dsynchandler.h

Go to the documentation of this file.

/*
** Copyright (C) 2004 Russell Leighton
**
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation; either version 2 of the License, or
** (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
** GNU General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program; if not, write to the Free Software
** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/




#ifndef __AWHANDLER_DSYNC__
#define __AWHANDLER_DSYNC__

#include "monitor.h"

#include "wire.h"

#include "eventrxhandler.h"
#include "eventtxhandler.h"

/* default ip and port  */
#define AW_DSYNC_DEFAULT_MCAST_GROUP "239.255.255.228"
#define AW_DSYC_DEFAULT_MCAST_PORT 1800

/* the smallest error considered acceptable to declare converged */
#define AW_DSYNC_CONVERGENCE_ERROR (AW_TIMESTAMP_PER_SEC / 10)

typedef struct {

  aw_event_sig_t
   interrupt;                  /* handler went off */

} aw_dsynchandler_events_t;


typedef struct {

  /* non-zero if all OTHER handlers have phases measured
     in the first left or right bins */
  int32_t
   converged;

  /* the index of the bin that , below which, is the covergence interval */
  int32_t
   convergence_bin;

  /* how long to accumulate before adapting */
  int32_t
   integration_step,
   integration_interval;

  /* Phase Distribution
     
     It is split into 2 histograms, one (pos) plus 1/2 period and the other (neg) minus 1/2 period.
     
     The bin size is not uniform, rather it is log base 2 per
     the following definition:
      - the last bin holds the count of those values >= upper half of the interval
      - the next bin holds the count of those values >= upper half of the remaining interval
      - etc., to 0
      The point of this is to have hyper resolution near the inside side where we
      are more concerned with accuracy.
      NOTE: we re-normalize if any bin overflows 
  */
  u_int16_t
   hist_pos[8],
   hist_neg[8];

  /* count of total in both hists */
  u_int32_t
   total_samples;

} aw_dsynchandler_pdist_t;

typedef struct {

  aw_handler_t 
   handler_header;

  aw_dsynchandler_events_t
   events;

  /* if non-zero, only emit events if converged */
  int32_t 
   onsync;

  /* phase distribution */
  aw_dsynchandler_pdist_t
   pdist;

  /* multicast inteface, defaults to NULL -> INADDR_ANY */
  byte_t *mcinterface;

  /* multicast group */
  aw_ip_addr_t mcaddress;

  /* non-zero if allow local multicast traffic, defaults to 0 */
  u_int32_t mcloopback;

  /* port */
  int32_t mcport;

  /* send events to others */
  aw_eventtxhandler_t
   *tx;

  /* received events from others */
  aw_eventrxhandler_t
   *rx;
  
  /* event sending dsync events */
  aw_event_sig_t 
   tx_event;

  /* event for received dsync events */
  aw_eventrxhandler_events_t 
   rx_event;

  /* the time that send_dsync_event() was called */
  aw_timestamp_t
   last_dsync_tstamp;

  /* id used in ire callback to delay events */
  int32_t
   delay_event_id;

} aw_dsynchandler_t ;

typedef struct {

  /* the tag for this group */
  const byte_t 
   *tag;

  /* multicast inteface, defaults to NULL -> INADDR_ANY */
  const byte_t 
   *mcinterface;

  /* multicast group */
  aw_ip_addr_t 
   mcaddress;

  /* non-zero if allow local multicast traffic, defaults to 0 */
  u_int32_t 
   mcloopback;

  /* port */
  int32_t 
   mcport;

  /* if non-zero, only emit events if converged */
  int32_t 
   onsync;

} aw_dsynchandler_options_t;

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
                                          );

void aw_free_dsynchandler(aw_dsynchandler_t *h);


aw_handler_t *aw_wire_dsynchandler(aw_wire_mkhandler_args_t *args);

#endif

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