Blocking TCP Server fault‏

Haya Lebel

Other Parts Discussed in Thread: CC3100

The components I'm working on them : CC3100 + Tiva C .

I am connectig to the AccessPoint and creating a blocking TCP Server socket.
I have a client software which connects to my server socket.

all works fine till I added a local variable (long nonBlocking= 1; -- preparing in order to do non-blocking socket)and since then I get a fault every time the client connects.

here is my code :

void TcpServer() {
    SlSockAddrIn_t Addr;
    SlSockAddrIn_t LocalAddr;

    int AddrSize = sizeof(SlSockAddrIn_t);
    int SockID, newSockID;
    int Status;
    char Recvbuff[20];
    long nonBlocking= 1;

    LocalAddr.sin_family = SL_AF_INET;
    LocalAddr.sin_port = sl_Htons((UINT16) 6000);
    LocalAddr.sin_addr.s_addr = 0;

    Addr.sin_family = SL_AF_INET;
    Addr.sin_port = sl_Htons((UINT16) 6000);
    Addr.sin_addr.s_addr = sl_Htonl(SL_IPV4_VAL(10,0,0,2));

    SockID = sl_Socket(SL_AF_INET, SL_SOCK_STREAM, 0);
    Status = sl_Bind(SockID, (SlSockAddr_t *) &LocalAddr, AddrSize);
    Status = sl_Listen(SockID, 0);

newSockID = sl_Accept(SockID, ( struct SlSockAddr_t *)&Addr,(SlSocklen_t*) &AddrSize);

while (1) {

        memset(Recvbuff, 0, sizeof(Recvbuff));
        Status = sl_Recv(newSockID, Recvbuff, 20, 0);

        if (Status > 0) {
            Recvbuff[Status] = '\0';

            if (strcmp(&Recvbuff[2], "end") == 0) {
                Status = sl_Send(newSockID, Recvbuff, Status, 0);
                sl_Close(newSockID);
                sl_Close(SockID);

                break;
            }
        }

        Status = sl_Send(newSockID, Recvbuff, Status, 0);
    }
}
I looked at the registers map and I see :

NVIC_FAULT_STAT = 0x00009200

I'm stuck and I'm waiting for a way to progress

thanks

over 11 years ago

0 Gagan Maur over 11 years ago

TI__Expert 8150 points

Haya, so just defining a variable causes the code to stat showing failures?

Well, I would assume adding a new variable increases the stack usage slightly and it is likely that the stack overflows. Are you able to increase the stack size and see if it makes a difference?

0 Alon Srednizki over 11 years ago in reply to Gagan Maur

TI__Mastermind 18455 points

Hi Haya,

Your code isn't written correctly to handle unblocking sockets.

You should be polling on sl_Accept() waiting for incoming connections before continuing to handle the child socket.

In non blocking the accept will return immediately and newSockID will be equal to SL_EAGAIN (negative value).

In your code you are not handling that and you will try to call sl_recv() on a non existing socket ID.

Please refer to our new programmers guide document in: http://www.ti.com/lit/pdf/swru368

In general this is how you need to handle non blocking accept (taken from the document, in TCP connection chapter):

long nonBlocking = 1;

int  newSockID;

Status = sl_SetSockOpt(SockID, SL_SOL_SOCKET, SL_SO_NONBLOCKING, &nonBlocking, sizeof(nonBlocking));

while( newSockID < 0 )

    newSockID = sl_Accept(SockID, ( struct SlSockAddr_t *)&Addr,(SlSocklen_t*)&AddrSize);

    if( newSockID == SL_EAGAIN )

        /* Wait for 1 ms */

        Delay(1);

    else if( newSockID < 0 )

        return -1;

If the problem persists, please also try debugging it step by step to see which API call is causing the assertion.

In addition, I would recommend to add code checking the API return values, handling error cases, it will make your application more robust.

Thanks,
Alon

0 Haya Lebel over 11 years ago in reply to Gagan Maur

Prodigy 65 points

The problem was actually the size of the stack ,it was too small.

Project properties -> ARM linker -> by default stack size is 500. I increase to 2048.

Wi-Fi

Wi-Fi forum

Blocking TCP Server fault‏