udpr.h

chat program in linux use multiple broadcase implement by c language

#ifndef __UDPR_H
#define __UDPR_H

struct rtt_info {
      float   rtt_rtt;                      // most recent measured RTT, in seconds 
      float   rtt_srtt;                     // smoothed RTT estimator, in seconds 
      float   rtt_rttvar;                   // smoothed mean deviation, in seconds 
      float   rtt_rto;                      // current RTO to use, in seconds 
      int     rtt_nrexmt;                   // # times retransmitted: 0, 1, 2, ... 
      unsigned int  rtt_base;               // # sec since 1/1/1970 at start 
 };

#define RTT_RXTMIN            2             // min retransmit timeout value, in seconds 
#define RTT_RXTMAX          60              // max retransmit timeout value, in seconds 
#define RTT_MAXNREXMT   3                   // max # times to retransmit 

// function prototypes 

int udp_send_recv (int fd,const void *outbuff,int outbytes,
			          void *inbuff,int inbytes,
			   const struct sockaddr *destaddr,int destlen);
void        rtt_init(struct rtt_info *);
void        rtt_newpack(struct rtt_info *);
int           rtt_start(struct rtt_info *);
void        rtt_stop(struct rtt_info *, uint32_t);
int           rtt_timeout(struct rtt_info *);
unsigned int rtt_ts(struct rtt_info *);
#endif  //