[En-Nut-Discussion] Thread stops executing after some time.

[Erik Lindstein]

Guys please help me out.
I'm on a wild goose chase trying to figure out what is happening with
a thread that handles communications with a PC thru a tcp/ip socket.

The setup is:
Ethernut V2.1
Software 4.4.0

The software is build up by a couple of threads each handling some
functions( lcd, push buttons, user functions etc )
Then i have one thread that communicates with a server software on my PC.
The communication is pretty simple.
It's a client socket that connects to my server PC and then exchanges
some XML data, disconnects, sleeps for 300ms and then start all over
again.

This works fine for weeks without any problems if i have the server PC
up and running and connected to the same LAN my ethernut is connected
to.

Then one day i disconnected the server PC from the LAN and left a
couple of the ethernut clients running over the weekend, then on
Monday i connected my PC again and started up the server software but
i noticed that only 1 out of 4 clients where still connecting (all of
them uses the same software just different MACs and IPs )

I looked at the incoming traffic with wireshark and could not see any
sign of life at all from the 3 clients not connecting.
I tried to ping them and they all answer on pings and also all other
threads that handles the LCD and push buttons are still up and running
so the software is not dead.
I tested to deactivate/activate the network connection on my PC to see
if anyone of the clients woke up. No luck.

I then added another thread to the software ( i took the sample code
for the tcps in the apps dir and created a thread to run that code )
And when everything is ok i see the "inetd" thread timeout counting
all the time and the thread executes as expected.

When the inetd thread stops executing i can connect to the unit and i
get the output seen below:
------------------------------------------------------------------------------------------------------------------------
220 List of threads with name,state,prio,stack,mem,timeout follows
tcpsm   Sleep   32      461     OK      27
TcpS    Run     64      2546    OK      None
inetd   Sleep   64      2381    OK      None
rxi5    Sleep   9       603     OK      1392
wdt     Sleep   40      255     OK      8
SmuTh   Sleep   64      65      OK      71
PcuTh   Sleep   64      805     OK      1
HvpsTh  Sleep   64      605     OK      24
IppsTh  Sleep   64      965     OK      4
TaTh    Sleep   64      65      OK      35
LcdTh   Sleep   64      929     OK      34
main    Sleep   64      733     OK      451
idle    Ready   254     356     OK      None
------------------------------------------------------------------------------------------------------------------------

For some reason the thread(inetd) just gets a timeout set to "None"
instead of the NutSleep value.

I only have one place in the code that sets the thread to sleep and i
have a fixed value there of 300. (NutSleep(300))
So there must be somewhere else in the code the thread gets set to
some wait state, but i have no idea how to figure out where and why
this happens.

Can it be something that happens when the socket tries to connect to a
IP/Server that doesn't exist on the LAN.

If it happens all the time it would be easier to figure out whats
wrong but this can run for days without happening.
Also if there was low memory the tcps thread wouldn't answer the
incoming connection attempts i guess.

The thread code is below:
------------------------------------------------------------------------------------------------------------------------
THREAD(InetdThread, arg)
{
	TCPSOCKET *socket;
	FILE *stream = 0;
	u_long rip = inet_addr("192.168.0.115");
	u_long tmo = 500;
	int socket_error = 0;
	uint8_t *start = 0, *stop = 0;
	uint8_t unit[20], cmd[40], value[40];
	uint8_t data_exchange_buffer[100] = "0";

	for(;;)
	{
		if ((socket = NutTcpCreateSocket()) != 0)
		{
			NutTcpSetSockOpt(socket, SO_RCVTIMEO, &tmo, sizeof(tmo));
			NutTcpSetSockOpt(socket, SO_SNDTIMEO, &tmo, sizeof(tmo));
			if(NutTcpConnect(socket, rip, TCPSERVERPORT) == 0)
			{
				stream = _fdopen((int) ((uptr_t) socket), "r+b");
				if(stream != 0)
				{
					fprintf_P(stream, info_P, INFO_P_ARGS); // Send some XML DATA
					fflush(stream);
					fgets(data_exchange_buffer, sizeof(data_exchange_buffer),
stream); // Get some XML DATA
					{
						// Handle XML data
					}
					fclose(stream);
					/*
						info_text is a extern variable that another thread prints on the
LCD for debug output.
					*/
					sprintf(info_text ,"COK\n%lu", (u_long)NutGetMillis());
				}
			}
			else
			{
				socket_error = NutTcpError(socket);
				sprintf(info_text ,"CE:%d \n%lu", socket_error, (u_long)NutGetMillis());
			}
			NutTcpCloseSocket(socket);
		}
		NutSleep(300);
	}
}
------------------------------------------------------------------------------------------------------------------------



-- 
/Erik