hdf5/test/tskiplist.c

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * Copyright by The HDF Group.                                               *
 * All rights reserved.                                                      *
 *                                                                           *
 * This file is part of HDF5.  The full HDF5 copyright notice, including     *
 * terms governing use, modification, and redistribution, is contained in    *
 * the COPYING file, which can be found at the root of the source code       *
 * distribution tree, or in https://www.hdfgroup.org/licenses.               *
 * If you do not have access to either file, you may request a copy from     *
 * help@hdfgroup.org.                                                        *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/*
   Test HDF Skip List routines.

   REMARKS

   DESIGN

   BUGS/LIMITATIONS

   EXPORTED ROUTINES

 */

#include "testhdf5.h"
#include "H5SLprivate.h"

/* The number of elements in testing arrays */
#define NUM_ELEMS 1000

/* Random numbers */
static int *rand_num;
static int *sort_rand_num;
static int *rev_sort_rand_num;

static int
tst_sort(const void *i1, const void *i2)
{
    return (*(const int *)i1 - *(const int *)i2);
}

static int
tst_rev_sort(const void *i1, const void *i2)
{
    return (*(const int *)i2 - *(const int *)i1);
}

/****************************************************************
**
**  test_skiplist_init(): Test H5SL (skiplist) code.
**      Initialize data for skip list testing
**
****************************************************************/
static void
test_skiplist_init(void)
{
    time_t   curr_time; /* Current time, for seeding random number generator */
    int      new_val;   /* New value to insert */
    unsigned found;     /* Flag to indicate value was inserted already */
    size_t   u, v;      /* Local index variables */

    /* Allocate arrays */
    rand_num = (int *)malloc(sizeof(int) * NUM_ELEMS);
    CHECK_PTR(rand_num, "malloc");
    sort_rand_num = (int *)malloc(sizeof(int) * NUM_ELEMS);
    CHECK_PTR(sort_rand_num, "malloc");
    rev_sort_rand_num = (int *)malloc(sizeof(int) * NUM_ELEMS);
    CHECK_PTR(rev_sort_rand_num, "malloc");

    /* Initialize random number seed */
    curr_time = HDtime(NULL);
    HDsrandom((unsigned)curr_time);

    /* Create randomized set of numbers */
    for (u = 0; u < NUM_ELEMS; u++) {
        do {
            /* Reset flag */
            found = 0;

            /* Generate random numbers from -5000 to 5000 */
            new_val = (int)(HDrandom() % 10001) - 5001;

            /* Check if the value is already in the array */
            for (v = 0; v < u; v++)
                if (rand_num[v] == new_val)
                    found = 1;
        } while (found);

        /* Set unique value in array */
        rand_num[u] = new_val;
    } /* end for */

    /* Copy random values to sorted array */
    memcpy(sort_rand_num, rand_num, sizeof(int) * NUM_ELEMS);

    /* Sort random numbers */
    qsort(sort_rand_num, (size_t)NUM_ELEMS, sizeof(int), tst_sort);

    /* Copy random values to reverse sorted array */
    memcpy(rev_sort_rand_num, rand_num, sizeof(int) * NUM_ELEMS);

    /* Sort random numbers */
    qsort(rev_sort_rand_num, (size_t)NUM_ELEMS, sizeof(int), tst_rev_sort);
} /* end test_skiplist_init() */

/****************************************************************
**
**  test_skiplist_create(): Test basic H5SL (skiplist) code.
**      Tests creating and closing skip lists.
**
****************************************************************/
static void
test_skiplist_create(void)
{
    H5SL_t *slist; /* Skip list created */
    herr_t  ret;   /* Generic return value */

    /* Output message about test being performed */
    MESSAGE(6, ("Testing Creating & Closing Skip Lists\n"));

    /* Try creating a skip list */
    slist = H5SL_create(H5SL_TYPE_INT, NULL);
    CHECK_PTR(slist, "H5SL_create");

    /* Try closing the skip list */
    ret = H5SL_close(slist);
    CHECK(ret, FAIL, "H5SL_close");

} /* end test_skiplist_create() */

/****************************************************************
**
**  test_skiplist_insert(): Test H5SL (skip list) code.
**      Tests inserting single object into skip list.
**
****************************************************************/
static void
test_skiplist_insert(void)
{
    H5SL_t *slist;     /* Skip list created */
    int     key,       /* Key of item to insert */
        item;          /* Item to insert */
    int    search_key; /* Key of item to search for in skip list */
    int   *found_item; /* Item found in skip list */
    size_t num;        /* Number of elements in skip list */
    herr_t ret;        /* Generic return value */

    /* Output message about test being performed */
    MESSAGE(7, ("Testing Insertion Into Skip List\n"));

    /* Create a skip list */
    slist = H5SL_create(H5SL_TYPE_INT, NULL);
    CHECK_PTR(slist, "H5SL_create");

    /* Check that the skip list has no elements */
    num = H5SL_count(slist);
    VERIFY(num, 0, "H5SL_count");

    /* Try searching for item in empty skip list */
    key        = 37;
    found_item = (int *)H5SL_search(slist, &key);
    CHECK_PTR_NULL(found_item, "H5SL_search");

    /* Insert an object into the skip list */
    key  = 2;
    item = 10;
    ret  = H5SL_insert(slist, &item, &key);
    CHECK(ret, FAIL, "H5SL_insert");

    /* Check that the skip list has one element */
    num = H5SL_count(slist);
    VERIFY(num, 1, "H5SL_count");

    /* Search for the item just inserted */
    found_item = (int *)H5SL_search(slist, &key);
    CHECK_PTR(found_item, "H5SL_search");
    VERIFY(*found_item, item, "H5SL_search");

    /* Search for an item not in list */
    search_key = 37;
    found_item = (int *)H5SL_search(slist, &search_key);
    CHECK_PTR_NULL(found_item, "H5SL_search");

    /* Attempt to insert duplicate key (should fail) */
    search_key = 2;
    ret        = H5SL_insert(slist, &search_key, &search_key);
    VERIFY(ret, FAIL, "H5SL_insert");

    /* Close the skip list */
    ret = H5SL_close(slist);
    CHECK(ret, FAIL, "H5SL_close");

} /* end test_skiplist_insert() */

/****************************************************************
**
**  test_skiplist_insert_many(): Test H5SL (skip list) code.
**      Tests inserting many objects into skip list.
**
****************************************************************/
static void
test_skiplist_insert_many(void)
{
    H5SL_t *slist;      /* Skip list created */
    size_t  num;        /* Number of elements in skip list */
    size_t  u;          /* Local index variable */
    int    *found_item; /* Item found in skip list */
    herr_t  ret;        /* Generic return value */

    /* Output message about test being performed */
    MESSAGE(7, ("Testing Insertion of Many Items Into Skip List\n"));

    /* Create a skip list */
    slist = H5SL_create(H5SL_TYPE_INT, NULL);
    CHECK_PTR(slist, "H5SL_create");

    /* Check that the skip list has no elements */
    num = H5SL_count(slist);
    VERIFY(num, 0, "H5SL_count");

    /* Insert many objects into the skip list */
    for (u = 0; u < NUM_ELEMS; u++) {
        ret = H5SL_insert(slist, &rand_num[u], &rand_num[u]);
        CHECK(ret, FAIL, "H5SL_insert");
    } /* end for */

