osaTimeServer Class Reference

Class for relative time. More...

#include <osaTimeServer.h>

Inheritance diagram for osaTimeServer:

Public Member Functions
	osaTimeServer ()
	~osaTimeServer ()
void	SetTimeOrigin (void)
void	SetTimeOriginFrom (const osaTimeServer *other)
bool	GetTimeOrigin (osaAbsoluteTime &origin) const
double	GetRelativeTime (void) const
double	GetAbsoluteTimeInSeconds (void) const
osaAbsoluteTime	GetAbsoluteTime (void) const
double	EstimateDrift (void) const
void	RelativeToAbsolute (double relative, osaAbsoluteTime &absolute) const
double	AbsoluteToRelative (const osaAbsoluteTime &absolute) const
Public Member Functions inherited from cmnGenericObject
virtual	~cmnGenericObject (void)
virtual const cmnClassServicesBase *	Services (void) const =0
bool	ReconstructFrom (const cmnGenericObject &other)
std::string	ToString (void) const
virtual void	ToStream (std::ostream &outputStream) const
virtual void	ToStreamRaw (std::ostream &outputStream, const char delimiter=' ', bool headerOnly=false, const std::string &headerPrefix="") const
virtual bool	FromStreamRaw (std::istream &inputStream, const char delimiter=' ')
virtual void	SerializeRaw (std::ostream &outputStream) const
virtual void	DeSerializeRaw (std::istream &inputStream)
virtual cmnLogger::StreamBufType *	GetLogMultiplexer (void) const
virtual size_t	ScalarNumber (void) const
virtual bool	ScalarNumberIsFixed (void) const
virtual double	Scalar (const size_t CMN_UNUSED(index)) const CISST_THROW(std
virtual std::string	ScalarDescription (const size_t CMN_UNUSED(index), const std::string &CMN_UNUSED(userDescription)) const

Friends
class	osaTimeServerTest

Detailed Description

Class for relative time.

The osaRelativeTime class is used to manage the relationship between relative and absolute time. Specifically, the GetRelativeTime method returns the number of seconds that have elapsed since the time origin was set (via a call to SetTimeOrigin).

Although it might seem possible to implement this class without OS dependencies (e.g., by using osaGetAbsoluteTime), this is problematic on some platforms, such as Windows, where it is necessary to synchronize multiple time sources to get a high resolution time that is relative to an absolute time. Also, even on non-Windows platforms, it would not have been as efficient because the native (OS-specific) "absolute time" structure would have to converted to an osaAbsoluteTime structure for every call to GetRelativeTime.

This class has significant overlap with osaStopwatch.

Constructor & Destructor Documentation

osaTimeServer()

osaTimeServer::osaTimeServer

(

)

Default constructor.

~osaTimeServer()

osaTimeServer::~osaTimeServer

(

)

Destructor

Member Function Documentation

AbsoluteToRelative()

double osaTimeServer::AbsoluteToRelative

(

const osaAbsoluteTime &

absolute

)

const

Convert the specified absolute time to a relative time by subtracting from the time origin and converting to seconds.

Parameters

absolute

The absolute time value (input)

Returns

The relative time value in seconds

EstimateDrift()

double osaTimeServer::EstimateDrift

(

void

)

const

Estimate drift between synchronized clocks (Windows only)

GetAbsoluteTime()

osaAbsoluteTime osaTimeServer::GetAbsoluteTime

(

void

)

const

Get the absolute time since 1970.

Returns

The number of seconds

GetAbsoluteTimeInSeconds()

double osaTimeServer::GetAbsoluteTimeInSeconds

(

void

)

const

Get the number of seconds that have elapsed since 1970.

Returns

The number of seconds

GetRelativeTime()

double osaTimeServer::GetRelativeTime

(

void

)

const

Get the number of seconds that have elapsed since the time origin.

Returns

The number of seconds

GetTimeOrigin()

bool osaTimeServer::GetTimeOrigin

(

osaAbsoluteTime &

origin

)

const

Get the time origin that is in effect for the relative time measurements.

Parameters

origin

Returns the current origin

RelativeToAbsolute()

void osaTimeServer::RelativeToAbsolute	(	double	relative,
		osaAbsoluteTime &	absolute ) const

Convert the specified relative time (in seconds) to an absolute time by adding it to the time origin.

Parameters

relative	The relative time value in seconds (input)
absolute	The absolute time value (output)

SetTimeOrigin()

void osaTimeServer::SetTimeOrigin

(

void

)

Set the time origin for the relative time measurements to "now". Subsequent calls to GetRelativeTime will return the number of seconds that have elaspsed since this call was made.

SetTimeOriginFrom()

void osaTimeServer::SetTimeOriginFrom

(

const osaTimeServer *

other

)

Set the time origin based on the specified time server. For systems that need to synchronize to the performance counter, this also sets the offset (i.e., does not call Synchronize again).

Friends And Related Symbol Documentation

osaTimeServerTest

friend class osaTimeServerTest

friend

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The documentation for this class was generated from the following file:

• tmp/cisst-saw/cisst/cisstOSAbstraction/osaTimeServer.h