I am running lwip v1.2.0 with FreeRTOS 4.2.1 on a AT91SAM7X-EK board with an X512 chip. I have been actively adding UDP and TCP application programs with only minor issues, but when trying to resolve a resource (memory) issue I've dropped back to running just the standard BasicWeb.c webserver so I could better understand what the lwipopts.h values actually do in terms of TCP internal data structures. I am able to do source level debugging with Eclipse and the Amontec JTAGKEY along with OpenOCD.
What I've noticed when running just the Webserver application with my other tasks disabled (all other FreeRTOS tasks are not created) is that the lwip_stats.memp[3] statistics show that the number of TCP_PCBs used seems to keep getting bumped everytime the webserver returns a webpage. I've got MEMP_NUM_TCP_PCB set to 10 (in lwipopts.h) and I see that memp[3].used and memp[3].max keep climbing with each web browser connection until the limit of 10 is reached. Then I see memp[3].err get incremented while the memp[3].used and memp[3].max stay at 10. The webserver continues to operate, seemingly normally. Is this due to previous TCP connections (i.e.. webserver) hanging around for a while and continuing to tie up TCP_PCBs? I just checked the system after stopping the web browser and it appears that after some time, the number of used TCP_PCBs goes back to zero. So I assume there is a time-out associated with these connections. But why aren't the TCP_PCBs freed immediately when the webserver executes the netconn_close and netconn_delete functions? The webserver seems to continue to operate OK even when it's run out of TCP_PCBs and is bumping the memp[3].err counter. Is this normal behavior? I am just getting my feet wet with lwip and FreeRTOS, so please excuse my ignorance. Thanks, Dave Squires ----------------------------------- SQUIRES ENGINEERING, INC. 2604 Lowell Circle Melbourne, FL 32935-2215 phone: (321) 242-8611 fax: (321) 242-0949 website: http://www.squires-eng.com ----------------------------------- _______________________________________________ lwip-users mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/lwip-users
