[svn-r7932] Purpose:

    Add new feature

Description:
    Add new H5I{dec|get|inc}_ref() routines and tests for them.

Platforms tested:
    FreeBSD 4.9 (sleipnir)
    h5committest

3 files changed, 649 insertions, 36 deletions

diff --git a/src/H5I.c b/src/H5I.c
index 6d624cd..ad2f450 100644
--- a/src/H5I.c
+++ b/src/H5I.c
@@ -118,6 +118,7 @@ H5FL_DEFINE_STATIC(H5I_id_info_t);
 static herr_t H5I_init_interface(void);
 static H5I_id_info_t *H5I_find_id(hid_t id);
 static hid_t H5I_get_file_id(hid_t obj_id);
+static int H5I_get_ref(hid_t id);
 #ifdef H5I_DEBUG_OUTPUT
 static herr_t H5I_debug(H5I_type_t grp);
 #endif /* H5I_DEBUG_OUTPUT */
@@ -959,6 +960,44 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5Idec_ref
+ *
+ * Purpose:	Decrements the number of references outstanding for an ID.
+ *              If the reference count for an ID reaches zero, the object
+ *              will be closed.
+ *
+ * Return:	Success:	New reference count
+ *		Failure:	Negative
+ *
+ * Programmer:  Quincey Koziol
+ *              Dec  7, 2003
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+int
+H5Idec_ref(hid_t id)
+{
+    int ret_value;                      /* Return value */
+
+    FUNC_ENTER_API(H5Idec_ref, FAIL);
+    H5TRACE1("Is","i",id);
+
+    /* Check arguments */
+    if (id<0)
+	HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "invalid ID");
+
+    /* Do actual decrement operation */
+    if((ret_value = H5I_dec_ref(id))<0)
+        HGOTO_ERROR (H5E_ATOM, H5E_CANTDEC, FAIL, "can't decrement ID ref count");
+
+done:
+    FUNC_LEAVE_API(ret_value);
+} /* end H5Idec_ref() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5I_dec_ref
  *
  * Purpose:	Decrements the number of references outstanding for an ID.
@@ -999,41 +1038,47 @@ done:
 int
 H5I_dec_ref(hid_t id)
 {
-    H5I_type_t		grp = H5I_GRP(id);	/*group the object is in*/
-    H5I_id_group_t	*grp_ptr = NULL;	/*ptr to the group	*/
-    H5I_id_info_t	*id_ptr = NULL;		/*ptr to the new ID	*/
-    int		ret_value=FAIL;	/*return value		*/
+    H5I_type_t		grp;		/*group the object is in*/
+    H5I_id_group_t	*grp_ptr;	/*ptr to the group	*/
+    H5I_id_info_t	*id_ptr;	/*ptr to the new ID	*/
+    int ret_value;                      /* Return value */
 
     FUNC_ENTER_NOAPI(H5I_dec_ref, FAIL);
 
+    /* Sanity check */
+    assert(id>=0);
+
     /* Check arguments */
+    grp = H5I_GRP(id);
+    if (grp <= H5I_BADID || grp >= H5I_NGROUPS)
+	HGOTO_ERROR(H5E_ARGS, H5E_BADRANGE, NULL, "invalid group number");
     grp_ptr = H5I_id_group_list_g[grp];
     if (grp_ptr == NULL || grp_ptr->count <= 0)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADRANGE, FAIL, "invalid group number");
     
     /* General lookup of the ID */
-    if ((id_ptr=H5I_find_id(id))) {
-	/*
-	 * If this is the last reference to the object then invoke the group's
-	 * free method on the object. If the free method is undefined or
-	 * successful then remove the object from the group; otherwise leave
-	 * the object in the group without decrementing the reference
-	 * count. If the reference count is more than one then decrement the
-	 * reference count without calling the free method.
-	 *
-	 * Beware: the free method may call other H5I functions.
-	 */
-	if (1==id_ptr->count) {
-	    if (!grp_ptr->free_func ||
-		(grp_ptr->free_func)(id_ptr->obj_ptr)>=0) {
-		H5I_remove(id);
-		ret_value = 0;
-	    } else {
-		ret_value = FAIL;
-	    }
-	} else {
-	    ret_value = --(id_ptr->count);
-	}
+    if ((id_ptr=H5I_find_id(id))==NULL)
+	HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't locate ID");
+
+    /*
+     * If this is the last reference to the object then invoke the group's
+     * free method on the object. If the free method is undefined or
+     * successful then remove the object from the group; otherwise leave
+     * the object in the group without decrementing the reference
+     * count. If the reference count is more than one then decrement the
+     * reference count without calling the free method.
+     *
+     * Beware: the free method may call other H5I functions.
+     */
+    if (1==id_ptr->count) {
+        if (!grp_ptr->free_func || (grp_ptr->free_func)(id_ptr->obj_ptr)>=0) {
+            H5I_remove(id);
+            ret_value = 0;
+        } else {
+            ret_value = FAIL;
+        }
+    } else {
+        ret_value = --(id_ptr->count);
     }
 
