Qthread socket debugging

blocking_action.c

#include <stdio.h>  //printf
#include <string.h> //strcpy
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <netdb.h>
#include <fcntl.h>
#include <stdlib.h>
#include <errno.h>
#include <qthread/io.h>

typedef struct sockaddr_storage sys_sockaddr_storage_t;

int main(int argc, char *argv[])
{
  int socket_desc;
  int iport = 8000;

  //Create socket
  const int val_sock = AF_INET;
  socket_desc = socket(val_sock, SOCK_STREAM|SOCK_NONBLOCK, 0);
  if (socket_desc == -1)
  {
    printf("Could not create socket");
  }

  int flags = fcntl(socket_desc, F_GETFL, 0);
  fcntl(socket_desc, F_SETFL, flags | O_NONBLOCK);

  // fill in address
  sys_sockaddr_storage_t x;
  memset(&x, 0, sizeof(x));
  if(val_sock == AF_INET){
    struct sockaddr_in *x1 = (struct sockaddr_in *)&x;
    x1->sin_family = AF_INET;
    x1->sin_port = htons(iport);
    x1->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
  }
  else {
    struct sockaddr_in6 *x1 = (struct sockaddr_in6 *)&x;
    x1->sin6_family = AF_INET6;
    x1->sin6_port = htons(iport);
    x1->sin6_addr = in6addr_loopback;
  }

  // extract out data
  char address[NI_MAXHOST], port[NI_MAXSERV];
  int err = getnameinfo((struct sockaddr*)&x, sizeof(sys_sockaddr_storage_t), address, sizeof(address), port, sizeof(port), NI_NUMERICHOST | NI_NUMERICSERV);
  puts(address);
  puts(port);

  int n;

  qt_begin_blocking_action();
  if ((n = connect(socket_desc, (struct sockaddr *)&x, sizeof(x))) < 0)
  {
    if(errno != EINPROGRESS){
      puts(strerror(errno));
      exit(0);
    }
  }
  qt_end_blocking_action();

  puts("connect tried");

  if(n == 0){
    printf("connect success");
    exit(0);
  }

  fd_set rset, wset;
  FD_ZERO(&wset);
  FD_ZERO(&rset);
  FD_SET(socket_desc, &rset);
  FD_SET(socket_desc, &wset);
  struct timeval tval;
  tval.tv_sec = 10;
  tval.tv_usec = 0;


  qt_begin_blocking_action();
  if((n = select(socket_desc + 1, NULL, &wset, NULL, &tval)) == 0){
    puts(strerror(ETIMEDOUT));
    exit(0);
  }
  qt_end_blocking_action();
  puts("select tried");


  if(n < 0){
    puts(strerror(errno));
    exit(0);
  }
  puts("select error checked");


  if(FD_ISSET(socket_desc,&rset) || FD_ISSET(socket_desc, &wset)) {
    socklen_t len;
    if(getpeername(socket_desc, (struct sockaddr *)&x, &len) < 0){
      puts("peername fail");
      puts(strerror(errno));
      exit(0);
      if(errno == ENOTCONN){
        int err_t;
        socklen_t len = sizeof(err_t);
        if(getsockopt(socket_desc, SOL_SOCKET, SO_ERROR, &err_t, &len) < 0) {
          puts("getsockopt fail");
          close(socket_desc);
          puts(strerror(errno));
          exit(0);
        }
        if(err_t){
          close(socket_desc);
          puts(strerror(err_t));
          exit(0);
        }
      }
    }
  }
  else {
    close(socket_desc);
    puts("Select error: socketFd not set");
    exit(0);
  }
  puts("rset wset pass");


  printf("connect success");
}

connect.c

#include <stdio.h>  //printf
#include <string.h> //strcpy
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <netdb.h>
#include <fcntl.h>
#include <stdlib.h>
#include <errno.h>

typedef struct sockaddr_storage sys_sockaddr_storage_t;

int main(int argc, char *argv[])
{
  int socket_desc;
  int iport = 8000;

  //Create socket
  const int val_sock = AF_INET;
  socket_desc = socket(val_sock, SOCK_STREAM|SOCK_NONBLOCK, 0);
  if (socket_desc == -1)
  {
    printf("Could not create socket");
  }

  int flags = fcntl(socket_desc, F_GETFL, 0);
  fcntl(socket_desc, F_SETFL, flags | O_NONBLOCK);

  // fill in address
  sys_sockaddr_storage_t x;
  memset(&x, 0, sizeof(x));
  if(val_sock == AF_INET){
    struct sockaddr_in *x1 = (struct sockaddr_in *)&x;
    x1->sin_family = AF_INET;
    x1->sin_port = htons(iport);
    x1->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
  }
  else {
    struct sockaddr_in6 *x1 = (struct sockaddr_in6 *)&x;
    x1->sin6_family = AF_INET6;
    x1->sin6_port = htons(iport);
    x1->sin6_addr = in6addr_loopback;
  }

