echoping/SRC/rtt.h
Stephane Bortzmeyer 40d676b534 Initial revision
2000-04-13 09:19:23 +00:00

58 lines
1.7 KiB
C

/*
* Definitions for RTT timing.
*/
#include "systype.h"
#include <stdio.h>
#ifdef BSD
#include <sys/time.h>
#include <sys/resource.h>
#endif
#ifdef SYS5
#include <sys/times.h> /* requires <sys/types.h> */
#include <sys/param.h> /* need the definition of HZ */
#define TICKS HZ /* see times(2); usually 60 or 100 */
#endif
/*
* Structure to contain everything needed for RTT timing.
* One of these required per socket being timed.
* The caller allocates this structure, then passes its address to
* all the rtt_XXX() functions.
*/
struct rtt_struct {
float rtt_rtt; /* most recent round-trip time (RTT), seconds */
float rtt_srtt; /* smoothed round-trip time (SRTT), seconds */
float rtt_rttdev; /* smoothed mean deviation, seconds */
short rtt_nrexmt; /* #times retransmitted: 0, 1, 2, ... */
short rtt_currto; /* current retransmit timeout (RTO), seconds */
short rtt_nxtrto; /* retransmit timeout for next packet, if nonzero */
#ifdef BSD
struct timeval time_start; /* for elapsed time */
struct timeval time_stop; /* for elapsed time */
#endif
#ifdef SYS5
long time_start; /* for elapsed time */
long time_stop; /* for elapsed time */
struct tms tms_start; /* arg to times(2), but not used */
struct tms tms_stop; /* arg to times(2), but not used */
#endif
};
#define RTT_RXTMIN 2 /* min retransmit timeout value, seconds */
#define RTT_RXTMAX 120 /* max retransmit timeout value, seconds */
#define RTT_MAXNREXMT 4 /* max #times to retransmit: must also
change exp_backoff[] if this changes */
#ifdef SYS5
long times(); /* the system call */
#endif
extern int rtt_d_flag; /* can be set nonzero by caller for addl info */