Timestamp interaction

Namespaces
	osvr::util::time
	Functionality related to time and the OSVR_TimeValue abstraction.Note that this is for C API-bordering areas. For purely C++ code, please use std::chrono for your time needs.

Classes
struct	OSVR_TimeValue
	Standardized, portable parallel to struct timeval for representing both absolute times and time intervals. More...

Typedefs
typedef int64_t	OSVR_TimeValue_Seconds
	The signed integer type storing the seconds in a struct OSVR_TimeValue.
typedef int32_t	OSVR_TimeValue_Microseconds
	The signed integer type storing the microseconds in a struct OSVR_TimeValue.
typedef struct OSVR_TimeValue	OSVR_TimeValue
	Standardized, portable parallel to struct timeval for representing both absolute times and time intervals. More...

Functions
void	osvrTimeValueGetNow (OSVR_TimeValue *dest)
	Gets the current time in the TimeValue. Parallel to gettimeofday.
void	osvrTimeValueToStructTimeval (struct timeval *dest, const OSVR_TimeValue *src)
	Converts from a TimeValue struct to your system's struct timeval. More...
void	osvrStructTimevalToTimeValue (OSVR_TimeValue *dest, const struct timeval *src)
	Converts from a TimeValue struct to your system's struct timeval. More...
void	osvrTimeValueNormalize (OSVR_TimeValue *tv)
	"Normalizes" a time value so that the absolute number of microseconds is less than 1,000,000, and that the sign of both components is the same. More...
void	osvrTimeValueSum (OSVR_TimeValue *tvA, const OSVR_TimeValue *tvB)
	Sums two time values, replacing the first with the result. More...
void	osvrTimeValueDifference (OSVR_TimeValue *tvA, const OSVR_TimeValue *tvB)
	Computes the difference between two time values, replacing the first with the result. More...
int	osvrTimeValueCmp (const OSVR_TimeValue *tvA, const OSVR_TimeValue *tvB)
	Compares two time values (assumed to be normalized), returning the same values as strcmp. More...
OSVR_EXTERN_C_END double	osvrTimeValueDurationSeconds (const OSVR_TimeValue *tvA, const OSVR_TimeValue *tvB)
	Compute the difference between the two time values, returning the duration as a double-precision floating-point number of seconds. More...
OSVR_CBool	osvrTimeValueGreater (const OSVR_TimeValue *tvA, const OSVR_TimeValue *tvB)
	True if A is later than B.
bool	osvrTimeValueIsNormalized (const OSVR_TimeValue &tv)
	Returns true if the time value is normalized. Typically used in assertions.
bool	osvrTimeValueGreater (const OSVR_TimeValue &tvA, const OSVR_TimeValue &tvB)
	True if A is later than B.
bool	operator> (const OSVR_TimeValue &tvA, const OSVR_TimeValue &tvB)
	Operator > overload for time values.
bool	operator< (const OSVR_TimeValue &tvA, const OSVR_TimeValue &tvB)
	Operator < overload for time values.
bool	operator== (const OSVR_TimeValue &tvA, const OSVR_TimeValue &tvB)
	Operator == overload for time values.
bool	operator!= (const OSVR_TimeValue &tvA, const OSVR_TimeValue &tvB)
	Operator == overload for time values.

Detailed Description

This provides a level of interoperability with struct timeval on systems with that facility. It provides a neutral representation with sufficiently large types.

For C++ code, use of std::chrono or boost::chrono instead is recommended.

Note that these time values may not necessarily correlate between processes so should not be used to estimate or measure latency, etc.

Typedef Documentation

typedef struct OSVR_TimeValue OSVR_TimeValue

#include <osvr/Util/TimeValueC.h>

Standardized, portable parallel to struct timeval for representing both absolute times and time intervals.

Where interpreted as an absolute time, its meaning is to be considered the same as that of the POSIX struct timeval: time since 00:00 Coordinated Universal Time (UTC), January 1, 1970.

For best results, please keep normalized. Output of all functions here is normalized.

Function Documentation

void osvrTimeValueToStructTimeval	(	struct timeval *	dest,
		const OSVR_TimeValue *	src
	)

#include <osvr/Util/TimeValueC.h>

Converts from a TimeValue struct to your system's struct timeval.

Parameters

dest	Pointer to an empty struct timeval for your platform.
src	A pointer to an OSVR_TimeValue you'd like to convert from.

If either parameter is NULL, the function will return without doing anything.

void osvrStructTimevalToTimeValue	(	OSVR_TimeValue *	dest,
		const struct timeval *	src
	)

#include <osvr/Util/TimeValueC.h>

Converts from a TimeValue struct to your system's struct timeval.

Parameters

dest	An OSVR_TimeValue destination pointer.
src	Pointer to a struct timeval you'd like to convert from.

The result is normalized.

If either parameter is NULL, the function will return without doing anything.

void osvrTimeValueNormalize

(

OSVR_TimeValue *

tv

)

#include <osvr/Util/TimeValueC.h>

"Normalizes" a time value so that the absolute number of microseconds is less than 1,000,000, and that the sign of both components is the same.

Parameters

tv	Address of a struct TimeValue to normalize in place.

If the given pointer is NULL, this function returns without doing anything.

void osvrTimeValueSum	(	OSVR_TimeValue *	tvA,
		const OSVR_TimeValue *	tvB
	)

#include <osvr/Util/TimeValueC.h>

Sums two time values, replacing the first with the result.

Parameters

tvA	Destination and first source.
tvB	second source

If a given pointer is NULL, this function returns without doing anything.

Both parameters are expected to be in normalized form.

void osvrTimeValueDifference	(	OSVR_TimeValue *	tvA,
		const OSVR_TimeValue *	tvB
	)

#include <osvr/Util/TimeValueC.h>

Computes the difference between two time values, replacing the first with the result.

Effectively, *tvA = *tvA - *tvB

Parameters

tvA	Destination and first source.
tvB	second source

If a given pointer is NULL, this function returns without doing anything.

Both parameters are expected to be in normalized form.

int osvrTimeValueCmp	(	const OSVR_TimeValue *	tvA,
		const OSVR_TimeValue *	tvB
	)

#include <osvr/Util/TimeValueC.h>

Compares two time values (assumed to be normalized), returning the same values as strcmp.

Returns

<0 if A is earlier than B, 0 if they are the same, and >0 if A is later than B.

OSVR_EXTERN_C_END double osvrTimeValueDurationSeconds	(	const OSVR_TimeValue *	tvA,
		const OSVR_TimeValue *	tvB
	)

#include <osvr/Util/TimeValueC.h>

Compute the difference between the two time values, returning the duration as a double-precision floating-point number of seconds.

Effectively, ret = *tvA - *tvB

Parameters

tvA	first source.
tvB	second source

Returns

Duration of timespan in seconds (floating-point)

Definition at line 185 of file TimeValueC.h.