns

ct_con_alloc returns the following values:

The most common reason for a ct_con_alloc failure is a lack of adequate memory.

Examples

Example 1

        /*

         ** DoConnect()

         **

         ** Type of function:

         ** async example program api

         */

         CS_STATIC CS_CONNECTION CS_INTERNAL *

         DoConnect(argc, argv)

         int      argc;

         char     **argv;

         {

             CS_CONNECTION   *connection;

             CS_INT          netio_type = CS_ASYNC_IO;

             CS_RETCODE      retcode;

            /* Open a connection to the server */

             retcode = ct_con_alloc(Ex_context, &connection);

             if (retcode != CS_SUCCEED)

             {

                 ex_panic("ct_con_alloc failed");

             }

            /* Set properties for the connection */

             ...ct_con_props calls deleted ...

            /* Open the connection */

             ...ct_connect call deleted.....

         }

Usage

• A CS_CONNECTION structure, also called a connection structure, contains information about a particular client/server connection.

• Before calling ct_con_alloc, an application must allocate a context structure by calling the CS-Library routine cs_ctx_alloc, and must initialize Client-Library by calling ct_init.

• Connecting to a server is a three-step process. To connect to a server, an application:

  1. Calls ct_con_alloc to allocate a CS_CONNECTION structure.

  2. Calls ct_con_props to set the values of connection-specific properties, if desired.

  3. Calls ct_connect to create the connection and log in to the server.

• An application can have multiple open connections to one or more servers at the same time.

  For example, an application can simultaneously have two connections to the server MARS, one connection to VENUS, and one connection to PLUTO. The context property CS_MAX_CONNECT, set by ct_config, determines the maximum number of open connections allowed per context.

  Each server connection requires a separate CS_CONNECTION structure.

• To send commands to a server, one or more command structures must be allocated for a connection. ct_cmd_alloc allocates a command structure.

See also