    /* Check that the skip list has correct # of elements */
    num = H5SL_count(slist);
    VERIFY(num, NUM_ELEMS, "H5SL_count");

    /* Search for all objects in the skip list */
    for (u = 0; u < NUM_ELEMS; u++) {
        found_item = (int *)H5SL_search(slist, &rand_num[u]);
        CHECK_PTR(found_item, "H5SL_search");
        VERIFY(*found_item, rand_num[u], "H5SL_search");
    } /* end for */

    /* Release all the items from the list */
    ret = H5SL_release(slist);
    CHECK(ret, FAIL, "H5SL_release");

    /* Check that the skip list has no elements */
    num = H5SL_count(slist);
    VERIFY(num, 0, "H5SL_count");

    /* Insert many objects into the skip list */
    for (u = 0; u < NUM_ELEMS; u++) {
        ret = H5SL_insert(slist, &rand_num[u], &rand_num[u]);
        CHECK(ret, FAIL, "H5SL_insert");
    } /* end for */

    /* Check that the skip list has correct # of elements */
    num = H5SL_count(slist);
    VERIFY(num, NUM_ELEMS, "H5SL_count");

    /* Release all the items from the list */
    ret = H5SL_release(slist);
    CHECK(ret, FAIL, "H5SL_release");

    /* Close the skip list */
    ret = H5SL_close(slist);
    CHECK(ret, FAIL, "H5SL_close");

} /* end test_skiplist_insert_many() */

/****************************************************************
**
**  test_skiplist_remove(): Test H5SL (skip list) code.
**      Tests basic object removal from skip list.
**
****************************************************************/
static void
test_skiplist_remove(void)
{
    H5SL_t *slist;     /* Skip list created */
    int     key1,      /* Key of 1st item to insert */
        key2,          /* Key of 2nd item to insert */
        key3;          /* Key of 3rd item to insert */
    int    search_key; /* Key of item to search for in skip list */
    int   *found_item; /* Item found in skip list */
    size_t num;        /* Number of elements in skip list */
    herr_t ret;        /* Generic return value */

    /* Output message about test being performed */
    MESSAGE(7, ("Testing Removal From Skip List\n"));

    /* Create a skip list */
    slist = H5SL_create(H5SL_TYPE_INT, NULL);
    CHECK_PTR(slist, "H5SL_create");

    /* Check that the skip list has no elements */
    num = H5SL_count(slist);
    VERIFY(num, 0, "H5SL_count");

    /* Try removing an item in empty skip list */
    search_key = 37;
    found_item = (int *)H5SL_remove(slist, &search_key);
    CHECK_PTR_NULL(found_item, "H5SL_remove");

    /* Insert three objects into the skip list */
    key1 = 15;
    ret  = H5SL_insert(slist, &key1, &key1);
    CHECK(ret, FAIL, "H5SL_insert");

    key2 = 10;
    ret  = H5SL_insert(slist, &key2, &key2);
    CHECK(ret, FAIL, "H5SL_insert");

    key3 = 20;
    ret  = H5SL_insert(slist, &key3, &key3);
    CHECK(ret, FAIL, "H5SL_insert");

    /* Check that the skip list has three elements */
    num = H5SL_count(slist);
    VERIFY(num, 3, "H5SL_count");

    /* Try removing items from skip list */
    search_key = key1;
    found_item = (int *)H5SL_remove(slist, &search_key);
    CHECK_PTR(found_item, "H5SL_remove");
    CHECK_PTR_EQ(found_item, &key1, "H5SL_remove");

    search_key = key2;
    found_item = (int *)H5SL_remove(slist, &search_key);
    CHECK_PTR(found_item, "H5SL_remove");
    CHECK_PTR_EQ(found_item, &key2, "H5SL_remove");

    search_key = key3;
    found_item = (int *)H5SL_remove(slist, &search_key);
    CHECK_PTR(found_item, "H5SL_remove");
    CHECK_PTR_EQ(found_item, &key3, "H5SL_remove");

    /* Check that the skip list has no elements */
    num = H5SL_count(slist);
    VERIFY(num, 0, "H5SL_count");

    /* Try removing items from empty skip list (after its been worked on) */
    search_key = key1;
    found_item = (int *)H5SL_remove(slist, &search_key);
    CHECK_PTR_NULL(found_item, "H5SL_remove");

    /* Close the skip list */
    ret = H5SL_close(slist);
    CHECK(ret, FAIL, "H5SL_close");

} /* end test_skiplist_remove() */

/****************************************************************
**
**  test_skiplist_remove_many(): Test H5SL (skip list) code.
**      Tests removing many objects from skip list.
**
****************************************************************/
static void
test_skiplist_remove_many(void)
{
    H5SL_t *slist;      /* Skip list created */
    size_t  num;        /* Number of elements in skip list */
    size_t  u;          /* Local index variable */
    int    *found_item; /* Item found in skip list */
    herr_t  ret;        /* Generic return value */

    /* Output message about test being performed */
    MESSAGE(7, ("Testing Removal of Many Items From Skip List\n"));

    /* Create a skip list */
    slist = H5SL_create(H5SL_TYPE_INT, NULL);
    CHECK_PTR(slist, "H5SL_create");

    /* Check that the skip list has no elements */
    num = H5SL_count(slist);
    VERIFY(num, 0, "H5SL_count");

    /* Insert many objects into the skip list */
    for (u = 0; u < NUM_ELEMS; u++) {
        ret = H5SL_insert(slist, &rand_num[u], &rand_num[u]);
        CHECK(ret, FAIL, "H5SL_insert");
    } /* end for */

    /* Check that the skip list has correct # of elements */
    num = H5SL_count(slist);
    VERIFY(num, NUM_ELEMS, "H5SL_count");

    /* Remove all objects from the skip list (in random order) */
    for (u = 0; u < NUM_ELEMS; u++) {
        found_item = (int *)H5SL_remove(slist, &rand_num[u]);
        CHECK_PTR(found_item, "H5SL_remove");
        VERIFY(*found_item, rand_num[u], "H5SL_remove");
    } /* end for */

    /* Check that the skip list has correct # of elements */
    num = H5SL_count(slist);
    VERIFY(num, 0, "H5SL_count");

    /* Insert & remove again (in sorted order), to check that completely empty skip lists can be added again
     */

    /* Insert many objects into the skip list */
    for (u = 0; u < NUM_ELEMS; u++) {
        ret = H5SL_insert(slist, &rand_num[u], &rand_num[u]);
        CHECK(ret, FAIL, "H5SL_insert");
    } /* end for */

    /* Check that the skip list has correct # of elements */
    num = H5SL_count(slist);
    VERIFY(num, NUM_ELEMS, "H5SL_count");

    /* Remove all objects from the skip list */
    for (u = 0; u < NUM_ELEMS; u++) {
        found_item = (int *)H5SL_remove(slist, &sort_rand_num[u]);
        CHECK_PTR(found_item, "H5SL_remove");
        VERIFY(*found_item, sort_rand_num[u], "H5SL_remove");
    } /* end for */

    /* Check that the skip list has correct # of elements */
    num = H5SL_count(slist);
    VERIFY(num, 0, "H5SL_count");

    /* Insert & remove again (in reverse sorted order), to check that completely empty skip lists can be added
     * again */

    /* Insert many objects into the skip list */
    for (u = 0; u < NUM_ELEMS; u++) {
        ret = H5SL_insert(slist, &rand_num[u], &rand_num[u]);
        CHECK(ret, FAIL, "H5SL_insert");
    } /* end for */

