An application handles server errors and informational messages inline or through a server message callback routine.
When a connection is allocated, it picks up a default server message callback from its parent context. If the parent context has no server message callback installed, then the connection is created without a default server message callback.
After allocating a connection, an application:
Installs a different server message callback for the connection.
Calls ct_diag to initialize inline message handling for the connection. Note that ct_diag automatically deinstalls all message callbacks for the connection.
If a server message callback is not installed and inline message handling is not enabled, Client-Library discards the server message information.
If callbacks are not implemented for a particular programming language and platform version of Client-Library, an application must handle server messages inline, using ct_diag.
If a connection is handling server messages through a server message callback, then the callback is called whenever a server message arrives.
