Add API context interface and use it throughout the library.

1 files changed, 254 insertions, 213 deletions

diff --git a/src/H5A.c b/src/H5A.c
index 07aca92..1b42106 100644
--- a/src/H5A.c
+++ b/src/H5A.c
@@ -24,6 +24,7 @@
 /***********/
 #include "H5private.h"		/* Generic Functions			*/
 #include "H5Apkg.h"		/* Attributes				*/
+#include "H5CXprivate.h"        /* API Contexts                         */
 #include "H5Eprivate.h"		/* Error handling		  	*/
 #include "H5FLprivate.h"	/* Free Lists				*/
 #include "H5Iprivate.h"		/* IDs			  		*/
@@ -91,7 +92,7 @@ static const H5I_class_t H5I_ATTR_CLS[1] = {{
     H5I_ATTR,                   /* ID class value */
     0,                          /* Class flags */
     0,                          /* # of reserved IDs for class */
-    (H5I_free_t)H5A_close       /* Callback routine for closing objects of this class */
+    (H5I_free_t)H5A__close_cb   /* Callback routine for closing objects of this class */
 }};
 
 /* Flag indicating "top" of interface has been initialized */
@@ -250,7 +251,7 @@ H5Acreate2(hid_t loc_id, const char *attr_name, hid_t type_id, hid_t space_id,
     H5G_loc_t           loc;                    /* Object location */
     H5T_t		*type;                  /* Datatype to use for attribute */
     H5S_t		*space;                 /* Dataspace to use for attribute */
-    hid_t               dxpl_id = H5AC_ind_read_dxpl_id; /* dxpl used by library */
+hbool_t     api_ctx_pushed = FALSE;             /* Whether API context pushed */
     hid_t		ret_value;              /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -270,12 +271,16 @@ H5Acreate2(hid_t loc_id, const char *attr_name, hid_t type_id, hid_t space_id,
     if(NULL == (space = (H5S_t *)H5I_object_verify(space_id, H5I_DATASPACE)))
 	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a data space")
 
-    /* Verify access property list and get correct dxpl */
-    if(H5P_verify_apl_and_dxpl(&aapl_id, H5P_CLS_AACC, &dxpl_id, loc_id, TRUE) < 0)
-        HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access and transfer property lists")
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, H5I_INVALID_HID, "can't set API context")
+api_ctx_pushed = TRUE;
+/* Verify access property list and set up collective metadata if appropriate */
+if(H5CX_set_apl(&aapl_id, H5P_CLS_AACC, loc_id, TRUE) < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, H5I_INVALID_HID, "can't set access property list info")
 
     /* Go do the real work for attaching the attribute to the object */
-    if(NULL == (attr = H5A_create(&loc, attr_name, type, space, acpl_id, dxpl_id)))
+    if(NULL == (attr = H5A__create(&loc, attr_name, type, space, acpl_id)))
 	HGOTO_ERROR(H5E_ATTR, H5E_CANTINIT, FAIL, "unable to create attribute")
 
     /* Register the new attribute and get an ID for it */
@@ -284,8 +289,10 @@ H5Acreate2(hid_t loc_id, const char *attr_name, hid_t type_id, hid_t space_id,
 
 done:
     /* Cleanup on failure */
-    if(ret_value < 0 && attr && H5A_close(attr) < 0)
+    if(ret_value < 0 && attr && H5A__close(attr) < 0)
         HDONE_ERROR(H5E_ATTR, H5E_CANTFREE, FAIL, "can't close attribute")
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_ATTR, H5E_CANTRESET, H5I_INVALID_HID, "can't reset API context")
 
     FUNC_LEAVE_API(ret_value)
 } /* H5Acreate2() */
@@ -328,13 +335,9 @@ H5Acreate_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
 {
     H5A_t	        *attr = NULL;           /* Attribute created */
     H5G_loc_t           loc;                    /* Object location */
-    H5G_loc_t           obj_loc;                /* Location used to open group */
-    H5G_name_t          obj_path;            	/* Opened object group hier. path */
-    H5O_loc_t           obj_oloc;            	/* Opened object object location */
-    hbool_t             loc_found = FALSE;      /* Entry at 'obj_name' found */
     H5T_t		*type;                  /* Datatype to use for attribute */
     H5S_t		*space;                 /* Dataspace to use for attribute */
-    hid_t               dxpl_id = H5AC_ind_read_dxpl_id; /* dxpl used by library */
+hbool_t     api_ctx_pushed = FALSE;             /* Whether API context pushed */
     hid_t		ret_value;              /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -357,33 +360,34 @@ H5Acreate_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
     if(NULL == (space = (H5S_t *)H5I_object_verify(space_id, H5I_DATASPACE)))
 	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a data space")
 
-    /* Set up opened group location to fill in */
-    obj_loc.oloc = &obj_oloc;
-    obj_loc.path = &obj_path;
-    H5G_loc_reset(&obj_loc);
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, H5I_INVALID_HID, "can't set API context")
+api_ctx_pushed = TRUE;
+/* Verify access property list and set up collective metadata if appropriate */
+if(H5CX_set_apl(&aapl_id, H5P_CLS_AACC, loc_id, TRUE) < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, H5I_INVALID_HID, "can't set access property list info")
 