    /* Check that the skip list has correct # of elements */
    num = H5SL_count(slist);
    VERIFY(num, NUM_ELEMS, "H5SL_count");

    /* Remove all objects from the skip list */
    for (u = 0; u < NUM_ELEMS; u++) {
        found_item = (int *)H5SL_remove(slist, &rev_sort_rand_num[u]);
        CHECK_PTR(found_item, "H5SL_remove");
        VERIFY(*found_item, rev_sort_rand_num[u], "H5SL_remove");
    } /* end for */

    /* Check that the skip list has correct # of elements */
    num = H5SL_count(slist);
    VERIFY(num, 0, "H5SL_count");

    /* Close the skip list */
    ret = H5SL_close(slist);
    CHECK(ret, FAIL, "H5SL_close");

} /* end test_skiplist_remove_many() */

/****************************************************************
**
**  test_skiplist_firstnext(): Test H5SL (skip list) code.
**      Tests iterating over nodes in skip list with first/next calls.
**
****************************************************************/
static void
test_skiplist_firstnext(void)
{
    H5SL_t      *slist;      /* Skip list created */
    H5SL_node_t *node;       /* Skip list node */
    size_t       num;        /* Number of elements in skip list */
    size_t       u;          /* Local index variable */
    int         *found_item; /* Item found in skip list */
    herr_t       ret;        /* Generic return value */

    /* Output message about test being performed */
    MESSAGE(7, ("Testing Iterating Over Skip List With First/Next\n"));

    /* Create a skip list */
    slist = H5SL_create(H5SL_TYPE_INT, NULL);
    CHECK_PTR(slist, "H5SL_create");

    /* Check that the skip list has no elements */
    num = H5SL_count(slist);

    VERIFY(num, 0, "H5SL_count");
    /* Check that the list appears empty */
    node = H5SL_first(slist);
    CHECK_PTR_NULL(node, "H5SL_first");

    /* Insert many objects into the skip list */
    for (u = 0; u < NUM_ELEMS; u++) {
        ret = H5SL_insert(slist, &rand_num[u], &rand_num[u]);
        CHECK(ret, FAIL, "H5SL_insert");
    } /* end for */

    /* Check that the skip list has correct # of elements */
    num = H5SL_count(slist);
    VERIFY(num, NUM_ELEMS, "H5SL_count");

    /* Iterate over all the nodes in the skip list */
    node = H5SL_first(slist);
    CHECK_PTR(node, "H5SL_first");
    u = 0;
    while (node != NULL) {
        found_item = (int *)H5SL_item(node);
        VERIFY(*found_item, sort_rand_num[u], "H5SL_next");
        u++;
        node = H5SL_next(node);
    } /* end while */

    /* Release all the items from the list */
    ret = H5SL_release(slist);
    CHECK(ret, FAIL, "H5SL_release");

    /* Check that the list appears empty again */
    node = H5SL_first(slist);
    CHECK_PTR_NULL(node, "H5SL_first");

    /* Close the skip list */
    ret = H5SL_close(slist);
    CHECK(ret, FAIL, "H5SL_close");

} /* end test_skiplist_firstnext() */

/****************************************************************
**
**  test_skiplist_string(): Test H5SL (skip list) code.
**      Tests using strings for keys in skip lists.
**
****************************************************************/
static void
test_skiplist_string(void)
{
    H5SL_t      *slist; /* Skip list created */
    H5SL_node_t *node;  /* Skip list node */
    size_t       num;   /* Number of elements in skip list */
    size_t       u;     /* Local index variable */
    typedef struct string_node {
        int         i;
        const char *s;
    } string_node;
    string_node  data[10]        = {{10, "10"}, {20, "20"}, {15, "15"}, {5, "05"},  {50, "50"},
                            {30, "30"}, {31, "31"}, {32, "32"}, {80, "80"}, {90, "90"}};
    string_node  hashed_data[10] = {{5, "05"},  {10, "10"}, {15, "15"}, {20, "20"}, {30, "30"},
                                   {31, "31"}, {32, "32"}, {50, "50"}, {80, "80"}, {90, "90"}};
    string_node *found_item; /* Item found in skip list */
    herr_t       ret;        /* Generic return value */

    /* Output message about test being performed */
    MESSAGE(7, ("Testing Skip List With String Keys\n"));

    /* Create a skip list */
    slist = H5SL_create(H5SL_TYPE_STR, NULL);
    CHECK_PTR(slist, "H5SL_create");

    /* Check that the skip list has no elements */
    num = H5SL_count(slist);
    VERIFY(num, 0, "H5SL_count");

    /* Insert objects into the skip list */
    for (u = 0; u < 10; u++) {
        ret = H5SL_insert(slist, &data[u], data[u].s);
        CHECK(ret, FAIL, "H5SL_insert");
    } /* end for */

    /* Check that the skip list has correct # of elements */
    num = H5SL_count(slist);
    VERIFY(num, 10, "H5SL_count");

    /* Iterate over all the nodes in the skip list */
    node = H5SL_first(slist);
    u    = 0;
    while (node != NULL) {
        found_item = (string_node *)H5SL_item(node);
        VERIFY(found_item->i, hashed_data[u].i, "H5SL_next");
        u++;
        node = H5SL_next(node);
    } /* end while */

    /* Close the skip list */
    ret = H5SL_close(slist);
    CHECK(ret, FAIL, "H5SL_close");

} /* end test_skiplist_string() */

static herr_t
test_skiplist_iter(void *item, void H5_ATTR_UNUSED *key, void *op_data)
{
    size_t *up = (size_t *)op_data;

    VERIFY(*(int *)item, sort_rand_num[*up], "H5SL_iterate");
    (*up)++;

    return (0);
}

/****************************************************************
**
**  test_skiplist_iterate(): Test H5SL (skip list) code.
**      Tests iterating over nodes in skip list with callbacks.
**
****************************************************************/
static void
test_skiplist_iterate(void)
{
    H5SL_t *slist; /* Skip list created */
    size_t  num;   /* Number of elements in skip list */
    size_t  u;     /* Local index variable */
    herr_t  ret;   /* Generic return value */

    /* Output message about test being performed */
    MESSAGE(7, ("Testing Iterating Over Skip List\n"));

    /* Create a skip list */
    slist = H5SL_create(H5SL_TYPE_INT, NULL);
    CHECK_PTR(slist, "H5SL_create");

    /* Check that the skip list has no elements */
    num = H5SL_count(slist);
    VERIFY(num, 0, "H5SL_count");

    /* Insert many objects into the skip list */
    for (u = 0; u < NUM_ELEMS; u++) {
        ret = H5SL_insert(slist, &rand_num[u], &rand_num[u]);
        CHECK(ret, FAIL, "H5SL_insert");
    } /* end for */

    /* Check that the skip list has correct # of elements */
    num = H5SL_count(slist);
    VERIFY(num, NUM_ELEMS, "H5SL_count");

    /* Iterate over all the nodes in the skip list */
    u   = 0;
    ret = H5SL_iterate(slist, test_skiplist_iter, &u);
    CHECK(ret, FAIL, "H5SL_iterate");

    /* Close the skip list */
    ret = H5SL_close(slist);
    CHECK(ret, FAIL, "H5SL_close");

