[svn-r12078] Purpose:

    New features

Description:
    Add "find node greater than or equal to key" and "remove first" operations
to skip lists.

Platforms tested:
    FreeBSD 4.11 (sleipnir)
    Too minor to require h5committest

3 files changed, 334 insertions, 41 deletions

diff --git a/src/H5SL.c b/src/H5SL.c
index 4202481..2e37dc0 100644
--- a/src/H5SL.c
+++ b/src/H5SL.c
@@ -57,11 +57,12 @@
 /* Local Macros */
 
 /* Define the code template for insertions for the "OP" in the H5SL_LOCATE macro */
-#define H5SL_LOCATE_INSERT_FOUND(SLIST,X,UPDATE,I,ITEM)                   \
+#define H5SL_LOCATE_INSERT_FOUND(SLIST,X,UPDATE,I)                      \
         HGOTO_ERROR(H5E_SLIST,H5E_CANTINSERT,NULL,"can't insert duplicate key");
 
 /* Define the code template for removals for the "OP" in the H5SL_LOCATE macro */
-#define H5SL_LOCATE_REMOVE_FOUND(SLIST,X,UPDATE,I,ITEM)                   \
+/* (NOTE: the code in H5SL_remove_first() is largely the same, fix bugs in both places) */
+#define H5SL_LOCATE_REMOVE_FOUND(SLIST,X,UPDATE,I)                      \
         void *tmp;                                                      \
                                                                         \
         for(I=0; I<=(int)SLIST->curr_level; I++) {                      \
@@ -81,11 +82,11 @@
         HGOTO_DONE(tmp);
 
 /* Define the code template for searches for the "OP" in the H5SL_LOCATE macro */
-#define H5SL_LOCATE_SEARCH_FOUND(SLIST,X,UPDATE,I,ITEM)                 \
+#define H5SL_LOCATE_SEARCH_FOUND(SLIST,X,UPDATE,I)                      \
         HGOTO_DONE(X->item);
 
 /* Define the code template for finds for the "OP" in the H5SL_LOCATE macro */
-#define H5SL_LOCATE_FIND_FOUND(SLIST,X,UPDATE,I,ITEM)                   \
+#define H5SL_LOCATE_FIND_FOUND(SLIST,X,UPDATE,I)                        \
         HGOTO_DONE(X);
 
 /* Define a code template for updating the "update" vector for the "DOUPDATE" in the H5SL_LOCATE macro */
@@ -112,7 +113,7 @@
         (HDstrcmp(PKEY1,PKEY2)==0)
 
 /* Macro used to find node for operation */
-#define H5SL_LOCATE(OP,DOUPDATE,CMP,SLIST,X,UPDATE,I,TYPE,ITEM,KEY,CHECKED) \
+#define H5SL_LOCATE(OP,DOUPDATE,CMP,SLIST,X,UPDATE,I,TYPE,KEY,CHECKED)  \
     CHECKED=NULL;                                                       \
     for(I=(int)SLIST->curr_level; I>=0; I--) {                          \
         if(X->forward[I]!=CHECKED) {                                    \
@@ -125,24 +126,24 @@
     X=X->forward[0];                                                    \
     if(X!=NULL && H5_GLUE3(H5SL_LOCATE_,CMP,_EQ)(TYPE,X->key,KEY) ) {   \
         /* What to do when a node is found */				\
-        H5_GLUE3(H5SL_LOCATE_,OP,_FOUND)(SLIST,X,UPDATE,I,ITEM)         \
+        H5_GLUE3(H5SL_LOCATE_,OP,_FOUND)(SLIST,X,UPDATE,I)              \
     } /* end if */
 
 /* Macro used to insert node */
-#define H5SL_INSERT(CMP,SLIST,X,UPDATE,I,TYPE,ITEM,KEY,CHECKED)         \
-    H5SL_LOCATE(INSERT,YES,CMP,SLIST,X,UPDATE,I,TYPE,ITEM,KEY,CHECKED)
+#define H5SL_INSERT(CMP, SLIST, X, UPDATE, I, TYPE, KEY, CHECKED)       \
+    H5SL_LOCATE(INSERT, YES, CMP, SLIST, X, UPDATE, I, TYPE, KEY, CHECKED)
 
