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Can't debug: assert error with gdb (no problem without)

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# 8  
Old 01-11-2013
Are you sure there is NOT a logical fall through? Meaning your code hits the goto err_abort label no matter what logic happened before it.

What you showed me says there is a fall through.
# 9  
Old 01-11-2013
I'm not familiar with the fall-through concept by its name, although I think I grasp it and there should be none, or at least there is none I can see.

The code is this and starts at line 311
Code:
        if (pgm_error->domain == PGM_ERROR_DOMAIN_SOCKET)
        {     
           if(pgm_error->code != PGM_ERROR_INVAL)
           {
              if(pgm_error->code != PGM_ERROR_BADF )
              {
                  if(pgm_error->code != PGM_ERROR_FAULT)
                    do_this=1;
              }
           }
        }            
        if(pgm_error->domain == PGM_ERROR_DOMAIN_IF) 
        {     
           if(pgm_error->code != PGM_ERROR_INVAL)
           {
              if(pgm_error->code != PGM_ERROR_BADF )
              {
                  if(pgm_error->code != PGM_ERROR_FAULT)
                    do_this=1;
              }
           }
        }            
        if(do_this)
        {
            goto err_abort;
        }
        
        
        //  Fatal OpenPGM internal error.
        zmq_assert (false);

The last line of the snippet above is 340 and the line to which the jump points is 405, there are lots of other instructions including other conditional jumps between these points.
None of which gets executed.
I can't see no baseline to which the code could fall.

---------- Post updated at 05:39 PM ---------- Previous update was at 05:36 PM ----------

I doubt anyone wants to have a look at it, but here is the whole code of the function from which I have since posted various snippets
Code:
//  Create, bind and connect PGM socket.
int zmq::pgm_socket_t::init (bool udp_encapsulation_, const char *network_)
{
    //  Can not open transport before destroying old one.
    zmq_assert (sock == NULL);
    zmq_assert (options.rate > 0);
    int do_this=0;
    //  Zero counter used in msgrecv.
    nbytes_rec = 0;
    nbytes_processed = 0;
    pgm_msgv_processed = 0;

    uint16_t port_number;
    struct pgm_addrinfo_t *res = NULL;
    sa_family_t sa_family;

    pgm_error_t *pgm_error = NULL;

    if (init_address(network_, &res, &port_number) < 0) {
        goto err_abort;
    }

    zmq_assert (res != NULL);

    //  Pick up detected IP family.
    sa_family = res->ai_send_addrs[0].gsr_group.ss_family;

    //  Create IP/PGM or UDP/PGM socket.
    if (udp_encapsulation_) {
        if (!pgm_socket (&sock, sa_family, SOCK_SEQPACKET, IPPROTO_UDP,
              &pgm_error)) {

            //  Invalid parameters don't set pgm_error_t.
            zmq_assert (pgm_error != NULL);
            if (pgm_error->domain == PGM_ERROR_DOMAIN_SOCKET && (
                  pgm_error->code != PGM_ERROR_BADF &&
                  pgm_error->code != PGM_ERROR_FAULT &&
                  pgm_error->code != PGM_ERROR_NOPROTOOPT &&
                  pgm_error->code != PGM_ERROR_FAILED))

                //  User, host, or network configuration or transient error.
                goto err_abort;

            //  Fatal OpenPGM internal error.
            zmq_assert (false);
        }

        //  All options are of data type int
        const int encapsulation_port = port_number;
        if (!pgm_setsockopt (sock, IPPROTO_PGM, PGM_UDP_ENCAP_UCAST_PORT,
                &encapsulation_port, sizeof (encapsulation_port)))
            goto err_abort;
        if (!pgm_setsockopt (sock, IPPROTO_PGM, PGM_UDP_ENCAP_MCAST_PORT,
                &encapsulation_port, sizeof (encapsulation_port)))
            goto err_abort;
    }
    else {
        if (!pgm_socket (&sock, sa_family, SOCK_SEQPACKET, IPPROTO_PGM,
              &pgm_error)) {

            //  Invalid parameters don't set pgm_error_t.
            zmq_assert (pgm_error != NULL);
            if (pgm_error->domain == PGM_ERROR_DOMAIN_SOCKET && (
                  pgm_error->code != PGM_ERROR_BADF &&
                  pgm_error->code != PGM_ERROR_FAULT &&
                  pgm_error->code != PGM_ERROR_NOPROTOOPT &&
                  pgm_error->code != PGM_ERROR_FAILED))

