/*---------------------------------------------------------------------------*/ struct neighbor * neighbor_best(void) { int found; /* int lowest, best;*/ struct neighbor *n, *best; uint16_t rtmetric; rtmetric = RTMETRIC_MAX; best = NULL; found = 0; /* PRINTF("%d: ", node_id);*/ /* Find the lowest rtmetric. */ for(n = list_head(neighbors_list); n != NULL; n = n->next) { if(!rimeaddr_cmp(&n->addr, &rimeaddr_null) && rtmetric > n->rtmetric + neighbor_etx(n)) { rtmetric = n->rtmetric + neighbor_etx(n); best = n; } } return best; }
/*---------------------------------------------------------------------------*/ struct neighbor * neighbor_best(void) { struct neighbor *n = NULL; struct neighbor *best = NULL; uint16_t rtmetric = RTMETRIC_MAX; /* Find lowest rtmetric + etx. */ for(n = list_head(neighbors_list); n != NULL; n = n->next) { PRINTF("%u.%u: neighbor_best: neighbor %u.%u with rtmetric %u and etx %u\n", rimeaddr_node_addr.u8[0], rimeaddr_node_addr.u8[1], n->addr.u8[0], n->addr.u8[1], n->rtmetric, neighbor_etx(n)); if( !rimeaddr_cmp(&n->addr, &rimeaddr_null) && rtmetric > n->rtmetric + neighbor_etx(n)) { rtmetric = n->rtmetric + neighbor_etx(n); best = n; } } if (last_best == NULL) { // printf("%d: first parent %d (rtmetric %u)\n", rimeaddr_node_addr.u8[0], best->addr.u8[0], rtmetric); last_best = best; } else { if (! (rtmetric + 2 < last_best->rtmetric + neighbor_etx(last_best))) { /* No improvement in rtmetric, so we keep the current best. */ best = last_best; } else { /* Improvement in rtmetric, so we switch to new best. */ // printf("%d: new parent %d (rtmetric %u), old parent %d (rtmetric %u)\n", rimeaddr_node_addr.u8[0], best->addr.u8[0], rtmetric, last_best->addr.u8[0], last_best->rtmetric + neighbor_etx(last_best)); last_best = best; } } return best; }
/*---------------------------------------------------------------------------*/ void neighbor_add(const rimeaddr_t *addr, uint8_t nrtmetric, uint8_t netx) { uint16_t rtmetric; uint16_t etx; struct neighbor *n, *max; int i; PRINTF("neighbor_add: adding %d.%d\n", addr->u8[0], addr->u8[1]); /* Check if the neighbor is already on the list. */ for(n = list_head(neighbors_list); n != NULL; n = n->next) { if(rimeaddr_cmp(&n->addr, &rimeaddr_null) || rimeaddr_cmp(&n->addr, addr)) { PRINTF("neighbor_add: already on list %d.%d\n", addr->u8[0], addr->u8[1]); break; } } /* If the neighbor was not on the list, we try to allocate memory for it. */ if(n == NULL) { PRINTF("neighbor_add: not on list, allocating %d.%d\n", addr->u8[0], addr->u8[1]); n = memb_alloc(&neighbors_mem); if(n != NULL) { list_add(neighbors_list, n); } } /* If we could not allocate memory, we try to recycle an old neighbor */ if(n == NULL) { PRINTF("neighbor_add: not on list, not allocated, recycling %d.%d\n", addr->u8[0], addr->u8[1]); /* Find the first unused entry or the used entry with the highest rtmetric and highest etx. */ rtmetric = 0; etx = 0; max = NULL; for(n = list_head(neighbors_list); n != NULL; n = n->next) { if(!rimeaddr_cmp(&n->addr, &rimeaddr_null)) { if(n->rtmetric > rtmetric) { rtmetric = n->rtmetric; etx = neighbor_etx(n); max = n; } else if(n->rtmetric == rtmetric) { if(neighbor_etx(n) > etx) { rtmetric = n->rtmetric; etx = neighbor_etx(n); max = n; /* PRINTF("%d: found worst neighbor %d with rtmetric %d, signal %d\n", node_id, neighbors[n].nodeid, rtmetric, signal);*/ } } } } n = max; } /* PRINTF("%d: adding neighbor %d with rtmetric %d, signal %d at %d\n", node_id, neighbors[n].nodeid, rtmetric, signal, n);*/ if(n != NULL) { n->time = 0; rimeaddr_copy(&n->addr, addr); n->rtmetric = nrtmetric; for(i = 0; i < NEIGHBOR_NUM_ETXS; ++i) { n->etxs[i] = netx; } n->etxptr = 0; } }
/*---------------------------------------------------------------------------*/ static void update_rtmetric(struct collect_conn *tc) { struct neighbor *n; /* We should only update the rtmetric if we are not the sink. */ if(tc->rtmetric != SINK) { /* Find the neighbor with the lowest rtmetric. */ n = neighbor_best(); /* If n is NULL, we have no best neighbor. */ if(n == NULL) { /* If we have don't have any neighbors, we set our rtmetric to the maximum value to indicate that we do not have a route. */ if(tc->rtmetric != RTMETRIC_MAX) { PRINTF("%d.%d: didn't find a best neighbor, setting rtmetric to max\n", rimeaddr_node_addr.u8[RIMEADDR_SIZE-2], rimeaddr_node_addr.u8[RIMEADDR_SIZE-1]); } tc->rtmetric = RTMETRIC_MAX; announcement_set_value(&tc->announcement, tc->rtmetric); } else { /* We set our rtmetric to the rtmetric of our best neighbor plus the expected transmissions to reach that neighbor. */ if(n->rtmetric + neighbor_etx(n) != tc->rtmetric) { uint16_t old_rtmetric = tc->rtmetric; tc->rtmetric = n->rtmetric + neighbor_etx(n); #if !COLLECT_ANNOUNCEMENTS neighbor_discovery_start(&tc->neighbor_discovery_conn, tc->rtmetric); #else announcement_set_value(&tc->announcement, tc->rtmetric); #endif /* !COLLECT_ANNOUNCEMENTS */ PRINTF("%d.%d: new rtmetric %d\n", rimeaddr_node_addr.u8[RIMEADDR_SIZE-2], rimeaddr_node_addr.u8[RIMEADDR_SIZE-1], tc->rtmetric); /* We got a new, working, route we send any queued packets we may have. */ if(old_rtmetric == RTMETRIC_MAX) { send_queued_packet(); } } } } /* DEBUG_PRINTF("%d: new rtmetric %d\n", node_id, rtmetric);*/ #if CONTIKI_TARGET_NETSIM { char buf[8]; if(tc->rtmetric == RTMETRIC_MAX) { strcpy(buf, " "); } else { sprintf(buf, "%.1f", (float)tc->rtmetric / NEIGHBOR_ETX_SCALE); } ether_set_text(buf); } #endif }