TMS320C6655: How to keep connected status after calling dtask_tcp_echo

Hi,

There is dtask_tcp_echo() implemented inside the NDK already. This is the same as customer's dtask_tcp_proc() function. I saw the NDK function has the same 5 seconds time out and close the socket connection. But we never have any issue to receive the packet after a while.

/* Configure our socket timeout to be 5 seconds */
to.tv_sec = 5;
to.tv_usec = 0;
setsockopt( s, SOL_SOCKET, SO_SNDTIMEO, &to, sizeof( to ) );
setsockopt( s, SOL_SOCKET, SO_RCVTIMEO, &to, sizeof( to ) );

i = 1;
setsockopt( s, IPPROTO_TCP, NDK_TCP_NOPUSH, &i, 4 );

for(;;)
{
i = (int)recvnc( s, (void **)&pBuf, 0, &hBuffer );

/* If we read data, echo it back */
if( i > 0 )
{
if( send( s, pBuf, i, 0 ) < 0 )
break;
recvncfree( hBuffer );
}
/* If the connection got an error or disconnect, close */
else
break;
}

fdClose( s );

/* Return "0" since we closed the socket */
return(0);
}

Can she use the NDK function? Or what the difference between her function and NDK one? I saw the TI example used:

do
{
rc = NC_NetStart( hCfg, NIMU_testNetworkOpen, NIMU_testNetworkClose, NIMU_testNetworkIpAddr );
} while( rc > 0 );

Then 

static void NIMU_testNetworkOpen()
{
/* Create our local servers */
hEcho = DaemonNew( SOCK_STREAMNC, 0, 7, dtask_tcp_echo,
OS_TASKPRINORM, OS_TASKSTKNORM, 0, 3 );
hEchoUdp = DaemonNew( SOCK_DGRAM, 0, 7, dtask_udp_echo,
OS_TASKPRINORM, OS_TASKSTKNORM, 0, 1 );
hData = DaemonNew( SOCK_STREAM, 0, 1000, dtask_tcp_datasrv,
OS_TASKPRINORM, OS_TASKSTKNORM, 0, 3 );
hNull = DaemonNew( SOCK_STREAMNC, 0, 1001, dtask_tcp_nullsrv,
OS_TASKPRINORM, OS_TASKSTKNORM, 0, 3 );
hOob = DaemonNew( SOCK_STREAMNC, 0, 999, dtask_tcp_oobsrv,
OS_TASKPRINORM, OS_TASKSTKNORM, 0, 3 );

}

Isn't the same use her function or NDK provided dtask_tcp_echo()?

Regards, Eric

hi，

the dtask_tcp_proc() function is same as the dtask_tcp_echo();

I can use the NDK function, and I can perform the dtask_tcp_echo() function, but  the problem is that only when making a TCP connection can enter into this function, after receive the data or 5 seconds,the TCP connection is broken;

I want to monitor PC data reception at any time, don't need a PC to TCP connection repeatedly, but to make TCP has been in a state of link.

thinks.

Amelia

Hi,

I see. "after receive the data or 5 seconds,the TCP connection is broken; I want to monitor PC data reception at any time, don't need a PC to TCP connection repeatedly". There is 

to.tv_sec = 5;
to.tv_usec = 0;

setsockopt( s, SOL_SOCKET, SO_SNDTIMEO, &to, sizeof( to ) );
setsockopt( s, SOL_SOCKET, SO_RCVTIMEO, &to, sizeof( to ) );

I am checking the NDK team if this can be override.

Regards, Eric

Hi,

After a tcp connection is closed, either due to natural causes or due to a timeout, dtask_tcp_echo will exit. The task that creates the dtask_tcp_echo task will still remain open and listen to the listening socket. If any new connections come to the socket, then a separate socket is opened at the accept() call and the dtask_tcp_echo task will be created again.

Can you clarify what you mean by "I want to monitor PC data reception, don't need a PC to TCP connection repeatedly, but to make TCP has been in a state of link"?

Can you describe how you want to change this functionality?

Thanks,
Brandon

Hi，

I mean，when the PC is connected with the dsp,  Whether the connection can be opened continuously, and when the PC is send data to dsp, an callback function can runs to told the main process that there was some data must to process.

Now , I change the dtask_tcp_echo(), and it will never exit until the tcp connection is broken. and it always attempt to receive the data. 

but now I have an other question, if the code is run into the  dtask_tcp_echo(), it means an connection is set up between the dsp and PC,A Socket is used to  transfer data for this connection, right? I can send data to PC in dtask_tcp_echo(), like the code above.

I want send data to PC through this connetion in other task, so , I create an Semaphore to tell the other task that the connection is set up. and I give the socket to global variable(s_send = s;). 

Hi,

Did you fix your first problem?

Yes, you are correct. Is it possible that you are closing the socket before the other task gets a chance to run and send data to the socket?

Can you check the value of errno after the call to send fails?

Regards,
Brandon