} /* end test_skiplist_iterate() */

/****************************************************************
**
**  test_skiplist_hsize(): Test H5SL (skip list) code.
**      Tests using hsize_t for keys in skip lists.
**
****************************************************************/
static void
test_skiplist_hsize(void)
{
    H5SL_t      *slist; /* Skip list created */
    H5SL_node_t *node;  /* Skip list node */
    size_t       num;   /* Number of elements in skip list */
    size_t       u;     /* Local index variable */
    hsize_t      data[10]        = {10, 20, 15, 5, 50, 30, 31, 32, 80, 90};
    hsize_t      sorted_data[10] = {5, 10, 15, 20, 30, 31, 32, 50, 80, 90};
    hsize_t     *found_item; /* Item found in skip list */
    herr_t       ret;        /* Generic return value */

    /* Output message about test being performed */
    MESSAGE(7, ("Testing Skip List With hsize_t Keys\n"));

    /* Create a skip list */
    slist = H5SL_create(H5SL_TYPE_HSIZE, NULL);
    CHECK_PTR(slist, "H5SL_create");

    /* Check that the skip list has no elements */
    num = H5SL_count(slist);
    VERIFY(num, 0, "H5SL_count");

    /* Insert objects into the skip list */
    for (u = 0; u < 10; u++) {
        ret = H5SL_insert(slist, &data[u], &data[u]);
        CHECK(ret, FAIL, "H5SL_insert");
    } /* end for */

    /* Check that the skip list has correct # of elements */
    num = H5SL_count(slist);
    VERIFY(num, 10, "H5SL_count");

    /* Iterate over all the nodes in the skip list */
    node = H5SL_first(slist);
    u    = 0;
    while (node != NULL) {
        found_item = (hsize_t *)H5SL_item(node);
        VERIFY(*found_item, sorted_data[u], "H5SL_next");
        u++;
        node = H5SL_next(node);
    } /* end while */

    /* Close the skip list */
    ret = H5SL_close(slist);
    CHECK(ret, FAIL, "H5SL_close");

} /* end test_skiplist_hsize() */

/****************************************************************
**
**  test_skiplist_unsigned(): Test H5SL (skip list) code.
**      Tests using unsigned for keys in skip lists.
**
****************************************************************/
static void
test_skiplist_unsigned(void)
{
    H5SL_t      *slist; /* Skip list created */
    H5SL_node_t *node;  /* Skip list node */
    size_t       num;   /* Number of elements in skip list */
    size_t       u;     /* Local index variable */
    unsigned     data[10]        = {10, 20, 15, 5, 50, 30, 31, 32, 80, 90};
    unsigned     sorted_data[10] = {5, 10, 15, 20, 30, 31, 32, 50, 80, 90};
    unsigned    *found_item; /* Item found in skip list */
    herr_t       ret;        /* Generic return value */

    /* Output message about test being performed */
    MESSAGE(7, ("Testing Skip List With unsigned Keys\n"));

    /* Create a skip list */
    slist = H5SL_create(H5SL_TYPE_UNSIGNED, NULL);
    CHECK_PTR(slist, "H5SL_create");

    /* Check that the skip list has no elements */
    num = H5SL_count(slist);
    VERIFY(num, 0, "H5SL_count");

    /* Insert objects into the skip list */
    for (u = 0; u < 10; u++) {
        ret = H5SL_insert(slist, &data[u], &data[u]);
        CHECK(ret, FAIL, "H5SL_insert");
    } /* end for */

    /* Check that the skip list has correct # of elements */
    num = H5SL_count(slist);
    VERIFY(num, 10, "H5SL_count");

    /* Iterate over all the nodes in the skip list */
    node = H5SL_first(slist);
    u    = 0;
    while (node != NULL) {
        found_item = (unsigned *)H5SL_item(node);
        VERIFY(*found_item, sorted_data[u], "H5SL_next");
        u++;
        node = H5SL_next(node);
    } /* end while */

    /* Close the skip list */
    ret = H5SL_close(slist);
    CHECK(ret, FAIL, "H5SL_close");

} /* end test_skiplist_unsigned() */

/****************************************************************
**
**  test_skiplist_obj(): Test H5SL (skip list) code.
**      Tests using H5_obj_t's for keys in skip lists.
**
****************************************************************/
static void
test_skiplist_obj(void)
{
    H5SL_t      *slist; /* Skip list created */
    H5SL_node_t *node;  /* Skip list node */
    size_t       num;   /* Number of elements in skip list */
    size_t       u;     /* Local index variable */
    H5_obj_t     data[10]        = {{10, 12}, {20, 12}, {10, 32}, {10, 11}, {50, 1},
                         {8, 12},  {31, 12}, {20, 11}, {31, 11}, {8, 32}};
    H5_obj_t     sorted_data[10] = {{8, 12},  {8, 32},  {10, 11}, {10, 12}, {10, 32},
                                {20, 11}, {20, 12}, {31, 11}, {31, 12}, {50, 1}};
    H5_obj_t    *found_item; /* Item found in skip list */
    herr_t       ret;        /* Generic return value */

    /* Output message about test being performed */
    MESSAGE(7, ("Testing Skip List With H5_obj_t Keys\n"));

    /* Create a skip list */
    slist = H5SL_create(H5SL_TYPE_OBJ, NULL);
    CHECK_PTR(slist, "H5SL_create");

    /* Check that the skip list has no elements */
    num = H5SL_count(slist);
    VERIFY(num, 0, "H5SL_count");

    /* Insert objects into the skip list */
    for (u = 0; u < 10; u++) {
        ret = H5SL_insert(slist, &data[u], &data[u]);
        CHECK(ret, FAIL, "H5SL_insert");
    } /* end for */

    /* Check that the skip list has correct # of elements */
    num = H5SL_count(slist);
    VERIFY(num, 10, "H5SL_count");

    /* Iterate over all the nodes in the skip list */
    node = H5SL_first(slist);
    u    = 0;
    while (node != NULL) {
        found_item = (H5_obj_t *)H5SL_item(node);
        VERIFY(found_item->fileno, sorted_data[u].fileno, "H5SL_next");
        VERIFY(found_item->addr, sorted_data[u].addr, "H5SL_next");
        u++;
        node = H5SL_next(node);
    } /* end while */

    /* Close the skip list */
    ret = H5SL_close(slist);
    CHECK(ret, FAIL, "H5SL_close");

} /* end test_skiplist_obj() */

/****************************************************************
**
**  test_skiplist_generic(): Test H5SL (skip list) code.
**      Tests using generic keys in skip lists.  Define
**      structure for keys, and define comparison using
**      key.a-key.b.
**
****************************************************************/
typedef struct generic_t {
    unsigned a;
    unsigned b;
} generic_t;

static int
test_skiplist_generic_cmp(const void *_key1, const void *_key2)
{
    const generic_t *key1 = (const generic_t *)_key1;
    const generic_t *key2 = (const generic_t *)_key2;
    long long        result =
        (long long)(key1->a) - (long long)(key1->b) - (long long)(key2->a) + (long long)(key2->b);

    if (result < 0)
        return -1;
    else if (result > 0)
        return 1;
    else
        return 0;
} /* end test_skiplist_generic_cmp */

static void
test_skiplist_generic(void)
{
    H5SL_t      *slist; /* Skip list created */
    H5SL_node_t *node;  /* Skip list node */
    size_t       num;   /* Number of elements in skip list */
    size_t       u;     /* Local index variable */
    generic_t    data[10]        = {{10, 1},   {20, 13}, {15, 32}, {5, 2},   {50, 37},
                          {30, 100}, {31, 38}, {32, 34}, {80, 32}, {90, 0}};
    generic_t    sorted_data[10] = {{30, 100}, {15, 32}, {31, 38}, {32, 34}, {5, 2},
                                 {20, 13},  {10, 1},  {50, 37}, {80, 32}, {90, 0}};
    generic_t   *found_item; /* Item found in skip list */
    herr_t       ret;        /* Generic return value */

