Add API context interface and use it throughout the library.

1 files changed, 200 insertions, 121 deletions

diff --git a/src/H5O.c b/src/H5O.c
index cf84b47..1795b71 100644
--- a/src/H5O.c
+++ b/src/H5O.c
@@ -31,6 +31,7 @@
 /* Headers */
 /***********/
 #include "H5private.h"          /* Generic Functions                        */
+#include "H5CXprivate.h"        /* API Contexts                             */
 #include "H5Eprivate.h"         /* Error handling                           */
 #include "H5Fprivate.h"         /* File access                              */
 #include "H5Iprivate.h"         /* IDs                                      */
@@ -99,8 +100,8 @@
 hid_t
 H5Oopen(hid_t loc_id, const char *name, hid_t lapl_id)
 {
-    H5G_loc_t	loc;
-    hid_t       dxpl_id = H5AC_ind_read_dxpl_id; /* dxpl used by library */
+    H5G_loc_t	loc;                    /* Location of group */
+hbool_t     api_ctx_pushed = FALSE;             /* Whether API context pushed */
     hid_t       ret_value = FAIL;
 
     FUNC_ENTER_API(FAIL)
@@ -112,15 +113,21 @@ H5Oopen(hid_t loc_id, const char *name, hid_t lapl_id)
     if(!name || !*name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no 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_OHDR, H5E_CANTSET, FAIL, "can't set access and transfer property lists")
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_OHDR, 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(&lapl_id, H5P_CLS_LACC, loc_id, FALSE) < 0)
+    HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, H5I_INVALID_HID, "can't set access property list info")
 
     /* Open the object */
-    if((ret_value = H5O_open_name(&loc, name, lapl_id, dxpl_id, TRUE)) < 0)
+    if((ret_value = H5O__open_name(&loc, name)) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTOPENOBJ, FAIL, "unable to open object")
 
 done:
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_OHDR, H5E_CANTRESET, H5I_INVALID_HID, "can't reset API context")
     FUNC_LEAVE_API(ret_value)
 } /* end H5Oopen() */
 
@@ -152,12 +159,8 @@ hid_t
 H5Oopen_by_idx(hid_t loc_id, const char *group_name, H5_index_t idx_type,
     H5_iter_order_t order, hsize_t n, hid_t lapl_id)
 {
-    H5G_loc_t	loc;
-    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 */
-    hid_t       dxpl_id = H5AC_ind_read_dxpl_id; /* dxpl used by library */
-    hbool_t     loc_found = FALSE;      /* Entry at 'name' found */
+    H5G_loc_t	loc;                    /* Location of group */
+hbool_t     api_ctx_pushed = FALSE;             /* Whether API context pushed */
     hid_t       ret_value = FAIL;
 
     FUNC_ENTER_API(FAIL)
@@ -173,30 +176,21 @@ H5Oopen_by_idx(hid_t loc_id, const char *group_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_OHDR, 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, according to the order in the index */
-    if(H5G_loc_find_by_idx(&loc, group_name, idx_type, order, n, &obj_loc/*out*/, lapl_id, dxpl_id) < 0)
-        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "group not found")
-    loc_found = TRUE;
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_OHDR, 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(&lapl_id, H5P_CLS_LACC, loc_id, FALSE) < 0)
+    HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, H5I_INVALID_HID, "can't set access property list info")
 
     /* Open the object */
-    if((ret_value = H5O_open_by_loc(&obj_loc, lapl_id, dxpl_id, TRUE)) < 0)
+    if((ret_value = H5O__open_by_idx(&loc, group_name, idx_type, order, n)) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTOPENOBJ, FAIL, "unable to open object")
 
 done:
-    /* Release the object location if we failed after copying it */
-    if(ret_value < 0 && loc_found)
-        if(H5G_loc_free(&obj_loc) < 0)
-            HDONE_ERROR(H5E_OHDR, H5E_CANTRELEASE, FAIL, "can't free location")
-
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_OHDR, H5E_CANTRESET, H5I_INVALID_HID, "can't reset API context")
     FUNC_LEAVE_API(ret_value)
 } /* end H5Oopen_by_idx() */
 