  // extract out data
  char address[NI_MAXHOST], port[NI_MAXSERV];
  int err = getnameinfo((struct sockaddr*)&x, sizeof(sys_sockaddr_storage_t), address, sizeof(address), port, sizeof(port), NI_NUMERICHOST | NI_NUMERICSERV);
  puts(address);
  puts(port);

  int n;

  if ((n = connect(socket_desc, (struct sockaddr *)&x, sizeof(x))) < 0)
  {
    if(errno != EINPROGRESS){
      puts(strerror(errno));
      exit(0);
    }
  }

  puts("connect tried");

  if(n == 0){
    printf("connect success");
    exit(0);
  }

  fd_set rset, wset;
  FD_ZERO(&wset);
  FD_ZERO(&rset);
  FD_SET(socket_desc, &rset);
  FD_SET(socket_desc, &wset);
  struct timeval tval;
  tval.tv_sec = 10;
  tval.tv_usec = 0;


  if((n = select(socket_desc + 1, NULL, &wset, NULL, &tval)) == 0){
    puts(strerror(ETIMEDOUT));
    exit(0);
  }
  puts("select tried");


  if(n < 0){
    puts(strerror(errno));
    exit(0);
  }
  puts("select error checked");


  if(FD_ISSET(socket_desc,&rset) || FD_ISSET(socket_desc, &wset)) {
    socklen_t len;
    if(getpeername(socket_desc, (struct sockaddr *)&x, &len) < 0){
      puts("peername fail");
      puts(strerror(errno));
      exit(0);
      if(errno == ENOTCONN){
        int err_t;
        socklen_t len = sizeof(err_t);
        if(getsockopt(socket_desc, SOL_SOCKET, SO_ERROR, &err_t, &len) < 0) {
          puts("getsockopt fail");
          close(socket_desc);
          puts(strerror(errno));
          exit(0);
        }
        if(err_t){
          close(socket_desc);
          puts(strerror(err_t));
          exit(0);
        }
      }
    }
  }
  else {
    close(socket_desc);
    puts("Select error: socketFd not set");
    exit(0);
  }
  puts("rset wset pass");


  printf("connect success");
}

qtconnect.c

#include <stdio.h>  //printf
#include <string.h> //strcpy
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <netdb.h>
#include <fcntl.h>
#include <stdlib.h>
#include <errno.h>
#include <qthread/io.h>
#include <qthread/qt_syscalls.h>
#include <qthread.h>

typedef struct sockaddr_storage sys_sockaddr_storage_t;

int main(int argc, char *argv[])
{
  int socket_desc;
  int iport = 8000;

  //Create socket
  const int val_sock = AF_INET;
  socket_desc = socket(val_sock, SOCK_STREAM|SOCK_NONBLOCK, 0);
  if (socket_desc == -1)
  {
    printf("Could not create socket");
  }

  int flags = fcntl(socket_desc, F_GETFL, 0);
  fcntl(socket_desc, F_SETFL, flags | O_NONBLOCK);

  // fill in address
  sys_sockaddr_storage_t x;
  memset(&x, 0, sizeof(x));
  if(val_sock == AF_INET){
    struct sockaddr_in *x1 = (struct sockaddr_in *)&x;
    x1->sin_family = AF_INET;
    x1->sin_port = htons(iport);
    x1->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
  }
  else {
    struct sockaddr_in6 *x1 = (struct sockaddr_in6 *)&x;
    x1->sin6_family = AF_INET6;
    x1->sin6_port = htons(iport);
    x1->sin6_addr = in6addr_loopback;
  }

  // extract out data
  char address[NI_MAXHOST], port[NI_MAXSERV];
  int err = getnameinfo((struct sockaddr*)&x, sizeof(sys_sockaddr_storage_t), address, sizeof(address), port, sizeof(port), NI_NUMERICHOST | NI_NUMERICSERV);
  puts(address);
  puts(port);

  int n;

  if ((n = qt_connect(socket_desc, (struct sockaddr *)&x, sizeof(x))) < 0)
  {
    if(errno != EINPROGRESS){
      puts(strerror(errno));
      exit(0);
    }
  }

  puts("connect tried");

  if(n == 0){
    printf("connect success");
    exit(0);
  }

  fd_set rset, wset;
  FD_ZERO(&wset);
  FD_ZERO(&rset);
  FD_SET(socket_desc, &rset);
  FD_SET(socket_desc, &wset);
  struct timeval tval;
  tval.tv_sec = 10;
  tval.tv_usec = 0;


  if((n = qt_select(socket_desc + 1, NULL, &wset, NULL, &tval)) == 0){
    puts(strerror(ETIMEDOUT));
    exit(0);
  }
  puts("select tried");


  if(n < 0){
    puts(strerror(errno));
    exit(0);
  }
  puts("select error checked");


  if(FD_ISSET(socket_desc,&rset) || FD_ISSET(socket_desc, &wset)) {
    socklen_t len;
    if(getpeername(socket_desc, (struct sockaddr *)&x, &len) < 0){
      puts("peername fail");
      puts(strerror(errno));
      exit(0);
      if(errno == ENOTCONN){
        int err_t;
        socklen_t len = sizeof(err_t);
        if(getsockopt(socket_desc, SOL_SOCKET, SO_ERROR, &err_t, &len) < 0) {
          puts("getsockopt fail");
          close(socket_desc);
          puts(strerror(errno));
          exit(0);
        }
        if(err_t){
          close(socket_desc);
          puts(strerror(err_t));
          exit(0);
        }
      }
    }
  }
  else {
    close(socket_desc);
    puts("Select error: socketFd not set");
    exit(0);
  }
  puts("rset wset pass");


  printf("connect success");
}

import select
import socket
from time import sleep

HEADER_LENGTH = 10

IP = "127.0.0.1"
PORT = 8000

#ipv4 and tcp
server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
#reconnect to same server
server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
server_socket.bind((IP, PORT))
#queue length
server_socket.listen()
sockets_list = [server_socket]

clients = {}

print(f'Listening for connections on {IP}:{PORT}...')

while True:
    read_sockets, _, exception_sockets = select.select(
        sockets_list, [], sockets_list)
    if server_socket in read_sockets:
      client_socket, client_address = server_socket.accept()
      print('Accepted new connection from {}:{}'.format(*client_address))
      client_socket.send("greb".encode())
      sleep(4)
    break

Sample server code