 done:
@@ -1042,6 +1087,42 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5Iinc_ref
+ *
+ * Purpose:	Increments the number of references outstanding for an ID.
+ *
+ * Return:	Success:	New reference count
+ *		Failure:	Negative
+ *
+ * Programmer:  Quincey Koziol
+ *              Dec  7, 2003
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+int
+H5Iinc_ref(hid_t id)
+{
+    int ret_value;                      /* Return value */
+
+    FUNC_ENTER_API(H5Iinc_ref, FAIL);
+    H5TRACE1("Is","i",id);
+
+    /* Check arguments */
+    if (id<0)
+	HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "invalid ID");
+
+    /* Do actual increment operation */
+    if((ret_value = H5I_inc_ref(id))<0)
+        HGOTO_ERROR (H5E_ATOM, H5E_CANTINC, FAIL, "can't increment ID ref count");
+
+done:
+    FUNC_LEAVE_API(ret_value);
+} /* end H5Iinc_ref() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5I_inc_ref
  *
  * Purpose:	Increment the reference count for an object.
@@ -1060,16 +1141,105 @@ done:
 int
 H5I_inc_ref(hid_t id)
 {
-    H5I_type_t		grp = H5I_GRP(id);	/*group the object is in*/
-    H5I_id_group_t	*grp_ptr = NULL;	/*ptr to the group	*/
-    H5I_id_info_t	*id_ptr = NULL;		/*ptr to the ID		*/
-    int ret_value;                              /* Return value */
+    H5I_type_t		grp;		/*group the object is in*/
+    H5I_id_group_t	*grp_ptr;	/*ptr to the group	*/
+    H5I_id_info_t	*id_ptr;	/*ptr to the ID		*/
+    int ret_value;                      /* Return value */
 
     FUNC_ENTER_NOAPI(H5I_inc_ref, FAIL);
 
+    /* Sanity check */
+    assert(id>=0);
+
+    /* Check arguments */
+    grp = H5I_GRP(id);
+    if (grp <= H5I_BADID || grp >= H5I_NGROUPS)
+	HGOTO_ERROR(H5E_ARGS, H5E_BADRANGE, NULL, "invalid group number");
+    grp_ptr = H5I_id_group_list_g[grp];
+    if (!grp_ptr || grp_ptr->count<=0)
+	HGOTO_ERROR(H5E_ATOM, H5E_BADGROUP, FAIL, "invalid group");
+
+    /* General lookup of the ID */
+    if (NULL==(id_ptr=H5I_find_id(id)))
+	HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't locate ID");
+
+    /* Set return value */
+    ret_value=++(id_ptr->count);
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5Iget_ref
+ *
+ * Purpose:	Retrieves the number of references outstanding for an ID.
+ *
+ * Return:	Success:	Reference count
+ *		Failure:	Negative
+ *
+ * Programmer:  Quincey Koziol
+ *              Dec  7, 2003
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+int
+H5Iget_ref(hid_t id)
+{
+    int ret_value;                      /* Return value */
+
+    FUNC_ENTER_API(H5Iget_ref, FAIL);
+    H5TRACE1("Is","i",id);
+
     /* Check arguments */
     if (id<0)
 	HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "invalid ID");
+
+    /* Do actual retrieve operation */
+    if((ret_value = H5I_get_ref(id))<0)
+        HGOTO_ERROR (H5E_ATOM, H5E_CANTGET, FAIL, "can't get ID ref count");
+
+done:
+    FUNC_LEAVE_API(ret_value);
+} /* end H5Iget_ref() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5I_get_ref
+ *
+ * Purpose:	Retrieve the reference count for an object.
+ *
+ * Return:	Success:	The reference count.
+ *
+ *		Failure:	Negative
+ *
+ * Programmer:	Quincey Koziol
+ *              Saturday, Decemeber  6, 2003
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static int
+H5I_get_ref(hid_t id)
+{
+    H5I_type_t		grp;		/*group the object is in*/
+    H5I_id_group_t	*grp_ptr;	/*ptr to the group	*/
+    H5I_id_info_t	*id_ptr;	/*ptr to the ID		*/
+    int ret_value;                      /* Return value */
+
+    FUNC_ENTER_NOAPI(H5I_get_ref, FAIL);
+
+    /* Sanity check */
+    assert(id>=0);
+
+    /* Check arguments */
+    grp = H5I_GRP(id);
+    if (grp <= H5I_BADID || grp >= H5I_NGROUPS)
+	HGOTO_ERROR(H5E_ARGS, H5E_BADRANGE, NULL, "invalid group number");
     grp_ptr = H5I_id_group_list_g[grp];
     if (!grp_ptr || grp_ptr->count<=0)
 	HGOTO_ERROR(H5E_ATOM, H5E_BADGROUP, FAIL, "invalid group");
@@ -1077,14 +1247,13 @@ H5I_inc_ref(hid_t id)
     /* General lookup of the ID */
     if (NULL==(id_ptr=H5I_find_id(id)))
 	HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't locate ID");
-    id_ptr->count++;
 