@@ -239,36 +233,31 @@ done:
 hid_t
 H5Oopen_by_addr(hid_t loc_id, haddr_t addr)
 {
-    H5G_loc_t	loc;
-    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 */
-    hid_t       lapl_id = H5P_LINK_ACCESS_DEFAULT; /* lapl to use to open this object */
-    hid_t       ret_value = FAIL;
+    H5G_loc_t	loc;                    /* Location within file */
+hbool_t     api_ctx_pushed = FALSE;             /* Whether API context pushed */
+    hid_t       ret_value = H5I_INVALID_HID;	/* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE2("i", "ia", loc_id, addr);
 
     /* Check args */
     if(H5G_loc(loc_id, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not a location")
     if(!H5F_addr_defined(addr))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no address supplied")
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "no address supplied")
 
-    /* Set up opened group location to fill in */
-    obj_loc.oloc = &obj_oloc;
-    obj_loc.path = &obj_path;
-    H5G_loc_reset(&obj_loc);
-    obj_loc.oloc->addr = addr;
-    obj_loc.oloc->file = loc.oloc->file;
-    H5G_name_reset(obj_loc.path);       /* objects opened through this routine don't have a path name */
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, H5I_INVALID_HID, "can't set API context")
+api_ctx_pushed = TRUE;
 
     /* Open the object */
-    if((ret_value = H5O_open_by_loc(&obj_loc, lapl_id, H5AC_ind_read_dxpl_id, TRUE)) < 0)
+    if((ret_value = H5O__open_by_addr(&loc, addr)) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTOPENOBJ, FAIL, "unable to open object")
 
 done:
-
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_OHDR, H5E_CANTRESET, H5I_INVALID_HID, "can't reset API context")
     FUNC_LEAVE_API(ret_value)
 } /* end H5Oopen_by_addr() */
 
@@ -298,9 +287,9 @@ herr_t
 H5Olink(hid_t obj_id, hid_t new_loc_id, const char *new_name, hid_t lcpl_id,
     hid_t lapl_id)
 {
-    H5G_loc_t	new_loc;
-    H5G_loc_t	obj_loc;
-    hid_t       dxpl_id = H5AC_ind_read_dxpl_id; /* dxpl used by library */
+    H5G_loc_t	new_loc;		/* Location of group to link from */
+    H5G_loc_t	obj_loc;		/* Location of object to link to */
+hbool_t     api_ctx_pushed = FALSE;             /* Whether API context pushed */
     herr_t      ret_value = SUCCEED;       /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -323,15 +312,21 @@ H5Olink(hid_t obj_id, hid_t new_loc_id, const char *new_name, hid_t lcpl_id,
     if(lcpl_id != H5P_DEFAULT && (TRUE != H5P_isa_class(lcpl_id, H5P_LINK_CREATE)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a link creation property list")
 
-    /* Verify access property list and get correct dxpl */
-    if(H5P_verify_apl_and_dxpl(&lapl_id, H5P_CLS_LACC, &dxpl_id, obj_id, TRUE) < 0)
-        HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set access and transfer property lists")
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_OHDR, 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, obj_id, TRUE) < 0)
+    HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set access property list info")
 
-    /* Link to the object */
-    if(H5L_link(&new_loc, new_name, &obj_loc, lcpl_id, lapl_id, dxpl_id) < 0)
+    /* Create a link to the object */
+    if(H5O__create_link(&new_loc, new_name, &obj_loc, lcpl_id) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTINIT, FAIL, "unable to create link")
 
 done:
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_OHDR, H5E_CANTRESET, FAIL, "can't reset API context")
     FUNC_LEAVE_API(ret_value)
 } /* end H5Olink() */
 
