#undef G_DISABLE_ASSERT
#undef G_LOG_DOMAIN

#include <time.h>
#include <stdlib.h>

#include <glib.h>


static gboolean verbose = FALSE;


static void
check_integrity (GQueue *queue)
{
  GList *list;
  GList *last;
  GList *links;
  GList *link;
  gint n;
  
  g_assert (queue->length < 4000000000u);
  
  g_assert (g_queue_get_length (queue) == queue->length);
  
  if (!queue->head)
    g_assert (!queue->tail);
  if (!queue->tail)
    g_assert (!queue->head);
  
  n = 0;
  last = NULL;
  for (list = queue->head; list != NULL; list = list->next)
    {
      if (!list->next)
	last = list;
      ++n;
    }
  g_assert (n == queue->length); 
  g_assert (last == queue->tail);
  
  n = 0;
  last = NULL;
  for (list = queue->tail; list != NULL; list = list->prev)
    {
      if (!list->prev)
	last = list;
      ++n;
    }
  g_assert (n == queue->length);
  g_assert (last == queue->head);
  
  links = NULL;
  for (list = queue->head; list != NULL; list = list->next)
    links = g_list_prepend (links, list);
  
  link = links;
  for (list = queue->tail; list != NULL; list = list->prev)
    {
      g_assert (list == link->data);
      link = link->next;
    }
  g_list_free (links);
  
  links = NULL;
  for (list = queue->tail; list != NULL; list = list->prev)
    links = g_list_prepend (links, list);
  
  link = links;
  for (list = queue->head; list != NULL; list = list->next)
    {
      g_assert (list == link->data);
      link = link->next;
    }
  g_list_free (links);
}

static gboolean
rnd_bool (void)
{
  return g_random_int_range (0, 2);
}

static void
check_max (gpointer elm, gpointer user_data)
{
  gint *best = user_data;
  gint element = GPOINTER_TO_INT (elm);

  if (element > *best)
    *best = element;
}

static void
check_min (gpointer elm, gpointer user_data)
{
  gint *best = user_data;
  gint element = GPOINTER_TO_INT (elm);

  if (element < *best)
    *best = element;
}

static gint
find_min (GQueue *queue)
{
  gint min = G_MAXINT;

  g_queue_foreach (queue, check_min, &min);

  return min;
}

static gint
find_max (GQueue *queue)
{
  gint max = G_MININT;
  
  g_queue_foreach (queue, check_max, &max);

  return max;
}

static void
delete_elm (gpointer elm, gpointer user_data)
{
  g_queue_remove ((GQueue *)user_data, elm);
  check_integrity ((GQueue *)user_data);
}

static void
delete_all (GQueue *queue)
{
  g_queue_foreach (queue, delete_elm, queue);
}

static int
compare_int (gconstpointer a, gconstpointer b, gpointer data)
{
  int ai = GPOINTER_TO_INT (a);
  int bi = GPOINTER_TO_INT (b);

  if (ai > bi)
    return 1;
  else if (ai == bi)
    return 0;
  else
    return -1;
}

static gint
get_random_position (GQueue *queue, gboolean allow_offlist)
{
  int n;
  enum { OFF_QUEUE, HEAD, TAIL, MIDDLE, LAST } where;

  if (allow_offlist)
    where = g_random_int_range (OFF_QUEUE, LAST);
  else
    where = g_random_int_range (HEAD, LAST);

  switch (where)
    {
    case OFF_QUEUE:
      n = g_random_int ();
      break;

    case HEAD:
      n = 0;
      break;

    case TAIL:
      if (allow_offlist)
	n = queue->length;
      else
	n = queue->length - 1;
      break;

    case MIDDLE:
      if (queue->length == 0)
	n = 0;
      else
	n = g_random_int_range (0, queue->length);
      break;

    default:
      g_assert_not_reached();
      n = 100;
      break;

    }

  return n;
}

static void
random_test (int seed)
{
  typedef enum {
    IS_EMPTY, GET_LENGTH, REVERSE, COPY,
    FOREACH, FIND, FIND_CUSTOM, SORT,
    PUSH_HEAD, PUSH_TAIL, PUSH_NTH, POP_HEAD,
    POP_TAIL, POP_NTH, PEEK_HEAD, PEEK_TAIL,
    PEEK_NTH, INDEX, REMOVE, REMOVE_ALL,
    INSERT_BEFORE, INSERT_AFTER, INSERT_SORTED, PUSH_HEAD_LINK,
    PUSH_TAIL_LINK, PUSH_NTH_LINK, POP_HEAD_LINK, POP_TAIL_LINK,
    POP_NTH_LINK, PEEK_HEAD_LINK, PEEK_TAIL_LINK, PEEK_NTH_LINK,
    LINK_INDEX, UNLINK, DELETE_LINK, LAST_OP
  } QueueOp;

