mcast-srv.c

一个C编写网络广播的程序

/* mcast-srv.c -- multicasting server main thread 
 *  
 * This file is part of 'netcast' program, released under BSD License. 
 * (c) 2001-2002 Stanis砤w Pa秌o <[e-mail]>. All rights reserved.   
 */

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <pthread.h>
#include <signal.h>

#include "mdist.h"
#include "mcast.h"
#include "util.h"
#include "server.h"

void *mcast_srv_main(void *args) {
  struct sockaddr_in sin;                         /* endpoint address */
  int ms,i;                                       /* multicast socket */
  struct sempack *msp;                            /* Sync with TCP */
  char adr[128];
  long long total=0;
  int start,now;
  float speed;
  
  /* Open some random multicast group */
  msp = (struct sempack *) args;   
  srand(time(0));
  sprintf(adr,"%s%d",MCAST_ADDR_BASE,rand()%254+1);
  sin = make_addr(adr,server_port);
  mdini.group = sin;
  ms = init_mcast_socket(&sin); 
  md_init();  
  /* Let TCP servers accept connections */
  V(msp->init);
  P(msp->accept);
  MSG(7,"All your bases are belong to us.");
  start=time(0);
  do {     
    /* Read data from stdin */
    i = md_fill(0);
    if (!client_count) {
      i=0; mdhead.pkt=0;
    }
    MSG(7,"Lower your shields and surrender your ships.");
    /* tcp: Send headers */
    V(msp->prepare);
    P(msp->ready);
    /* multicast data */
    while (i--) 
      sendto(ms,mdbuf[i],mdbuf[i]->siz+sizeof(struct mdmsg),0,(struct sockaddr *)&sin,sizeof(sin));
    MSG(7,"Your biological distinctiveness will serve us.");
    /* tcp: Send end-of-data marks */
    V(msp->prepare);
    P(msp->finish);
    now=time(0);
    total=total+mdhead.siz;
    speed=(((float)total)/(1024*1024))/((float) now-start);
    fprintf(stderr,"\rnetcast: sent %lld bytes in %d secs at %.3f MBps",
                    total,now-start,speed);                   
  } while (mdhead.pkt); 
  /* fin. */
  MSG(7,"Resistance is futile. You shall be assimilated.");
  fprintf(stderr,"\nnetcast: done.\n");
  return 0;
}