/*
 * Copyright 2000, International Business Machines Corporation and others.
 * All Rights Reserved.
 * 
 * This software has been released under the terms of the IBM Public
 * License.  For details, see the LICENSE file in the top-level source
 * directory or online at http://www.openafs.org/dl/license10.html
 */

/* Elapsed time package */
/* This package maintains a clock which is independent of the time of day.  It uses the 4.3BSD interval timer (getitimer/setitimer) in TIMER_REAL mode.  Any other use of the timer voids this package's warranty. */

#ifndef _CLOCK_
#define _CLOCK_

#ifdef	KERNEL
#if defined(AFS_AIX_ENV) || defined(AFS_AUX_ENV)
#include "../h/systm.h"
#include "../h/time.h"
#endif	/* System V */
#else /* KERNEL */
#ifndef AFS_NT40_ENV
#ifndef ITIMER_REAL
#include <sys/time.h>
#endif /* ITIMER_REAL */
#else
#include <time.h>
#include <afs/afsutil.h>
#endif
#endif /* KERNEL */

/* Some macros to make macros more reasonable (this allows a block to be used within a macro which does not cause if statements to screw up).   That is, you can use "if (...) macro_name(); else ...;" without having things blow up on the semi-colon. */

#ifndef BEGIN
#define BEGIN do {
#define END } while(0)
#endif

/* A clock value is the number of seconds and microseconds that have elapsed since calling clock_Init. */
struct clock {
    afs_int32 sec;	    /* Seconds since clock_Init */
    afs_int32 usec;	    /* Microseconds since clock_Init */
};

#ifndef	KERNEL
#if defined(AFS_USE_GETTIMEOFDAY) || defined(AFS_PTHREAD_ENV)
#define clock_Init()
#define clock_NewTime()
#define clock_UpdateTime()
#define clock_GetTime(cv) (gettimeofday((struct timeval *)cv, NULL))
#define clock_Sec() (time(NULL))
#define clock_haveCurrentTime 1
#else /* AFS_USE_GETTIMEOFDAY || AFS_PTHREAD_ENV */

/* For internal use.  The last value returned from clock_GetTime() */
extern struct clock clock_now;

/* For internal use:  this flag, if set, indicates a new time should be read by clock_getTime() */
extern int clock_haveCurrentTime;

/* For external use: the number of times the clock value is actually updated */
extern int clock_nUpdates;

/* Initialize the clock package */
extern void clock_Init();

#define	clock_NewTime()	(clock_haveCurrentTime = 0)

/* Update the value to be returned by gettime */
extern void clock_UpdateTime();

/* Return the current clock time.  If the clock value has not been updated since the last call to clock_NewTime, it is updated now */
#define	clock_GetTime(cv)				\
    BEGIN						\
	if (!clock_haveCurrentTime) clock_UpdateTime(); \
	(cv)->sec = clock_now.sec;			\
	(cv)->usec = clock_now.usec;			\
    END

/* Current clock time, truncated to seconds */
#define	clock_Sec() ((!clock_haveCurrentTime)? clock_UpdateTime(), clock_now.sec:clock_now.sec)
#endif /* AFS_USE_GETTIMEOFDAY || AFS_PTHREAD_ENV */
#else /* KERNEL */
#include "../afs/afs_osi.h"
#define clock_Init()
#if defined(AFS_SGI61_ENV) || defined(AFS_HPUX_ENV) || defined(AFS_LINUX_64BIT_KERNEL)
#define clock_GetTime(cv) osi_GetTime((osi_timeval_t *)cv)
#else
#define clock_GetTime(cv) osi_GetTime((struct timeval *)cv)
#endif
#define clock_Sec() osi_Time()
#define	clock_NewTime()    /* don't do anything; clock is fast enough in kernel */
#endif /* KERNEL */

/* Returns the elapsed time in milliseconds between clock values (*cv1) and (*cv2) */
#define clock_ElapsedTime(cv1, cv2) \
    (((cv2)->sec - (cv1)->sec)*1000 + ((cv2)->usec - (cv1)->usec)/1000)