@@ -359,8 +354,9 @@ done:
 herr_t
 H5Oincr_refcount(hid_t object_id)
 {
-    H5O_loc_t  *oloc;
-    herr_t      ret_value = SUCCEED;
+    H5O_loc_t  *oloc;			/* Object location */
+hbool_t     api_ctx_pushed = FALSE;             /* Whether API context pushed */
+    herr_t      ret_value = SUCCEED;	/* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE1("e", "i", object_id);
@@ -369,10 +365,21 @@ H5Oincr_refcount(hid_t object_id)
     if((oloc = H5O_get_loc(object_id)) == NULL)
         HGOTO_ERROR(H5E_ATOM, H5E_BADVALUE, FAIL, "unable to get object location from ID")
 
-    if(H5O_link(oloc, 1, H5AC_ind_read_dxpl_id) < 0)
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set API context")
+api_ctx_pushed = TRUE;
+/* Set up collective metadata if appropriate */
+if(H5CX_set_loc(object_id, TRUE) < 0)
+    HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set access property list info")
+
+    /* Change the object's refcount */
+    if(H5O__link(oloc, 1) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_LINKCOUNT, FAIL, "modifying object link count failed")
 
 done:
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_OHDR, H5E_CANTRESET, FAIL, "can't reset API context")
     FUNC_LEAVE_API(ret_value)
 } /* end H5O_incr_refcount() */
 
@@ -400,8 +407,9 @@ done:
 herr_t
 H5Odecr_refcount(hid_t object_id)
 {
-    H5O_loc_t  *oloc;
-    herr_t      ret_value = SUCCEED;
+    H5O_loc_t  *oloc;			/* Object location */
+hbool_t     api_ctx_pushed = FALSE;             /* Whether API context pushed */
+    herr_t      ret_value = SUCCEED;	/* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE1("e", "i", object_id);
@@ -410,10 +418,21 @@ H5Odecr_refcount(hid_t object_id)
     if((oloc = H5O_get_loc(object_id)) == NULL)
         HGOTO_ERROR(H5E_ATOM, H5E_BADVALUE, FAIL, "unable to get object location from ID")
 
-    if(H5O_link(oloc, -1, H5AC_ind_read_dxpl_id) < 0)
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set API context")
+api_ctx_pushed = TRUE;
+/* Set up collective metadata if appropriate */
+if(H5CX_set_loc(object_id, TRUE) < 0)
+    HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set access property list info")
+
+    /* Change the object's refcount */
+    if(H5O__link(oloc, -1) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_LINKCOUNT, FAIL, "modifying object link count failed")
 
 done:
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_OHDR, H5E_CANTRESET, FAIL, "can't reset API context")
     FUNC_LEAVE_API(ret_value)
 } /* end H5Odecr_refcount() */
 
@@ -435,7 +454,7 @@ htri_t
 H5Oexists_by_name(hid_t loc_id, const char *name, hid_t lapl_id)
 {
     H5G_loc_t	loc;                    /* Location info */
-    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 = FAIL;       /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -447,15 +466,21 @@ H5Oexists_by_name(hid_t loc_id, const char *name, hid_t lapl_id)
     if(!name || !*name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no 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_OHDR, H5E_CANTSET, FAIL, "can't set access and transfer property lists")
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_OHDR, 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_OHDR, H5E_CANTSET, FAIL, "can't set access property list info")
 
     /* Check if the object exists */
-    if((ret_value = H5G_loc_exists(&loc, name, lapl_id, dxpl_id)) < 0)
+    if((ret_value = H5O__exists_by_name(&loc, name)) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "unable to determine if '%s' exists", name)
 
 done:
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_OHDR, H5E_CANTRESET, FAIL, "can't reset API context")
     FUNC_LEAVE_API(ret_value)
 } /* end H5Oexists_by_name() */
 