                //  User, host, or network configuration or transient error.
                goto err_abort;

            //  Fatal OpenPGM internal error.
            zmq_assert (false);
        }
    }

    {
        const int rcvbuf = (int) options.rcvbuf;
        if (rcvbuf) {
            if (!pgm_setsockopt (sock, SOL_SOCKET, SO_RCVBUF, &rcvbuf,
                  sizeof (rcvbuf)))
                goto err_abort;
        }

        const int sndbuf = (int) options.sndbuf;
        if (sndbuf) {
            if (!pgm_setsockopt (sock, SOL_SOCKET, SO_SNDBUF, &sndbuf,
                  sizeof (sndbuf)))
                goto err_abort;
        }

        const int max_tpdu = (int) pgm_max_tpdu;
        if (!pgm_setsockopt (sock, IPPROTO_PGM, PGM_MTU, &max_tpdu,
              sizeof (max_tpdu)))
            goto err_abort;
    }

    if (receiver) {
        const int recv_only        = 1,
                  rxw_max_tpdu     = (int) pgm_max_tpdu,
                  rxw_sqns         = compute_sqns (rxw_max_tpdu),
                  peer_expiry      = pgm_secs (300),
                  spmr_expiry      = pgm_msecs (25),
                  nak_bo_ivl       = pgm_msecs (50),
                  nak_rpt_ivl      = pgm_msecs (200),
                  nak_rdata_ivl    = pgm_msecs (200),
                  nak_data_retries = 50,
                  nak_ncf_retries  = 50;

        if (!pgm_setsockopt (sock, IPPROTO_PGM, PGM_RECV_ONLY, &recv_only,
                sizeof (recv_only)) ||
            !pgm_setsockopt (sock, IPPROTO_PGM, PGM_RXW_SQNS, &rxw_sqns,
                sizeof (rxw_sqns)) ||
            !pgm_setsockopt (sock, IPPROTO_PGM, PGM_PEER_EXPIRY, &peer_expiry,
                sizeof (peer_expiry)) ||
            !pgm_setsockopt (sock, IPPROTO_PGM, PGM_SPMR_EXPIRY, &spmr_expiry,
                sizeof (spmr_expiry)) ||
            !pgm_setsockopt (sock, IPPROTO_PGM, PGM_NAK_BO_IVL, &nak_bo_ivl,
                sizeof (nak_bo_ivl)) ||
            !pgm_setsockopt (sock, IPPROTO_PGM, PGM_NAK_RPT_IVL, &nak_rpt_ivl,
                sizeof (nak_rpt_ivl)) ||
            !pgm_setsockopt (sock, IPPROTO_PGM, PGM_NAK_RDATA_IVL,
                &nak_rdata_ivl, sizeof (nak_rdata_ivl)) ||
            !pgm_setsockopt (sock, IPPROTO_PGM, PGM_NAK_DATA_RETRIES,
                &nak_data_retries, sizeof (nak_data_retries)) ||
            !pgm_setsockopt (sock, IPPROTO_PGM, PGM_NAK_NCF_RETRIES,
                &nak_ncf_retries, sizeof (nak_ncf_retries)))
            goto err_abort;
    } else {
        const int send_only        = 1,
                  max_rte      = (int) ((options.rate * 1000) / 8),
                  txw_max_tpdu     = (int) pgm_max_tpdu,
                  txw_sqns         = compute_sqns (txw_max_tpdu),
                  ambient_spm      = pgm_secs (30),
                  heartbeat_spm[]  = { pgm_msecs (100),
                                       pgm_msecs (100),
                                       pgm_msecs (100),
                                       pgm_msecs (100),
                                       pgm_msecs (1300),
                                       pgm_secs  (7),
                                       pgm_secs  (16),
                                       pgm_secs  (25),
                                       pgm_secs  (30) };

        if (!pgm_setsockopt (sock, IPPROTO_PGM, PGM_SEND_ONLY,
                &send_only, sizeof (send_only)) ||
            !pgm_setsockopt (sock, IPPROTO_PGM, PGM_ODATA_MAX_RTE,
                &max_rte, sizeof (max_rte)) ||
            !pgm_setsockopt (sock, IPPROTO_PGM, PGM_TXW_SQNS,
                &txw_sqns, sizeof (txw_sqns)) ||
            !pgm_setsockopt (sock, IPPROTO_PGM, PGM_AMBIENT_SPM,
                &ambient_spm, sizeof (ambient_spm)) ||
            !pgm_setsockopt (sock, IPPROTO_PGM, PGM_HEARTBEAT_SPM,
                &heartbeat_spm, sizeof (heartbeat_spm)))
            goto err_abort;
    }