 /* Macro used to remove node */
-#define H5SL_REMOVE(CMP,SLIST,X,UPDATE,I,TYPE,ITEM,KEY,CHECKED)         \
-    H5SL_LOCATE(REMOVE,YES,CMP,SLIST,X,UPDATE,I,TYPE,ITEM,KEY,CHECKED)
+#define H5SL_REMOVE(CMP, SLIST, X, UPDATE, I, TYPE, KEY, CHECKED)       \
+    H5SL_LOCATE(REMOVE, YES, CMP, SLIST, X, UPDATE, I, TYPE, KEY, CHECKED)
 
 /* Macro used to search for node */
-#define H5SL_SEARCH(CMP,SLIST,X,UPDATE,I,TYPE,ITEM,KEY,CHECKED)         \
-    H5SL_LOCATE(SEARCH,NO,CMP,SLIST,X,UPDATE,I,TYPE,ITEM,KEY,CHECKED)
+#define H5SL_SEARCH(CMP, SLIST, X, UPDATE, I, TYPE, KEY, CHECKED)       \
+    H5SL_LOCATE(SEARCH, NO, CMP, SLIST, X, UPDATE, I, TYPE, KEY, CHECKED)
 
 /* Macro used to find a node */
-#define H5SL_FIND(CMP,SLIST,X,UPDATE,I,TYPE,ITEM,KEY,CHECKED)           \
-    H5SL_LOCATE(FIND,NO,CMP,SLIST,X,UPDATE,I,TYPE,ITEM,KEY,CHECKED)
+#define H5SL_FIND(CMP, SLIST, X, UPDATE, I, TYPE, KEY, CHECKED)         \
+    H5SL_LOCATE(FIND, NO, CMP, SLIST, X, UPDATE, I, TYPE, KEY, CHECKED)
 
 
 /* Private typedefs & structs */
@@ -363,23 +364,27 @@ H5SL_insert_common(H5SL_t *slist, void *item, const void *key)
     x=slist->header;
     switch(slist->type) {
         case H5SL_TYPE_INT:
-            H5SL_INSERT(SCALAR,slist,x,update,i,const int,item,key,checked)
+            H5SL_INSERT(SCALAR, slist, x, update, i, const int, key, checked)
             break;
 
         case H5SL_TYPE_HADDR:
-            H5SL_INSERT(SCALAR,slist,x,update,i,const haddr_t,item,key,checked)
+            H5SL_INSERT(SCALAR, slist, x, update, i, const haddr_t, key, checked)
             break;
 
         case H5SL_TYPE_STR:
-            H5SL_INSERT(STRING,slist,x,update,i,char *,item,key,checked)
+            H5SL_INSERT(STRING, slist, x, update, i, char *, key, checked)
             break;
 
         case H5SL_TYPE_HSIZE:
-            H5SL_INSERT(SCALAR,slist,x,update,i,const hsize_t,item,key,checked)
+            H5SL_INSERT(SCALAR, slist, x, update, i, const hsize_t, key, checked)
             break;
 
         case H5SL_TYPE_UNSIGNED:
-            H5SL_INSERT(SCALAR,slist,x,update,i,const unsigned,item,key,checked)
+            H5SL_INSERT(SCALAR, slist, x, update, i, const unsigned, key, checked)
+            break;
+
+        case H5SL_TYPE_SIZE:
+            H5SL_INSERT(SCALAR, slist, x, update, i, const size_t, key, checked)
             break;
     } /* end switch */
 
@@ -574,7 +579,7 @@ H5SL_create(H5SL_type_t type, double p, size_t max_level)
     /* Check args */
     HDassert(p>0.0 && p<1.0);
     HDassert(max_level>0 && max_level<=H5SL_LEVEL_MAX);
-    HDassert(type>=H5SL_TYPE_INT && type<=H5SL_TYPE_UNSIGNED);
+    HDassert(type>=H5SL_TYPE_INT && type<=H5SL_TYPE_SIZE);
 
