tag.h File Reference

Time and tag definitions and functions for Lingua Franca. More...

#include <stdint.h>
#include <stddef.h>
#include <limits.h>

Go to the source code of this file.

Data Structures
struct	tag_t
	A tag is a time, microstep pair. More...

Macros
#define	BILLION   ((instant_t)1000000000LL)
	The number of nanoseconds in one second.
#define	CHECK_TIMEOUT(start, duration)
	Expression that is true if physical time since start exceeds the duration.
#define	DAY(t)
	Number of days.
#define	DAYS(t)
	Number of days.
#define	FOREVER   ((interval_t)LLONG_MAX)
	Time greater than all other times.
#define	FOREVER_MICROSTEP   UINT_MAX
	Largest microstep.
#define	FOREVER_TAG    (tag_t) { .time = FOREVER, .microstep = FOREVER_MICROSTEP }
	Tag later than all other tags.
#define	FOREVER_TAG_INITIALIZER   {FOREVER, FOREVER_MICROSTEP}
	Initializer for tag later than all other tags.
#define	HOUR(t)
	Number of hours.
#define	HOURS(t)
	Number of hours.
#define	LF_TIME_BUFFER_LENGTH   64
	For user-friendly reporting of time values, the buffer length required.
#define	MINUTE(t)
	Number of minutes.
#define	MINUTES(t)
	Number of minutes.
#define	MSEC(t)
	Number of milliseconds.
#define	MSECS(t)
	Number of milliseconds.
#define	NEVER   ((interval_t)LLONG_MIN)
	Time earlier than all other times.
#define	NEVER_MICROSTEP   0u
	Smallest microstep.
#define	NEVER_TAG    (tag_t) { .time = NEVER, .microstep = NEVER_MICROSTEP }
	Tag earlier than all other tags.
#define	NEVER_TAG_INITIALIZER   {NEVER, NEVER_MICROSTEP}
	Initializer for tag earlier than all other tags.
#define	NSEC(t)
	Number of nanoseconds.
#define	NSECS(t)
	Number of nanoseconds.
#define	SEC(t)
	Number of seconds.
#define	SECOND(t)
	Number of seconds.
#define	SECONDS(t)
	Number of seconds.
#define	SECS(t)
	Number of seconds.
#define	USEC(t)
	Number of microseconds.
#define	USECS(t)
	Number of microseconds.
#define	WEEK(t)
	Number of weeks.
#define	WEEKS(t)
	Number of weeks.
#define	ZERO_TAG   (tag_t){.time = 0LL, .microstep = 0u}
	Zero tag.

Typedefs
typedef int64_t	instant_t
	Time instant.
typedef int64_t	interval_t
	Interval of time.
typedef uint32_t	microstep_t
	Microstep.

Functions
size_t	lf_comma_separated_time (char *buffer, instant_t time)
	Print a non-negative time value in nanoseconds with commas separating thousands into the specified buffer.
tag_t	lf_delay_strict (tag_t tag, interval_t interval)
	Return the latest tag strictly less than the specified tag plus the interval, unless tag is NEVER or interval is negative (including NEVER),.
tag_t	lf_delay_tag (tag_t tag, interval_t interval)
	Delay a tag by the specified time interval to realize the "after" keyword.
size_t	lf_readable_time (char *buffer, instant_t time)
	Store into the specified buffer a string giving a human-readable rendition of the specified time.
tag_t	lf_tag (void *env)
	Return the current tag, a logical time, microstep pair.
tag_t	lf_tag_add (tag_t a, tag_t b)
	Add two tags.
int	lf_tag_compare (tag_t tag1, tag_t tag2)
	Compare two tags.
tag_t	lf_tag_latest_earlier (tag_t tag)
	Return the greatest tag earlier than the given tag.
tag_t	lf_tag_max (tag_t tag1, tag_t tag2)
	Return the greater out of two tags.
tag_t	lf_tag_min (tag_t tag1, tag_t tag2)
	Return the lesser out of two tags.
instant_t	lf_time_add (instant_t a, interval_t b)
	Return the sum of an interval and an instant, saturating on overflow and underflow.
instant_t	lf_time_logical (void *env)
	Return the current logical time in nanoseconds.
interval_t	lf_time_logical_elapsed (void *env)
	Return the elapsed logical time in nanoseconds since the start of execution.
instant_t	lf_time_physical (void)
	Return the current physical time in nanoseconds.
instant_t	lf_time_physical_elapsed (void)
	Return the elapsed physical time in nanoseconds.
instant_t	lf_time_start (void)
	Return the physical and logical time of the start of execution in nanoseconds.
instant_t	lf_time_subtract (instant_t a, interval_t b)
	Return an instant minus an interval, saturating on overflow and underflow.

Detailed Description

Time and tag definitions and functions for Lingua Franca.

Author

Edward A. Lee

Soroush Bateni

Hou Seng (Steven) Wong

This file defines the core time and tag types and operations used throughout the Lingua Franca runtime. It provides functions for manipulating logical and physical time, as well as the tag structure that combines time with microsteps.