ospfh_thread.c

实现禁位自动排列在禁位中具体实现了此方法所以这是一个创新很有应用价值在VC平台上调试通过

  for (tt = m->timer.head; tt; tt = tt->next)
    if (timeval_cmp (thread->u.sands, tt->u.sands) <= 0)
      break;

  if (tt)
    thread_list_add_before (&m->timer, tt, thread);
  else
    thread_list_add (&m->timer, thread);
#endif /* TIMER_NO_SORT */

  return thread;
}

/* Add simple event thread. */
struct thread *
thread_add_event (struct thread_master *m,
		  int (*func) (struct thread *), void *arg, int val)
{
  struct thread *thread;

  assert (m != NULL);

  thread = thread_get (m, THREAD_EVENT, func, arg);
  thread->u.val = val;
  thread_list_add (&m->event, thread);

  return thread;
}

/* Cancel thread from scheduler. */
void
thread_cancel (struct thread *thread)
{
  switch (thread->type)
    {
    case THREAD_READ:
      assert (FD_ISSET (thread->u.fd, &thread->master->readfd));
      FD_CLR (thread->u.fd, &thread->master->readfd);
      thread_list_delete (&thread->master->read, thread);
      break;
    case THREAD_WRITE:
      assert (FD_ISSET (thread->u.fd, &thread->master->writefd));
      FD_CLR (thread->u.fd, &thread->master->writefd);
      thread_list_delete (&thread->master->write, thread);
      break;
    case THREAD_TIMER:
      thread_list_delete (&thread->master->timer, thread);
      break;
    case THREAD_EVENT:
      thread_list_delete (&thread->master->event, thread);
      break;
    case THREAD_READY:
      thread_list_delete (&thread->master->ready, thread);
      break;
    default:
      break;
    }
  thread->type = THREAD_UNUSED;
  thread_add_unuse (thread->master, thread);
}

/* Delete all events which has argument value arg. */
void
thread_cancel_event (struct thread_master *m, void *arg)
{
  struct thread *thread;

  thread = m->event.head;
  while (thread)
    {
      struct thread *t;

      t = thread;
      thread = t->next;

      if (t->arg == arg)
	{
	  thread_list_delete (&m->event, t);
	  t->type = THREAD_UNUSED;
	  thread_add_unuse (m, t);
	}
    }
}

#ifdef TIMER_NO_SORT
struct timeval *
thread_timer_wait (struct thread_master *m, struct timeval *timer_val)
{
  struct timeval timer_now;
  struct timeval timer_min;
  struct timeval *timer_wait;

  gettimeofday (&timer_now, NULL);

  timer_wait = NULL;
  for (thread = m->timer.head; thread; thread = thread->next)
    {
      if (! timer_wait)
	timer_wait = &thread->u.sands;
      else if (timeval_cmp (thread->u.sands, *timer_wait) < 0)
	timer_wait = &thread->u.sands;
    }

  if (m->timer.head)
    {
      timer_min = *timer_wait;
      timer_min = timeval_subtract (timer_min, timer_now);
      if (timer_min.tv_sec < 0)
	{
	  timer_min.tv_sec = 0;
	  timer_min.tv_usec = 10;
	}
      timer_wait = &timer_min;
    }
  else
    timer_wait = NULL;

  if (timer_wait)
    {
      *timer_val = timer_wait;
      return timer_val;
    }
  return NULL;
}
#else /* ! TIMER_NO_SORT */
struct timeval *
thread_timer_wait (struct thread_master *m, struct timeval *timer_val)
{
  struct timeval timer_now;
  struct timeval timer_min;

  if (m->timer.head)
    {
      gettimeofday (&timer_now, NULL);
      timer_min = m->timer.head->u.sands;
      timer_min = timeval_subtract (timer_min, timer_now);
      if (timer_min.tv_sec < 0)
	{
	  timer_min.tv_sec = 0;
	  timer_min.tv_usec = 10;
	}
      *timer_val = timer_min;
      return timer_val;
    }
  return NULL;
}
#endif /* TIMER_NO_SORT */

struct thread *
thread_run (struct thread_master *m, struct thread *thread,
	    struct thread *fetch)
{
  *fetch = *thread;
  thread->type = THREAD_UNUSED;
  thread_add_unuse (m, thread);
  return fetch;
}

int
thread_process_fd (struct thread_master *m, struct thread_list *list,
		   fd_set *fdset, fd_set *mfdset)
{
  struct thread *thread;
  struct thread *next;
  int ready = 0;

  for (thread = list->head; thread; thread = next)
    {
      next = thread->next;

      if (FD_ISSET (THREAD_FD (thread), fdset))
	{
	  assert (FD_ISSET (THREAD_FD (thread), mfdset));
	  FD_CLR(THREAD_FD (thread), mfdset);
	  thread_list_delete (list, thread);
	  thread_list_add (&m->ready, thread);
	  thread->type = THREAD_READY;
	  ready++;
	}
    }
  return ready;
}