     /* Allocate skip list structure */
     if((new_slist=H5FL_MALLOC(H5SL_t))==NULL)
@@ -789,23 +794,27 @@ H5SL_remove(H5SL_t *slist, const void *key)
     x=slist->header;
     switch(slist->type) {
         case H5SL_TYPE_INT:
-            H5SL_REMOVE(SCALAR,slist,x,update,i,const int,-,key,checked)
+            H5SL_REMOVE(SCALAR, slist, x, update, i, const int, key, checked)
             break;
 
         case H5SL_TYPE_HADDR:
-            H5SL_REMOVE(SCALAR,slist,x,update,i,const haddr_t,-,key,checked)
+            H5SL_REMOVE(SCALAR, slist, x, update, i, const haddr_t, key, checked)
             break;
 
         case H5SL_TYPE_STR:
-            H5SL_REMOVE(STRING,slist,x,update,i,char *,-,key,checked)
+            H5SL_REMOVE(STRING, slist, x, update, i, char *, key, checked)
             break;
 
         case H5SL_TYPE_HSIZE:
-            H5SL_REMOVE(SCALAR,slist,x,update,i,const hsize_t,-,key,checked)
+            H5SL_REMOVE(SCALAR, slist, x, update, i, const hsize_t, key, checked)
             break;
 
         case H5SL_TYPE_UNSIGNED:
-            H5SL_REMOVE(SCALAR,slist,x,update,i,const unsigned,-,key,checked)
+            H5SL_REMOVE(SCALAR, slist, x, update, i, const unsigned, key, checked)
+            break;
+
+        case H5SL_TYPE_SIZE:
+            H5SL_REMOVE(SCALAR, slist, x, update, i, const size_t, key, checked)
             break;
     } /* end switch */
 
@@ -816,6 +825,80 @@ done:
 
 /*--------------------------------------------------------------------------
  NAME
+    H5SL_remove_first
+ PURPOSE
+    Removes the first object from a skip list
+ USAGE
+    void *H5SL_remove_first(slist)
+        H5SL_t *slist;          IN/OUT: Pointer to skip list
+
+ RETURNS
+    Returns pointer to item removed on success, NULL on failure.
+ DESCRIPTION
+    Remove first element from a skip list.
+ GLOBAL VARIABLES
+ COMMENTS, BUGS, ASSUMPTIONS
+    This algorithm is basically the same as the one in the
+        H5SL_LOCATE_REMOVE_FOUND macro, fix bugs in both places
+ EXAMPLES
+ REVISION LOG
+--------------------------------------------------------------------------*/
+void *
+H5SL_remove_first(H5SL_t *slist)
+{
+    void *ret_value = NULL;                     /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5SL_remove_first)
+
+    /* Check args */
+    HDassert(slist);
+
+    /* Check internal consistency */
+    /* (Pre-condition) */
+
+    /* Remove item from skip list */
+
+    /* Check for empty list */
+    if(slist->last != slist->header) {
+        H5SL_node_t *x;                             /* Current node to examine */
+        int i;                                      /* Local index value */
+
+        /* Get pointer to first node on the list */
+        x = slist->header->forward[0];
+
+        /* Patch forward pointers in list header around node to remove */
+        for(i = 0; i <= (int)slist->curr_level; i++) {
+            if(slist->header->forward[i] != x)
+                break;
+            slist->header->forward[i] = x->forward[i];
+        } /* end for */
+
+        /* Update tail/backward pointer */
+        if(slist->last == x)
+            slist->last = x->backward;
+        else
+            x->forward[0]->backward = x->backward;
+
+        /* Get the item to return */
+        ret_value = x->item;
+
+        /* Free the skip list node */
+        H5FL_ARR_FREE(H5SL_node_ptr_t, x);
+
+        /* Lower the level of the list, if we removed the tallest node */
+        while(slist->curr_level > 0 && slist->header->forward[slist->curr_level] == NULL)
+            slist->curr_level--;
+
+        /* Decrement the # of objects in the list */
+        slist->nobjs--;
+    } /* end if */
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5SL_remove_first() */
+
+
+/*--------------------------------------------------------------------------
+ NAME
     H5SL_search
  PURPOSE
     Search for object in a skip list
@@ -858,23 +941,27 @@ H5SL_search(H5SL_t *slist, const void *key)
     x=slist->header;
     switch(slist->type) {
         case H5SL_TYPE_INT:
-            H5SL_SEARCH(SCALAR,slist,x,-,i,const int,-,key,checked)
+            H5SL_SEARCH(SCALAR, slist, x, -, i, const int, key, checked)
             break;
 
