Re: [lwip-users] TCP windows Full

[brak brak2]

> Lack of pbufs to send a packet?

How can I check pbuf availability?

I release pbuf of received package until I process whole received data.
Then I call pbuf_free:
                SYS_ARCH_PROTECT(lev);
                pbuf_free(gpBufsToRelease[i]); //pointer to received data pbuf
                SYS_ARCH_UNPROTECT(lev);


>  An error called tcp_recved() (although
> you say this is not the problem)?
> The fact that even after a long idle
> period the advertised window is not getting back to 4096 (its starting
> value) suggests to me that there could well be a problem with your use
> of tcp_recved().

I call tcp_recved for every processed pbuf in the received data chain.
It looks like this in log:
Package received:  1460 //total among of received data in tcp_recv
Package received:  1460
tcp_recved called: 202 //among of data in tcp_recved call
tcp_recved called: 256
tcp_recved called: 256
tcp_recved called: 256
Package received:  951
tcp_recved called: 256
tcp_recved called: 234
tcp_recved called: 202
tcp_recved called: 256
tcp_recved called: 256
tcp_recved called: 256
tcp_recved called: 256
tcp_recved called: 234
tcp_recved called: 202
tcp_recved called: 256
tcp_recved called: 256
tcp_recved called: 237


The call of recved is surrounded with protecting code:

                        SYS_ARCH_PROTECT(lev);
                        tcp_recved(gTcpRecAck[i].pcb, gTcpRecAck[i].length);
                        SYS_ARCH_UNPROTECT(lev);

So no lwip core code could interrupt execution of tcp_recved.


> For full details of when lwIP will send an explicit window update, take
> a look at the source (start in tcp_recved()), but to summarise: if we
> can increase the advertised window by a significant amount (e.g. 1 MSS)
> then we do.

But it is done only in recved or is it check in one of the timer also?

Best regards
Tomasz