#ifdef AFS_PTHREAD_ENV
#define clock_Advance(cv)
#else
/* Advance the known value of the current clock time (clock_now) by the specified clock value */
#define clock_Advance(cv) clock_Add(&clock_now, cv)
#endif /* AFS_PTHREAD_ENV */

/* Some comparison operators for clock values */
#define	clock_Gt(a, b)	((a)->sec>(b)->sec || ((a)->sec==(b)->sec && (a)->usec>(b)->usec))
#define	clock_Ge(a, b)	((a)->sec>(b)->sec || ((a)->sec==(b)->sec && (a)->usec>=(b)->usec))
#define	clock_Eq(a, b)	((a)->sec==(b)->sec && (a)->usec==(b)->usec)
#define	clock_Le(a, b)	((a)->sec<(b)->sec || ((a)->sec==(b)->sec && (a)->usec<=(b)->usec))
#define	clock_Lt(a, b)	((a)->sec<(b)->sec || ((a)->sec==(b)->sec && (a)->usec<(b)->usec))

/* Is the clock value zero? */
#define	clock_IsZero(c)	((c)->sec == 0 && (c)->usec == 0)

/* Set the clock value to zero */
#define	clock_Zero(c)	((c)->sec = (c)->usec = 0)

/* Add time c2 to time c1.  Both c2 and c1 must be positive times. */
#define	clock_Add(c1, c2)					\
    BEGIN							\
	if (((c1)->usec += (c2)->usec) >= 1000000) {		\
	    (c1)->usec -= 1000000;				\
	    (c1)->sec++;					\
	}							\
	(c1)->sec += (c2)->sec;					\
    END

#define MSEC(cp)	((cp->sec * 1000) + (cp->usec / 1000))

/* Add ms milliseconds to time c1.  Both ms and c1 must be positive */
#define	clock_Addmsec(c1, ms)					 \
    BEGIN							 \
	if ((ms) >= 1000) {					 \
	    (c1)->sec += (afs_int32)((ms) / 1000);			 \
	    (c1)->usec += (afs_int32)(((ms) % 1000) * 1000);	 \
	} else {						 \
	    (c1)->usec += (afs_int32)((ms) * 1000);			 \
	}							 \
        if ((c1)->usec >= 1000000) {		                 \
	    (c1)->usec -= 1000000;				 \
	    (c1)->sec++;					 \
	}							 \
    END

/* Subtract time c2 from time c1.  c2 should be less than c1 */
#define	clock_Sub(c1, c2)					\
    BEGIN							\
	if (((c1)->usec	-= (c2)->usec) < 0) {			\
	    (c1)->usec += 1000000;				\
	    (c1)->sec--;					\
	}							\
	(c1)->sec -= (c2)->sec;					\
    END

#define clock_Float(c) ((c)->sec + (c)->usec/1e6)

/* Add square of time c2 to time c1.  Both c2 and c1 must be positive times. */
#define	clock_AddSq(c1, c2)					              \
    BEGIN							              \
   if((c2)->sec > 0 )                                                         \
     {                                                                        \
       (c1)->sec += (c2)->sec * (c2)->sec                                     \
                    +  2 * (c2)->sec * (c2)->usec /1000000;                   \
       (c1)->usec += (2 * (c2)->sec * (c2)->usec) % 1000000                   \
                     + ((c2)->usec / 1000)*((c2)->usec / 1000)                \
                     + 2 * ((c2)->usec / 1000) * ((c2)->usec % 1000) / 1000   \
                     + ((((c2)->usec % 1000) > 707) ? 1 : 0);                 \
     }                                                                        \
   else                                                                       \
     {                                                                        \
       (c1)->usec += ((c2)->usec / 1000)*((c2)->usec / 1000)                  \
                     + 2 * ((c2)->usec / 1000) * ((c2)->usec % 1000) / 1000   \
                     + ((((c2)->usec % 1000) > 707) ? 1 : 0);                 \
     }                                                                        \
   if ((c1)->usec > 1000000) {                                                \
        (c1)->usec -= 1000000;                                                \
        (c1)->sec++;                                                          \
   }                                                                          \
    END

#endif /* _CLOCK_ */