         case H5SL_TYPE_HADDR:
-            H5SL_SEARCH(SCALAR,slist,x,-,i,const haddr_t,-,key,checked)
+            H5SL_SEARCH(SCALAR, slist, x, -, i, const haddr_t, key, checked)
             break;
 
         case H5SL_TYPE_STR:
-            H5SL_SEARCH(STRING,slist,x,-,i,char *,-,key,checked)
+            H5SL_SEARCH(STRING, slist, x, -, i, char *, key, checked)
             break;
 
         case H5SL_TYPE_HSIZE:
-            H5SL_SEARCH(SCALAR,slist,x,-,i,const hsize_t,-,key,checked)
+            H5SL_SEARCH(SCALAR, slist, x, -, i, const hsize_t, key, checked)
             break;
 
         case H5SL_TYPE_UNSIGNED:
-            H5SL_SEARCH(SCALAR,slist,x,-,i,const unsigned,-,key,checked)
+            H5SL_SEARCH(SCALAR, slist, x, -, i, const unsigned, key, checked)
+            break;
+
+        case H5SL_TYPE_SIZE:
+            H5SL_SEARCH(SCALAR, slist, x, -, i, const size_t, key, checked)
             break;
     } /* end switch */
 
@@ -933,23 +1020,27 @@ H5SL_less(H5SL_t *slist, const void *key)
     x=slist->header;
     switch(slist->type) {
         case H5SL_TYPE_INT:
-            H5SL_SEARCH(SCALAR,slist,x,-,i,const int,-,key,checked)
+            H5SL_SEARCH(SCALAR, slist, x, -, i, const int, key, checked)
             break;
 
         case H5SL_TYPE_HADDR:
-            H5SL_SEARCH(SCALAR,slist,x,-,i,const haddr_t,-,key,checked)
+            H5SL_SEARCH(SCALAR, slist, x, -, i, const haddr_t, key, checked)
             break;
 
         case H5SL_TYPE_STR:
-            H5SL_SEARCH(STRING,slist,x,-,i,char *,-,key,checked)
+            H5SL_SEARCH(STRING, slist, x, -, i, char *, key, checked)
             break;
 
         case H5SL_TYPE_HSIZE:
-            H5SL_SEARCH(SCALAR,slist,x,-,i,const hsize_t,-,key,checked)
+            H5SL_SEARCH(SCALAR, slist, x, -, i, const hsize_t, key, checked)
             break;
 
         case H5SL_TYPE_UNSIGNED:
-            H5SL_SEARCH(SCALAR,slist,x,-,i,const unsigned,-,key,checked)
+            H5SL_SEARCH(SCALAR, slist, x, -, i, const unsigned, key, checked)
+            break;
+
+        case H5SL_TYPE_SIZE:
+            H5SL_SEARCH(SCALAR, slist, x, -, i, const size_t, key, checked)
             break;
     } /* end switch */
 
@@ -976,6 +1067,89 @@ done:
 