-    /* Verify access property list and get correct dxpl */
-    if(H5P_verify_apl_and_dxpl(&aapl_id, H5P_CLS_AACC, &dxpl_id, loc_id, TRUE) < 0)
-        HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access and transfer property lists")
-
-    /* Find the object's location */
-    if(H5G_loc_find(&loc, obj_name, &obj_loc/*out*/, lapl_id, dxpl_id) < 0)
-        HGOTO_ERROR(H5E_ATTR, H5E_NOTFOUND, FAIL, "object not found")
-    loc_found = TRUE;
+    if(H5P_DEFAULT != lapl_id) {
+        if(TRUE != H5P_isa_class(lapl_id, H5P_LINK_ACCESS))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not link access property list ID")
+        H5CX_set_lapl(lapl_id);
+    } /* end if */
 
-    /* Go do the real work for attaching the attribute to the dataset */
-    if(NULL == (attr = H5A_create(&obj_loc, attr_name, type, space, acpl_id, dxpl_id)))
+    /* Create the attribute on the object */
+    if(NULL == (attr = H5A__create_by_name(&loc, obj_name, attr_name, type, space, acpl_id)))
 	HGOTO_ERROR(H5E_ATTR, H5E_CANTINIT, FAIL, "unable to create attribute")
 
     /* Register the new attribute and get an ID for it */
     if((ret_value = H5I_register(H5I_ATTR, attr, TRUE)) < 0)
         HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "unable to register attribute for ID")
+
 done:
-    /* Release resources */
-    if(loc_found && H5G_loc_free(&obj_loc) < 0)
-        HDONE_ERROR(H5E_ATTR, H5E_CANTRELEASE, FAIL, "can't free location")
-    if(ret_value < 0 && attr && H5A_close(attr) < 0)
-            HDONE_ERROR(H5E_ATTR, H5E_CANTFREE, FAIL, "can't close attribute")
+    /* Cleanup on failure */
+    if(ret_value < 0 && attr && H5A__close(attr) < 0)
+        HDONE_ERROR(H5E_ATTR, H5E_CANTFREE, FAIL, "can't close attribute")
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_ATTR, H5E_CANTRESET, H5I_INVALID_HID, "can't reset API context")
 
     FUNC_LEAVE_API(ret_value)
 } /* H5Acreate_by_name() */
@@ -413,7 +417,7 @@ H5Aopen(hid_t loc_id, const char *attr_name, hid_t aapl_id)
 {
     H5G_loc_t    	loc;            /* Object location */
     H5A_t               *attr = NULL;   /* Attribute opened */
-    hid_t               dxpl_id  = H5AC_ind_read_dxpl_id; /* dxpl used by library */
+hbool_t     api_ctx_pushed = FALSE;             /* Whether API context pushed */
     hid_t		ret_value;
 
     FUNC_ENTER_API(FAIL)
@@ -427,17 +431,17 @@ H5Aopen(hid_t loc_id, const char *attr_name, hid_t aapl_id)
     if(!attr_name || !*attr_name)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no attribute name")
 
-    /* Verify access property list and get correct dxpl */
-    if(H5P_verify_apl_and_dxpl(&aapl_id, H5P_CLS_AACC, &dxpl_id, loc_id, FALSE) < 0)
-        HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access and transfer property lists")
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set API context")
+api_ctx_pushed = TRUE;
+/* Verify access property list and set up collective metadata if appropriate */
+if(H5CX_set_apl(&aapl_id, H5P_CLS_AACC, loc_id, FALSE) < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access property list info")
 
     /* Read in attribute from object header */
-    if(NULL == (attr = H5O_attr_open_by_name(loc.oloc, attr_name, dxpl_id)))
-        HGOTO_ERROR(H5E_ATTR, H5E_CANTINIT, FAIL, "unable to load attribute info from object header for attribute: '%s'", attr_name)
-
-    /* Finish initializing attribute */
-    if(H5A__open_common(&loc, attr) < 0)
-        HGOTO_ERROR(H5E_ATTR, H5E_CANTINIT, FAIL, "unable to initialize attribute")
+    if(NULL == (attr = H5A__open(&loc, attr_name)))
+        HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "unable to load attribute info from object header for attribute: '%s'", attr_name)
 
     /* Register the attribute and get an ID for it */
     if((ret_value = H5I_register(H5I_ATTR, attr, TRUE)) < 0)
@@ -446,8 +450,10 @@ H5Aopen(hid_t loc_id, const char *attr_name, hid_t aapl_id)
 done:
     /* Cleanup on failure */
     if(ret_value < 0)
-        if(attr && H5A_close(attr) < 0)
+        if(attr && H5A__close(attr) < 0)
             HDONE_ERROR(H5E_ATTR, H5E_CANTFREE, FAIL, "can't close attribute")
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_ATTR, H5E_CANTRESET, H5I_INVALID_HID, "can't reset API context")
 
     FUNC_LEAVE_API(ret_value)
 } /* H5Aopen() */
@@ -480,7 +486,7 @@ H5Aopen_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
 {
     H5G_loc_t    	loc;            /* Object location */
     H5A_t               *attr = NULL;   /* Attribute opened */
-    hid_t               dxpl_id  = H5AC_ind_read_dxpl_id; /* dxpl used by library */
+hbool_t     api_ctx_pushed = FALSE;             /* Whether API context pushed */
     hid_t		ret_value;
 
