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lqe_util.c from EmStar at Krugle


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/*
 *
 * Copyright (c) 2003 The Regents of the University of California.  All 
 * rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Neither the name of the University nor the names of its
 *   contributors may be used to endorse or promote products derived
 *   from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS''
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 * PARTICULAR  PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */
 

/*
 * lqe_util.c: Some utilities for lqe, e.g. updating the
 * statistical information on a neighbor.
 *
 * $Id: lqe_util.c,v 1.2 2005/01/31 22:43:49 mlukac Exp $
 */

char lqe_util_c_cvsid[] = "$Id: lqe_util.c,v 1.2 2005/01/31 22:43:49 mlukac Exp $";

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

#include "link/link.h"
#include "lqe_i.h"


/*******************************************************************/

/* Get the neighbor from the neighbor queue */
static neighbor_el_t * get_neighbor(neighbor_list_t *nl,
				    const link_pkt_t *lpkt,
                                    lqe_pkt_t *spkt)
{
  neighbor_el_t *ne;
  
  elog(LOG_DEBUG(10), "get neighbor called!");
  
  /* first see if this neighbor already exists */
  for (ne = neighbor_list_top(nl); ne; ne = neighbor_list_next(ne)) {    
    elog(LOG_DEBUG(10), "Iterating list neigh: %d", ne->info.if_id);
    if (ne->info.if_id == lpkt->src.id) {
      elog(LOG_DEBUG(10), "Found neighbor %d in list", lpkt->src.id);
      return ne;
    }
  }
    
  /* not found - create a new neighbor */
  if ((ne = malloc(sizeof(neighbor_el_t))) == NULL) {
    elog(LOG_CRIT, "cannot allocate memory for neighbor elem: %m");
    return NULL;
  }
  memset(ne, 0, sizeof(neighbor_el_t));
    
  /* initialize neighbor element fields */
  ne->info.if_id = lpkt->src.id;
    
  /* set the initial connectivity */
  ne->info.conn_in[spkt->sender_id] = nl->init_rnp[spkt->src_id];
    
  /* init to (seqno - 1) so the new rnp equal to one */
  ne->last_seqno_heard[spkt->sender_id] = spkt->seqno - 1;
    
  /* add the new neighbor to the queue */
  neighbor_list_push(nl, ne);
  
  return ne;
}


/*
 * Update the link statistics for this neighbor.
 */
void update_stats(neighbor_list_t *nl, link_pkt_t *lpkt, 
                  lqe_pkt_t *spkt)
{
  neighbor_el_t *ne;
  conn_t rnp;
  struct timeval now;
  
  elog(LOG_DEBUG(0), "updating stats for neighbor: %d, source: %d, "
       "with seqno: %llu", spkt->src_id, spkt->sender_id, spkt->seqno);
  
  /* Find out if neighbor exists in our list */
  if ((ne = get_neighbor(nl, lpkt, spkt)) == NULL)
    return;
    
  /* find out the current rnp */
  rnp = (int) (spkt->seqno - ne->last_seqno_heard[spkt->sender_id]);
  
  elog(LOG_DEBUG(1), "Current RNP: %f -- neigh: %d -- source: %d",
       rnp, spkt->src_id, spkt->sender_id);
  
  /* update the current rnp for this packet (used by routing) */
  lpkt->rnp = rnp;
  
  /* if the rnp is negative (neighbor reboot?) we clear the state and 
     start again */
  if (rnp < 0) {
    elog(LOG_NOTICE, "Possible neighbor reboot, clearing stats state "
         "and restarting...");
    memset(ne, 0, sizeof(neighbor_el_t));
    ne->info.conn_in[spkt->sender_id] = nl->init_rnp[spkt->src_id];
    rnp = 1;
  } 
  
  /* if we receive a packet with the same seqno, we ignore it */
  if (rnp == 0) {
    elog(LOG_WARNING, "Received duplicate seqno: %llu from neighbor "
         "[%d] and source[%d], alas ignoring it...", spkt->seqno, 
          spkt->src_id, spkt->sender_id);
    return;
  }
  