/* Fetch next ready thread. */
struct thread *
thread_fetch (struct thread_master *m, struct thread *fetch)
{
  int num;
  int ready;
  struct thread *thread;
  fd_set readfd;
  fd_set writefd;
  fd_set exceptfd;
  struct timeval timer_now;
  struct timeval timer_val;
  struct timeval *timer_wait;
  struct timeval timer_nowait;

  timer_nowait.tv_sec = 0;
  timer_nowait.tv_usec = 0;

 while (1)
    {
      /* Normal event is the highest priority.  */
      if ((thread = thread_trim_head (&m->event)) != NULL)
	      return thread_run (m, thread, fetch);

      /* Execute timer.  */
      gettimeofday (&timer_now, NULL);

      for (thread = m->timer.head; thread; thread = thread->next)
	  if (timeval_cmp (timer_now, thread->u.sands) >= 0)
	  {
	    thread_list_delete (&m->timer, thread);
	    return thread_run (m, thread, fetch);
	  }

      /* If there are any ready threads, process top of them.  */
      if ((thread = thread_trim_head (&m->ready)) != NULL)
	return thread_run (m, thread, fetch);

      /* Structure copy.  */
      readfd = m->readfd;
      writefd = m->writefd;
      exceptfd = m->exceptfd;

      /* Calculate select wait timer. */
      timer_wait = thread_timer_wait (m, &timer_val);

      num = select (FD_SETSIZE, &readfd, &writefd, &exceptfd, timer_wait);

      if (num == 0)
	continue;

      if (num < 0)
	{
	  //if (errno == EINTR)
	    continue;

	  zlog_warn ("select() error: %s", strerror (errno));
	  return NULL;
	}

      /* Normal priority read thead. */
      ready = thread_process_fd (m, &m->read, &readfd, &m->readfd);

      /* Write thead. */
      ready = thread_process_fd (m, &m->write, &writefd, &m->writefd);

      if ((thread = thread_trim_head (&m->ready)) != NULL)
	return thread_run (m, thread, fetch);
    }
}

static unsigned long
thread_consumed_time (RUSAGE_T *now, RUSAGE_T *start)
{
  unsigned long thread_time;

#ifdef HAVE_RUSAGE
  /* This is 'user + sys' time.  */
  thread_time = timeval_elapsed (now->ru_utime, start->ru_utime);
  thread_time += timeval_elapsed (now->ru_stime, start->ru_stime);
#else
  /* When rusage is not available, simple elapsed time is used.  */
  thread_time = timeval_elapsed (*now, *start);
#endif /* HAVE_RUSAGE */

  return thread_time;
}

/* We should aim to yield after THREAD_YIELD_TIME_SLOT
   milliseconds.  */
int
thread_should_yield (struct thread *thread)
{
  RUSAGE_T ru;

  GETRUSAGE (&ru);

  if (thread_consumed_time (&ru, &thread->ru) > THREAD_YIELD_TIME_SLOT)
    return 1;
  else
    return 0;
}

/* We check thread consumed time. If the system has getrusage, we'll
   use that to get indepth stats on the performance of the thread.  If
   not - we'll use gettimeofday for some guestimation.  */
void
thread_call (struct thread *thread)
{
  unsigned long thread_time;
  RUSAGE_T ru;

  GETRUSAGE (&thread->ru);


  (*thread->func) (thread);

  GETRUSAGE (&ru);

  thread_time = thread_consumed_time (&ru, &thread->ru);

#ifdef THREAD_CONSUMED_TIME_CHECK
  if (thread_time > 200000L)
    {
      /*
       * We have a CPU Hog on our hands.
       * Whinge about it now, so we're aware this is yet another task
       * to fix.
       */
      zlog_err ("CPU HOG task %lx ran for %ldms",
                /* FIXME: report the name of the function somehow */
		(unsigned long) thread->func,
		thread_time / 1000L);
    }
#endif /* THREAD_CONSUMED_TIME_CHECK */
}

/* Execute thread */
struct thread *
thread_execute (struct thread_master *m,
                int (*func)(struct thread *), 
                void *arg,
                int val)
{
  struct thread dummy; 

  memset (&dummy, 0, sizeof (struct thread));

  dummy.type = THREAD_EVENT;
  dummy.master = NULL;
  dummy.func = func;
  dummy.arg = arg;
  dummy.u.val = val;
  thread_call (&dummy);

  return NULL;
}