     FUNC_ENTER_API(FAIL)
@@ -495,18 +501,23 @@ H5Aopen_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no object name")
     if(!attr_name || !*attr_name)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no attribute name")
-    if(H5P_DEFAULT == lapl_id)
-        lapl_id = H5P_LINK_ACCESS_DEFAULT;
-    else
+
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set API context")
+api_ctx_pushed = TRUE;
+/* Verify access property list and set up collective metadata if appropriate */
+if(H5CX_set_apl(&aapl_id, H5P_CLS_AACC, loc_id, FALSE) < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access property list info")
+
+    if(H5P_DEFAULT != lapl_id) {
         if(TRUE != H5P_isa_class(lapl_id, H5P_LINK_ACCESS))
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not link access property list ID")
-
-    /* Verify access property list and get correct dxpl */
-    if(H5P_verify_apl_and_dxpl(&aapl_id, H5P_CLS_AACC, &dxpl_id, loc_id, FALSE) < 0)
-        HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access and transfer property lists")
+        H5CX_set_lapl(lapl_id);
+    } /* end if */
 
     /* Open the attribute on the object header */
-    if(NULL == (attr = H5A_open_by_name(&loc, obj_name, attr_name, lapl_id, dxpl_id)))
+    if(NULL == (attr = H5A__open_by_name(&loc, obj_name, attr_name)))
         HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "can't open attribute")
 
     /* Register the attribute and get an ID for it */
@@ -516,8 +527,10 @@ H5Aopen_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
 done:
     /* Cleanup on failure */
     if(ret_value < 0)
-        if(attr && H5A_close(attr) < 0)
+        if(attr && H5A__close(attr) < 0)
             HDONE_ERROR(H5E_ATTR, H5E_CANTFREE, FAIL, "can't close attribute")
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_ATTR, H5E_CANTRESET, H5I_INVALID_HID, "can't reset API context")
 
     FUNC_LEAVE_API(ret_value)
 } /* H5Aopen_by_name() */
@@ -553,7 +566,7 @@ H5Aopen_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
 {
     H5A_t       *attr = NULL;   /* Attribute opened */
     H5G_loc_t	loc;	        /* Object location */
-    hid_t       dxpl_id  = H5AC_ind_read_dxpl_id; /* dxpl used by library */
+hbool_t     api_ctx_pushed = FALSE;             /* Whether API context pushed */
     hid_t	ret_value;      /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -571,18 +584,23 @@ H5Aopen_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid index type specified")
     if(order <= H5_ITER_UNKNOWN || order >= H5_ITER_N)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid iteration order specified")
-    if(H5P_DEFAULT == lapl_id)
-        lapl_id = H5P_LINK_ACCESS_DEFAULT;
-    else
+
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set API context")
+api_ctx_pushed = TRUE;
+/* Verify access property list and set up collective metadata if appropriate */
+if(H5CX_set_apl(&aapl_id, H5P_CLS_AACC, loc_id, FALSE) < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access property list info")
+
+    if(H5P_DEFAULT != lapl_id) {
         if(TRUE != H5P_isa_class(lapl_id, H5P_LINK_ACCESS))
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not link access property list ID")
-
-    /* Verify access property list and get correct dxpl */
-    if(H5P_verify_apl_and_dxpl(&aapl_id, H5P_CLS_AACC, &dxpl_id, loc_id, FALSE) < 0)
-        HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access and transfer property lists")
+        H5CX_set_lapl(lapl_id);
+    } /* end if */
 
     /* Open the attribute in the object header */
-    if(NULL == (attr = H5A_open_by_idx(&loc, obj_name, idx_type, order, n, lapl_id, dxpl_id)))
+    if(NULL == (attr = H5A__open_by_idx(&loc, obj_name, idx_type, order, n)))
         HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "unable to open attribute")
 
     /* Register the attribute and get an ID for it */
@@ -592,8 +610,10 @@ H5Aopen_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
 done:
     /* Cleanup on failure */
     if(ret_value < 0)
-        if(attr && H5A_close(attr) < 0)
+        if(attr && H5A__close(attr) < 0)
             HDONE_ERROR(H5E_ATTR, H5E_CANTFREE, FAIL, "can't close attribute")
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_ATTR, H5E_CANTRESET, H5I_INVALID_HID, "can't reset API context")
 
     FUNC_LEAVE_API(ret_value)
 } /* H5Aopen_by_idx() */
@@ -620,8 +640,7 @@ H5Awrite(hid_t attr_id, hid_t dtype_id, const void *buf)
 {
     H5A_t *attr;                /* Attribute object for ID */
     H5T_t *mem_type;            /* Memory datatype */
-    hid_t  dxpl_id = H5AC_ind_read_dxpl_id; /* dxpl used by library */
-    hid_t  aapl_id = H5P_DEFAULT;  /* temp access plist */
+hbool_t     api_ctx_pushed = FALSE;             /* Whether API context pushed */
     herr_t ret_value;           /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -635,15 +654,21 @@ H5Awrite(hid_t attr_id, hid_t dtype_id, const void *buf)
     if(NULL == buf)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "null attribute buffer")
 
-    /* Verify access property list and get correct dxpl */
-    if(H5P_verify_apl_and_dxpl(&aapl_id, H5P_CLS_AACC, &dxpl_id, attr_id, TRUE) < 0)
-        HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access and transfer property lists")
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set API context")
+api_ctx_pushed = TRUE;
+/* Set up collective metadata if appropriate */
+if(H5CX_set_loc(attr_id, TRUE) < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set collective metadata read")
 
     /* Go write the actual data to the attribute */
-    if((ret_value = H5A__write(attr, mem_type, buf, dxpl_id)) < 0)
+    if((ret_value = H5A__write(attr, mem_type, buf)) < 0)
         HGOTO_ERROR(H5E_ATTR, H5E_WRITEERROR, FAIL, "unable to write attribute")
 
 done:
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_ATTR, H5E_CANTRESET, FAIL, "can't reset API context")
     FUNC_LEAVE_API(ret_value)
 } /* H5Awrite() */
 
