#include <netinet/in.h>
#include <pthread.h>
#include <stdio.h>
#include <sys/socket.h>
#include <sys/types.h>


struct sockaddr_in  addr_0, addr_1, addr_2 ;
int                 fd0, fd1, rv0, rv1, addrlen;
char                buf_0[1024], buf_1[1024];
pthread_t           thread;
void*               thread_rv;


void* thread_main (void* arg) {

  int i;  for ( i=0;  i<3;  i++ ) {

    addr_2.sin_family       =  0;
    addr_2.sin_port         =  0;
    addr_2.sin_addr.s_addr  =  0;

    addrlen = sizeof addr_2;
    rv1 = recvfrom ( fd1, buf_0, sizeof buf_0, 0,
		     (struct sockaddr*) &addr_2, &addrlen );

    int fam   =  addr_2.sin_family;
    int port  =  addr_2.sin_port;
    int addr  =  addr_2.sin_addr.s_addr;

    printf ("\n");
    perror ("thread  recvfrom");
    printf ( "  rv %d  addrlen %d  fam %d  port %d  addr %x\n",
	     rv1, addrlen, fam, ntohs (port), addr );
    ;;; }

  return NULL; }


void main_main () {

  send ( fd0, "hello", 6, 0);
  send ( fd0, "",      0, 0);
  usleep (100000);

  rv0 = shutdown ( fd1, SHUT_RD );
  printf ("\n");
  perror ("main    shutdown");
  printf ("  %d\n", rv0)

  ;;; }


int main () {

  addr_0.sin_family = AF_INET;
  addr_0.sin_port = htons (8000);
  inet_pton ( AF_INET, "127.0.0.1", &addr_0.sin_addr );

  addr_1.sin_family = AF_INET;
  addr_1.sin_port = htons (8001);
  inet_pton ( AF_INET, "127.0.0.1", &addr_1.sin_addr );

  fd0 = socket ( AF_INET, SOCK_DGRAM, 0 );
  bind    ( fd0, (struct sockaddr*) &addr_0, sizeof addr_0 );
  connect ( fd0, (struct sockaddr*) &addr_1, sizeof addr_1 );

  fd1 = socket ( AF_INET, SOCK_DGRAM, 0 );
  bind    ( fd1, (struct sockaddr*) &addr_1, sizeof addr_1 );
  connect ( fd1, (struct sockaddr*) &addr_0, sizeof addr_0 );

  pthread_create ( &thread, NULL, thread_main, NULL );
  main_main ();
  pthread_join ( thread, &thread_rv );

  return 0; }