    //  PGM transport GSI.
    struct pgm_sockaddr_t addr;

    memset (&addr, 0, sizeof(addr));
    addr.sa_port = port_number;
    addr.sa_addr.sport = DEFAULT_DATA_SOURCE_PORT;

    //  Create random GSI.
    uint32_t buf [2];
    buf [0] = generate_random ();
    buf [1] = generate_random ();
    if (!pgm_gsi_create_from_data (&addr.sa_addr.gsi, (uint8_t*) buf, 8))
        goto err_abort;


    //  Bind a transport to the specified network devices.
    struct pgm_interface_req_t if_req;
    memset (&if_req, 0, sizeof(if_req));
    if_req.ir_interface = res->ai_recv_addrs[0].gsr_interface;
    if_req.ir_scope_id  = 0;
    if (AF_INET6 == sa_family) {
        struct sockaddr_in6 sa6;
        memcpy (&sa6, &res->ai_recv_addrs[0].gsr_group, sizeof (sa6));
        if_req.ir_scope_id = sa6.sin6_scope_id;
    }
    if (!pgm_bind3 (sock, &addr, sizeof (addr), &if_req, sizeof (if_req),
          &if_req, sizeof (if_req), &pgm_error)) {

        //  Invalid parameters don't set pgm_error_t.
        zmq_assert (pgm_error != NULL);
        /*if ((pgm_error->domain == PGM_ERROR_DOMAIN_SOCKET ||
             pgm_error->domain == PGM_ERROR_DOMAIN_IF) && (
             pgm_error->code != PGM_ERROR_INVAL &&
             pgm_error->code != PGM_ERROR_BADF &&
             pgm_error->code != PGM_ERROR_FAULT))

            //  User, host, or network configuration or transient error.
            goto err_abort;*/

        
        if (pgm_error->domain == PGM_ERROR_DOMAIN_SOCKET)
        {     
           if(pgm_error->code != PGM_ERROR_INVAL)
           {
              if(pgm_error->code != PGM_ERROR_BADF )
              {
                  if(pgm_error->code != PGM_ERROR_FAULT)
                    do_this=1;
              }
           }
        }            
        if(pgm_error->domain == PGM_ERROR_DOMAIN_IF) 
        {     
           if(pgm_error->code != PGM_ERROR_INVAL)
           {
              if(pgm_error->code != PGM_ERROR_BADF )
              {
                  if(pgm_error->code != PGM_ERROR_FAULT)
                    do_this=1;
              }
           }
        }            
        if(do_this)
        {
            goto err_abort;
        }
        
        
        //  Fatal OpenPGM internal error.
        zmq_assert (false);
    }

    //  Join IP multicast groups.
    for (unsigned i = 0; i < res->ai_recv_addrs_len; i++) {
        if (!pgm_setsockopt (sock, IPPROTO_PGM, PGM_JOIN_GROUP,
              &res->ai_recv_addrs [i], sizeof (struct group_req)))
            goto err_abort;
    }
    if (!pgm_setsockopt (sock, IPPROTO_PGM, PGM_SEND_GROUP,
          &res->ai_send_addrs [0], sizeof (struct group_req)))
        goto err_abort;

    pgm_freeaddrinfo (res);
    res = NULL;

    //  Set IP level parameters.
    {
        // Multicast loopback disabled by default
        const int multicast_loop = 0;
        if (!pgm_setsockopt (sock, IPPROTO_PGM, PGM_MULTICAST_LOOP,
              &multicast_loop, sizeof (multicast_loop)))
            goto err_abort;

        const int multicast_hops = options.multicast_hops;
        if (!pgm_setsockopt (sock, IPPROTO_PGM, PGM_MULTICAST_HOPS,
                &multicast_hops, sizeof (multicast_hops)))
            goto err_abort;

