Pauses I/O on msg.
This can be used when you need to return from the server handler without having the full response ready yet. Use [ [email protected]_message] to resume I/O.
This must only be called on a [class@ServerMessage] which was created by the Server and are
currently doing I/O, such as those passed into a [callback@ServerCallback] or emitted in a [signal@Server:SoupServer:request-read
] signal.
| this |
a Server |
| msg |
a ServerMessage associated with this. |