@@ -669,8 +694,7 @@ H5Aread(hid_t attr_id, hid_t dtype_id, void *buf)
 {
     H5A_t *attr;                /* Attribute object for ID */
     H5T_t *mem_type;            /* Memory datatype */
-    hid_t  dxpl_id = H5AC_ind_read_dxpl_id; /* dxpl used by library */
-    hid_t  aapl_id = H5P_DEFAULT;  /* temp access plist */
+hbool_t     api_ctx_pushed = FALSE;             /* Whether API context pushed */
     herr_t ret_value;           /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -684,15 +708,18 @@ H5Aread(hid_t attr_id, hid_t dtype_id, void *buf)
     if(NULL == buf)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "null attribute buffer")
 
-    /* Verify access property list and get correct dxpl */
-    if(H5P_verify_apl_and_dxpl(&aapl_id, H5P_CLS_AACC, &dxpl_id, attr_id, FALSE) < 0)
-        HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access and transfer property lists")
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set API context")
+api_ctx_pushed = TRUE;
 
     /* Go write the actual data to the attribute */
-    if((ret_value = H5A__read(attr, mem_type, buf, dxpl_id)) < 0)
+    if((ret_value = H5A__read(attr, mem_type, buf)) < 0)
         HGOTO_ERROR(H5E_ATTR, H5E_READERROR, FAIL, "unable to read attribute")
 
 done:
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_ATTR, H5E_CANTRESET, FAIL, "can't reset API context")
     FUNC_LEAVE_API(ret_value)
 } /* H5Aread() */
 
@@ -752,8 +779,9 @@ done:
 hid_t
 H5Aget_type(hid_t attr_id)
 {
-    H5A_t	*attr;          /* Attribute object for ID */
-    hid_t	 ret_value;     /* Return value */
+    H5A_t *attr;        /* Attribute object for ID */
+hbool_t     api_ctx_pushed = FALSE;             /* Whether API context pushed */
+    hid_t ret_value;     /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE1("i", "i", attr_id);
@@ -762,9 +790,17 @@ H5Aget_type(hid_t attr_id)
     if(NULL == (attr = (H5A_t *)H5I_object_verify(attr_id, H5I_ATTR)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not an attribute")
 
-    if((ret_value = H5A_get_type(attr)) < 0)
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, H5I_INVALID_HID, "can't set API context")
+api_ctx_pushed = TRUE;
+
+    if((ret_value = H5A__get_type(attr)) < 0)
         HGOTO_ERROR(H5E_ARGS, H5E_CANTGET, FAIL, "can't get datatype ID of attribute")
+
 done:
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_ATTR, H5E_CANTRESET, H5I_INVALID_HID, "can't reset API context")
     FUNC_LEAVE_API(ret_value)
 } /* H5Aget_type() */
 
@@ -803,7 +839,7 @@ H5Aget_create_plist(hid_t attr_id)
     if(NULL == (attr = (H5A_t *)H5I_object_verify(attr_id, H5I_ATTR)))
 	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not an attribute")
 
-    if((ret_value = H5A_get_create_plist(attr)) < 0)
+    if((ret_value = H5A__get_create_plist(attr)) < 0)
         HGOTO_ERROR(H5E_ARGS, H5E_CANTGET, FAIL, "can't get creation property list for attr")
 
 done:
@@ -880,7 +916,7 @@ H5Aget_name_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
 {
     H5G_loc_t   loc;            /* Object location */
     H5A_t	*attr = NULL;   /* Attribute object for name */
-    hid_t       dxpl_id  = H5AC_ind_read_dxpl_id; /* dxpl used by library */
+hbool_t     api_ctx_pushed = FALSE;             /* Whether API context pushed */
     ssize_t	ret_value;      /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -899,12 +935,16 @@ H5Aget_name_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
     if(order <= H5_ITER_UNKNOWN || order >= H5_ITER_N)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid iteration order specified")
 
-    /* Verify access property list and get correct dxpl */
-    if(H5P_verify_apl_and_dxpl(&lapl_id, H5P_CLS_LACC, &dxpl_id, loc_id, FALSE) < 0)
-        HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access and transfer property lists")
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set API context")
+api_ctx_pushed = TRUE;
+/* Verify access property list and set up collective metadata if appropriate */
+if(H5CX_set_apl(&lapl_id, H5P_CLS_LACC, loc_id, FALSE) < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access property list info")
 
     /* Open the attribute on the object header */
-    if(NULL == (attr = H5A_open_by_idx(&loc, obj_name, idx_type, order, n, lapl_id, dxpl_id)))
+    if(NULL == (attr = H5A__open_by_idx(&loc, obj_name, idx_type, order, n)))
         HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "can't open attribute")
 
     /* Get the length of the name */
@@ -919,8 +959,10 @@ H5Aget_name_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
 
 done:
     /* Release resources */
-    if(attr && H5A_close(attr) < 0)
+    if(attr && H5A__close(attr) < 0)
         HDONE_ERROR(H5E_ATTR, H5E_CANTFREE, FAIL, "can't close attribute")
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_ATTR, H5E_CANTRESET, FAIL, "can't reset API context")
 