     /* Set return value */
     ret_value=id_ptr->count;
 
 done:
     FUNC_LEAVE_NOAPI(ret_value);
-}
+} /* end H5I_get_ref() */
 
 
 /*-------------------------------------------------------------------------
diff --git a/src/H5Ipublic.h b/src/H5Ipublic.h
index eb97994..9c4d950 100644
--- a/src/H5Ipublic.h
+++ b/src/H5Ipublic.h
@@ -27,6 +27,10 @@
  * tracing output look better when hid_t values are large numbers.  Change the
  * GROUP_BITS in H5I.c if the MAXID gets larger than 32 (an assertion will
  * fail otherwise).
+ *
+ * When adding groups here, add a section to the 'misc19' test in test/tmisc.c
+ * to verify that the H5I{inc|dec|get}_ref() routines work correctly with in.
+ *
  */
 typedef enum {
     H5I_BADID		= (-1),	/*invalid Group				    */
@@ -59,8 +63,11 @@ extern "C" {
 
 /* Public API functions */
 H5_DLL H5I_type_t H5Iget_type(hid_t id);
-H5_DLL hid_t H5Iget_file_id(hid_t obj_id);
-H5_DLL ssize_t H5Iget_name(hid_t object_id, char *name/*out*/, size_t size);
+H5_DLL hid_t H5Iget_file_id(hid_t id);
+H5_DLL ssize_t H5Iget_name(hid_t id, char *name/*out*/, size_t size);
+H5_DLL int H5Iinc_ref(hid_t id);
+H5_DLL int H5Idec_ref(hid_t id);
+H5_DLL int H5Iget_ref(hid_t id);
 
 #ifdef __cplusplus
 }
diff --git a/test/tmisc.c b/test/tmisc.c
index 9b750c8..4bfbde4 100644
--- a/test/tmisc.c
+++ b/test/tmisc.c
@@ -12,8 +12,6 @@
  * access to either file, you may request a copy from hdfhelp@ncsa.uiuc.edu. *
  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
-/* $Id$ */
-
 /***********************************************************
 *
 * Test program:	 tmisc
@@ -213,6 +211,11 @@ unsigned m13_rdata[MISC13_DIM1][MISC13_DIM2];          /* Data read from dataset
 #define MISC18_DSET1_NAME       "Dataset1"
 #define MISC18_DSET2_NAME       "Dataset2"
 
+/* Definitions for misc. test #19 */
+#define MISC19_FILE             "tmisc19.h5"
+#define MISC19_DSET_NAME        "Dataset"
+#define MISC19_ATTR_NAME        "Attribute"
+#define MISC19_GROUP_NAME       "Group"
 
