dsynchandler.h File Reference

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Detailed Description

NOTE: not quite finished...need to account for phase difference of clocks on remote machines

The dsynchandler is like a timerhandler BUT it synchronizes with other dsynchandlers (perhaps on different machines) such that they all emit their events at the same time. This is done without requiring that clocks be sychronized (e.g., NTP). The method used is to adapt the phase of all event emissions such that they converge. Each dsychhandler broadcasts to the other dsychhandlers on the same multicast group.

The is useful for triggering actions that need to be synchronized with each other but not to an absolute time.

NOTE: only the cycletime scheduling keyword is supported (not cron).

Wire keywords (standard handler keywords documented in Wire ):

• interrupt: event
• tag: tag, string tag to allow multiple groups of handlers to share same multicast group (optional)
• onsync: , only emit interrupt events when converged to syncrony with all others in group (optional)
• mcinterface: interface name, multicast interface (optional, defaults to ANY)
• mcaddress: ip, valid mutlicast ip group address (optional, defaults to 239.255.255.228)
• mcport: int, mc port (optional, defaults to 1800)
• mcinterface: interface name, multicast interface (optional, defaults to ANY)

Example:

  set interrupt create event { name: "dsync(1sec)"  priority: 1 }
  create handler dsync { interrupt: $interrupt cycletime: 1 }

Events generated:

Event Name	Type	Description
interrupt	AW_EVENT_TYPE_TIMESTAMP	It's time :)

#include "monitor.h"
#include "wire.h"
#include "eventrxhandler.h"
#include "eventtxhandler.h"

Go to the source code of this file.

Data Structures
struct	aw_dsynchandler_events_t
	Events generated. More...
struct	aw_dsynchandler_options_t
	Options. More...
struct	aw_dsynchandler_pdist_t
	Phase Distribution. More...
struct	aw_dsynchandler_t
	Dsync handler object. More...
Defines
#define	AW_DSYC_DEFAULT_MCAST_PORT   1800
#define	AW_DSYNC_CONVERGENCE_ERROR   (AW_TIMESTAMP_PER_SEC / 10)
#define	AW_DSYNC_DEFAULT_MCAST_GROUP   "239.255.255.228"
Functions
aw_dsynchandler_t *	aw_create_dsynchandler (const aw_dsynchandler_events_t *events, aw_dsynchandler_options_t *options, const aw_alarm_sched_t *sched, aw_logger_t *logger, aw_monitor_t *mon)
	Create a dsync handler.
void	aw_free_dsynchandler (aw_dsynchandler_t *h)
	Free handler and all associated resources.
aw_handler_t *	aw_wire_dsynchandler (aw_wire_mkhandler_args_t *args)
	Create a dsync handler using "wire". See header doc for keyword documentation.

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Define Documentation

#define AW_DSYC_DEFAULT_MCAST_PORT   1800

#define AW_DSYNC_CONVERGENCE_ERROR   (AW_TIMESTAMP_PER_SEC / 10)

#define AW_DSYNC_DEFAULT_MCAST_GROUP   "239.255.255.228"

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Function Documentation

aw_dsynchandler_t* aw_create_dsynchandler (  const aw_dsynchandler_events_t *  events, aw_dsynchandler_options_t *  options, const aw_alarm_sched_t *  sched, aw_logger_t *  logger, aw_monitor_t *  mon )

Create a dsync handler. Parameters: events  Events to generate options  Options sched  Run schedule logger  Logger object mon  Monitor Returns: Handler object

void aw_free_dsynchandler (  aw_dsynchandler_t *  h  )

Free handler and all associated resources. Parameters: h  The handler

aw_handler_t* aw_wire_dsynchandler (  aw_wire_mkhandler_args_t *  args  )

Create a dsync handler using "wire". See header doc for keyword documentation.

Aware 0.11.1 Copyright (C) 1998-2005 Russell Leighton (russ@elegant-software.com)