#define N_ITERATIONS 500000
#define N_QUEUES 3

#define RANDOM_QUEUE() &(queues[g_random_int_range(0, N_QUEUES)])

  typedef struct QueueInfo QueueInfo;
  struct QueueInfo
  {
    GQueue *queue;
    GList *tail;
    GList *head;
    guint length;
  };
  
  gint i;
  QueueOp op;
  QueueInfo queues[N_QUEUES];

  if (verbose)
    g_print ("seed: %d\n", seed);

  g_random_set_seed (seed);
  
  for (i = 0; i < N_QUEUES; ++i)
    {
      queues[i].queue = g_queue_new ();
      queues[i].head = NULL;
      queues[i].tail = NULL;
      queues[i].length = 0;
    }
  
  for (i = 0; i < N_ITERATIONS; ++i)
    {
      int j;
      QueueInfo *qinf = RANDOM_QUEUE();
      GQueue *q = qinf->queue;
      op = g_random_int_range (IS_EMPTY, LAST_OP);

      g_assert (qinf->head == q->head);
      g_assert (qinf->tail == q->tail);
      g_assert (qinf->length == q->length);
      
      switch (op)
	{
	case IS_EMPTY:
	  {
	    if (g_queue_is_empty (qinf->queue))
	      {
		g_assert (q->head == NULL);
		g_assert (q->tail == NULL);
		g_assert (q->length == 0);
	      }
	    else
	      {
		g_assert (q->head);
		g_assert (q->tail);
		g_assert (q->length > 0);
	      }
	  }
	  break;
	case GET_LENGTH:
	  {
	    int l;
	    
	    l = g_queue_get_length (q);
	    
	    g_assert (qinf->length == q->length);
	    g_assert (qinf->length == l);
	  }
	  break;
	case REVERSE:
	  g_queue_reverse (q);
	  g_assert (qinf->tail == q->head);
	  g_assert (qinf->head == q->tail);
	  g_assert (qinf->length == q->length);
	  qinf->tail = q->tail;
	  qinf->head = q->head;
	  break;
	case COPY:
	  {
	    QueueInfo *random_queue = RANDOM_QUEUE();
	    GQueue *new_queue = g_queue_copy (random_queue->queue);
	    
	    g_queue_free (qinf->queue);
	    q = qinf->queue = new_queue;
	    qinf->head = new_queue->head;
	    qinf->tail = g_list_last (new_queue->head);
	    qinf->length = new_queue->length;
	  }
	  break;
	case FOREACH:
	  delete_all (q);
	  qinf->head = NULL;
	  qinf->tail = NULL;
	  qinf->length = 0;
	  break;
	case FIND:
	  {
	    gboolean find_existing = rnd_bool ();
	    int first = find_max (q);
	    int second = find_min (q);

	    if (q->length == 0)
	      find_existing = FALSE;
	    
	    if (!find_existing)
	      first++;
	    if (!find_existing)
	      second--;

	    if (find_existing)
	      {
		g_assert (g_queue_find (q, GINT_TO_POINTER (first)));
		g_assert (g_queue_find (q, GINT_TO_POINTER (second)));
	      }
	    else
	      {
		g_assert (!g_queue_find (q, GINT_TO_POINTER (first)));
		g_assert (!g_queue_find (q, GINT_TO_POINTER (second)));
	      }
	  }
	  break;
	case FIND_CUSTOM:
	  break;
	case SORT:
	  {
	    if (!g_queue_is_empty (q))
	      {
		int max = find_max (q);
		int min = find_min (q);
		g_queue_remove_all (q, GINT_TO_POINTER (max));
		check_integrity (q);
		g_queue_remove_all (q, GINT_TO_POINTER (min));
		check_integrity (q);
		g_queue_push_head (q, GINT_TO_POINTER (max));
		if (max != min)
		  g_queue_push_head (q, GINT_TO_POINTER (min));
		qinf->length = q->length;
	      }

	    check_integrity (q);
	    
	    g_queue_sort (q, compare_int, NULL);

