rfm_model.c

传感器网络中的嵌入式操作系统源代码

  model->init = static_init;
  model->transmit = static_transmit;
  model->stop_transmit = static_stops_transmit;
  model->hears = static_hears;
  model->connected = static_connected;
  model->neighbors = simple_neighbors;
  return model;
}


bool lossy_connected(int moteID1, int moteID2) {
  // this method is rather slow, and runs on the order of the number
  // of links attached moteID1 because it traverses moteID1's
  // adjacency list to make this a constant time operation, add a
  // hashtable to the adjacency list implementation
  link_t* current_link;

  pthread_mutex_lock(&radioConnectivityLock);
  current_link = radio_connectivity[moteID1];
  dbg(DBG_TEMP, "connections for %i\n", moteID1);
  while (current_link) {
    if ((current_link->mote == moteID2) &&
	(current_link->data < 1.0)) {
      dbg(DBG_TEMP, "connected to %i\n", moteID2);
      pthread_mutex_unlock(&radioConnectivityLock);
      return TRUE;
    }
    current_link = current_link->next_link;
  }
  pthread_mutex_unlock(&radioConnectivityLock);
  return FALSE;
}

void lossy_transmit(int moteID, char bit) {
  link_t* current_link; 
  
  pthread_mutex_lock(&radioConnectivityLock);
  current_link = radio_connectivity[moteID];
  transmitting[moteID] = bit;
  while (current_link) {
    int r = rand() % 100000;
    double prob = ((double)r) / 100000.0;
    int tmp_bit = bit;
    if (prob < current_link->data) { // bit error, reverse the bit
      tmp_bit = (tmp_bit)? 0:1;
    }
    radio_active[current_link->mote] += tmp_bit;
    radio_idle_state[current_link->mote] = 0;
    current_link->bit = tmp_bit;
    current_link = current_link->next_link;
  }
  pthread_mutex_unlock(&radioConnectivityLock);
}

void lossy_stop_transmit(int moteID) {
  link_t* current_link;
  
  pthread_mutex_lock(&radioConnectivityLock);
  current_link = radio_connectivity[moteID];
  transmitting[moteID] = 0;
  while (current_link) {
    radio_active[current_link->mote] -= current_link->bit;
    current_link->bit = 0;
    current_link = current_link->next_link;
  }      
  pthread_mutex_unlock(&radioConnectivityLock);
}

char lossy_hears(int moteID) {
  char bit_heard = (radio_active[moteID] > 0)? 1:0;
  if (radio_idle_state[moteID]) {
      int r = rand() % 100000;
      double prob = ((double)r) / 100000.0;
      if (prob < noise_prob) { // noise has caused this bit to be reversed
	bit_heard = (bit_heard)? 0:1;
      }
  }
  else {
      short temp_heard = radio_heard[moteID];
      temp_heard <<= 1;
      temp_heard |= bit_heard;
      radio_heard[moteID] = temp_heard;
      if ((radio_heard[moteID] & IDLE_STATE_MASK) == 0) {
	  radio_idle_state[moteID] = 1;
      }
  }
  return bit_heard;
}

int read_lossy_entry(FILE* file, int* mote_one, int* mote_two, double* loss) {
  char buf[128];
  int findex = 0;
  int ch;

  // Read in first number
  while(1) {
    ch = getc(file);
    if (ch == EOF) {return 0;}
    else if (ch >= '0' && ch <= '9') {
      buf[findex] = (char)ch;
      findex++;
    }
    else if (ch == ':') {
      buf[findex] = 0;
      break;
    }
    else if (ch == '\n' || ch == ' ' || ch == '\t') {
      if (findex > 0) {return 0;}
    }
    else {
      return 0;
    }
  }

  *mote_one = atoi(buf);
  findex = 0;
  // Read in second number
  while(1) {
    ch = getc(file);
    if (ch == EOF) {return 0;}
    else if (ch >= '0' && ch <= '9') {
      buf[findex] = (char)ch;
      findex++;
    }
    else if (ch == ':') {
      buf[findex] = 0;
      break;
    }
    else if (ch == '\n' || ch == ' ' || ch == '\t') {
      if (findex == 0) {return 0;}
      else {
	buf[findex] = 0;
	break;
      }
    }
    else {
      return 0;
    }
  }