 /****************************************************************
 **
@@ -2907,6 +2910,438 @@ test_misc18(void)
 
 /****************************************************************
 **
+**  test_misc19(): Test incrementing & decrementing ref count on IDs
+**
+****************************************************************/
+static void
+test_misc19(void)
+{
+    hid_t fid;          /* File ID */
+    hid_t sid;          /* 'Space ID */
+    hid_t did;          /* Dataset ID */
+    hid_t tid;          /* 'Type ID */
+    hid_t aid;          /* Attribute ID */
+    hid_t plid;         /* Property List ID */
+    hid_t pcid;         /* Property Class ID */
+    hid_t gid;          /* Group ID */
+    hid_t ecid;         /* Error Class ID */
+    hid_t emid;         /* Error Message ID */
+    hid_t esid;         /* Error Stack ID */
+    int rc;             /* Reference count */
+    herr_t ret;         /* Generic return value */
+
+/* Check H5I operations on files */
+
+    /* Create the file */
+    fid = H5Fcreate(MISC19_FILE, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
+    CHECK(fid, FAIL, "H5Fcreate");
+
+    /* Check the reference count */
+    rc = H5Iget_ref(fid);
+    VERIFY(rc, 1, "H5Iget_ref");
+
+    /* Inc the reference count */
+    rc = H5Iinc_ref(fid);
+    VERIFY(rc, 2, "H5Iinc_ref");
+
+    /* Close the file normally */
+    ret = H5Fclose(fid);
+    CHECK(ret, FAIL, "H5Fclose");
+
+    /* Check the reference count */
+    rc = H5Iget_ref(fid);
+    VERIFY(rc, 1, "H5Iget_ref");
+
+    /* Close the file by decrementing the reference count */
+    rc = H5Idec_ref(fid);
+    VERIFY(rc, 0, "H5Idec_ref");
+
+    /* Try closing the file again (should fail) */
+    H5E_BEGIN_TRY {
+        ret = H5Fclose(fid);
+    } H5E_END_TRY;
+    VERIFY(ret, FAIL, "H5Fclose");
+
+/* Check H5I operations on property lists */
+
+    /* Create the property list */
+    plid = H5Pcreate(H5P_DATASET_CREATE);
+    CHECK(plid, FAIL, "H5Pcreate");
+
+    /* Check the reference count */
+    rc = H5Iget_ref(plid);
+    VERIFY(rc, 1, "H5Iget_ref");
+
+    /* Inc the reference count */
+    rc = H5Iinc_ref(plid);
+    VERIFY(rc, 2, "H5Iinc_ref");
+
+    /* Close the property list normally */
+    ret = H5Pclose(plid);
+    CHECK(ret, FAIL, "H5Pclose");
+
+    /* Check the reference count */
+    rc = H5Iget_ref(plid);
+    VERIFY(rc, 1, "H5Iget_ref");
+
+    /* Close the property list by decrementing the reference count */
+    rc = H5Idec_ref(plid);
+    VERIFY(rc, 0, "H5Idec_ref");
+
+    /* Try closing the property list again (should fail) */
+    H5E_BEGIN_TRY {
+        ret = H5Pclose(plid);
+    } H5E_END_TRY;
+    VERIFY(ret, FAIL, "H5Pclose");
+
+/* Check H5I operations on property classes */
+
+    /* Create a property class */
+    pcid = H5Pcreate_class(H5P_DATASET_CREATE,"foo",NULL,NULL,NULL,NULL,NULL,NULL);
+    CHECK(pcid, FAIL, "H5Pcreate_class");
+
+    /* Check the reference count */
+    rc = H5Iget_ref(pcid);
+    VERIFY(rc, 1, "H5Iget_ref");
+
+    /* Inc the reference count */
+    rc = H5Iinc_ref(pcid);
+    VERIFY(rc, 2, "H5Iinc_ref");
+
+    /* Close the property class normally */
+    ret = H5Pclose_class(pcid);
+    CHECK(ret, FAIL, "H5Pclose_class");
+