	    check_integrity (q);
	    
	    qinf->head = g_queue_find (q, GINT_TO_POINTER (find_min(q)));
	    qinf->tail = g_queue_find (q, GINT_TO_POINTER (find_max(q)));

	    g_assert (qinf->tail == q->tail);
	  }
	  break;
	case PUSH_HEAD:
	  {
	    int x = g_random_int_range (0, 435435);
	    g_queue_push_head (q, GINT_TO_POINTER (x));
	    if (!qinf->head)
	      qinf->tail = qinf->head = q->head;
	    else
	      qinf->head = qinf->head->prev;
	    qinf->length++;
	  }
	  break;
	case PUSH_TAIL:
	  {
	    int x = g_random_int_range (0, 236546);
	    g_queue_push_tail (q, GINT_TO_POINTER (x));
	    if (!qinf->tail)
	      qinf->tail = qinf->head = q->head;
	    else
	      qinf->tail = qinf->tail->next;
	    qinf->length++;
	  }
	  break;
	case PUSH_NTH:
	  {
	    int pos = get_random_position (q, TRUE);
	    int x = g_random_int_range (0, 236546);
	    g_queue_push_nth (q, GINT_TO_POINTER (x), pos);
	    if (qinf->head && qinf->head->prev)
	      qinf->head = qinf->head->prev;
	    else
	      qinf->head = q->head;
	    if (qinf->tail && qinf->tail->next)
	      qinf->tail = qinf->tail->next;
	    else
	      qinf->tail = g_list_last (qinf->head);
	    qinf->length++;
	  }
	  break;
	case POP_HEAD:
	  if (qinf->head)
	    qinf->head = qinf->head->next;
	  if (!qinf->head)
	    qinf->tail = NULL;
	  qinf->length = (qinf->length == 0)? 0 : qinf->length - 1;
	  g_queue_pop_head (q);
	  break;
	case POP_TAIL:
	  if (qinf->tail)
	    qinf->tail = qinf->tail->prev;
	  if (!qinf->tail)
	    qinf->head = NULL;
	  qinf->length = (qinf->length == 0)? 0 : qinf->length - 1;
	  g_queue_pop_tail (q);
	  break;
	case POP_NTH:
	  if (!g_queue_is_empty (q))
	    {
	      int n = get_random_position (q, TRUE);
	      gpointer elm = g_queue_peek_nth (q, n);

	      if (n == q->length - 1)
		qinf->tail = qinf->tail->prev;
	      
	      if (n == 0)
		qinf->head = qinf->head->next;

	      if (n >= 0 && n < q->length)
		qinf->length--;
	      
	      g_assert (elm == g_queue_pop_nth (q, n));
	    }
	  break;
	case PEEK_HEAD:
	  if (qinf->head)
	    g_assert (qinf->head->data == g_queue_peek_head (q));
	  else
	    g_assert (g_queue_peek_head (q) == NULL);
	  break;
	case PEEK_TAIL:
	  if (qinf->head)
	    g_assert (qinf->tail->data == g_queue_peek_tail (q));
	  else
	    g_assert (g_queue_peek_tail (q) == NULL);
	  break;
	case PEEK_NTH:
	  if (g_queue_is_empty (q))
	    {
	      for (j = -10; j < 10; ++j)
		g_assert (g_queue_peek_nth (q, j) == NULL);
	    }
	  else
	    {
	      GList *list;
	      int n = get_random_position (q, TRUE);
	      if (n < 0 || n >= q->length)
		{
		  g_assert (g_queue_peek_nth (q, n) == NULL);
		}
	      else
		{
		  list = qinf->head;
		  for (j = 0; j < n; ++j)
		    list = list->next;
		  
		  g_assert (list->data == g_queue_peek_nth (q, n));
		}
	    }
	  break;
	case INDEX:
	case LINK_INDEX:
	  {
	    int x = g_random_int_range (0, 386538);
	    int n;
	    GList *list;

	    g_queue_remove_all (q, GINT_TO_POINTER (x));
 	    check_integrity (q);
	    g_queue_push_tail (q, GINT_TO_POINTER (x));
 	    check_integrity (q);
	    g_queue_sort (q, compare_int, NULL);
 	    check_integrity (q);