     FUNC_LEAVE_API(ret_value)
 } /* end H5Aget_name_by_idx() */
@@ -1018,7 +1060,7 @@ H5Aget_info_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
 {
     H5G_loc_t   loc;                    /* Object location */
     H5A_t	*attr = NULL;           /* Attribute object for name */
-    hid_t       dxpl_id  = H5AC_ind_read_dxpl_id; /* dxpl used by library */
+hbool_t     api_ctx_pushed = FALSE;             /* Whether API context pushed */
     herr_t	ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -1036,12 +1078,16 @@ H5Aget_info_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
     if(NULL == ainfo)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid info pointer")
 
-    /* Verify access property list and get correct dxpl */
-    if(H5P_verify_apl_and_dxpl(&lapl_id, H5P_CLS_LACC, &dxpl_id, loc_id, FALSE) < 0)
-        HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access and transfer property lists")
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set API context")
+api_ctx_pushed = TRUE;
+/* Verify access property list and set up collective metadata if appropriate */
+if(H5CX_set_apl(&lapl_id, H5P_CLS_LACC, loc_id, FALSE) < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access property list info")
 
     /* Open the attribute on the object header */
-    if(NULL == (attr = H5A_open_by_name(&loc, obj_name, attr_name, lapl_id, dxpl_id)))
+    if(NULL == (attr = H5A__open_by_name(&loc, obj_name, attr_name)))
         HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "can't open attribute")
 
     /* Get the attribute information */
@@ -1049,9 +1095,11 @@ H5Aget_info_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
 	HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, FAIL, "unable to get attribute info")
 
 done:
-    /* Cleanup on failure */
-    if(attr && H5A_close(attr) < 0)
+    /* Release resources */
+    if(attr && H5A__close(attr) < 0)
         HDONE_ERROR(H5E_ATTR, H5E_CANTFREE, FAIL, "can't close attribute")
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_ATTR, H5E_CANTRESET, FAIL, "can't reset API context")
 
     FUNC_LEAVE_API(ret_value)
 } /* end H5Aget_info_by_name() */
@@ -1077,7 +1125,7 @@ H5Aget_info_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
 {
     H5G_loc_t   loc;                    /* Object location */
     H5A_t	*attr = NULL;           /* Attribute object for name */
-    hid_t       dxpl_id  = H5AC_ind_read_dxpl_id; /* dxpl used by library */
+hbool_t     api_ctx_pushed = FALSE;             /* Whether API context pushed */
     herr_t	ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -1098,12 +1146,16 @@ H5Aget_info_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
     if(NULL == ainfo)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid info pointer")
 
-    /* Verify access property list and get correct dxpl */
-    if(H5P_verify_apl_and_dxpl(&lapl_id, H5P_CLS_LACC, &dxpl_id, loc_id, FALSE) < 0)
-        HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access and transfer property lists")
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set API context")
+api_ctx_pushed = TRUE;
+/* Verify access property list and set up collective metadata if appropriate */
+if(H5CX_set_apl(&lapl_id, H5P_CLS_LACC, loc_id, FALSE) < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access property list info")
 
     /* Open the attribute on the object header */
-    if(NULL == (attr = H5A_open_by_idx(&loc, obj_name, idx_type, order, n, lapl_id, dxpl_id)))
+    if(NULL == (attr = H5A__open_by_idx(&loc, obj_name, idx_type, order, n)))
         HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "can't open attribute")
 
     /* Get the attribute information */
@@ -1112,8 +1164,10 @@ H5Aget_info_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
 
 done:
     /* Release resources */
-    if(attr && H5A_close(attr) < 0)
+    if(attr && H5A__close(attr) < 0)
         HDONE_ERROR(H5E_ATTR, H5E_CANTFREE, FAIL, "can't close attribute")
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_ATTR, H5E_CANTRESET, FAIL, "can't reset API context")
 
     FUNC_LEAVE_API(ret_value)
 } /* end H5Aget_info_by_idx() */
@@ -1135,6 +1189,7 @@ done:
 herr_t
 H5Arename(hid_t loc_id, const char *old_name, const char *new_name)
 {
+hbool_t     api_ctx_pushed = FALSE;             /* Whether API context pushed */
     herr_t	ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -1153,12 +1208,22 @@ H5Arename(hid_t loc_id, const char *old_name, const char *new_name)
         if(H5G_loc(loc_id, &loc) < 0)
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
 
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set API context")
+api_ctx_pushed = TRUE;
+/* Set up collective metadata if appropriate */
+if(H5CX_set_loc(loc_id, TRUE) < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set collective metadata read")
+
         /* Call private attribute rename routine */
-        if(H5O_attr_rename(loc.oloc, H5AC_ind_read_dxpl_id, old_name, new_name) < 0)
+        if(H5A__rename(&loc, old_name, new_name) < 0)
             HGOTO_ERROR(H5E_ATTR, H5E_CANTRENAME, FAIL, "can't rename attribute")
     } /* end if */
 
 done:
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_ATTR, H5E_CANTRESET, FAIL, "can't reset API context")
     FUNC_LEAVE_API(ret_value)
 } /* H5Arename() */
 
@@ -1180,6 +1245,7 @@ herr_t
 H5Arename_by_name(hid_t loc_id, const char *obj_name, const char *old_attr_name,
     const char *new_attr_name, hid_t lapl_id)
 {
+hbool_t     api_ctx_pushed = FALSE;             /* Whether API context pushed */
     herr_t	ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -1199,21 +1265,26 @@ H5Arename_by_name(hid_t loc_id, const char *obj_name, const char *old_attr_name,
     /* Avoid thrashing things if the names are the same */
     if(HDstrcmp(old_attr_name, new_attr_name)) {
         H5G_loc_t loc;                /* Object location */
-        hid_t dxpl_id = H5AC_ind_read_dxpl_id; /* dxpl used by the library */
 