+    /* Check the reference count */
+    rc = H5Iget_ref(pcid);
+    VERIFY(rc, 1, "H5Iget_ref");
+
+    /* Close the property class by decrementing the reference count */
+    rc = H5Idec_ref(pcid);
+    VERIFY(rc, 0, "H5Idec_ref");
+
+    /* Try closing the property class again (should fail) */
+    H5E_BEGIN_TRY {
+        ret = H5Pclose_class(pcid);
+    } H5E_END_TRY;
+    VERIFY(ret, FAIL, "H5Pclose_class");
+
+/* Check H5I operations on datatypes */
+
+    /* Create a datatype */
+    tid = H5Tcreate(H5T_OPAQUE,16);
+    CHECK(tid, FAIL, "H5Tcreate");
+
+    /* Check the reference count */
+    rc = H5Iget_ref(tid);
+    VERIFY(rc, 1, "H5Iget_ref");
+
+    /* Inc the reference count */
+    rc = H5Iinc_ref(tid);
+    VERIFY(rc, 2, "H5Iinc_ref");
+
+    /* Close the datatype normally */
+    ret = H5Tclose(tid);
+    CHECK(ret, FAIL, "H5Tclose");
+
+    /* Check the reference count */
+    rc = H5Iget_ref(tid);
+    VERIFY(rc, 1, "H5Iget_ref");
+
+    /* Close the datatype by decrementing the reference count */
+    rc = H5Idec_ref(tid);
+    VERIFY(rc, 0, "H5Idec_ref");
+
+    /* Try closing the datatype again (should fail) */
+    H5E_BEGIN_TRY {
+        ret = H5Tclose(tid);
+    } H5E_END_TRY;
+    VERIFY(ret, FAIL, "H5Tclose");
+
+/* Check H5I operations on dataspaces */
+
+    /* Create a dataspace */
+    sid = H5Screate(H5S_SCALAR);
+    CHECK(sid, FAIL, "H5Screate");
+
+    /* Check the reference count */
+    rc = H5Iget_ref(sid);
+    VERIFY(rc, 1, "H5Iget_ref");
+
+    /* Inc the reference count */
+    rc = H5Iinc_ref(sid);
+    VERIFY(rc, 2, "H5Iinc_ref");
+
+    /* Close the dataspace normally */
+    ret = H5Sclose(sid);
+    CHECK(ret, FAIL, "H5Sclose");
+
+    /* Check the reference count */
+    rc = H5Iget_ref(sid);
+    VERIFY(rc, 1, "H5Iget_ref");
+
+    /* Close the dataspace by decrementing the reference count */
+    rc = H5Idec_ref(sid);
+    VERIFY(rc, 0, "H5Idec_ref");
+
+    /* Try closing the dataspace again (should fail) */
+    H5E_BEGIN_TRY {
+        ret = H5Sclose(sid);
+    } H5E_END_TRY;
+    VERIFY(ret, FAIL, "H5Sclose");
+
+/* Check H5I operations on datasets */
+
+    /* Create a file */
+    fid = H5Fcreate(MISC19_FILE, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
+    CHECK(fid, FAIL, "H5Fcreate");
+
+    /* Create a dataspace */
+    sid = H5Screate(H5S_SCALAR);
+    CHECK(sid, FAIL, "H5Screate");
+
+    /* Create a dataset */
+    did = H5Dcreate(fid,MISC19_DSET_NAME,H5T_NATIVE_INT,sid,H5P_DEFAULT);
+    CHECK(did, FAIL, "H5Dcreate");
+
+    /* Check the reference count */
+    rc = H5Iget_ref(did);
+    VERIFY(rc, 1, "H5Iget_ref");
+
+    /* Inc the reference count */
+    rc = H5Iinc_ref(did);
+    VERIFY(rc, 2, "H5Iinc_ref");
+
+    /* Close the dataset normally */
+    ret = H5Dclose(did);
+    CHECK(ret, FAIL, "H5Dclose");
+
+    /* Check the reference count */
+    rc = H5Iget_ref(did);
+    VERIFY(rc, 1, "H5Iget_ref");
+
+    /* Close the dataset by decrementing the reference count */
+    rc = H5Idec_ref(did);
+    VERIFY(rc, 0, "H5Idec_ref");
+
+    /* Try closing the dataset again (should fail) */
+    H5E_BEGIN_TRY {
+        ret = H5Dclose(did);
+    } H5E_END_TRY;
+    VERIFY(ret, FAIL, "H5Dclose");
+