    /* Output message about test being performed */
    MESSAGE(7, ("Testing Skip List With generic Keys\n"));

    /* Create a skip list */
    slist = H5SL_create(H5SL_TYPE_GENERIC, test_skiplist_generic_cmp);
    CHECK_PTR(slist, "H5SL_create");

    /* Check that the skip list has no elements */
    num = H5SL_count(slist);
    VERIFY(num, 0, "H5SL_count");

    /* Insert objects into the skip list */
    for (u = 0; u < 10; u++) {
        ret = H5SL_insert(slist, &data[u], &data[u]);
        CHECK(ret, FAIL, "H5SL_insert");
    } /* end for */

    /* Check that the skip list has correct # of elements */
    num = H5SL_count(slist);
    VERIFY(num, 10, "H5SL_count");

    /* Iterate over all the nodes in the skip list */
    node = H5SL_first(slist);
    u    = 0;
    while (node != NULL) {
        found_item = (generic_t *)H5SL_item(node);
        VERIFY(found_item->a, sorted_data[u].a, "H5SL_next");
        VERIFY(found_item->b, sorted_data[u].b, "H5SL_next");
        u++;
        node = H5SL_next(node);
    } /* end while */

    /* Close the skip list */
    ret = H5SL_close(slist);
    CHECK(ret, FAIL, "H5SL_close");

} /* end test_skiplist_generic() */

/****************************************************************
**
**  test_skiplist_lastprev(): Test H5SL (skip list) code.
**      Tests iterating over nodes in skip list with last/prev calls.
**
****************************************************************/
static void
test_skiplist_lastprev(void)
{
    H5SL_t      *slist;      /* Skip list created */
    H5SL_node_t *node;       /* Skip list node */
    size_t       num;        /* Number of elements in skip list */
    size_t       u;          /* Local index variable */
    int         *found_item; /* Item found in skip list */
    herr_t       ret;        /* Generic return value */

    /* Output message about test being performed */
    MESSAGE(7, ("Testing Iterating Over Skip List With Last/Prev\n"));

    /* Create a skip list */
    slist = H5SL_create(H5SL_TYPE_INT, NULL);
    CHECK_PTR(slist, "H5SL_create");

    /* Check that the skip list has no elements */
    num = H5SL_count(slist);
    VERIFY(num, 0, "H5SL_count");

    /* Check that the list appears empty */
    node = H5SL_last(slist);
    CHECK_PTR_NULL(node, "H5SL_last");

    /* Insert many objects into the skip list */
    for (u = 0; u < NUM_ELEMS; u++) {
        ret = H5SL_insert(slist, &rand_num[u], &rand_num[u]);
        CHECK(ret, FAIL, "H5SL_insert");
    } /* end for */

    /* Check that the skip list has correct # of elements */
    num = H5SL_count(slist);
    VERIFY(num, NUM_ELEMS, "H5SL_count");

    /* Iterate over all the nodes in the skip list */
    node = H5SL_last(slist);
    CHECK_PTR(node, "H5SL_last");
    u = NUM_ELEMS - 1;
    while (node != NULL) {
        found_item = (int *)H5SL_item(node);
        VERIFY(*found_item, sort_rand_num[u], "H5SL_prev");
        u--;
        node = H5SL_prev(node);
    } /* end while */

    /* Release all the items from the list */
    ret = H5SL_release(slist);
    CHECK(ret, FAIL, "H5SL_release");

    /* Check that the list appears empty again */
    node = H5SL_last(slist);
    CHECK_PTR_NULL(node, "H5SL_last");

    /* Close the skip list */
    ret = H5SL_close(slist);
    CHECK(ret, FAIL, "H5SL_close");

} /* end test_skiplist_lastprev() */

/****************************************************************
**
**  test_skiplist_find(): Test H5SL (skip list) code.
**      Tests 'find' operation in skip lists.
**
****************************************************************/
static void
test_skiplist_find(void)
{
    H5SL_t      *slist; /* Skip list created */
    H5SL_node_t *node;  /* Skip list node */
    size_t       u;     /* Local index variable */
    unsigned     data[10]        = {10, 20, 15, 5, 50, 30, 31, 32, 80, 90};
    unsigned     sorted_data[10] = {5, 10, 15, 20, 30, 31, 32, 50, 80, 90};
    unsigned    *found_item; /* Item found in skip list */
    unsigned     find_item;  /* Item to find in skip list */
    herr_t       ret;        /* Generic return value */

    /* Output message about test being performed */
    MESSAGE(7, ("Testing Skip List 'Find' Operation\n"));

    /* Create a skip list */
    slist = H5SL_create(H5SL_TYPE_UNSIGNED, NULL);
    CHECK_PTR(slist, "H5SL_create");

    /* Insert objects into the skip list */
    for (u = 0; u < 10; u++) {
        ret = H5SL_insert(slist, &data[u], &data[u]);
        CHECK(ret, FAIL, "H5SL_insert");
    } /* end for */

    /* Find the element with key==30 in the skip list */
    find_item = 30;
    node      = H5SL_find(slist, &find_item);
    CHECK_PTR(node, "H5SL_find");

    /* Iterate over the rest of the nodes in the skip list */
    u = 4;
    while (node != NULL) {
        found_item = (unsigned *)H5SL_item(node);
        VERIFY(*found_item, sorted_data[u], "H5SL_next");
        u++;
        node = H5SL_next(node);
    } /* end while */

    /* Check for trying to locate non-existent item */
    find_item = 81;
    node      = H5SL_find(slist, &find_item);
    CHECK_PTR_NULL(node, "H5SL_find");

    /* Close the skip list */
    ret = H5SL_close(slist);
    CHECK(ret, FAIL, "H5SL_close");

} /* end test_skiplist_find() */

/****************************************************************
**
**  test_skiplist_add(): Test H5SL (skip list) code.
**      Tests 'add' operation in skip lists.
**
****************************************************************/
static void
test_skiplist_add(void)
{
    H5SL_t      *slist; /* Skip list created */
    H5SL_node_t *node;  /* Skip list node */
    size_t       u;     /* Local index variable */
    unsigned     data[10]        = {10, 20, 15, 5, 50, 30, 31, 32, 80, 90};
    unsigned     sorted_data[10] = {5, 10, 15, 20, 30, 31, 32, 50, 80, 90};
    unsigned    *found_item; /* Item found in skip list */
    unsigned     new_item;   /* Item to add to skip list */
    herr_t       ret;        /* Generic return value */

    /* Output message about test being performed */
    MESSAGE(7, ("Testing Skip List 'Add' Operation\n"));

    /* Create a skip list */
    slist = H5SL_create(H5SL_TYPE_UNSIGNED, NULL);
    CHECK_PTR(slist, "H5SL_create");

    /* Insert objects into the skip list */
    for (u = 0; u < 10; u++) {
        ret = H5SL_insert(slist, &data[u], &data[u]);
        CHECK(ret, FAIL, "H5SL_insert");
    } /* end for */

