event_queue.c

用于传感器网络的节点操作系统 TinyOS 结构设计非常有意思

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/*
 *
 * Authors:             Philip Levis
 *
 */

/*
 *   FILE: event_queue.c
 * AUTHOR: Philip Levis <[e-mail]>
 *   DESC: Event queue for discrete event simulation
 */

//#include "external_comm.h"
#include <unistd.h>
#include <time.h>

//*********renamed from length to event_queue_length
struct timespec event_queue_length;

//static void dbg(TOS_dbg_mode mode, const char *format, ...); 

void queue_init(event_queue_t* queue, int fpause) {
  init_heap(&(queue->heap));
  queue->pause = fpause;
  pthread_mutex_init(&(queue->lock), NULL);
}

void queue_insert_event(event_queue_t* queue, event_t* event) {
  if (dbg_active(DBG_QUEUE)) {
    char ftime[128];
    ftime[0] = 0;
    printOtherTime(ftime, 128, event->time);
    dbg(DBG_QUEUE, "Inserting event with time %s.\n", ftime);
  }
  pthread_mutex_lock(&(queue->lock));
  heap_insert(&(queue->heap), event, event->time);
  pthread_mutex_unlock(&(queue->lock));
}

event_t* queue_pop_event(event_queue_t* queue) {
  long long ftime;
  event_t* event;

  pthread_mutex_lock(&(queue->lock));
  event = (event_t*)(heap_pop_min_data(&(queue->heap), &ftime));
  pthread_mutex_unlock(&(queue->lock));

  if(dbg_active(DBG_QUEUE)) {
    char timeStr[128];
    timeStr[0] = 0;
    printOtherTime(timeStr, 128, ftime);
    dbg(DBG_QUEUE, "Popping event for mote %i with time %s.\n", event->mote, timeStr);
  }
  
  if (queue->pause > 0 && event->pause) {
    sleep(queue->pause);
    //dbg(DBG_ALL, "\n");
  }
  
  return event;
}

int queue_is_empty(event_queue_t* queue) {
  int rval;
  pthread_mutex_lock(&(queue->lock));
  rval = heap_is_empty(&(queue->heap));
  pthread_mutex_unlock(&(queue->lock));
  return rval;
}

long long queue_peek_event_time(event_queue_t* queue) {
  long long rval;
  
  pthread_mutex_lock(&(queue->lock));
  if (heap_is_empty(&(queue->heap))) {
    rval = -1;
  }
  else {
    rval = heap_get_min_key(&(queue->heap));
  }

  pthread_mutex_unlock(&(queue->lock));
  return rval;
}

void queue_handle_next_event(event_queue_t* queue) {
  event_t* event = queue_pop_event(queue);
  if (event != NULL) {
    NODE_NUM = event->mote;
    dbg(DBG_QUEUE, "Setting TOS_LOCAL_ADDRESS to %hi\n", (short)(event->mote & 0xffff));
    TOS_LOCAL_ADDRESS = (short)(event->mote & 0xffff);
    event->handle(event, &tos_state); 
  }
}