+    /* Close the dataspace */
+    ret = H5Sclose(sid);
+    CHECK(ret, FAIL, "H5Sclose");
+
+    /* Close the file */
+    ret = H5Fclose(fid);
+    CHECK(ret, FAIL, "H5Fclose");
+
+/* Check H5I operations on attributes */
+
+    /* Create a file */
+    fid = H5Fcreate(MISC19_FILE, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
+    CHECK(fid, FAIL, "H5Fcreate");
+
+    /* Open the root group */
+    gid = H5Gopen(fid,"/");
+    CHECK(gid, FAIL, "H5Gopen");
+
+    /* Create a dataspace */
+    sid = H5Screate(H5S_SCALAR);
+    CHECK(sid, FAIL, "H5Screate");
+
+    /* Create an attribute */
+    aid = H5Acreate(gid,MISC19_ATTR_NAME,H5T_NATIVE_INT,sid,H5P_DEFAULT);
+    CHECK(aid, FAIL, "H5Acreate");
+
+    /* Check the reference count */
+    rc = H5Iget_ref(aid);
+    VERIFY(rc, 1, "H5Iget_ref");
+
+    /* Inc the reference count */
+    rc = H5Iinc_ref(aid);
+    VERIFY(rc, 2, "H5Iinc_ref");
+
+    /* Close the dataset normally */
+    ret = H5Aclose(aid);
+    CHECK(ret, FAIL, "H5Aclose");
+
+    /* Check the reference count */
+    rc = H5Iget_ref(aid);
+    VERIFY(rc, 1, "H5Iget_ref");
+
+    /* Close the attribute by decrementing the reference count */
+    rc = H5Idec_ref(aid);
+    VERIFY(rc, 0, "H5Idec_ref");
+
+    /* Try closing the attribute again (should fail) */
+    H5E_BEGIN_TRY {
+        ret = H5Aclose(aid);
+    } H5E_END_TRY;
+    VERIFY(ret, FAIL, "H5Aclose");
+
+    /* Close the root group */
+    ret = H5Gclose(gid);
+    CHECK(ret, FAIL, "H5Gclose");
+
+    /* Close the dataspace */
+    ret = H5Sclose(sid);
+    CHECK(ret, FAIL, "H5Sclose");
+
+    /* Close the file */
+    ret = H5Fclose(fid);
+    CHECK(ret, FAIL, "H5Fclose");
+
+/* Check H5I operations on groups */
+
+    /* Create a file */
+    fid = H5Fcreate(MISC19_FILE, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
+    CHECK(fid, FAIL, "H5Fcreate");
+
+    /* Create a group */
+    gid = H5Gcreate(fid,MISC19_GROUP_NAME,0);
+    CHECK(gid, FAIL, "H5Gcreate");
+
+    /* Check the reference count */
+    rc = H5Iget_ref(gid);
+    VERIFY(rc, 1, "H5Iget_ref");
+
+    /* Inc the reference count */
+    rc = H5Iinc_ref(gid);
+    VERIFY(rc, 2, "H5Iinc_ref");
+
+    /* Close the group normally */
+    ret = H5Gclose(gid);
+    CHECK(ret, FAIL, "H5Gclose");
+
+    /* Check the reference count */
+    rc = H5Iget_ref(gid);
+    VERIFY(rc, 1, "H5Iget_ref");
+
+    /* Close the group by decrementing the reference count */
+    rc = H5Idec_ref(gid);
+    VERIFY(rc, 0, "H5Idec_ref");
+
+    /* Try closing the group again (should fail) */
+    H5E_BEGIN_TRY {
+        ret = H5Gclose(gid);
+    } H5E_END_TRY;
+    VERIFY(ret, FAIL, "H5Gclose");
+
+    /* Close the file */
+    ret = H5Fclose(fid);
+    CHECK(ret, FAIL, "H5Fclose");
+
+/* Check H5I operations on error classes */
+
+    /* Create an error class */
+    ecid = H5Eregister_class("foo","bar","baz");
+    CHECK(ecid, FAIL, "H5Eregister_class");
+
+    /* Check the reference count */
+    rc = H5Iget_ref(ecid);
+    VERIFY(rc, 1, "H5Iget_ref");
+
+    /* Inc the reference count */
+    rc = H5Iinc_ref(ecid);
+    VERIFY(rc, 2, "H5Iinc_ref");
+
+    /* Close the error class normally */
+    ret = H5Eunregister_class(ecid);