	    n = 0;
	    for (list = q->head; list != NULL; list = list->next)
	      {
		if (list->data == GINT_TO_POINTER (x))
		  break;
		n++;
	      }
	    g_assert (list);
	    g_assert (g_queue_index (q, GINT_TO_POINTER (x)) ==
		      g_queue_link_index (q, list));
	    g_assert (g_queue_link_index (q, list) == n);

	    qinf->head = q->head;
	    qinf->tail = q->tail;
	    qinf->length = q->length;
	  }
	  break;
	case REMOVE:
	  if (!g_queue_is_empty (q))
	    g_queue_remove (q, qinf->tail->data);
	  if (!g_queue_is_empty (q))
	    g_queue_remove (q, qinf->head->data);
	  if (!g_queue_is_empty (q))
	    g_queue_remove (q, g_queue_peek_nth (q, get_random_position (q, TRUE)));

	  qinf->head = q->head;
	  qinf->tail = q->tail;
	  qinf->length = q->length;
	  break;
	case REMOVE_ALL:
	  if (!g_queue_is_empty (q))
	    g_queue_remove_all (q, qinf->tail->data);
	  if (!g_queue_is_empty (q))
	    g_queue_remove_all (q, qinf->head->data);
	  if (!g_queue_is_empty (q))
	    g_queue_remove_all (q, g_queue_peek_nth (q, get_random_position (q, TRUE)));

	  qinf->head = q->head;
	  qinf->tail = q->tail;
	  qinf->length = q->length;
	  break;
	case INSERT_BEFORE:
	  if (!g_queue_is_empty (q))
	    {
	      gpointer x = GINT_TO_POINTER (g_random_int_range (0, 386538));
	      
	      g_queue_insert_before (q, qinf->tail, x);
	      g_queue_insert_before (q, qinf->head, x);
	      g_queue_insert_before (q, g_queue_find (q, x), x);
	    }
	  qinf->head = q->head;
	  qinf->tail = q->tail;
	  qinf->length = q->length;
	  break;
	case INSERT_AFTER:
	  if (!g_queue_is_empty (q))
	    {
	      gpointer x = GINT_TO_POINTER (g_random_int_range (0, 386538));
	      
	      g_queue_insert_after (q, qinf->tail, x);
	      g_queue_insert_after (q, qinf->head, x);
	      g_queue_insert_after (q, g_queue_find (q, x), x);
	    }
	  qinf->head = q->head;
	  qinf->tail = q->tail;
	  qinf->length = q->length;
	  break;
	case INSERT_SORTED:
	  {
	    int max = find_max (q);
	    int min = find_min (q);

	    if (g_queue_is_empty (q))
	      {
		max = 345;
		min = -12;
	      }
	    
	    g_queue_sort (q, compare_int, NULL);
 	    check_integrity (q);
	    g_queue_insert_sorted (q, GINT_TO_POINTER (max + 1), compare_int, NULL);
 	    check_integrity (q);
	    g_assert (GPOINTER_TO_INT (q->tail->data) == max + 1);
	    g_queue_insert_sorted (q, GINT_TO_POINTER (min - 1), compare_int, NULL);
 	    check_integrity (q);
	    g_assert (GPOINTER_TO_INT (q->head->data) == min - 1);
	    qinf->head = q->head;
	    qinf->tail = q->tail;
	    qinf->length = q->length;
	  }
	  break;
	case PUSH_HEAD_LINK:
	  {
	    GList *link = g_list_prepend (NULL, GINT_TO_POINTER (i));
	    g_queue_push_head_link (q, link);
	    if (!qinf->tail)
	      qinf->tail = link;
	    qinf->head = link;
	    qinf->length++;
	  }
	  break;
	case PUSH_TAIL_LINK:
	  {
	    GList *link = g_list_prepend (NULL, GINT_TO_POINTER (i));
	    g_queue_push_tail_link (q, link);
	    if (!qinf->head)
	      qinf->head = link;
	    qinf->tail = link;
	    qinf->length++;
	  }
	  break;
	case PUSH_NTH_LINK:
	  {
	    GList *link = g_list_prepend (NULL, GINT_TO_POINTER (i));
	    gint n = get_random_position (q, TRUE);
	    g_queue_push_nth_link (q, n, link);