 /*--------------------------------------------------------------------------
  NAME
+    H5SL_greater
+ PURPOSE
+    Search for object in a skip list that is greater than or equal to 'key'
+ USAGE
+    void *H5SL_greater(slist, key)
+        H5SL_t *slist;          IN/OUT: Pointer to skip list
+        void *key;              IN: Key for item to search for
+
+ RETURNS
+    Returns pointer to item who key is greater than or equal to 'key' on success,
+        NULL on failure
+ DESCRIPTION
+    Search for an object in a skip list, according to it's key, returning the
+    object itself (for an exact match), or the object with the next lowest
+    key that is greater than 'key'
+ GLOBAL VARIABLES
+ COMMENTS, BUGS, ASSUMPTIONS
+ EXAMPLES
+ REVISION LOG
+--------------------------------------------------------------------------*/
+void *
+H5SL_greater(H5SL_t *slist, const void *key)
+{
+    H5SL_node_t *checked;                       /* Pointer to last node checked */
+    H5SL_node_t *x;                             /* Current node to examine */
+    int i;                                      /* Local index value */
+    void *ret_value;                            /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5SL_greater);
+
+    /* Check args */
+    HDassert(slist);
+    HDassert(key);
+
+    /* Check internal consistency */
+    /* (Pre-condition) */
+
+    /* Insert item into skip list */
+
+    /* Work through the forward pointers for a node, finding the node at each
+     * level that is before the location to insert
+     */
+    x = slist->header;
+    switch(slist->type) {
+        case H5SL_TYPE_INT:
+            H5SL_SEARCH(SCALAR, slist, x, -, i, const int, key, checked)
+            break;
+
+        case H5SL_TYPE_HADDR:
+            H5SL_SEARCH(SCALAR, slist, x, -, i, const haddr_t, key, checked)
+            break;
+
+        case H5SL_TYPE_STR:
+            H5SL_SEARCH(STRING, slist, x, -, i, char *, key, checked)
+            break;
+
+        case H5SL_TYPE_HSIZE:
+            H5SL_SEARCH(SCALAR, slist, x, -, i, const hsize_t, key, checked)
+            break;
+
+        case H5SL_TYPE_UNSIGNED:
+            H5SL_SEARCH(SCALAR, slist, x, -, i, const unsigned, key, checked)
+            break;
+
+        case H5SL_TYPE_SIZE:
+            H5SL_SEARCH(SCALAR, slist, x, -, i, const size_t, key, checked)
+            break;
+    } /* end switch */
+
+    /* An exact match for 'key' must not have been found in list, if we get here */
+    /* ('x' must be the next node with a key greater than the 'key', or NULL) */
+    if(x)
+        ret_value = x->item;
+    else
+        ret_value = NULL;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value);
+} /* end H5SL_greater() */
+
+
+/*--------------------------------------------------------------------------
+ NAME
     H5SL_find
  PURPOSE
     Search for _node_ in a skip list
@@ -1020,23 +1194,27 @@ H5SL_find(H5SL_t *slist, const void *key)
     x=slist->header;
     switch(slist->type) {
         case H5SL_TYPE_INT:
-            H5SL_FIND(SCALAR,slist,x,-,i,const int,-,key,checked)
+            H5SL_FIND(SCALAR, slist, x, -, i, const int, key, checked)
             break;
 
         case H5SL_TYPE_HADDR:
-            H5SL_FIND(SCALAR,slist,x,-,i,const haddr_t,-,key,checked)
+            H5SL_FIND(SCALAR, slist, x, -, i, const haddr_t, key, checked)
             break;
 
         case H5SL_TYPE_STR:
-            H5SL_FIND(STRING,slist,x,-,i,char *,-,key,checked)
+            H5SL_FIND(STRING, slist, x, -, i, char *, key, checked)
             break;
 
         case H5SL_TYPE_HSIZE:
-            H5SL_FIND(SCALAR,slist,x,-,i,const hsize_t,-,key,checked)
+            H5SL_FIND(SCALAR, slist, x, -, i, const hsize_t, key, checked)
             break;
 
         case H5SL_TYPE_UNSIGNED:
-            H5SL_FIND(SCALAR,slist,x,-,i,const unsigned,-,key,checked)
+            H5SL_FIND(SCALAR, slist, x, -, i, const unsigned, key, checked)
+            break;
+
+        case H5SL_TYPE_SIZE:
+            H5SL_FIND(SCALAR, slist, x, -, i, const size_t, key, checked)
             break;
     } /* end switch */
 