@@ -477,6 +502,7 @@ herr_t
 H5Oget_info(hid_t loc_id, H5O_info_t *oinfo)
 {
     H5G_loc_t	loc;                    /* Location of group */
+hbool_t     api_ctx_pushed = FALSE;             /* Whether API context pushed */
     herr_t      ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -488,11 +514,18 @@ H5Oget_info(hid_t loc_id, H5O_info_t *oinfo)
     if(!oinfo)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no info struct")
 
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set API context")
+api_ctx_pushed = TRUE;
+
     /* Retrieve the object's information */
-    if(H5G_loc_info(&loc, ".", TRUE, oinfo/*out*/, H5P_LINK_ACCESS_DEFAULT, H5AC_ind_read_dxpl_id) < 0)
-        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "object not found")
+    if(H5O__get_info_by_name(&loc, ".", oinfo/*out*/) < 0)
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "can't get info for object")
 
 done:
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_OHDR, H5E_CANTRESET, FAIL, "can't reset API context")
     FUNC_LEAVE_API(ret_value)
 } /* end H5Oget_info() */
 
@@ -514,7 +547,7 @@ herr_t
 H5Oget_info_by_name(hid_t loc_id, const char *name, H5O_info_t *oinfo, hid_t lapl_id)
 {
     H5G_loc_t	loc;                    /* Location of group */
-    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)
@@ -528,15 +561,21 @@ H5Oget_info_by_name(hid_t loc_id, const char *name, H5O_info_t *oinfo, hid_t lap
     if(!oinfo)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no info struct")
 
-    /* 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_OHDR, H5E_CANTSET, FAIL, "can't set access and transfer property lists")
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_OHDR, 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_OHDR, H5E_CANTSET, FAIL, "can't set access property list info")
 
     /* Retrieve the object's information */
-    if(H5G_loc_info(&loc, name, TRUE, oinfo/*out*/, lapl_id, dxpl_id) < 0)
-        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "object not found")
+    if(H5O__get_info_by_name(&loc, name, oinfo/*out*/) < 0)
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "can't get info for object: '%s'", name)
 
 done:
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_OHDR, H5E_CANTRESET, FAIL, "can't reset API context")
     FUNC_LEAVE_API(ret_value)
 } /* end H5Oget_info_by_name() */
 
@@ -560,11 +599,7 @@ H5Oget_info_by_idx(hid_t loc_id, const char *group_name, H5_index_t idx_type,
     H5_iter_order_t order, hsize_t n, H5O_info_t *oinfo, hid_t lapl_id)
 {
     H5G_loc_t	loc;                    /* Location of group */
-    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 '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)
@@ -583,29 +618,21 @@ H5Oget_info_by_idx(hid_t loc_id, const char *group_name, H5_index_t idx_type,
     if(!oinfo)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no info struct")
 
-    /* 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_OHDR, 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, according to the order in the index */
-    if(H5G_loc_find_by_idx(&loc, group_name, idx_type, order, n, &obj_loc/*out*/, lapl_id, dxpl_id) < 0)
-        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "group not found")
-    loc_found = TRUE;
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_OHDR, 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_OHDR, H5E_CANTSET, FAIL, "can't set access property list info")
 
     /* Retrieve the object's information */
-    if(H5O_get_info(obj_loc.oloc, dxpl_id, TRUE, oinfo) < 0)
-        HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "can't retrieve object info")
+    if(H5O__get_info_by_idx(&loc, group_name, idx_type, order, n, oinfo) < 0)
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "can't get info for object")
 
 done:
-    /* Release the object location */
-    if(loc_found && H5G_loc_free(&obj_loc) < 0)
-        HDONE_ERROR(H5E_OHDR, H5E_CANTRELEASE, FAIL, "can't free location")
-
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_OHDR, H5E_CANTRESET, FAIL, "can't reset API context")
     FUNC_LEAVE_API(ret_value)
 } /* end H5Oget_info_by_idx() */
 