    /* Add the element with key==12 in the skip list */
    new_item = 12;
    node     = H5SL_add(slist, &new_item, &new_item);
    CHECK_PTR(node, "H5SL_add");

    /* Advance to next node in list */
    node = H5SL_next(node);
    CHECK_PTR(node, "H5SL_next");

    /* Iterate over the rest of the nodes in the skip list */
    u = 2;
    while (node != NULL) {
        found_item = (unsigned *)H5SL_item(node);
        VERIFY(*found_item, sorted_data[u], "H5SL_item");
        u++;
        node = H5SL_next(node);
    } /* end while */

    /* Close the skip list */
    ret = H5SL_close(slist);
    CHECK(ret, FAIL, "H5SL_close");

} /* end test_skiplist_add() */

static herr_t
test_skiplist_destroy_free(void *item, void H5_ATTR_UNUSED *key, void *op_data)
{
    unsigned *free_count = (unsigned *)op_data;

    VERIFY(*(int *)item, sort_rand_num[*free_count], "H5SL_destroy");
    (*free_count)++;

    return (0);
}

/****************************************************************
**
**  test_skiplist_destroy(): Test H5SL (skip list) code.
**      Tests 'destroy' operation in skip lists.
**
****************************************************************/
static void
test_skiplist_destroy(void)
{
    H5SL_t  *slist;      /* Skip list created */
    size_t   u;          /* Local index variable */
    unsigned free_count; /* Number of items freed */
    herr_t   ret;        /* Generic return value */

    /* Output message about test being performed */
    MESSAGE(7, ("Testing Skip List 'Destroy' Operation\n"));

    /* Create a skip list */
    slist = H5SL_create(H5SL_TYPE_INT, NULL);
    CHECK_PTR(slist, "H5SL_create");

    /* Insert objects into the skip list */
    for (u = 0; u < NUM_ELEMS; u++) {
        ret = H5SL_insert(slist, &rand_num[u], &rand_num[u]);
        CHECK(ret, FAIL, "H5SL_insert");
    } /* end for */

    /* Destroy the skip list */
    free_count = 0;
    ret        = H5SL_destroy(slist, test_skiplist_destroy_free, &free_count);
    CHECK(ret, FAIL, "H5SL_destroy");
    VERIFY(free_count, NUM_ELEMS, "H5SL_destroy");

} /* end test_skiplist_destroy() */

/****************************************************************
**
**  test_skiplist_free(): Test H5SL (skip list) code.
**      Tests 'free' operation in skip lists.
**
****************************************************************/
static void
test_skiplist_free(void)
{
    H5SL_t  *slist;      /* Skip list created */
    size_t   num;        /* Number of elements in skip list */
    size_t   u;          /* Local index variable */
    unsigned free_count; /* Number of items freed */
    herr_t   ret;        /* Generic return value */

    /* Output message about test being performed */
    MESSAGE(7, ("Testing Skip List 'Free' Operation\n"));

    /* Create a skip list */
    slist = H5SL_create(H5SL_TYPE_INT, NULL);
    CHECK_PTR(slist, "H5SL_create");

    /* Insert objects into the skip list */
    for (u = 0; u < NUM_ELEMS; u++) {
        ret = H5SL_insert(slist, &rand_num[u], &rand_num[u]);
        CHECK(ret, FAIL, "H5SL_insert");
    } /* end for */

    /* Destroy the skip list */
    free_count = 0;
    ret        = H5SL_free(slist, test_skiplist_destroy_free, &free_count);
    CHECK(ret, FAIL, "H5SL_destroy");
    VERIFY(free_count, NUM_ELEMS, "H5SL_free");

    /* Check that the skip list has correct # of elements */
    num = H5SL_count(slist);
    VERIFY(num, 0, "H5SL_count");

    /* Insert objects into the skip list again */
    for (u = 0; u < NUM_ELEMS; u++) {
        ret = H5SL_insert(slist, &rand_num[u], &rand_num[u]);
        CHECK(ret, FAIL, "H5SL_insert");
    } /* end for */

    /* Check that the skip list has correct # of elements */
    num = H5SL_count(slist);
    VERIFY(num, NUM_ELEMS, "H5SL_count");

    /* Close the skip list */
    ret = H5SL_close(slist);
    CHECK(ret, FAIL, "H5SL_close");

} /* end test_skiplist_free() */

/****************************************************************
**
**  test_skiplist_less(): Test H5SL (skip list) code.
**      Tests 'less' operation in skip lists.
**
****************************************************************/
static void
test_skiplist_less(void)
{
    H5SL_t  *slist; /* Skip list created */
    size_t   u;     /* Local index variable */
    unsigned data[10] = {10, 20, 15, 5, 50, 30, 31, 32, 80, 90};
    /* unsigned sorted_data[10]={ 5, 10, 15, 20, 30, 31, 32, 50, 80, 90}; */
    unsigned *found_item; /* Item found in skip list */
    unsigned  find_item;  /* Item to add to skip list */
    herr_t    ret;        /* Generic return value */

    /* Output message about test being performed */
    MESSAGE(7, ("Testing Skip List 'Less' Operation\n"));

    /* Create a skip list */
    slist = H5SL_create(H5SL_TYPE_UNSIGNED, NULL);
    CHECK_PTR(slist, "H5SL_create");

    /* Insert objects into the skip list */
    for (u = 0; u < 10; u++) {
        ret = H5SL_insert(slist, &data[u], &data[u]);
        CHECK(ret, FAIL, "H5SL_insert");
    } /* end for */

    /* Check for exact match of items in various positions */
    find_item  = 20;
    found_item = (unsigned *)H5SL_less(slist, &find_item);
    VERIFY(*found_item, find_item, "H5SL_less");
    find_item  = 90;
    found_item = (unsigned *)H5SL_less(slist, &find_item);
    VERIFY(*found_item, find_item, "H5SL_less");
    find_item  = 5;
    found_item = (unsigned *)H5SL_less(slist, &find_item);
    VERIFY(*found_item, find_item, "H5SL_less");

    /* Find item less than a missing key, in various positions */
    find_item  = 19;
    found_item = (unsigned *)H5SL_less(slist, &find_item);
    VERIFY(*found_item, 15, "H5SL_less");
    find_item  = 89;
    found_item = (unsigned *)H5SL_less(slist, &find_item);
    VERIFY(*found_item, 80, "H5SL_less");
    find_item  = 100;
    found_item = (unsigned *)H5SL_less(slist, &find_item);
    VERIFY(*found_item, 90, "H5SL_less");
    find_item  = 9;
    found_item = (unsigned *)H5SL_less(slist, &find_item);
    VERIFY(*found_item, 5, "H5SL_less");
    find_item  = 4;
    found_item = (unsigned *)H5SL_less(slist, &find_item);
    CHECK_PTR_NULL(found_item, "H5SL_less");

    /* Close the skip list */
    ret = H5SL_close(slist);
    CHECK(ret, FAIL, "H5SL_close");

} /* end test_skiplist_less() */

/****************************************************************
**
**  test_skiplist_greater(): Test H5SL (skip list) code.
**      Tests 'greater' operation in skip lists.
**
****************************************************************/
static void
test_skiplist_greater(void)
{
    H5SL_t  *slist; /* Skip list created */
    size_t   u;     /* Local index variable */
    unsigned data[10] = {10, 20, 15, 5, 50, 30, 31, 32, 80, 90};
    /* unsigned sorted_data[10]={ 5, 10, 15, 20, 30, 31, 32, 50, 80, 90}; */
    unsigned *found_item; /* Item found in skip list */
    unsigned  find_item;  /* Item to add to skip list */
    herr_t    ret;        /* Generic return value */

