TMR.h File Reference

Provides a set of timing macros. More...

#include <IPBS/PTS.h>

Classes
struct	_TMR_usecs_nsecs
	Structure to hold the time in terms of two integers, one giving the number of micro-seconds, the other the number of milliseconds. More...
Defines
#define	TMR_GET()   PTS_GETS()
	Macro to get the processor time.
#define	TMR_TO_NSECS(_ticks)   PTS_PTUS_TO_NSECS(_ticks)
	Convert a time processor time ticks to nanoseconds.
#define	TMR_DELTA(_beg, _end)   PTS_DELTAS(_beg, _end)
	Subtracts two times in ticks, returning the result in ticks.
#define	TMR_DELTA_IN_NSECS(_beg, _end)   PTS_DELTAS_IN_NSECS(_beg, _end)
	Subtracts two times in tickss, returning the result in nanoseconds.
Typedefs
typedef unsigned int	TMR_tick
	The type of an elapsed unit of time.
typedef struct _TMR_usecs_nsecs	TMR_usecs_nsecs
	Typedef for struct _TMR_usecs_nsecs.
Functions
unsigned int	TMR_ticks_to_nsecs (TMR_tick ticks)
	Convert a number of ticks to nanoseconds.
TMR_usecs_nsecs	TMR_ticks_to_usecs_nsecs (TMR_tick ticks)
	Convert a number of ticks useconds.nanoseconds.

---

Detailed Description

Provides a set of timing macros.

Author:

JJRussell - russell@slac.stanford.edu

   CVS $Id: TMR.h,v 1.2 2011/03/25 21:15:03 saxton Exp $

SYNPOSIS

This implements a facility to time accurately short duration events. The implementation is platform dependent, seeking to use the highest resolution clock that is available. The facility provides a uniform and consistent compile time interface. Note that this is not the same as a uniform and consistent run time interface. In particular the timer units may vary platform to platform. However, TMR_get always returns an unsigned int, independent of the actual resolution.

Finally, to keep the overhead low, consistent with timing short duration events, certain compromises where made. In general, do not use this facility to time events > 4 secs. The normal system clocks should be used instead.

USAGE

    TMR_tick     beg;
    TMR_tick     end;
    TMR_tick elapsed;
  
    beg     = TMR_GET();
    .
    eventToTime ();
    .
    end     = TMR_GET();
    elapsed = end - beg;
  
    printf ("Begin   Time: %8d ticks\n", beg);
    printf ("End     Time: %8d ticks\n", end);
    printf ("Elasped Time: %8d ticks\n", elapsed);
    printf ("Elasped Time: %8d"ticks\n", TMR_TO_NSECS (elapsed);

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Define Documentation

#define TMR_DELTA	(	_beg,
		_end		)	PTS_DELTAS(_beg, _end)

Subtracts two times in ticks, returning the result in ticks.

Parameters:

	_beg	The beginning time in processor timer ticks
	_end	The ending time in processor timer ticks

Returns:

The difference is processor timer ticks

For many processor's, this is just a subtraction.two 32 or 64 bit integer. However, on some platforms, the time is returned in a structure and the subtraction is not quite as trivial. If this were C++, one would have overloaded the '-' operator,

#define TMR_DELTA_IN_NSECS	(	_beg,
		_end		)	PTS_DELTAS_IN_NSECS(_beg, _end)

Subtracts two times in tickss, returning the result in nanoseconds.

Parameters:

	_beg	The beginning time in processor timer ticks
	_end	The ending time in processor timer ticks

Returns:

The difference is nanoseconds

#define TMR_TO_NSECS

(

_ticks

)

PTS_PTUS_TO_NSECS(_ticks)

Convert a time processor time ticks to nanoseconds.

Parameters:

_ticks

The value to convert

Returns:

The converted value

Referenced by TMR_ticks_to_nsecs(), and TMR_ticks_to_usecs_nsecs().

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Typedef Documentation

TMR_usecs_nsecs

Typedef for struct _TMR_usecs_nsecs.

Usage

This should be used for display purposes only.

---

Function Documentation

unsigned int TMR_ticks_to_nsecs

(

TMR_tick

ticks

)

Convert a number of ticks to nanoseconds.

Parameters:

ticks

The number of ticks to convert to nanoseconds

Returns:

The number of equivalent nanoseconds

References TMR_TO_NSECS.

TMR_usecs_nsecs TMR_ticks_to_usecs_nsecs

(

TMR_tick

ticks

)

Convert a number of ticks useconds.nanoseconds.

Parameters:

ticks

The number of ticks to convert

Returns:

The number of equivalent useconds, nanoseconds

References _TMR_usecs_nsecs::nsecs, TMR_TO_NSECS, and _TMR_usecs_nsecs::usecs.