-        /* Verify access property list and get correct dxpl */
-        if(H5P_verify_apl_and_dxpl(&lapl_id, H5P_CLS_LACC, &dxpl_id, loc_id, TRUE) < 0)
-            HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access and transfer property lists")
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set API context")
+api_ctx_pushed = TRUE;
+/* Verify access property list and set up collective metadata if appropriate */
+if(H5CX_set_apl(&lapl_id, H5P_CLS_LACC, loc_id, TRUE) < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access property list info")
 
         if(H5G_loc(loc_id, &loc) < 0)
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
 
         /* Call private attribute rename routine */
-        if(H5A_rename_by_name(loc, obj_name, old_attr_name, new_attr_name, lapl_id, dxpl_id) < 0)
+        if(H5A__rename_by_name(loc, obj_name, old_attr_name, new_attr_name) < 0)
             HGOTO_ERROR(H5E_ATTR, H5E_CANTRENAME, FAIL, "can't rename attribute")
     } /* end if */
 
 done:
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_ATTR, H5E_CANTRESET, FAIL, "can't reset API context")
     FUNC_LEAVE_API(ret_value)
 } /* H5Arename_by_name() */
 
@@ -1263,9 +1334,7 @@ herr_t
 H5Aiterate2(hid_t loc_id, H5_index_t idx_type, H5_iter_order_t order,
     hsize_t *idx, H5A_operator2_t op, void *op_data)
 {
-    H5A_attr_iter_op_t attr_op; /* Attribute operator */
-    hsize_t	start_idx;      /* Index of attribute to start iterating at */
-    hsize_t	last_attr;      /* Index of last attribute examined */
+hbool_t     api_ctx_pushed = FALSE;             /* Whether API context pushed */
     herr_t	ret_value;      /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -1279,20 +1348,18 @@ H5Aiterate2(hid_t loc_id, H5_index_t idx_type, H5_iter_order_t order,
     if(order <= H5_ITER_UNKNOWN || order >= H5_ITER_N)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid iteration order specified")
 
-    /* Build attribute operator info */
-    attr_op.op_type = H5A_ATTR_OP_APP2;
-    attr_op.u.app_op2 = op;
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set API context")
+api_ctx_pushed = TRUE;
 
     /* Call attribute iteration routine */
-    last_attr = start_idx = (idx ? *idx : 0);
-    if((ret_value = H5O_attr_iterate(loc_id, H5AC_ind_read_dxpl_id, idx_type, order, start_idx, &last_attr, &attr_op, op_data)) < 0)
+    if((ret_value = H5A__iterate(loc_id, idx_type, order, idx, op, op_data)) < 0)
         HERROR(H5E_ATTR, H5E_BADITER, "error iterating over attributes");
 
-    /* Set the last attribute information */
-    if(idx)
-        *idx = last_attr;
-
 done:
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_ATTR, H5E_CANTRESET, FAIL, "can't reset API context")
     FUNC_LEAVE_API(ret_value)
 } /* H5Aiterate2() */
 
@@ -1346,15 +1413,7 @@ H5Aiterate_by_name(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
     hid_t lapl_id)
 {
     H5G_loc_t	loc;	        /* Object location */
-    H5G_loc_t   obj_loc;        /* Location used to open group */
-    H5G_name_t  obj_path;       /* Opened object group hier. path */
-    H5O_loc_t   obj_oloc;       /* Opened object object location */
-    hbool_t     loc_found = FALSE;      /* Entry at 'obj_name' found */
-    hid_t       obj_loc_id = (-1);      /* ID for object located */
-    H5A_attr_iter_op_t attr_op; /* Attribute operator */
-    hsize_t	start_idx;      /* Index of attribute to start iterating at */
-    hsize_t	last_attr;      /* Index of last attribute examined */
-    hid_t       dxpl_id  = H5AC_ind_read_dxpl_id; /* dxpl used by library */
+hbool_t     api_ctx_pushed = FALSE;             /* Whether API context pushed */
     herr_t	ret_value;      /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -1373,46 +1432,21 @@ H5Aiterate_by_name(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
     if(order <= H5_ITER_UNKNOWN || order >= H5_ITER_N)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid iteration order specified")
 
-    /* Verify access property list and get correct dxpl */
-    if(H5P_verify_apl_and_dxpl(&lapl_id, H5P_CLS_LACC, &dxpl_id, loc_id, FALSE) < 0)
-        HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access and transfer property lists")
-
-    /* Set up opened group location to fill in */
-    obj_loc.oloc = &obj_oloc;
-    obj_loc.path = &obj_path;
-    H5G_loc_reset(&obj_loc);
-
-    /* Find the object's location */
-    if(H5G_loc_find(&loc, obj_name, &obj_loc/*out*/, lapl_id, dxpl_id) < 0)
-        HGOTO_ERROR(H5E_ATTR, H5E_NOTFOUND, FAIL, "object not found")
-    loc_found = TRUE;
-
-    /* Open the object */
-    if((obj_loc_id = H5O_open_by_loc(&obj_loc, lapl_id, dxpl_id, TRUE)) < 0)
-        HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "unable to open object")
-
-    /* Build attribute operator info */
-    attr_op.op_type = H5A_ATTR_OP_APP2;
-    attr_op.u.app_op2 = op;
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set API context")
+api_ctx_pushed = TRUE;
+/* Verify access property list and set up collective metadata if appropriate */
+if(H5CX_set_apl(&lapl_id, H5P_CLS_LACC, loc_id, FALSE) < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access property list info")
 