        //  Expedited Forwarding PHB for network elements, no ECN.
        const int dscp = 0x2e << 2;
        if (AF_INET6 != sa_family && !pgm_setsockopt (sock,
              IPPROTO_PGM, PGM_TOS, &dscp, sizeof (dscp)))
            goto err_abort;

        const int nonblocking = 1;
        if (!pgm_setsockopt (sock, IPPROTO_PGM, PGM_NOBLOCK,
              &nonblocking, sizeof (nonblocking)))
            goto err_abort;
    }

    //  Connect PGM transport to start state machine.
    if (!pgm_connect (sock, &pgm_error)) {

        //  Invalid parameters don't set pgm_error_t.
        zmq_assert (pgm_error != NULL);
        goto err_abort;
    }

    //  For receiver transport preallocate pgm_msgv array.
    if (receiver) {
        zmq_assert (in_batch_size > 0);
        size_t max_tsdu_size = get_max_tsdu_size ();
        pgm_msgv_len = (int) in_batch_size / max_tsdu_size;
        if ((int) in_batch_size % max_tsdu_size)
            pgm_msgv_len++;
        zmq_assert (pgm_msgv_len);

        pgm_msgv = (pgm_msgv_t*) malloc (sizeof (pgm_msgv_t) * pgm_msgv_len);
        alloc_assert (pgm_msgv);
    }

    return 0;

err_abort:
    if (sock != NULL) {
        pgm_close (sock, FALSE);
        sock = NULL;
    }
    if (res != NULL) {
        pgm_freeaddrinfo (res);
        res = NULL;
    }
    if (pgm_error != NULL) {
        pgm_error_free (pgm_error);
        pgm_error = NULL;
    }
    errno = EINVAL;
    return -1;
}

# 10  
Old 01-11-2013
This is one of the problems with the goto construct. Conditional jumps are a special problem in the logic construction of a progam. I personally seldom use them, except in descent parsers (setjmp/longjmp are a kind of conditional jump, too).

Consider removing most of those jumps. There are some folks who would go on a 'Never use goto' rant. But everything in C++/C is there for good reason, including goto.

But: Absolutely do make err_abort() a separate function.

you should also instrument your code - add fprintf() statements liberally, use the __LINE__ preprocessor command to show where you are in the code. When you have jumps debugging can be extra hard.
# 11  
Old 01-11-2013
Unfortunately none of this is mine.
This is part of the open source library ZeroMQ, I've never used jumps since I stopped using basic.
I prefer to find a more logical way of coding my programs (I'm quite akin to those "never use jumps" ranting guys Smilie).
# 12  
Old 01-14-2013
I managed to understand an important detail:

the problem arises from how I pass parameters to the child thread.

If I just pass a void pointer to the zmq context, all is fine.
If I pass a pointer to my struct (with explicit castings on both sides), the problems shows its head.

Now I don't know enough to understand this, I hope someone more knowledgeable can chime in.

Here are the two possibilities

working
Code:
void *zmq_cont_ptr = zmq_ctx_new();
pthread_create(&th_hndl_subber, NULL, th_subscriber, zmq_cont_ptr);

non working
Code:
typedef struct parameters{
    //Zmqcpp::Context * zmqcont;
    void * zmqcont;
    void (*callback) (std::string);
    std::string ip;
    int conntype;
    std::list<std::string> topics;
}parameters;

parameters myparams;

pthread_create(&th_hndl_subber, NULL, th_subscriber, (void *)&myparams);

void * th_subscriber(void * parameters)
{
    parameters *myparams = (parameters *) params;

---------- Post updated at 04:52 PM ---------- Previous update was at 01:52 PM ----------

I finally know what's the problem!!!
Thanks to chaingun from IRC channel #programming on FreeNode!

The problem is how long a temporary buffer lasts in memory.
As he pointed out when I pass something like
Code:
std::string mystring = "something";
myfunc(mystring.c_str());

A temporary buffer is allocated for the array of chars, but there are no guarantees on how much it will last.
That was the problem because when I moved the parameters into const char arrays, I was able to both run and debug the program.

Thank you to all who took the time to read this!
This User Gave Thanks to erupter For This Post:
Corona688
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