    /* Output message about test being performed */
    MESSAGE(7, ("Testing Skip List 'Greater' Operation\n"));

    /* Create a skip list */
    slist = H5SL_create(H5SL_TYPE_UNSIGNED, NULL);
    CHECK_PTR(slist, "H5SL_create");

    /* Insert objects into the skip list */
    for (u = 0; u < 10; u++) {
        ret = H5SL_insert(slist, &data[u], &data[u]);
        CHECK(ret, FAIL, "H5SL_insert");
    } /* end for */

    /* Check for exact match of items in various positions */
    find_item  = 20;
    found_item = (unsigned *)H5SL_greater(slist, &find_item);
    VERIFY(*found_item, find_item, "H5SL_greater");
    find_item  = 90;
    found_item = (unsigned *)H5SL_greater(slist, &find_item);
    VERIFY(*found_item, find_item, "H5SL_greater");
    find_item  = 5;
    found_item = (unsigned *)H5SL_greater(slist, &find_item);
    VERIFY(*found_item, find_item, "H5SL_greater");

    /* Find item greater than a missing key, in various positions */
    find_item  = 19;
    found_item = (unsigned *)H5SL_greater(slist, &find_item);
    VERIFY(*found_item, 20, "H5SL_greater");
    find_item  = 89;
    found_item = (unsigned *)H5SL_greater(slist, &find_item);
    VERIFY(*found_item, 90, "H5SL_greater");
    find_item  = 100;
    found_item = (unsigned *)H5SL_greater(slist, &find_item);
    CHECK_PTR_NULL(found_item, "H5SL_greater");
    find_item  = 6;
    found_item = (unsigned *)H5SL_greater(slist, &find_item);
    VERIFY(*found_item, 10, "H5SL_greater");
    find_item  = 4;
    found_item = (unsigned *)H5SL_greater(slist, &find_item);
    VERIFY(*found_item, 5, "H5SL_greater");

    /* Close the skip list */
    ret = H5SL_close(slist);
    CHECK(ret, FAIL, "H5SL_close");

} /* end test_skiplist_greater() */

/****************************************************************
**
**  test_skiplist_below(): Test H5SL (skip list) code.
**      Tests 'below' operation in skip lists.
**
****************************************************************/
static void
test_skiplist_below(void)
{
    H5SL_t      *slist; /* Skip list created */
    H5SL_node_t *node;  /* Skip list node */
    size_t       u;     /* Local index variable */
    unsigned     data[10] = {10, 20, 15, 5, 50, 30, 31, 32, 80, 90};
    /* unsigned sorted_data[10]={ 5, 10, 15, 20, 30, 31, 32, 50, 80, 90}; */
    unsigned *found_item; /* Item found in skip list */
    unsigned  find_item;  /* Item to add to skip list */
    herr_t    ret;        /* Generic return value */

    /* Output message about test being performed */
    MESSAGE(7, ("Testing Skip List 'Below' Operation\n"));

    /* Create a skip list */
    slist = H5SL_create(H5SL_TYPE_UNSIGNED, NULL);
    CHECK_PTR(slist, "H5SL_create");

    /* Insert objects into the skip list */
    for (u = 0; u < 10; u++) {
        ret = H5SL_insert(slist, &data[u], &data[u]);
        CHECK(ret, FAIL, "H5SL_insert");
    } /* end for */

    /* Check for exact match of items in various positions */
    find_item = 20;
    node      = H5SL_below(slist, &find_item);
    CHECK_PTR(node, "H5SL_below");
    found_item = (unsigned *)H5SL_item(node);
    VERIFY(*found_item, find_item, "H5SL_below");
    find_item = 90;
    node      = H5SL_below(slist, &find_item);
    CHECK_PTR(node, "H5SL_below");
    found_item = (unsigned *)H5SL_item(node);
    VERIFY(*found_item, find_item, "H5SL_below");
    find_item = 5;
    node      = H5SL_below(slist, &find_item);
    CHECK_PTR(node, "H5SL_below");
    found_item = (unsigned *)H5SL_item(node);
    VERIFY(*found_item, find_item, "H5SL_below");

    /* Find item less than a missing key, in various positions */
    find_item = 19;
    node      = H5SL_below(slist, &find_item);
    CHECK_PTR(node, "H5SL_below");
    found_item = (unsigned *)H5SL_item(node);
    VERIFY(*found_item, 15, "H5SL_below");
    find_item = 89;
    node      = H5SL_below(slist, &find_item);
    CHECK_PTR(node, "H5SL_below");
    found_item = (unsigned *)H5SL_item(node);
    VERIFY(*found_item, 80, "H5SL_below");
    find_item = 100;
    node      = H5SL_below(slist, &find_item);
    CHECK_PTR(node, "H5SL_below");
    found_item = (unsigned *)H5SL_item(node);
    VERIFY(*found_item, 90, "H5SL_below");
    find_item = 9;
    node      = H5SL_below(slist, &find_item);
    CHECK_PTR(node, "H5SL_below");
    found_item = (unsigned *)H5SL_item(node);
    VERIFY(*found_item, 5, "H5SL_below");
    find_item = 4;
    node      = (H5SL_node_t *)H5SL_less(slist, &find_item);
    CHECK_PTR_NULL(node, "H5SL_below");

    /* Close the skip list */
    ret = H5SL_close(slist);
    CHECK(ret, FAIL, "H5SL_close");

} /* end test_skiplist_below() */

/****************************************************************
**
**  test_skiplist_above(): Test H5SL (skip list) code.
**      Tests 'above' operation in skip lists.
**
****************************************************************/
static void
test_skiplist_above(void)
{
    H5SL_t      *slist; /* Skip list created */
    H5SL_node_t *node;  /* Skip list node */
    size_t       u;     /* Local index variable */
    unsigned     data[10] = {10, 20, 15, 5, 50, 30, 31, 32, 80, 90};
    /* unsigned sorted_data[10]={ 5, 10, 15, 20, 30, 31, 32, 50, 80, 90}; */
    unsigned *found_item; /* Item found in skip list */
    unsigned  find_item;  /* Item to add to skip list */
    herr_t    ret;        /* Generic return value */

    /* Output message about test being performed */
    MESSAGE(7, ("Testing Skip List 'Above' Operation\n"));

    /* Create a skip list */
    slist = H5SL_create(H5SL_TYPE_UNSIGNED, NULL);
    CHECK_PTR(slist, "H5SL_create");

    /* Insert objects into the skip list */
    for (u = 0; u < 10; u++) {
        ret = H5SL_insert(slist, &data[u], &data[u]);
        CHECK(ret, FAIL, "H5SL_insert");
    } /* end for */

    /* Check for exact match of items in various positions */
    find_item = 20;
    node      = H5SL_above(slist, &find_item);
    CHECK_PTR(node, "H5SL_above");
    found_item = (unsigned *)H5SL_item(node);
    VERIFY(*found_item, find_item, "H5SL_above");
    find_item = 90;
    node      = H5SL_above(slist, &find_item);
    CHECK_PTR(node, "H5SL_above");
    found_item = (unsigned *)H5SL_item(node);
    VERIFY(*found_item, find_item, "H5SL_above");
    find_item = 5;
    node      = H5SL_above(slist, &find_item);
    CHECK_PTR(node, "H5SL_above");
    found_item = (unsigned *)H5SL_item(node);
    VERIFY(*found_item, find_item, "H5SL_above");