diff --git a/src/H5SLprivate.h b/src/H5SLprivate.h
index bf8d3b7..d37f130 100644
--- a/src/H5SLprivate.h
+++ b/src/H5SLprivate.h
@@ -44,7 +44,8 @@ typedef enum {
     H5SL_TYPE_HADDR,    /* Skip list keys are 'haddr_t's */
     H5SL_TYPE_STR,      /* Skip list keys are 'char *'s (ie. strings) */
     H5SL_TYPE_HSIZE,    /* Skip list keys are 'hsize_t's */
-    H5SL_TYPE_UNSIGNED  /* Skip list keys are 'unsigned's */
+    H5SL_TYPE_UNSIGNED, /* Skip list keys are 'unsigned's */
+    H5SL_TYPE_SIZE      /* Skip list keys are 'size_t's */
 } H5SL_type_t;
 
 /**********/
@@ -64,8 +65,10 @@ H5_DLL size_t H5SL_count(H5SL_t *slist);
 H5_DLL herr_t H5SL_insert(H5SL_t *slist, void *item, const void *key);
 H5_DLL H5SL_node_t *H5SL_add(H5SL_t *slist, void *item, const void *key);
 H5_DLL void *H5SL_remove(H5SL_t *slist, const void *key);
+H5_DLL void *H5SL_remove_first(H5SL_t *slist);
 H5_DLL void *H5SL_search(H5SL_t *slist, const void *key);
 H5_DLL void *H5SL_less(H5SL_t *slist, const void *key);
+H5_DLL void *H5SL_greater(H5SL_t *slist, const void *key);
 H5_DLL H5SL_node_t *H5SL_find(H5SL_t *slist, const void *key);
 H5_DLL H5SL_node_t *H5SL_first(H5SL_t *slist);
 H5_DLL H5SL_node_t *H5SL_next(H5SL_node_t *slist_node);
diff --git a/test/tskiplist.c b/test/tskiplist.c
index 9a29c95..c76b79c 100644
--- a/test/tskiplist.c
+++ b/test/tskiplist.c
@@ -1099,6 +1099,116 @@ test_skiplist_less(void)
 
 /****************************************************************
 **
+**  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, 0.5, 16);
+    CHECK(slist, NULL, "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 = H5SL_greater(slist, &find_item);
+    VERIFY(*found_item, find_item, "H5SL_greater");
+    find_item = 90;
+    found_item = H5SL_greater(slist, &find_item);
+    VERIFY(*found_item, find_item, "H5SL_greater");
+    find_item = 5;
+    found_item = 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 = H5SL_greater(slist,&find_item);
+    VERIFY(*found_item, 20, "H5SL_greater");
+    find_item = 89;
+    found_item = H5SL_greater(slist, &find_item);
+    VERIFY(*found_item, 90, "H5SL_greater");
+    find_item = 100;
+    found_item = H5SL_greater(slist, &find_item);
+    VERIFY(found_item, NULL, "H5SL_greater");
+    find_item = 6;
+    found_item = H5SL_greater(slist, &find_item);
+    VERIFY(*found_item, 10, "H5SL_greater");
+    find_item = 4;
+    found_item = 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_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 */
+    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, 0.5, 16);
+    CHECK(slist, NULL, "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 = H5SL_remove_first(slist);
+        VERIFY(*found_item, sorted_data[u], "H5SL_remove_first");
+    } /* end for */
+
+    /* Check for removing object from empty list */
+    found_item = H5SL_remove_first(slist);
+    VERIFY(found_item, NULL, "H5SL_remove_first");
+
+    /* Close the skip list */
+    ret = H5SL_close(slist);
+    CHECK(ret, FAIL, "H5SL_close");
+
+} /* end test_skiplist_remove_first() */
+
+/****************************************************************
+**
 **  test_skiplist(): Main H5SL testing routine.
 **
 ****************************************************************/
@@ -1128,6 +1238,8 @@ test_skiplist(void)
     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_remove_first();       /* Test 'remove first' operation */
 
 }   /* end test_skiplist() */