Add API routines to retrieve, restore, reset, and free library state.

(Primarily for use in the async VOL connector, which has to schedule API
operations for future execution and then restore the state of the library when
the operation actually executes)

1 files changed, 246 insertions, 20 deletions

diff --git a/src/H5CX.c b/src/H5CX.c
index c97bdcd..b56d66d 100644
--- a/src/H5CX.c
+++ b/src/H5CX.c
@@ -64,17 +64,22 @@
 #define H5CX_get_my_context() (&H5CX_head_g)
 #endif /* H5_HAVE_THREADSAFE */
 
+/* Common macro for the retrieving the pointer to a property list */
+#define H5CX_RETRIEVE_PLIST(PL, FAILVAL)                                      \
+    /* Check if the property list is already available */                     \
+    if(NULL == (*head)->ctx.PL)                                               \
+        /* Get the property list pointer */                                   \
+        if(NULL == ((*head)->ctx.PL = (H5P_genplist_t *)H5I_object((*head)->ctx.H5_GLUE(PL,_id)))) \
+            HGOTO_ERROR(H5E_CONTEXT, H5E_BADTYPE, (FAILVAL), "can't get property list")
+
 /* Common macro for the duplicated code to retrieve properties from a property list */
 #define H5CX_RETRIEVE_PROP_COMMON(PL, DEF_PL, PROP_NAME, PROP_FIELD)          \
     /* Check for default property list */                                     \
     if((*head)->ctx.H5_GLUE(PL,_id) == (DEF_PL))                              \
         HDmemcpy(&(*head)->ctx.PROP_FIELD, &H5_GLUE3(H5CX_def_,PL,_cache).PROP_FIELD, sizeof(H5_GLUE3(H5CX_def_,PL,_cache).PROP_FIELD)); \
     else {                                                                    \
-        /* Check if the property list is already available */                 \
-        if(NULL == (*head)->ctx.PL)                                           \
-            /* Get the dataset transfer property list pointer */              \
-            if(NULL == ((*head)->ctx.PL = (H5P_genplist_t *)H5I_object((*head)->ctx.H5_GLUE(PL,_id)))) \
-                HGOTO_ERROR(H5E_CONTEXT, H5E_BADTYPE, FAIL, "can't get default dataset transfer property list") \
+        /* Retrieve the property list */                                      \
+        H5CX_RETRIEVE_PLIST(PL, FAIL)                                         \
                                                                               \
         /* Get the property */                                                \
         if(H5P_get((*head)->ctx.PL, (PROP_NAME), &(*head)->ctx.PROP_FIELD) < 0) \
@@ -108,11 +113,8 @@
                                                                               \
     /* Check if property exists in DXPL */                                    \
     if(!(*head)->ctx.H5_GLUE(PROP_FIELD,_set)) {                              \
-        /* Check if the property list is already available */                 \
-        if(NULL == (*head)->ctx.dxpl)                                         \
-            /* Get the dataset transfer property list pointer */              \
-            if(NULL == ((*head)->ctx.dxpl = (H5P_genplist_t *)H5I_object((*head)->ctx.dxpl_id))) \
-                HGOTO_ERROR(H5E_CONTEXT, H5E_BADTYPE, FAIL, "can't get default dataset transfer property list") \
+        /* Retrieve the dataset transfer property list */                     \
+        H5CX_RETRIEVE_PLIST(dxpl, FAIL)                                       \
                                                                               \
         if((check_prop = H5P_exist_plist((*head)->ctx.dxpl, PROP_NAME)) < 0)  \
             HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "error checking for property") \
@@ -129,15 +131,12 @@
 /* Macro for the duplicated code to test and set properties for a property list */
 #define H5CX_SET_PROP(PROP_NAME, PROP_FIELD)                                  \
     if((*head)->ctx.H5_GLUE(PROP_FIELD,_set)) {                               \
-        /* Check if the property list is already available */                 \
-        if(NULL == (*head)->ctx.dxpl)                                         \
-            /* Get the dataset transfer property list pointer */              \
-            if(NULL == ((*head)->ctx.dxpl = (H5P_genplist_t *)H5I_object((*head)->ctx.dxpl_id))) \
-                HGOTO_ERROR(H5E_CONTEXT, H5E_BADTYPE, NULL, "can't get default dataset transfer property list") \
+        /* Retrieve the dataset transfer property list */                     \
+        H5CX_RETRIEVE_PLIST(dxpl, NULL)                                       \
                                                                               \
-        /* Set the chunk filter mask property */                              \
+        /* Set the property */                              		      \
         if(H5P_set((*head)->ctx.dxpl, PROP_NAME, &(*head)->ctx.PROP_FIELD) < 0) \
-            HGOTO_ERROR(H5E_CONTEXT, H5E_CANTSET, NULL, "error setting filter mask xfer property") \
+            HGOTO_ERROR(H5E_CONTEXT, H5E_CANTSET, NULL, "error setting data xfer property") \
     } /* end if */
 #endif /* H5_HAVE_PARALLEL */
 
