Re: [lwip-users] tcp_enqueue problem, using socket:

[Jonathan Larmour]

Piero 74 wrote:
>   } else {
>     /* if ERR_MEM, we wait for sent_tcp or poll_tcp to be
> called                           <--------- wrong comment??? ERR_CONN
> instead ERR_MEM
>        on other errors we don't try writing any more */
>     conn->err = err;
>     write_finished = 1;
>   }
> 
>   if (write_finished) {
>     /* everything was written: set back connection state
>        and back to application task */
> 
> ....
> 
> first, i suppose there is a wrong comment (see above)
> second, i propose a patch (but i'm not sure);
> if tcp_enqueue returned ERR_MEM, instead of try tcp_output anyway, exit
> using
> 
>     conn->err = err;
>     write_finished = 1;
> 
> what do you think???

The comment could be better positioned. The bit:
/* if ERR_MEM, we wait for sent_tcp or poll_tcp to be called

applies to the previous block.

The bit:
on other errors we don't try writing any more */
applies to the block the comment is presently in.

If tcp_enqueue returns ERR_MEM, the present code is correct - it is not a
fatal error, it just means that it should be retried and the . The netconn
layer will do this as a result of its sent_tcp() and poll_tcp() callbacks.
The calling thread will only be woken up when the data really is sent, or
there _is_ a fatal error.

Jifl
-- 
eCosCentric Limited      http://www.eCosCentric.com/     The eCos experts
 **  Visit us at ESC Silicon Valley <http://www.embedded.com/esc/sv>  **
 **  April 15-17 2008, Booth 3012, San Jose McEnery Convention Center **
Barnwell House, Barnwell Drive, Cambridge, UK.       Tel: +44 1223 245571
Registered in England and Wales: Reg No 4422071.
------["Si fractum non sit, noli id reficere"]------       Opinions==mine