Simon,
Does it make sense to include a listen_pcb pointer in tcp_pcb that
tcp_bind fills in (otherwise it’s NULL). On the final close of the
pcb, if tcp_listen isn’t NULL, memp_free it as well. In spite of you
asking if it’s valid to bind to an open pcb, this resolves the leak
because tcp_listen is grabbing a new tcp.
Bill Auerbach
------------------------------------------------------------------------
*From:* address@hidden
[mailto:address@hidden *On
Behalf Of *Goldschmidt Simon
*Sent:* Monday, January 14, 2008 10:02 AM
*To:* Rick Culver; Mailing list for lwIP users
*Subject:* RE: [lwip-users] Releasing pcb after tcp_new()
I have filed a bug report about the tcp_bind() question, so that it
doesn't get lost:
http://savannah.nongnu.org/bugs/?22020
Simon
------------------------------------------------------------------------
*Von:*
address@hidden
[mailto:address@hidden
*Im Auftrag von *Rick Culver
*Gesendet:* Montag, 14. Januar 2008 15:28
*An:* Mailing list for lwIP users
*Betreff:* Re: [lwip-users] Releasing pcb after tcp_new()
Bill,
Thanks for the response. After some more investigation I
discovered that you are correct, it appears the pcb does get
released by the stack but not immediately after the tcp_close()
function. I can wait until the state == CLOSED but I would think
that by then the pcb would have already been released by the stack
and my pointer to the pcb could be pointing to erroneous memory.
Not sure about that. Anyway, thanks for the help and hopefully
someone else will pick up on this tread and provide some more input.
Rick
----- Original Message -----
*From:* Bill Auerbach <mailto:address@hidden>
*To:* 'Mailing list for lwIP users'
<mailto:address@hidden>
*Sent:* Wednesday, January 09, 2008 12:17 PM
*Subject:* RE: [lwip-users] Releasing pcb after tcp_new()
Rick,
We’re going down the same path, more or less. One thing to
watch on tcp_close is the tcb_pcb isn’t actually finished
being used until later – one of the tcp timers is completing
the connection. This ties up pcbs internally for older
connections until they are closed. Allocate MEMP_NUM_TCP_PCB
to twice what you think – or more if you are opening and
closing connections a lot.
One thing I would like to see is a callback when the pcb is
going to be deallocated so that dynamic memory associated with
it can be released when the data is sent and the connection
completes later. Maybe someone knows already how to do this?
Thanks,
Bill Auerbach
------------------------------------------------------------------------
*From:*
address@hidden
[mailto:address@hidden
*On Behalf Of *Rick Culver
*Sent:* Wednesday, January 09, 2008 12:29 PM
*To:* address@hidden
*Subject:* [lwip-users] Releasing pcb after tcp_new()
I am using CALLBACK API and set up a pcb using tcp_new()
followed by tcp_bind() followed by tcp_listen() &
tcp_accept(). In my accept() for a valid connection I use
tcp_close() to close the LISTEN connection to avoid any
additional connection requests for a new connection. When I am
done using the connection I use tcp_close() to shut it down
and then repeat the process with tcp_new() to start a new
LISTEN port. My problem is 2 fold.
First I find that the 2nd time through the tcp_bind() function
I get an ERR_USE return which appears to be caused by the
active list of pcb still having the old port number in it. I
think ther is a problem with tcp_bind() which causes this to
happen.
Secondly (and the biggest problem) is that once I get the
ERR_USE then I have a pcb allocated and this consumes pcb
space and I eventually run out of space. So the question is,
if I get an error with tcp_bind() how can I release the pcb
allocated by the tcp_new() so I do not consume pcb memory
space and fill it up. I think there could be a problem with
tcp_bind() giving this error which is also an issue. Can
anyone suggest how to approach these problems?
Rick
------------------------------------------------------------------------
_______________________________________________
lwip-users mailing list
address@hidden
http://lists.nongnu.org/mailman/listinfo/lwip-users
------------------------------------------------------------------------
_______________________________________________
lwip-users mailing list
address@hidden
http://lists.nongnu.org/mailman/listinfo/lwip-users
------------------------------------------------------------------------
No virus found in this incoming message.
Checked by AVG Free Edition.
Version: 7.5.516 / Virus Database: 269.19.0/1216 - Release Date: 09.01.2008 10:16