Re: Re: [lwip-users] Re: tx badnwidth

[Chen]

Sorry, but I have trouble logging in
https://savannah.nongnu.org/bugs/?func=additem&group=lwip

Here is more info to the problem I mentioned before:

Debug output:

In app level, I print out every received character (<cr> is 0xD in ASCII)

In api_msg.c, recv_tcp(void *arg, struct tcp_pcb *pcb, struct pbuf *p, err_t err),

add

print_dbg("+ ");

right before

API_EVENT(conn, NETCONN_EVT_RCVPLUS, len);

So that each time lwIP capture a packet, it prints out a "+ "

In sockets.c, lwip_recvfrom(int s, void *mem, int len, unsigned int flags,

        struct sockaddr *from, socklen_t *fromlen)

Add the following after the if (((flags & MSG_DONTWAIT) block of the function

      print_dbg("\ni am here");

      print_dbg_hex(sock->rcvevent);

So the non-blocking call to lwip_recvfrom won't have any debug output.

Add the following to the exit-point of the function

      print_dbg("\ndone with lwip_recvfrom");

      print_dbg_hex(sock->rcvevent);

So that we can track the change of event flags

Capture:
http://www.dataq.com/chen/extra_recvevent.cap

When my program is run, the following debug output is captured:

3+  

i am here00000001  done with lwip_recvfrom 00000000                                                       

FD<cr> 3+        

i am here00000001  done with lwip_recvfrom 00000000                                                       

MC<cr> 3+        

i am here00000001  done with lwip_recvfrom 00000000                                                       

XZ<cr> 3+  3+            

i am here00000002  done with lwip_recvfrom 00000001                                                       

FB<cr>     

i am here00000001  done with lwip_recvfrom 00000000                                                       

VR<cr> 3+        

i am here00000001  done with lwip_recvfrom 00000000                                                       

RM<cr> 3+  3+            

i am here00000002  done with lwip_recvfrom 00000001                                                       

BR 

i am here00000001  done with lwip_recvfrom 00000000                                                       

00107<cr> 3+  3+  3+  3+  3+  3+  3+  3+  3+  3+  3+  3+  3+  3+  3+  3+  3+  3+  3+  3+  3+  3+  3+                   

i am here00000017  done with lwip_recvfrom 00000016                                                       

BR 

BR 

00107<cr>

i am here00000015  done with lwip_recvfrom 00000014

IL00001

i am here00000014  done with lwip_recvfrom 00000013

,16416

i am here00000013  done with lwip_recvfrom 00000012

<cr>

i am here00000012  done with lwip_recvfrom 00000011

CL00001

i am here00000011 3+  3+   done with lwip_recvfrom 00000012

,00000

i am here00000012  done with lwip_recvfrom 00000011

<cr>TG00000,00000,00000,00000<cr>TG00000,00000,00000,00000<cr>FB<cr>TH15000<cr>F

L<cr>SG00001<cr>ES<cr>

packetsize=000007D0

i am here00000011

What I observed:

In the begining, each packet raised one rcvevent, and lwip_recvfrom picks up the packet and subtract rcvevent.

From the capture file, packets #27--48 are from PC, and matches the 3+ after 00107<cr> in the debug output

lwip_recvfrom continue to pick up one packet at a time, and subtract event count by one until after the line "i am here00000012  done with lwip_recvfrom 00000011"

At this point, lwip_recvfrom picks up *ALL* the remaining packets and sends them back to the main, but it failed to bring sock->rcvevent back to zero

As the result, the next call to lwip_recvfrom will see a non-zero sock->rcvevent but no data to pick up!

lwIP totally lost sync at this point.

Thanks for your time!

>>>>>>>>>>>>>>
Follow the links on the lwIP project page.  Should bring you out
here:

https://savannah.nongnu.org/bugs/?func=additem&group=lwip