talker.c,v

这是P2P流媒体方案－NICE的实现源码

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1.1
date	2002.07.02.19.30.29;	author rbraud;	state Exp;
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1.1
log
@Initial revision
@
text
@/*
 talker.c -- a datagram "client" demo
*/

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <sys/time.h>
#include <unistd.h>
#include <netinet/in.h>
#include <netdb.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <arpa/inet.h>
#define MAXBUF 1024*1024

#define MINIMUM_WAIT_TIME	150000
#define MAXIMUM_WAIT_TIME	700000

int confidence(long *, int, float, float *, float *);

double estimate_rtt(struct sockaddr_in their_addr) { // host is IP addr. 
  int sockfd, i=0;
  //  struct sockaddr_in my_addr;    /* my address information */
  //  struct sockaddr_in their_addr,their_addr1; /* connector's address information */
  //  struct hostent *he;
  struct timeval start_time, end_time, tv;
  long total_time_in_musecs = 0;
  int cnt = 0, numbytes, selectRet;
  long confArr[100] = { 0 };
  float avg, delta;
  char message[]="hello";
  char buf[MAXBUF];
  fd_set rset;
  //  int MYPORT;

  /*
  if (argc != 3) {
    fprintf(stderr,"usage: talker hostname portnumber\n");
    exit(1);
  }
  */

  avg = 0;
  FD_ZERO(&rset);
  //  MYPORT=portnumber; 
  gettimeofday(&start_time,NULL);
  //  if ((he=gethostbyname(host)) == NULL) {  /* get the host info */
  //    perror("gethostbyname");
  //    exit(1);
  //  }
  
  if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
    perror("socket");
    exit(1);
  }
  FD_SET(sockfd,&rset);
  //  their_addr.sin_family = AF_INET;         /* host byte order */
  //  their_addr.sin_port = htons(MYPORT);     /* short, network byte order */
  //  their_addr.sin_addr = *((struct in_addr *)he->h_addr);
  //  bzero(&(their_addr.sin_zero), 8);        /* zero the rest of the struct */
  

//  printf ("familty was %d, should be %d\n",   their_addr.sin_family, AF_INET);
  their_addr.sin_family = AF_INET;         /* host byte order */
  
//  printf ("sending to inet: %s", inet_ntoa((struct in_addr )(their_addr.sin_addr)));
  
  while ((i++<10) && (total_time_in_musecs < MAXIMUM_WAIT_TIME))  {
    sprintf(message,"%d",i);
   gettimeofday(&start_time,NULL);
   if ((numbytes=sendto(sockfd,message,strlen(message),0,
			 (struct sockaddr *)&their_addr, 
			sizeof(struct sockaddr))) == -1) {
      perror("sending problem");
      printf( "Continuing..  ");
      continue;
    }
    
   if(FD_ISSET(sockfd,&rset)) {
     tv.tv_sec = 0;
     tv.tv_usec = MINIMUM_WAIT_TIME;
     do {
       sprintf(buf,"%d",i);
       //printf("ENTER - select\n");
       fflush(0);
     //  do {
         if((selectRet = select(sockfd+1,&rset,NULL,NULL,&tv)) > 0 ) {
	   numbytes = recvfrom(sockfd,buf,MAXBUF,0,NULL,NULL);
	   if (numbytes<0) {
	     perror("Problem in recvfrom");
	     continue;
	   } 
           //printf("DONE - recvfrom\n");
           fflush(0);
           if(atoi(buf) == i) {
	     gettimeofday(&end_time,NULL);
	     confArr[cnt++] = 1000000L*(end_time.tv_sec-start_time.tv_sec)+
	       (end_time.tv_usec -start_time.tv_usec);
           }
         } 
         gettimeofday(&end_time,NULL);
	 total_time_in_musecs += 1000000L*(end_time.tv_sec-start_time.tv_sec)+
             (end_time.tv_usec -start_time.tv_usec);
        //printf("CHECK2 total in usec = %ld SELECT_RET %d ERR_NO %d\n",
        //        total_time_in_musecs, selectRet, errno);
        fflush(0);
       //} while ((selectRet == -1 && errno == EINTR) && 
      //           total_time_in_musecs < MAXIMUM_WAIT_TIME); 
     } while (atoi(buf)<i  && total_time_in_musecs < MAXIMUM_WAIT_TIME);
     FD_SET(sockfd,&rset);
   }
   if(cnt >= 3) {
     confidence(confArr, cnt, 0.95, &avg, &delta);
      if(delta <= 0.1 * avg)
	break;
   }
  }//end of while 
    close(sockfd);
    //      printf("CNT = %d  AVG = %.0f  DELTA = %.0f\n NUMPACKETS LOST = %d", cnt, avg, delta, i - cnt);
  if(avg == 0)
    return 200000;
  return avg;
}

double estimate_rtt_wrapper(struct sockaddr_in their_addr) {

  double dist = estimate_rtt(their_addr);
  if (dist < 1000.0) return 500.0;
  if (dist < 5000.0) return 3000.0;
  if (dist < 10000.0) return 7500.0;
  if (dist < 20000.0) return 15000.0;
  if (dist < 40000.0) return 30000.0;
  if (dist < 80000.0) return 60000.0;
  if (dist < 160000.0) return 120000.0;
  return 200000.0;
}


/*
int main(int argc, char ** argv) {

  struct hostent *he;
  struct sockaddr_in their_addr; 

  if (argc != 3) {
    fprintf(stderr,"usage: %s hostname portnumber\n", argv[0]);
    exit(1);
  }

  
  if ((he=gethostbyname(argv[1])) == NULL) { 
    perror("gethostbyname");
    exit(1);
  }

  their_addr.sin_family = AF_INET;         
  their_addr.sin_port = htons(atoi(argv[2]));
  their_addr.sin_addr = *((struct in_addr *)he->h_addr);
  bzero(&(their_addr.sin_zero), 8);        
  printf(" %8.4f is the delay \n", estimate_rtt(their_addr));
  return 0; 
}
*/
@