  /* update rnp estimate for this src/neigh pair */
  /* his is equivalent to (1 - alpha) * oldrnp + alpha * newrnp */
  ne->info.conn_in[spkt->sender_id] += 
                nl->alpha * (rnp - ne->info.conn_in[spkt->sender_id]);
  
  elog(LOG_DEBUG(1), "New RNP estimate: %f -- neigh: %d -- source: %d",
       ne->info.conn_in[spkt->sender_id], spkt->src_id, 
       spkt->sender_id);
  
  /* update the seqno */
  ne->last_seqno_heard[spkt->sender_id] = spkt->seqno;
  
  /* update the time */
  /* NOTE: we should use lpkt->rcv_time, but it is not set!! **FIX** */
  gettimeofday(&now, NULL);
  //ne->info.last_heard = now;
  ne->info.last_heard = lpkt->rcv_time;
}


void init_state(neighbor_list_t *nl)
{
  neighbor_el_t *ne;
  int i, j;
  
  /* for each available neighbor */
  for (i = 0; i < MAX_SRC; i++) {
    if (nl->init_rnp[i] != 0) {
      /* create a new neighbor */
      if ((ne = malloc(sizeof(neighbor_el_t))) == NULL) {
        elog(LOG_CRIT, "cannot allocate memory for neighbor elem: %m");
        return;
      }
      memset(ne, 0, sizeof(neighbor_el_t));
    
      /* initialize neighbor element fields */
      ne->info.if_id = i;
    
      /* set the initial connectivity coming from any source */
      for (j = 0; j < MAX_SRC; j++) {
        ne->info.conn_in[j] = nl->init_rnp[i];
        ne->last_seqno_heard[j] = 0;
      }
    
      /* add the new neighbor to the queue */
      neighbor_list_push(nl, ne);
    }  
  }
}


void lqe_util_init(neighbor_list_t *nl)
{
  buf_t *buf;
  parser_state_t *ps;
  
  elog(LOG_NOTICE, "Loading initialization file from file %s", 
       nl->init_file);

  buf = buf_new();
  if (file_to_buf(buf, nl->init_file) < 0) {
    elog(LOG_CRIT, "Unable to open initialization file: %m");
    exit(1);
  }

  /* ok now we parse the file to look for our data */
  ps = misc_parse_init(buf->buf, MISC_PARSE_LF_SCHEME);
    
  while (misc_parse_next_kvp(ps) >= 0) {
    uint src, dst;
    float quality;
    if (ps->key[0] == '#') continue;
    if (sscanf(ps->key, "%d %d %f", &src, &dst, &quality) == 3) {
      elog(LOG_DEBUG(4), "Read src=%d dst=%d q=%f", src, dst, quality);
      if(src != my_node_id) continue;
      /* 
       * NOTE: update init array for this neighbor, assuming quality is
       * the RR value, and the initial rnp is 1/RR 
       */
      nl->init_rnp[dst] = 1.0/quality;
    }
  }
  
  init_state(nl); 
}




See more files for this project here

EmStar

EmStar is a software system for developing and deploying wireless sensor networks involving Linux-based platforms. As the wireless sensor network community has attempted to deploy more complex designs---large-scale, long-lived systems that need self-organization and adaptivity---a number of difficult software design issues have arisen. Advances in software design have not kept pace with the capabilities of hardware. This is because designing for an adaptive, efficient, and useful sensor network has turned out to be surprisingly complex and difficult. EmStar is a Linux-based software framework, whose goal is to dramatically reduce this complexity, enabling work to be shared and reused, and simplifying and speeding the design of new sensor network applications.

Project homepage: http://cvs.cens.ucla.edu/emstar/
Programming language(s): C,Shell Script
License: other

  lqe_i.h
  lqe_main.c
  lqe_passthru.c
  lqe_status.c
  lqe_util.c