clock-sync.h File Reference

Utility functions for clock synchronization in federated Lingua Franca programs. More...

#include "low_level_platform.h"

Go to the source code of this file.

Data Structures
struct	lf_stat_ll
	Holds generic statistical data. More...
struct	socket_stat_t
	Statistics and state for clock synchronization over a socket connection. More...

Macros
#define	_LF_CLOCK_SYNC_ATTENUATION   10
	Runtime clock offset updates will be divided by this number.
#define	_LF_CLOCK_SYNC_COLLECT_STATS   true
	By default, collect statistics on clock synchronization.
#define	_LF_CLOCK_SYNC_EXCHANGES_PER_INTERVAL   10
	Number of required clock sync T4 messages per synchronization interval.
#define	CLOCK_SYNC_GUARD_BAND   USEC(100)
	Define a guard band to filter clock synchronization messages based on discrepancies in the network delay.
#define	LF_CLOCK_SYNC   LF_CLOCK_SYNC_INIT
	Clock synchronization mode.
#define	LF_CLOCK_SYNC_INIT   2
	Indicator for clock synchronization to be turned on at initialization.
#define	LF_CLOCK_SYNC_OFF   1
	Indicator for clock synchronization to be turned off altogether.
#define	LF_CLOCK_SYNC_ON   3
	Indicator for clock synchronization to be turned on at initialization and runtime.

Typedefs
typedef struct lf_stat_ll	lf_stat_ll
	Holds generic statistical data.
typedef struct socket_stat_t	socket_stat_t
	Statistics and state for clock synchronization over a socket connection.

Functions
void	clock_sync_add_offset (instant_t *t)
	Add the current clock synchronization offset to a specified timestamp.
void	clock_sync_set_constant_bias (interval_t offset)
	Set a fixed offset to the physical clock.
void	clock_sync_subtract_offset (instant_t *t)
	Subtract the clock synchronization offset from a timestamp.
int	create_clock_sync_thread (lf_thread_t *thread_id)
	Create the thread responsible for handling clock synchronization with the RTI if (runtime) clock synchronization is on.
int	handle_T1_clock_sync_message (unsigned char *buffer, int socket, instant_t t2)
	Handle a clock synchroninzation message T1 coming from the RTI.
void	handle_T4_clock_sync_message (unsigned char *buffer, int socket, instant_t r4)
	Handle a clock synchronization message T4 coming from the RTI.
void	reset_socket_stat (struct socket_stat_t *socket_stat)
	Reset statistics on the socket.
uint16_t	setup_clock_synchronization_with_rti (void)
	Setup necessary functionalities to synchronize clock with the RTI.
void	synchronize_initial_physical_clock_with_rti (int *rti_socket_TCP)
	Synchronize the initial physical clock with the RTI.

Detailed Description

Utility functions for clock synchronization in federated Lingua Franca programs.

Author

Edward A. Lee (eal@berkeley.edu)

Soroush Bateni (soroush@utdallas.edu)

This file provides utility functions and data structures for synchronizing physical clocks between federates and the RTI in federated Lingua Franca programs. It implements a variant of the Precision Time Protocol (PTP) for clock synchronization, with support for both initial synchronization and runtime synchronization. The file includes functions for handling clock synchronization messages, managing synchronization statistics, and adjusting clock offsets.