@@ -631,6 +658,7 @@ herr_t
 H5Oset_comment(hid_t obj_id, const char *comment)
 {
     H5G_loc_t	loc;                    /* Location of group */
+hbool_t     api_ctx_pushed = FALSE;             /* Whether API context pushed */
     herr_t      ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -640,11 +668,21 @@ H5Oset_comment(hid_t obj_id, const char *comment)
     if(H5G_loc(obj_id, &loc) < 0)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
 
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set API context")
+api_ctx_pushed = TRUE;
+/* Set up collective metadata if appropriate */
+if(H5CX_set_loc(obj_id, TRUE) < 0)
+    HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set collective metadata read info")
+
     /* (Re)set the object's comment */
-    if(H5G_loc_set_comment(&loc, ".", comment, H5P_LINK_ACCESS_DEFAULT, H5AC_ind_read_dxpl_id) < 0)
-        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "object not found")
+    if(H5O__set_comment_by_name(&loc, ".", comment) < 0)
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set comment for object")
 
 done:
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_OHDR, H5E_CANTRESET, FAIL, "can't reset API context")
     FUNC_LEAVE_API(ret_value)
 } /* end H5Oset_comment() */
 
@@ -671,7 +709,7 @@ H5Oset_comment_by_name(hid_t loc_id, const char *name, const char *comment,
     hid_t lapl_id)
 {
     H5G_loc_t	loc;                    /* Location of group */
-    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)
@@ -683,15 +721,21 @@ H5Oset_comment_by_name(hid_t loc_id, const char *name, const char *comment,
     if(!name || !*name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no 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_OHDR, H5E_CANTSET, FAIL, "can't set access and transfer property lists")
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_OHDR, 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_OHDR, H5E_CANTSET, FAIL, "can't set access property list info")
 
     /* (Re)set the object's comment */
-    if(H5G_loc_set_comment(&loc, name, comment, lapl_id, dxpl_id) < 0)
-        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "object not found")
+    if(H5O__set_comment_by_name(&loc, name, comment) < 0)
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set comment for object: '%s'", name)
 
 done:
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_OHDR, H5E_CANTRESET, FAIL, "can't reset API context")
     FUNC_LEAVE_API(ret_value)
 } /* end H5Oset_comment_by_name() */
 
@@ -716,6 +760,7 @@ ssize_t
 H5Oget_comment(hid_t obj_id, char *comment, size_t bufsize)
 {
     H5G_loc_t	loc;                    /* Location of group */
+hbool_t     api_ctx_pushed = FALSE;             /* Whether API context pushed */
     ssize_t     ret_value;              /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -725,11 +770,18 @@ H5Oget_comment(hid_t obj_id, char *comment, size_t bufsize)
     if(H5G_loc(obj_id, &loc) < 0)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
 
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set API context")
+api_ctx_pushed = TRUE;
+
     /* Retrieve the object's comment */
-    if((ret_value = H5G_loc_get_comment(&loc, ".", comment/*out*/, bufsize, H5P_LINK_ACCESS_DEFAULT, H5AC_ind_read_dxpl_id)) < 0)
-        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "object not found")
+    if((ret_value = H5O__get_comment_by_name(&loc, ".", comment/*out*/, bufsize)) < 0)
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "can't get comment for object")
 
 done:
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_OHDR, H5E_CANTRESET, FAIL, "can't reset API context")
     FUNC_LEAVE_API(ret_value)
 } /* end H5Oget_comment() */
 
@@ -755,7 +807,7 @@ H5Oget_comment_by_name(hid_t loc_id, const char *name, char *comment, size_t buf
     hid_t lapl_id)
 {
     H5G_loc_t	loc;                    /* Location of group */
-    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)
@@ -767,15 +819,21 @@ H5Oget_comment_by_name(hid_t loc_id, const char *name, char *comment, size_t buf
     if(!name || !*name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no 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_OHDR, H5E_CANTSET, FAIL, "can't set access and transfer property lists")
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_OHDR, 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_OHDR, H5E_CANTSET, FAIL, "can't set access property list info")
 
