timer.c

一个开源的sip源代码

    
    ht->max_size = new_size;
}

static void insert_node(pj_timer_heap_t *ht, pj_timer_entry *new_node)
{
    if (ht->cur_size + 2 >= ht->max_size)
	grow_heap(ht);
    
    reheap_up( ht, new_node, ht->cur_size, HEAP_PARENT(ht->cur_size));
    ht->cur_size++;
}


static pj_status_t schedule_entry( pj_timer_heap_t *ht,
				   pj_timer_entry *entry, 
				   const pj_time_val *future_time )
{
    if (ht->cur_size < ht->max_size)
    {
	// Obtain the next unique sequence number.
	// Set the entry
	entry->_timer_id = pop_freelist(ht);
	entry->_timer_value = *future_time;
	insert_node( ht, entry);
	return 0;
    }
    else
	return -1;
}


static int cancel( pj_timer_heap_t *ht, 
		   pj_timer_entry *entry, 
		   int dont_call)
{
  long timer_node_slot;

  PJ_CHECK_STACK();

  // Check to see if the timer_id is out of range
  if (entry->_timer_id < 0 || (pj_size_t)entry->_timer_id > ht->max_size)
    return 0;

  timer_node_slot = ht->timer_ids[entry->_timer_id];

  if (timer_node_slot < 0) // Check to see if timer_id is still valid.
    return 0;

  if (entry != ht->heap[timer_node_slot])
    {
      pj_assert(entry == ht->heap[timer_node_slot]);
      return 0;
    }
  else
    {
      remove_node( ht, timer_node_slot);

      if (dont_call == 0)
        // Call the close hook.
	(*ht->callback)(ht, entry);
      return 1;
    }
}


/*
 * Calculate memory size required to create a timer heap.
 */
PJ_DEF(pj_size_t) pj_timer_heap_mem_size(pj_size_t count)
{
    return /* size of the timer heap itself: */
           sizeof(pj_timer_heap_t) + 
           /* size of each entry: */
           (count+2) * (sizeof(pj_timer_entry*)+sizeof(pj_timer_id_t)) +
           /* lock, pool etc: */
           132;
}

/*
 * Create a new timer heap.
 */
PJ_DEF(pj_status_t) pj_timer_heap_create( pj_pool_t *pool,
					  pj_size_t size,
                                          pj_timer_heap_t **p_heap)
{
    pj_timer_heap_t *ht;
    pj_size_t i;

    PJ_ASSERT_RETURN(pool && p_heap, PJ_EINVAL);

    *p_heap = NULL;

    /* Magic? */
    size += 2;

    /* Allocate timer heap data structure from the pool */
    ht = PJ_POOL_ALLOC_T(pool, pj_timer_heap_t);
    if (!ht)
        return PJ_ENOMEM;

    /* Initialize timer heap sizes */
    ht->max_size = size;
    ht->cur_size = 0;
    ht->max_entries_per_poll = DEFAULT_MAX_TIMED_OUT_PER_POLL;
    ht->timer_ids_freelist = 1;
    ht->pool = pool;

    /* Lock. */
    ht->lock = NULL;
    ht->auto_delete_lock = 0;

    // Create the heap array.
    ht->heap = (pj_timer_entry**)
    	       pj_pool_alloc(pool, sizeof(pj_timer_entry*) * size);
    if (!ht->heap)
        return PJ_ENOMEM;

    // Create the parallel
    ht->timer_ids = (pj_timer_id_t *)
    		    pj_pool_alloc( pool, sizeof(pj_timer_id_t) * size);
    if (!ht->timer_ids)
        return PJ_ENOMEM;

    // Initialize the "freelist," which uses negative values to
    // distinguish freelist elements from "pointers" into the <heap_>
    // array.
    for (i=0; i<size; ++i)
	ht->timer_ids[i] = -((pj_timer_id_t) (i + 1));

    *p_heap = ht;
    return PJ_SUCCESS;
}

PJ_DEF(void) pj_timer_heap_destroy( pj_timer_heap_t *ht )
{
    if (ht->lock && ht->auto_delete_lock) {
        pj_lock_destroy(ht->lock);
        ht->lock = NULL;
    }
}

