FreeTDS Development Group

["Brian Bruns" <camber AT ais.org>]

> My original thoughts were along these lines...but as I looked further, I
> realized that tds_connect() really needs to be able to change the state at
> different points depending on various conditions.  The TDSSOCKET shouldn't
> appear live until after the connect() call, 

The socket is allocated with tds->s = 0 so it is by definition dead until
after connect().

> and if the login fails it should
> appear dead when the "Login incorrect." message is sent.  

Easy enough, just call tds_client_msg() with NULL, or close the socket and
set tds->s to 0.  Either way, DBDEAD will be true.

> So breaking up the
> calls in the ways that you suggest really don't provide the degree of
> control that I think is needed.

Unless I'm missing something, I think it should be possible to do this.
I'd vastly prefer to keep the call signatures of the tds_*() functions
simple.

> Here's an excerpt from my version, showing the critical sections where the
> state needs to change.  Note that the two calls to tds_client_msg() shown
> below need the state to be dead, while any calls to tds_client_msg()
> performed from tds_process_login_tokens() need the state to be live:
> 
>         if (connect(tds->s, (struct sockaddr *) &sin, sizeof(sin)) <0) {
>                 char message[128];
>                 sprintf(message, "src/tds/login.c: tds_connect: %s:%d",
>                         inet_ntoa(sin.sin_addr), ntohs(sin.sin_port));
>                 perror(message);
>                 tds_client_msg(tds->tds_ctx, tds, 20009, 9, 0, 0,
>                         "Server is unavailable or does not exist.");
>                 tds_free_config(config);
>                 tds_free_socket(tds);
>                 *tdsp = NULL;
>                 return;
>         }
>         }
>         /* END OF NEW CODE */
> 
>         /* We are now connected!
>          * Save our TDSSOCKET now, to ensure that we don't appear
>          * to be DBDEAD() upon entry to error/message handlers.
>          */
> --->    *tdsp = tds;

Done prior to entering function.

> 
>         if (IS_TDS7_PLUS(tds)) {
>                 tds->out_flag=0x10;
>                 tds7_send_login(tds,config);
>         } else {
>                 tds->out_flag=0x02;
>                 tds_send_login(tds,config);
>         }
>         if (!tds_process_login_tokens(tds)) {
>                 /* Login incorrect...mark the socket dead. */
> --->            *tdsp = NULL;
How about:
                  tds_close_socket(tds);
where: tds_close_socket(TDSSOCKET *tds) { close(tds->s); tds->s=0; }

>
>                 tds_client_msg(tds->tds_ctx, tds, 20014, 9, 0, 0,
>                         "Login incorrect.");
>
>                 tds_free_config(config);
>                 tds_free_socket(tds);

(remove free socket and becomes callers responsibility)

>                 return;

                  return TDS_FAIL;
>         }
>