     /* Retrieve the object's comment */
-    if((ret_value = H5G_loc_get_comment(&loc, name, comment/*out*/, bufsize, lapl_id, dxpl_id)) < 0)
-        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "object not found")
+    if((ret_value = H5O__get_comment_by_name(&loc, name, comment/*out*/, bufsize)) < 0)
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "can't get comment for object: '%s'", name)
 
 done:
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_OHDR, H5E_CANTRESET, FAIL, "can't reset API context")
     FUNC_LEAVE_API(ret_value)
 } /* end H5Oget_comment_by_name() */
 
@@ -816,6 +874,7 @@ herr_t
 H5Ovisit(hid_t obj_id, H5_index_t idx_type, H5_iter_order_t order,
     H5O_iterate_t op, void *op_data)
 {
+hbool_t     api_ctx_pushed = FALSE;             /* Whether API context pushed */
     herr_t      ret_value;              /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -829,11 +888,18 @@ H5Ovisit(hid_t obj_id, H5_index_t idx_type, H5_iter_order_t order,
     if(!op)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no callback operator specified")
 
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set API context")
+api_ctx_pushed = TRUE;
+
     /* Call internal object visitation routine */
-    if((ret_value = H5O_visit(obj_id, ".", idx_type, order, op, op_data, H5P_LINK_ACCESS_DEFAULT, H5AC_ind_read_dxpl_id)) < 0)
+    if((ret_value = H5O__visit(obj_id, ".", idx_type, order, op, op_data)) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_BADITER, FAIL, "object visitation failed")
 
 done:
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_OHDR, H5E_CANTRESET, FAIL, "can't reset API context")
     FUNC_LEAVE_API(ret_value)
 } /* end H5Ovisit() */
 
@@ -874,7 +940,7 @@ herr_t
 H5Ovisit_by_name(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
     H5_iter_order_t order, H5O_iterate_t op, void *op_data, hid_t lapl_id)
 {
-    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)
@@ -891,15 +957,21 @@ H5Ovisit_by_name(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
     if(!op)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no callback operator 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_OHDR, H5E_CANTSET, FAIL, "can't set access and transfer property lists")
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_OHDR, 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_OHDR, H5E_CANTSET, FAIL, "can't set access property list info")
 
     /* Call internal object visitation routine */
-    if((ret_value = H5O_visit(loc_id, obj_name, idx_type, order, op, op_data, lapl_id, dxpl_id)) < 0)
+    if((ret_value = H5O__visit(loc_id, obj_name, idx_type, order, op, op_data)) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_BADITER, FAIL, "object visitation failed")
 
 done:
+if(api_ctx_pushed && H5CX_pop() < 0)
+    HDONE_ERROR(H5E_OHDR, H5E_CANTRESET, FAIL, "can't reset API context")
     FUNC_LEAVE_API(ret_value)
 } /* end H5Ovisit_by_name() */
 
@@ -925,6 +997,7 @@ done:
 herr_t
 H5Oclose(hid_t object_id)
 {
+hbool_t     api_ctx_pushed = FALSE;             /* Whether API context pushed */
     herr_t       ret_value = SUCCEED;
 
     FUNC_ENTER_API(FAIL)
@@ -937,6 +1010,10 @@ H5Oclose(hid_t object_id)
         case H5I_DATASET:
             if(H5I_object(object_id) == NULL)
                 HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "not a valid object")
+/* Set API context */
+if(H5CX_push() < 0)
+    HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, FAIL, "can't set API context")
+api_ctx_pushed = TRUE;
             if(H5I_dec_app_ref(object_id) < 0)
                 HGOTO_ERROR(H5E_OHDR, H5E_CANTRELEASE, FAIL, "unable to close object")
             break;
@@ -960,6 +1037,8 @@ H5Oclose(hid_t object_id)
     } /* end switch */
 
 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)
 } /* end H5Oclose() */