	    if (qinf->head && qinf->head->prev)
	      qinf->head = qinf->head->prev;
	    else
	      qinf->head = q->head;
	    if (qinf->tail && qinf->tail->next)
	      qinf->tail = qinf->tail->next;
	    else
	      qinf->tail = g_list_last (qinf->head);
	    qinf->length++;
	  }
	  break;
	case POP_HEAD_LINK:
	  if (!g_queue_is_empty (q))
	    {
	      qinf->head = qinf->head->next;
	      if (!qinf->head)
		qinf->tail = NULL;
	      qinf->length--;
	      g_list_free (g_queue_pop_head_link (q));
	    }
	  break;
	case POP_TAIL_LINK:
	  if (!g_queue_is_empty (q))
	    {
	      qinf->tail = qinf->tail->prev;
	      if (!qinf->tail)
		qinf->head = NULL;
	      qinf->length--;
	      g_list_free (g_queue_pop_tail_link (q));
	    }
	  break;
	case POP_NTH_LINK:
	  if (g_queue_is_empty (q))
	    g_assert (g_queue_pop_nth_link (q, 200) == NULL);
	  else
	    {
	      int n = get_random_position (q, FALSE);
	      
	      if (n == g_queue_get_length (q) - 1)
		qinf->tail = qinf->tail->prev;
	      
	      if (n == 0)
		qinf->head = qinf->head->next;
	      
	      qinf->length--;
	      
	      g_list_free (g_queue_pop_nth_link (q, n));
	    }
	  break;
	case PEEK_HEAD_LINK:
	  if (g_queue_is_empty (q))
	    g_assert (g_queue_peek_head_link (q) == NULL);
	  else
	    g_assert (g_queue_peek_head_link (q) == qinf->head);
	  break;
	case PEEK_TAIL_LINK:
	  if (g_queue_is_empty (q))
	    g_assert (g_queue_peek_tail_link (q) == NULL);
	  else
	    g_assert (g_queue_peek_tail_link (q) == qinf->tail);
	  break;
	case PEEK_NTH_LINK:
	  if (g_queue_is_empty(q))
	    g_assert (g_queue_peek_nth_link (q, 1000) == NULL);
	  else
	    {
	      gint n = get_random_position (q, FALSE);
	      GList *link;

	      link = q->head;
	      for (j = 0; j < n; ++j)
		link = link->next;

	      g_assert (g_queue_peek_nth_link (q, n) == link);
	    }
	  break;
	case UNLINK:
	  if (!g_queue_is_empty (q))
	    {
	      gint n = g_random_int_range (0, g_queue_get_length (q));
	      GList *link;

	      link = q->head;
	      for (j = 0; j < n; ++j)
		link = link->next;

	      g_queue_unlink (q, link);
	      check_integrity (q);

	      g_list_free (link);

	      qinf->head = q->head;
	      qinf->tail = q->tail;
	      qinf->length--;
	    }
	  break;
	case DELETE_LINK:
	  if (!g_queue_is_empty (q))
	    {
	      gint n = g_random_int_range (0, g_queue_get_length (q));
	      GList *link;

	      link = q->head;
	      for (j = 0; j < n; ++j)
		link = link->next;

	      g_queue_delete_link (q, link);
	      check_integrity (q);

	      qinf->head = q->head;
	      qinf->tail = q->tail;
	      qinf->length--;
	    }
	  break;
	case LAST_OP:
	default:
	  g_assert_not_reached();
	  break;
	}

      if (qinf->head != q->head ||
	  qinf->tail != q->tail ||
	  qinf->length != q->length)
	g_print ("op: %d\n", op);

      g_assert (qinf->head == q->head);
      g_assert (qinf->tail == q->tail);
      g_assert (qinf->length == q->length);
      
      for (j = 0; j < N_QUEUES; ++j)
	check_integrity (queues[j].queue);
    }
  
  for (i = 0; i < N_QUEUES; ++i)
    g_queue_free (queues[i].queue);
}

static void
remove_item (gpointer data, gpointer q)
{
  GQueue *queue = q;
  
  g_queue_remove (queue, data);
}

int main(int argc, gchar *args[])
{
  GQueue *q, *q2;
  GList *node;
  gpointer data;
  int i;
  
  if (argc > 1 && args[1][0] == '-' && args[1][1] == 'v')
    verbose = TRUE;

  q = g_queue_new ();
  
  g_assert (g_queue_is_empty (q) == TRUE);
  
