Thomas Taranowski wrote: > 95% of the time my ftp/telnet apps work fine. However, once in awhile I > get into a cycle where the tcp connections totally hose up. The cause > appears to be related to the fact that in sys_mbox_fetch(), the > again:/goto again loop is spinning with wild abandon. I put a counter > inside sys_mbox_fetch, which easily upticks into the several hundreds > within seconds of stack startup. I've verified that the > sys_arch_mbox_fetch is returning sane values. The odd thing is that > this only crops up once in awhile, and will stay around. Last time I > thought I had a bad ethernet card, and switched test targets, and > everything started working. However, now that I'm seeing it again on > different hardware/ethernet card combo, I'm concerned that I've got a > critical bug floating around somewhere. > > I've attached a wireshark capture of the link output. It's a portion of > the ftp session. You'll see that it basically works, but will spew out > loads of TCP Dup ACK, TCP Retransmits, and finally drops the connection > at the end with a series of 7 RSTs in a row. Presumably I'm seeing > these cause the timers are firing way to fast. > > Note: This is a custom port of lwIP to an OS I'm working on. > > Any ideas on how to debug this, or what the issue is? When this occurs, > I do have an inetd server start listening on several tcp ports at system > startup.
Given sys_mbox_fetch is spinning, I would initially suspect your port's sys_arch_timeouts() call. It should return a list of timeouts only for the current thread. Jifl -- eCosCentric Limited http://www.eCosCentric.com/ The eCos experts 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 _______________________________________________ lwip-users mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/lwip-users