    /* Find item greater than a missing key, in various positions */
    find_item = 19;
    node      = H5SL_above(slist, &find_item);
    CHECK_PTR(node, "H5SL_above");
    found_item = (unsigned *)H5SL_item(node);
    VERIFY(*found_item, 20, "H5SL_above");
    find_item = 89;
    node      = H5SL_above(slist, &find_item);
    CHECK_PTR(node, "H5SL_above");
    found_item = (unsigned *)H5SL_item(node);
    VERIFY(*found_item, 90, "H5SL_above");
    find_item = 100;
    node      = H5SL_above(slist, &find_item);
    CHECK_PTR_NULL(node, "H5SL_above");
    find_item = 6;
    node      = H5SL_above(slist, &find_item);
    CHECK_PTR(node, "H5SL_above");
    found_item = (unsigned *)H5SL_item(node);
    VERIFY(*found_item, 10, "H5SL_above");
    find_item = 4;
    node      = H5SL_above(slist, &find_item);
    CHECK_PTR(node, "H5SL_above");
    found_item = (unsigned *)H5SL_item(node);
    VERIFY(*found_item, 5, "H5SL_above");

    /* Close the skip list */
    ret = H5SL_close(slist);
    CHECK(ret, FAIL, "H5SL_close");

} /* end test_skiplist_above() */

/****************************************************************
**
**  test_skiplist_remote_first(): Test H5SL (skip list) code.
**      Tests 'remove first' operation in skip lists.
**
****************************************************************/
static void
test_skiplist_remove_first(void)
{
    H5SL_t   *slist; /* Skip list created */
    size_t    u;     /* Local index variable */
    unsigned  data[10]        = {10, 20, 15, 5, 50, 30, 31, 32, 80, 90};
    unsigned  sorted_data[10] = {5, 10, 15, 20, 30, 31, 32, 50, 80, 90};
    unsigned *found_item; /* Item found in skip list */
    herr_t    ret;        /* Generic return value */

    /* Output message about test being performed */
    MESSAGE(7, ("Testing Skip List 'Remove First' Operation\n"));

    /* Create a skip list */
    slist = H5SL_create(H5SL_TYPE_UNSIGNED, NULL);
    CHECK_PTR(slist, "H5SL_create");

    /* Insert objects into the skip list */
    for (u = 0; u < 10; u++) {
        ret = H5SL_insert(slist, &data[u], &data[u]);
        CHECK(ret, FAIL, "H5SL_insert");
    } /* end for */

    /* Remove objects from the skip list */
    for (u = 0; u < 10; u++) {
        found_item = (unsigned *)H5SL_remove_first(slist);
        VERIFY(*found_item, sorted_data[u], "H5SL_remove_first");
    } /* end for */

    /* Check for removing object from empty list */
    found_item = (unsigned *)H5SL_remove_first(slist);
    CHECK_PTR_NULL(found_item, "H5SL_remove_first");

    /* Close the skip list */
    ret = H5SL_close(slist);
    CHECK(ret, FAIL, "H5SL_close");

} /* end test_skiplist_remove_first() */

/****************************************************************
**
**  test_skiplist_remote_first_many(): Test H5SL (skip list) code.
**      Tests 'remove first' operation in large skip lists.
**
****************************************************************/
static void
test_skiplist_remove_first_many(void)
{
    H5SL_t *slist;               /* Skip list created */
    size_t  u;                   /* Local index variable */
    int    *found_item;          /* Item found in skip list */
    int     prev_item = INT_MIN; /* Previously found item in skip list */
    herr_t  ret;                 /* Generic return value */

    /* Output message about test being performed */
    MESSAGE(7, ("Testing Skip List 'Remove First' Operation\n"));

    /* Create a skip list */
    slist = H5SL_create(H5SL_TYPE_INT, NULL);
    CHECK_PTR(slist, "H5SL_create");

    /* Insert objects into the skip list */
    for (u = 0; u < NUM_ELEMS; u++) {
        ret = H5SL_insert(slist, &rand_num[u], &rand_num[u]);
        CHECK(ret, FAIL, "H5SL_insert");
    } /* end for */

    /* Remove objects from the skip list */
    for (u = 0; u < NUM_ELEMS; u++) {
        found_item = (int *)H5SL_remove_first(slist);
        VERIFY(*found_item > prev_item, true, "H5SL_remove_first");
        prev_item = *found_item;
    } /* end for */

    /* Check for removing object from empty list */
    found_item = (int *)H5SL_remove_first(slist);
    CHECK_PTR_NULL(found_item, "H5SL_remove_first");

    /* Close the skip list */
    ret = H5SL_close(slist);
    CHECK(ret, FAIL, "H5SL_close");

} /* end test_skiplist_remove_first() */

/****************************************************************
**
**  test_skiplist_term(): Test H5SL (skiplist) code.
**      Release data for skip list testing
**
****************************************************************/
static void
test_skiplist_term(void)
{
    /* Release arrays */
    if (rand_num)
        free(rand_num);
    if (sort_rand_num)
        free(sort_rand_num);
    if (rev_sort_rand_num)
        free(rev_sort_rand_num);
} /* end test_skiplist_term() */

/****************************************************************
**
**  test_skiplist(): Main H5SL testing routine.
**
****************************************************************/
void
test_skiplist(void)
{
    /* Output message about test being performed */
    MESSAGE(5, ("Testing Skip Lists\n"));

    /* Initialize skip list testing data */
    test_skiplist_init();

    /* Actual skip list tests */
    test_skiplist_create();            /* Test skip list creation */
    test_skiplist_insert();            /* Test basic skip list insertion */
    test_skiplist_insert_many();       /* Test insertion of many items into skip list */
    test_skiplist_remove();            /* Test basic skip list removal */
    test_skiplist_remove_many();       /* Test removal of many items from skip list */
    test_skiplist_firstnext();         /* Test iteration over skip list nodes with first/next */
    test_skiplist_string();            /* Test skip list string keys */
    test_skiplist_iterate();           /* Test iteration over skip list nodes with callback */
    test_skiplist_hsize();             /* Test skip list hsize_t keys */
    test_skiplist_unsigned();          /* Test skip list unsigned keys */
    test_skiplist_obj();               /* Test skip list H5_obj_t keys */
    test_skiplist_generic();           /* Test skip list generic keys */
    test_skiplist_lastprev();          /* Test iteration over skip list nodes with last/prev */
    test_skiplist_find();              /* Test 'find' operation */
    test_skiplist_add();               /* Test 'add' operation */
    test_skiplist_destroy();           /* Test 'destroy' operation */
    test_skiplist_free();              /* Test 'free' operation */
    test_skiplist_less();              /* Test 'less' operation */
    test_skiplist_greater();           /* Test 'greater' operation */
    test_skiplist_below();             /* Test 'below' operation */
    test_skiplist_above();             /* Test 'above' operation */
    test_skiplist_remove_first();      /* Test 'remove first' operation */
    test_skiplist_remove_first_many(); /* Test 'remove first' operation on large skip lists */

    /* Release skip list testing data */
    test_skiplist_term();

} /* end test_skiplist() */