  g_queue_push_head (q, GINT_TO_POINTER (2));
  check_integrity (q);
  g_assert (g_queue_peek_head (q) == GINT_TO_POINTER (2));
  check_integrity (q);
  g_assert (g_queue_is_empty (q) == FALSE);
  check_integrity (q);
  g_assert (g_list_length (q->head) == 1);
  g_assert (q->head == q->tail);
  g_queue_push_head (q, GINT_TO_POINTER (1));
  check_integrity (q);
  g_assert (q->head->next == q->tail);
  g_assert (q->tail->prev == q->head);
  g_assert (g_list_length (q->head) == 2);
  check_integrity (q);
  g_assert (q->tail->data == GINT_TO_POINTER (2));
  g_assert (q->head->data == GINT_TO_POINTER (1));
  check_integrity (q);
  g_queue_push_tail (q, GINT_TO_POINTER (3));
  g_assert (g_list_length (q->head) == 3);
  g_assert (q->head->data == GINT_TO_POINTER (1));
  g_assert (q->head->next->data == GINT_TO_POINTER (2));
  g_assert (q->head->next->next == q->tail);
  g_assert (q->head->next == q->tail->prev);
  g_assert (q->tail->data == GINT_TO_POINTER (3));
  g_queue_push_tail (q, GINT_TO_POINTER (4));
  check_integrity (q);
  g_assert (g_list_length (q->head) == 4);
  g_assert (q->head->data == GINT_TO_POINTER (1));
  g_assert (g_queue_peek_tail (q) == GINT_TO_POINTER (4));
  g_queue_push_tail (q, GINT_TO_POINTER (5));
  check_integrity (q);
  g_assert (g_list_length (q->head) == 5);
  
  g_assert (g_queue_is_empty (q) == FALSE);
  check_integrity (q);
  
  g_assert (q->length == 5);
  g_assert (q->head->prev == NULL);
  g_assert (q->head->data == GINT_TO_POINTER (1));
  g_assert (q->head->next->data == GINT_TO_POINTER (2));
  g_assert (q->head->next->next->data == GINT_TO_POINTER (3));
  g_assert (q->head->next->next->next->data == GINT_TO_POINTER (4));
  g_assert (q->head->next->next->next->next->data == GINT_TO_POINTER (5));
  g_assert (q->head->next->next->next->next->next == NULL);
  g_assert (q->head->next->next->next->next == q->tail);
  g_assert (q->tail->data == GINT_TO_POINTER (5));
  g_assert (q->tail->prev->data == GINT_TO_POINTER (4));
  g_assert (q->tail->prev->prev->data == GINT_TO_POINTER (3));
  g_assert (q->tail->prev->prev->prev->data == GINT_TO_POINTER (2));
  g_assert (q->tail->prev->prev->prev->prev->data == GINT_TO_POINTER (1));
  g_assert (q->tail->prev->prev->prev->prev->prev == NULL);
  g_assert (q->tail->prev->prev->prev->prev == q->head);
  g_assert (g_queue_peek_tail (q) == GINT_TO_POINTER (5));
  g_assert (g_queue_peek_head (q) == GINT_TO_POINTER (1));
  
  g_assert (g_queue_pop_head (q) == GINT_TO_POINTER (1));
  check_integrity (q);
  g_assert (g_list_length (q->head) == 4 && q->length == 4);
  g_assert (g_queue_pop_tail (q) == GINT_TO_POINTER (5));
  check_integrity (q);
  g_assert (g_list_length (q->head) == 3);
  g_assert (g_queue_pop_head_link (q)->data == GINT_TO_POINTER (2));
  check_integrity (q);
  g_assert (g_list_length (q->head) == 2);
  g_assert (g_queue_pop_tail (q) == GINT_TO_POINTER (4));
  check_integrity (q);
  g_assert (g_list_length (q->head) == 1);
  g_assert (g_queue_pop_head_link (q)->data == GINT_TO_POINTER (3));
  check_integrity (q);
  g_assert (g_list_length (q->head) == 0);
  g_assert (g_queue_pop_tail (q) == NULL);
  check_integrity (q);
  g_assert (g_list_length (q->head) == 0);
  g_assert (g_queue_pop_head (q) == NULL);
  check_integrity (q);
  g_assert (g_list_length (q->head) == 0);
  
  g_assert (g_queue_is_empty (q) == TRUE);
  check_integrity (q);
  