-    /* Call attribute iteration routine */
-    last_attr = start_idx = (idx ? *idx : 0);
-    if((ret_value = H5O_attr_iterate(obj_loc_id, dxpl_id, idx_type, order, start_idx, &last_attr, &attr_op, op_data)) < 0)
+    /* Call attribute iteration by name routine */
+    if((ret_value = H5A__iterate_by_name(&loc, obj_name, idx_type, order, idx, op, op_data)) < 0)
         HERROR(H5E_ATTR, H5E_BADITER, "error iterating over attributes");
 
-    /* Set the last attribute information */
-    if(idx)
-        *idx = last_attr;
-
 done:
-    /* Release resources */
-    if(obj_loc_id > 0) {
-        if(H5I_dec_app_ref(obj_loc_id) < 0)
-            HDONE_ERROR(H5E_ATTR, H5E_CANTDEC, FAIL, "unable to close temporary object")
-    } /* end if */
-    else if(loc_found && H5G_loc_free(&obj_loc) < 0)
-        HDONE_ERROR(H5E_ATTR, H5E_CANTRELEASE, FAIL, "can't free location")
-
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_ATTR, H5E_CANTRESET, FAIL, "can't reset API context")
     FUNC_LEAVE_API(ret_value)
 } /* H5Aiterate_by_name() */
 
@@ -1435,6 +1469,7 @@ herr_t
 H5Adelete(hid_t loc_id, const char *name)
 {
     H5G_loc_t	loc;		        /* Object location */
+hbool_t     api_ctx_pushed = FALSE;             /* Whether API context pushed */
     herr_t	ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -1448,11 +1483,21 @@ H5Adelete(hid_t loc_id, const char *name)
     if(!name || !*name)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name")
 
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set API context")
+api_ctx_pushed = TRUE;
+/* Set up collective metadata if appropriate */
+if(H5CX_set_loc(loc_id, TRUE) < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set collective metadata read")
+
     /* Delete the attribute from the location */
-    if(H5O_attr_remove(loc.oloc, name, H5AC_ind_read_dxpl_id) < 0)
+    if(H5A__delete(&loc, name) < 0)
         HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, FAIL, "unable to delete attribute")
 
 done:
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_ATTR, H5E_CANTRESET, FAIL, "can't reset API context")
     FUNC_LEAVE_API(ret_value)
 } /* H5Adelete() */
 
@@ -1478,11 +1523,7 @@ H5Adelete_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
     hid_t lapl_id)
 {
     H5G_loc_t	loc;		        /* Object location */
-    H5G_loc_t   obj_loc;                /* Location used to open group */
-    H5G_name_t  obj_path;            	/* Opened object group hier. path */
-    H5O_loc_t   obj_oloc;            	/* Opened object object location */
-    hbool_t     loc_found = FALSE;      /* Entry at 'obj_name' found */
-    hid_t       dxpl_id = H5AC_ind_read_dxpl_id; /* dxpl used by library */
+hbool_t     api_ctx_pushed = FALSE;             /* Whether API context pushed */
     herr_t	ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -1498,29 +1539,21 @@ H5Adelete_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
     if(!attr_name || !*attr_name)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no attribute name")
 
-    /* Verify access property list and get correct dxpl */
-    if(H5P_verify_apl_and_dxpl(&lapl_id, H5P_CLS_LACC, &dxpl_id, loc_id, TRUE) < 0)
-        HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access and transfer property lists")
-
-    /* Set up opened group location to fill in */
-    obj_loc.oloc = &obj_oloc;
-    obj_loc.path = &obj_path;
-    H5G_loc_reset(&obj_loc);
-
-    /* Find the object's location */
-    if(H5G_loc_find(&loc, obj_name, &obj_loc/*out*/, lapl_id, dxpl_id) < 0)
-        HGOTO_ERROR(H5E_ATTR, H5E_NOTFOUND, FAIL, "object not found")
-    loc_found = TRUE;
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set API context")
+api_ctx_pushed = TRUE;
+/* Verify access property list and set up collective metadata if appropriate */
+if(H5CX_set_apl(&lapl_id, H5P_CLS_LACC, loc_id, TRUE) < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access property list info")
 
     /* Delete the attribute from the location */
-    if(H5O_attr_remove(obj_loc.oloc, attr_name, dxpl_id) < 0)
+    if(H5A__delete_by_name(&loc, obj_name, attr_name) < 0)
         HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, FAIL, "unable to delete attribute")
 
 done:
-    /* Release resources */
-    if(loc_found && H5G_loc_free(&obj_loc) < 0)
-        HDONE_ERROR(H5E_ATTR, H5E_CANTRELEASE, FAIL, "can't free location")
-
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_ATTR, H5E_CANTRESET, FAIL, "can't reset API context")
     FUNC_LEAVE_API(ret_value)
 } /* H5Adelete_by_name() */
 
@@ -1554,11 +1587,7 @@ H5Adelete_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
     H5_iter_order_t order, hsize_t n, hid_t lapl_id)
 {
     H5G_loc_t	loc;		        /* Object location */
-    H5G_loc_t   obj_loc;                /* Location used to open group */
-    H5G_name_t  obj_path;            	/* Opened object group hier. path */
-    H5O_loc_t   obj_oloc;            	/* Opened object object location */
-    hbool_t     loc_found = FALSE;      /* Entry at 'obj_name' found */
-    hid_t       dxpl_id = H5AC_ind_read_dxpl_id; /* dxpl used by library */
+hbool_t     api_ctx_pushed = FALSE;             /* Whether API context pushed */
     herr_t	ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -1576,29 +1605,21 @@ H5Adelete_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
     if(order <= H5_ITER_UNKNOWN || order >= H5_ITER_N)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid iteration order specified")
 