  *mote_two = atoi(buf);

  findex = 0;
  // Read in loss rate number
  while(1) {
    ch = getc(file);
    if (ch == EOF) {return 0;}
    else if ((ch >= '0' && ch <= '9') || ch == '.') {
      buf[findex] = (char)ch;
      findex++;
    }
    else if (ch == '\n' || ch == ' ' || ch == '\t') {
      if (findex == 0) {return 0;}
      else {
	buf[findex] = 0;
	break;
      }
    }
    else {
      return 0;
    }
  }
  *loss = atof(buf);

  return 1;
}

void lossy_init() {
  int sfd = open(lossyFileName, O_RDONLY);
  int i;
  FILE* file = fdopen(sfd, "r");
  link_t* new_link;

  dbg_clear(DBG_SIM, "Initializing lossy model from %s.\n", lossyFileName);
  pthread_mutex_init(&radioConnectivityLock, NULL);
  adjacency_list_init();

  if (sfd < 0) {
    dbg(DBG_SIM, "Cannot open %s - assuming single radio cell\n", lossyFileName);
    static_one_cell_init();
    return;
  }

  for (i = 0; i < TOSNODES; i++) {
    radio_connectivity[i] = NULL;
    radio_idle_state[i] = 0;
    radio_heard[i] = 0;
  }
  while(1) {
    int mote_one;
    int mote_two;
    double loss;
    if (read_lossy_entry(file, &mote_one, &mote_two, &loss)) {
      if (mote_one != mote_two) {
	new_link = allocate_link(mote_two);
	new_link->data = loss;
	new_link->next_link = radio_connectivity[mote_one];
	radio_connectivity[mote_one] = new_link;
      }
    }
    else {
      break;
    }
  }
  dbg(DBG_BOOT, ("RFM connectivity graph constructed.\n"));
}


link_t* lossy_neighbors(int moteID) {
  link_t *thelink;
  pthread_mutex_lock(&radioConnectivityLock);
  thelink = radio_connectivity[moteID];
  pthread_mutex_unlock(&radioConnectivityLock);
  return thelink;
}

rfm_model* create_lossy_model(char* file) {
  rfm_model* model = (rfm_model*)malloc(sizeof(rfm_model));
  if (file != NULL) {
    lossyFileName = file;
  }
  model->init = lossy_init;
  model->transmit = lossy_transmit;
  model->stop_transmit = lossy_stop_transmit;
  model->hears = lossy_hears;
  model->connected = lossy_connected;
  model->neighbors = lossy_neighbors;
  return model;
}

double get_link_prob_value(uint16_t moteID1, uint16_t moteID2) {
  link_t *current_link;

  pthread_mutex_lock(&radioConnectivityLock);
  current_link = radio_connectivity[moteID1];
  while (current_link) {
    if (current_link->mote == moteID2) {
      pthread_mutex_unlock(&radioConnectivityLock);
      return current_link->data;
    }
    current_link = current_link->next_link;
  }
  pthread_mutex_unlock(&radioConnectivityLock);
  return 1;  
}

void set_link_prob_value(uint16_t moteID1, uint16_t moteID2, double prob) {
  link_t* current_link;
  link_t* new_link;

  pthread_mutex_lock(&radioConnectivityLock);
  current_link = radio_connectivity[moteID1];
  dbg(DBG_SIM, "RFM: MDW: Setting loss prob %d->%d to %0.3f\n", moteID1, moteID2, prob);
  while (current_link) {
    if (current_link->mote == moteID2) {
      current_link->data = prob;
      pthread_mutex_unlock(&radioConnectivityLock);
      return;      
    }
    current_link = current_link->next_link;
  }
  new_link = allocate_link(moteID2);
  new_link->next_link = radio_connectivity[moteID1];
  new_link->data = prob;
  radio_connectivity[moteID1] = new_link;
  pthread_mutex_unlock(&radioConnectivityLock);
}

double get_noise_prob_value() {
  return noise_prob;
  
}

void set_noise_prob_value(double prob) {
  noise_prob = prob;
}

char get_wait_length_before_idle() {
  short temp = IDLE_STATE_MASK;
  char count = 0;
  while (temp) {
    count++;
    temp = temp >> 1;
    temp &= 0x7fff;
  }
  return count;
}

void set_wait_length_before_idle(int count) {
  short temp = 0;
  while (count) {
    temp = temp << 1;
    temp |= 1;
    count--;
  }
  IDLE_STATE_MASK = temp;
}