+    CHECK(ret, FAIL, "H5Eunregister_class");
+
+    /* Check the reference count */
+    rc = H5Iget_ref(ecid);
+    VERIFY(rc, 1, "H5Iget_ref");
+
+    /* Close the error class by decrementing the reference count */
+    rc = H5Idec_ref(ecid);
+    VERIFY(rc, 0, "H5Idec_ref");
+
+    /* Try closing the error class again (should fail) */
+    H5E_BEGIN_TRY {
+        ret = H5Eunregister_class(ecid);
+    } H5E_END_TRY;
+    VERIFY(ret, FAIL, "H5Eunregister_class");
+
+/* Check H5I operations on error messages */
+
+    /* Create an error class */
+    ecid = H5Eregister_class("foo","bar","baz");
+    CHECK(ecid, FAIL, "H5Eregister_class");
+
+    /* Create an error message */
+    emid = H5Ecreate_msg(ecid,H5E_MAJOR,"mumble");
+    CHECK(emid, FAIL, "H5Ecreate_msg");
+
+    /* Check the reference count */
+    rc = H5Iget_ref(emid);
+    VERIFY(rc, 1, "H5Iget_ref");
+
+    /* Inc the reference count */
+    rc = H5Iinc_ref(emid);
+    VERIFY(rc, 2, "H5Iinc_ref");
+
+    /* Close the error message normally */
+    ret = H5Eclose_msg(emid);
+    CHECK(ret, FAIL, "H5Eclose_msg");
+
+    /* Check the reference count */
+    rc = H5Iget_ref(emid);
+    VERIFY(rc, 1, "H5Iget_ref");
+
+    /* Close the error message by decrementing the reference count */
+    rc = H5Idec_ref(emid);
+    VERIFY(rc, 0, "H5Idec_ref");
+
+    /* Try closing the error message again (should fail) */
+    H5E_BEGIN_TRY {
+        ret = H5Eclose_msg(emid);
+    } H5E_END_TRY;
+    VERIFY(ret, FAIL, "H5Eclose_msg");
+
+    /* Close the error class */
+    ret = H5Eunregister_class(ecid);
+    CHECK(ret, FAIL, "H5Eunregister_class");
+
+/* Check H5I operations on error stacks */
+
+    /* Create an error stack */
+    esid = H5Eget_current_stack();
+    CHECK(esid, FAIL, "H5Eget_current_stack");
+
+    /* Check the reference count */
+    rc = H5Iget_ref(esid);
+    VERIFY(rc, 1, "H5Iget_ref");
+
+    /* Inc the reference count */
+    rc = H5Iinc_ref(esid);
+    VERIFY(rc, 2, "H5Iinc_ref");
+
+    /* Close the error stack normally */
+    ret = H5Eclose_stack(esid);
+    CHECK(ret, FAIL, "H5Eclose_stack");
+
+    /* Check the reference count */
+    rc = H5Iget_ref(esid);
+    VERIFY(rc, 1, "H5Iget_ref");
+
+    /* Close the error stack by decrementing the reference count */
+    rc = H5Idec_ref(esid);
+    VERIFY(rc, 0, "H5Idec_ref");
+
+    /* Try closing the error stack again (should fail) */
+    H5E_BEGIN_TRY {
+        ret = H5Eclose_stack(esid);
+    } H5E_END_TRY;
+    VERIFY(ret, FAIL, "H5Eclose_stack");
+
+} /* end test_misc19() */
+
+/****************************************************************
+**
 **  test_misc(): Main misc. test routine.
 ** 
 ****************************************************************/
@@ -2934,6 +3369,7 @@ test_misc(void)
     test_misc16();      /* Test array of fixed-length string */
     test_misc17();      /* Test array of ASCII character */
     test_misc18();      /* Test new object header information in H5G_stat_t struct */
+    test_misc19();      /* Test incrementing & decrementing ref count on IDs */
 
 } /* test_misc() */
 
@@ -2976,4 +3412,5 @@ cleanup_misc(void)
     HDremove(MISC16_FILE);
     HDremove(MISC17_FILE);
     HDremove(MISC18_FILE);
+    HDremove(MISC19_FILE);
 }