-    /* Verify access property list and get correct dxpl */
-    if(H5P_verify_apl_and_dxpl(&lapl_id, H5P_CLS_LACC, &dxpl_id, loc_id, TRUE) < 0)
-        HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access and transfer property lists")
-
-    /* Set up opened group location to fill in */
-    obj_loc.oloc = &obj_oloc;
-    obj_loc.path = &obj_path;
-    H5G_loc_reset(&obj_loc);
-
-    /* Find the object's location */
-    if(H5G_loc_find(&loc, obj_name, &obj_loc/*out*/, lapl_id, dxpl_id) < 0)
-        HGOTO_ERROR(H5E_ATTR, H5E_NOTFOUND, FAIL, "object not found")
-    loc_found = TRUE;
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set API context")
+api_ctx_pushed = TRUE;
+/* Verify access property list and set up collective metadata if appropriate */
+if(H5CX_set_apl(&lapl_id, H5P_CLS_LACC, loc_id, TRUE) < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access property list info")
 
     /* Delete the attribute from the location */
-    if(H5O_attr_remove_by_idx(obj_loc.oloc, idx_type, order, n, dxpl_id) < 0)
+    if(H5A__delete_by_idx(&loc, obj_name, idx_type, order, n) < 0)
         HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, FAIL, "unable to delete attribute")
 
 done:
-    /* Release resources */
-    if(loc_found && H5G_loc_free(&obj_loc) < 0)
-        HDONE_ERROR(H5E_ATTR, H5E_CANTRELEASE, FAIL, "can't free location")
-
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_ATTR, H5E_CANTRESET, FAIL, "can't reset API context")
     FUNC_LEAVE_API(ret_value)
 } /* H5Adelete_by_idx() */
 
@@ -1621,6 +1642,7 @@ done:
 herr_t
 H5Aclose(hid_t attr_id)
 {
+hbool_t     api_ctx_pushed = FALSE;             /* Whether API context pushed */
     herr_t ret_value = SUCCEED;   /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -1629,12 +1651,17 @@ H5Aclose(hid_t attr_id)
     /* check arguments */
     if(NULL == H5I_object_verify(attr_id, H5I_ATTR))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not an attribute")
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, FAIL, "can't set API context")
+api_ctx_pushed = TRUE;
 
     /* Decrement references to that atom (and close it) */
     if(H5I_dec_app_ref(attr_id) < 0)
         HGOTO_ERROR(H5E_ATTR, H5E_CANTDEC, FAIL, "can't close attribute")
 
 done:
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_DATASET, H5E_CANTRESET, FAIL, "can't reset API context")
     FUNC_LEAVE_API(ret_value)
 } /* H5Aclose() */
 
@@ -1657,6 +1684,7 @@ htri_t
 H5Aexists(hid_t obj_id, const char *attr_name)
 {
     H5G_loc_t   loc;                    /* Object location */
+hbool_t     api_ctx_pushed = FALSE;             /* Whether API context pushed */
     htri_t	ret_value;              /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -1670,11 +1698,18 @@ H5Aexists(hid_t obj_id, const char *attr_name)
     if (!attr_name || !*attr_name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no attribute name")
 
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set API context")
+api_ctx_pushed = TRUE;
+
     /* Check if the attribute exists */
-    if((ret_value = H5O_attr_exists(loc.oloc, attr_name, H5AC_ind_read_dxpl_id)) < 0)
+    if((ret_value = H5A__exists(&loc, attr_name)) < 0)
         HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, FAIL, "unable to determine if attribute exists")
 
 done:
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_ATTR, H5E_CANTRESET, FAIL, "can't reset API context")
     FUNC_LEAVE_API(ret_value)
 } /* H5Aexists() */
 
@@ -1697,7 +1732,7 @@ H5Aexists_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
     hid_t lapl_id)
 {
     H5G_loc_t   loc;                    /* Object location */
-    hid_t       dxpl_id = H5AC_ind_read_dxpl_id;     /* dxpl used by library */
+hbool_t     api_ctx_pushed = FALSE;             /* Whether API context pushed */
     htri_t	ret_value;              /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -1713,14 +1748,20 @@ H5Aexists_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
     if (!attr_name || !*attr_name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no attribute name")
 
-    /* Verify access property list and get correct dxpl */
-    if (H5P_verify_apl_and_dxpl(&lapl_id, H5P_CLS_LACC, &dxpl_id, loc_id, FALSE) < 0)
-        HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access and transfer property lists")
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set API context")
+api_ctx_pushed = TRUE;
+/* Verify access property list and set up collective metadata if appropriate */
+if(H5CX_set_apl(&lapl_id, H5P_CLS_LACC, loc_id, FALSE) < 0)
+    HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access property list info")
 
-    if ((ret_value = H5A_exists_by_name(loc, obj_name, attr_name, lapl_id, dxpl_id)) < 0)
+    if ((ret_value = H5A__exists_by_name(loc, obj_name, attr_name)) < 0)
         HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, FAIL, "unable to determine if attribute exists")
 
 done:
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_ATTR, H5E_CANTRESET, FAIL, "can't reset API context")
     FUNC_LEAVE_API(ret_value)
 } /* H5Aexists_by_name() */