  /************************/
  
  g_queue_push_head (q, GINT_TO_POINTER (1));
  check_integrity (q);
  g_assert (g_list_length (q->head) == 1 && 1 == q->length);
  g_queue_push_head (q, GINT_TO_POINTER (2));
  check_integrity (q);
  g_assert (g_list_length (q->head) == 2 && 2 == q->length);
  g_queue_push_head (q, GINT_TO_POINTER (3));
  check_integrity (q);
  g_assert (g_list_length (q->head) == 3 && 3 == q->length);
  g_queue_push_head (q, GINT_TO_POINTER (4));
  check_integrity (q);
  g_assert (g_list_length (q->head) == 4 && 4 == q->length);
  g_queue_push_head (q, GINT_TO_POINTER (5));
  check_integrity (q);
  g_assert (g_list_length (q->head) == 5 && 5 == q->length);
  
  g_assert (g_queue_pop_head (q) == GINT_TO_POINTER (5));
  check_integrity (q);
  g_assert (g_list_length (q->head) == 4);
  node = q->tail;
  g_assert (node == g_queue_pop_tail_link (q));
  check_integrity (q);
  g_assert (g_list_length (q->head) == 3);
  data = q->head->data;
  g_assert (data == g_queue_pop_head (q));
  check_integrity (q);
  g_assert (g_list_length (q->head) == 2);
  g_assert (g_queue_pop_tail (q) == GINT_TO_POINTER (2));
  check_integrity (q);
  g_assert (g_list_length (q->head) == 1);
  g_assert (q->head == q->tail);
  g_assert (g_queue_pop_tail (q) == GINT_TO_POINTER (3));
  check_integrity (q);
  g_assert (g_list_length (q->head) == 0);
  g_assert (g_queue_pop_head (q) == NULL);
  check_integrity (q);
  g_assert (g_queue_pop_head_link (q) == NULL);
  check_integrity (q);
  g_assert (g_list_length (q->head) == 0);
  g_assert (g_queue_pop_tail_link (q) == NULL);
  check_integrity (q);
  g_assert (g_list_length (q->head) == 0);
  
  /* */
  g_queue_reverse (q);
  check_integrity (q);
  g_assert (g_list_length (q->head) == 0);
  
  q2 = g_queue_copy (q);
  check_integrity (q);
  check_integrity (q2);
  g_assert (g_list_length (q->head) == 0);
  g_assert (g_list_length (q2->head) == 0);
  g_queue_sort (q, compare_int, NULL);
  check_integrity (q2);
  check_integrity (q);
  g_queue_sort (q2, compare_int, NULL);
  check_integrity (q2);
  check_integrity (q);
  
  for (i = 0; i < 200; ++i)
    {
      g_queue_push_nth (q, GINT_TO_POINTER (i), i);
      g_assert (g_queue_find (q, GINT_TO_POINTER (i)));
      check_integrity (q);
      check_integrity (q2);
    }
  
  for (i = 0; i < 200; ++i)
    {
      g_queue_remove (q, GINT_TO_POINTER (i));
      check_integrity (q);
      check_integrity (q2);
    }
  
  for (i = 0; i < 200; ++i)
    {
      GList *l = g_list_prepend (NULL, GINT_TO_POINTER (i));
      
      g_queue_push_nth_link (q, i, l);
      check_integrity (q);
      check_integrity (q2);
      g_queue_reverse (q);
      check_integrity (q);
      check_integrity (q2);
    }
  
  g_queue_free (q2);
  q2 = g_queue_copy (q);
  
  g_queue_foreach (q2, remove_item, q2);
  check_integrity (q2);
  check_integrity (q);

  /* some checks for off by one errors */  
  g_queue_push_tail (q, GINT_TO_POINTER (1234));
  check_integrity (q);
  node = g_queue_peek_tail_link (q);
  g_assert (node != NULL && node->data == GINT_TO_POINTER (1234));
  node = g_queue_peek_nth_link (q, g_queue_get_length (q));
  g_assert (node == NULL);
  node = g_queue_peek_nth_link (q, g_queue_get_length (q) - 1);
  g_assert (node->data == GINT_TO_POINTER (1234));
  node = g_queue_pop_nth_link (q, g_queue_get_length (q));
  g_assert (node == NULL);
  node = g_queue_pop_nth_link (q, g_queue_get_length (q) - 1);
  g_assert (node != NULL && node->data == GINT_TO_POINTER (1234));
  
  g_queue_free (q);

  if (argc > 2 && args[1][0] == '-' && args[1][1] == 'v')
    random_test (strtol (args[2], NULL, 0));    
  if (argc > 1)
    random_test (strtol (args[1], NULL, 0));
  else
    random_test (time (0));  

  return 0;
}