PJ_DEF(void) pj_timer_heap_set_lock(  pj_timer_heap_t *ht,
                                      pj_lock_t *lock,
                                      pj_bool_t auto_del )
{
    if (ht->lock && ht->auto_delete_lock)
        pj_lock_destroy(ht->lock);

    ht->lock = lock;
    ht->auto_delete_lock = auto_del;
}


PJ_DEF(unsigned) pj_timer_heap_set_max_timed_out_per_poll(pj_timer_heap_t *ht,
                                                          unsigned count )
{
    unsigned old_count = ht->max_entries_per_poll;
    ht->max_entries_per_poll = count;
    return old_count;
}

PJ_DEF(pj_timer_entry*) pj_timer_entry_init( pj_timer_entry *entry,
                                             int id,
                                             void *user_data,
                                             pj_timer_heap_callback *cb )
{
    pj_assert(entry && cb);

    entry->id = id;
    entry->user_data = user_data;
    entry->cb = cb;

    return entry;
}

PJ_DEF(pj_status_t) pj_timer_heap_schedule( pj_timer_heap_t *ht,
					    pj_timer_entry *entry, 
					    const pj_time_val *delay)
{
    pj_status_t status;
    pj_time_val expires;

    PJ_ASSERT_RETURN(ht && entry && delay, PJ_EINVAL);
    PJ_ASSERT_RETURN(entry->cb != NULL, PJ_EINVAL);

    /* Prevent same entry from being scheduled more than once */
    PJ_ASSERT_RETURN(entry->_timer_id < 1, PJ_EINVALIDOP);

    pj_gettimeofday(&expires);
    PJ_TIME_VAL_ADD(expires, *delay);
    
    lock_timer_heap(ht);
    status = schedule_entry(ht, entry, &expires);
    unlock_timer_heap(ht);

    return status;
}

PJ_DEF(int) pj_timer_heap_cancel( pj_timer_heap_t *ht,
				  pj_timer_entry *entry)
{
    int count;

    PJ_ASSERT_RETURN(ht && entry, PJ_EINVAL);

    lock_timer_heap(ht);
    count = cancel(ht, entry, 1);
    unlock_timer_heap(ht);

    return count;
}

PJ_DEF(unsigned) pj_timer_heap_poll( pj_timer_heap_t *ht, 
                                     pj_time_val *next_delay )
{
    pj_time_val now;
    unsigned count;

    PJ_ASSERT_RETURN(ht, 0);

    if (!ht->cur_size && next_delay) {
	next_delay->sec = next_delay->msec = PJ_MAXINT32;
	return 0;
    }

    count = 0;
    pj_gettimeofday(&now);

    lock_timer_heap(ht);
    while ( ht->cur_size && 
	    PJ_TIME_VAL_LTE(ht->heap[0]->_timer_value, now) &&
            count < ht->max_entries_per_poll ) 
    {
	pj_timer_entry *node = remove_node(ht, 0);
	++count;

	unlock_timer_heap(ht);
	if (node->cb)
	    (*node->cb)(ht, node);
	lock_timer_heap(ht);
    }
    if (ht->cur_size && next_delay) {
	*next_delay = ht->heap[0]->_timer_value;
	PJ_TIME_VAL_SUB(*next_delay, now);
	if (next_delay->sec < 0 || next_delay->msec < 0)
	    next_delay->sec = next_delay->msec = 0;
    } else if (next_delay) {
	next_delay->sec = next_delay->msec = PJ_MAXINT32;
    }
    unlock_timer_heap(ht);

    return count;
}

PJ_DEF(pj_size_t) pj_timer_heap_count( pj_timer_heap_t *ht )
{
    PJ_ASSERT_RETURN(ht, 0);

    return ht->cur_size;
}

PJ_DEF(pj_status_t) pj_timer_heap_earliest_time( pj_timer_heap_t * ht,
					         pj_time_val *timeval)
{
    pj_assert(ht->cur_size != 0);
    if (ht->cur_size == 0)
        return PJ_ENOTFOUND;

    lock_timer_heap(ht);
    *timeval = ht->heap[0]->_timer_value;
    unlock_timer_heap(ht);

    return PJ_SUCCESS;
}