reactor-c
C Runtime for Lingua Franca
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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 |
Typedefs | |
typedef int64_t | instant_t |
typedef int64_t | interval_t |
typedef uint32_t | microstep_t |
Functions | |
tag_t | lf_tag (void *env) |
tag_t | lf_tag_add (tag_t a, tag_t b) |
int | lf_tag_compare (tag_t tag1, tag_t tag2) |
tag_t | lf_delay_tag (tag_t tag, interval_t interval) |
tag_t | lf_delay_strict (tag_t tag, interval_t interval) |
instant_t | lf_time_logical (void *env) |
interval_t | lf_time_logical_elapsed (void *env) |
instant_t | lf_time_physical (void) |
instant_t | lf_time_physical_elapsed (void) |
instant_t | lf_time_start (void) |
size_t | lf_readable_time (char *buffer, instant_t time) |
size_t | lf_comma_separated_time (char *buffer, instant_t time) |
Time and tag definitions and functions for Lingua Franca.
#define DAY | ( | t | ) | ((interval_t)(t * 86400000000000LL)) |
#define DAYS | ( | t | ) | ((interval_t)(t * 86400000000000LL)) |
#define FOREVER ((interval_t)LLONG_MAX) |
#define FOREVER_TAG (tag_t) { .time = FOREVER, .microstep = FOREVER_MICROSTEP } |
#define FOREVER_TAG_INITIALIZER { FOREVER, FOREVER_MICROSTEP } |
#define HOUR | ( | t | ) | ((interval_t)(t * 3600000000000LL)) |
#define HOURS | ( | t | ) | ((interval_t)(t * 3600000000000LL)) |
#define LF_TIME_BUFFER_LENGTH 64 |
For user-friendly reporting of time values, the buffer length required. This is calculated as follows, based on 64-bit time in nanoseconds: Maximum number of weeks is 15,250 Maximum number of days is 6 Maximum number of hours is 23 Maximum number of minutes is 59 Maximum number of seconds is 59 Maximum number of nanoseconds is 999,999,999 Maximum number of microsteps is 4,294,967,295 Total number of characters for the above is 24. Text descriptions and spaces add an additional 30, for a total of 54. One more allows for a null terminator. Round up to a power of two.
#define MINUTE | ( | t | ) | ((interval_t)(t * 60000000000LL)) |
#define MINUTES | ( | t | ) | ((interval_t)(t * 60000000000LL)) |
#define MSEC | ( | t | ) | ((interval_t)(t * 1000000LL)) |
#define MSECS | ( | t | ) | ((interval_t)(t * 1000000LL)) |
#define NEVER ((interval_t)LLONG_MIN) |
#define NEVER_MICROSTEP 0u |
#define NEVER_TAG (tag_t) { .time = NEVER, .microstep = NEVER_MICROSTEP } |
#define NEVER_TAG_INITIALIZER { NEVER, NEVER_MICROSTEP } |
#define NSEC | ( | t | ) | ((interval_t)(t * 1LL)) |
#define NSECS | ( | t | ) | ((interval_t)(t * 1LL)) |
#define SEC | ( | t | ) | ((interval_t)(t * 1000000000LL)) |
#define SECOND | ( | t | ) | ((interval_t)(t * 1000000000LL)) |
#define SECONDS | ( | t | ) | ((interval_t)(t * 1000000000LL)) |
#define SECS | ( | t | ) | ((interval_t)(t * 1000000000LL)) |
#define USEC | ( | t | ) | ((interval_t)(t * 1000LL)) |
#define USECS | ( | t | ) | ((interval_t)(t * 1000LL)) |
#define WEEK | ( | t | ) | ((interval_t)(t * 604800000000000LL)) |
#define WEEKS | ( | t | ) | ((interval_t)(t * 604800000000000LL)) |
Time instant. Both physical and logical times are represented using this typedef.
Interval of time.
Microstep instant.
Print a non-negative time value in nanoseconds with commas separating thousands into the specified buffer. Ideally, this would use the locale to use periods if appropriate, but I haven't found a sufficiently portable way to do that.
buffer | A buffer long enough to contain a string like "9,223,372,036,854,775,807". |
time | A time value. |
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), in which case return the tag unmodified. Any interval less than 0 (including NEVER) is interpreted as "no delay", whereas an interval equal to 0 is interpreted as one microstep delay. If the time sum overflows, saturate the time value at FOREVER. For example:
tag | The tag to increment. |
interval | The time interval. |
tag_t lf_delay_tag | ( | tag_t | tag, |
interval_t | interval ) |
Delay a tag by the specified time interval to realize the "after" keyword. Any interval less than 0 (including NEVER) is interpreted as "no delay", whereas an interval equal to 0 is interpreted as one microstep delay. If the time field of the tag is NEVER or the interval is negative, return the unmodified tag. If the time interval is 0LL, add one to the microstep, leave the time field alone, and return the result. Otherwise, add the interval to the time field of the tag and reset the microstep to 0. If the sum overflows, saturate the time value at FOREVER. For example:
tag | The tag to increment. |
interval | The time interval. |
Store into the specified buffer a string giving a human-readable rendition of the specified time. The buffer must have length at least equal to LF_TIME_BUFFER_LENGTH. The format is:
where each x
is a string of numbers with commas inserted if needed every three numbers and unit
is ns, us, or ms.
buffer | The buffer into which to write the string. |
time | The time to write. |
Return the current tag, a logical time, microstep pair.
env | A pointer to the environment from which we want the current tag. |
Add two tags. If either tag has has NEVER or FOREVER in its time field, then return NEVER_TAG or FOREVER_TAG, respectively. Also return NEVER_TAG or FOREVER_TAG if the result underflows or overflows when adding the times. If the microstep overflows, also return FOREVER_TAG. If the time field of the second tag is greater than 0, then the microstep of the first tag is reset to 0 before adding. This models the delay semantics in LF and makes this addition operation non-commutative.
a | The first tag. |
b | The second tag. |
Compare two tags. Return -1 if the first is less than the second, 0 if they are equal, and +1 if the first is greater than the second. A tag is greater than another if its time is greater or if its time is equal and its microstep is greater.
tag1 | |
tag2 |
Return the current logical time in nanoseconds. On many platforms, this is the number of nanoseconds since January 1, 1970, but it is actually platform dependent.
env | The environment from which we want the current logical time. |
interval_t lf_time_logical_elapsed | ( | void * | env | ) |
Return the elapsed logical time in nanoseconds since the start of execution.
env | The environment from which we want the elapsed logical time. |
Return the current physical time in nanoseconds. On many platforms, this is the number of nanoseconds since January 1, 1970, but it is actually platform dependent.
Return the elapsed physical time in nanoseconds. This is the time returned by lf_time_physical(void) minus the physical start time as measured by lf_time_physical(void) when the program was started.