@@ -175,7 +174,7 @@
  *      corresponding property in the property list to be set when the API
  *      context is popped, when returning from the API routine.  Note that the
  *      naming of these fields, <foo> and <foo>_set, is important for the
-*       H5CX_TEST_SET_PROP and H5CX_SET_PROP macros to work properly.
+ *      H5CX_TEST_SET_PROP and H5CX_SET_PROP macros to work properly.
  */
 typedef struct H5CX_t {
     /* DXPL */
@@ -378,6 +377,9 @@ static H5CX_dcpl_cache_t H5CX_def_dcpl_cache;
 /* Declare a static free list to manage H5CX_node_t structs */
 H5FL_DEFINE_STATIC(H5CX_node_t);
 
+/* Declare a static free list to manage H5CX_state_t structs */
+H5FL_DEFINE_STATIC(H5CX_state_t);
+
 
 
 /*--------------------------------------------------------------------------
@@ -709,6 +711,226 @@ H5CX_push_special(void)
 
 
 /*-------------------------------------------------------------------------
+ * Function:    H5CX_retrieve_state
+ *
+ * Purpose:     Retrieve the state of an API context, for later resumption.
+ *
+ * Note:	This routine _only_ tracks the state of API context information
+ *		set before the VOL callback is invoked, not values that are
+ *		set internal to the library.  It's main purpose is to provide
+ *		API context state to VOL connectors.
+ *
+ * Return:      Non-negative on success / Negative on failure
+ *
+ * Programmer:  Quincey Koziol
+ *              January 8, 2019
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5CX_retrieve_state(H5CX_state_t **api_state)
+{
+    H5CX_node_t **head = H5CX_get_my_context();  /* Get the pointer to the head of the API context, for this thread */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity check */
+    HDassert(head && *head);
+    HDassert(api_state);
+
+    /* Allocate & clear API context state */
+    if(NULL == (*api_state = H5FL_CALLOC(H5CX_state_t)))
+        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTALLOC, FAIL, "unable to allocate new API context state")
+
+    /* Check for non-default DXPL */
+    if(H5P_DATASET_XFER_DEFAULT != (*head)->ctx.dxpl_id) {
+        /* Retrieve the DXPL property list */
+        H5CX_RETRIEVE_PLIST(dxpl, FAIL)
+
+        /* Copy the DXPL ID */
+        if(((*api_state)->dxpl_id = H5P_copy_plist((H5P_genplist_t *)(*head)->ctx.dxpl, FALSE)) < 0)
+            HGOTO_ERROR(H5E_CONTEXT, H5E_CANTCOPY, FAIL, "can't copy property list")
+    } /* end if */
+    else
+        (*api_state)->dxpl_id = H5P_DATASET_XFER_DEFAULT;
+
+    /* Check for non-default LAPL */
+    if(H5P_LINK_ACCESS_DEFAULT != (*head)->ctx.lapl_id) {
+        /* Retrieve the LAPL property list */
+        H5CX_RETRIEVE_PLIST(lapl, FAIL)
+
+        /* Copy the LAPL ID */
+        if(((*api_state)->lapl_id = H5P_copy_plist((H5P_genplist_t *)(*head)->ctx.lapl, FALSE)) < 0)
+            HGOTO_ERROR(H5E_CONTEXT, H5E_CANTCOPY, FAIL, "can't copy property list")
+    } /* end if */
+    else
+        (*api_state)->lapl_id = H5P_LINK_ACCESS_DEFAULT;
+
+    /* Keep a reference to the current VOL wrapping context */
+    (*api_state)->vol_wrap_ctx = (*head)->ctx.vol_wrap_ctx;
+    if(NULL != (*api_state)->vol_wrap_ctx)
+        if(H5VL_inc_vol_wrapper((*api_state)->vol_wrap_ctx) < 0)
+            HGOTO_ERROR(H5E_CONTEXT, H5E_CANTINC, FAIL, "can't increment refcount on VOL wrapping context")
+
+    /* Keep a copy of the VOL connector property, if there is one */
+    if((*head)->ctx.vol_connector_prop_valid && (*head)->ctx.vol_connector_prop.connector_id > 0) {
+        /* Get the connector property */
+        HDmemcpy(&(*api_state)->vol_connector_prop, &(*head)->ctx.vol_connector_prop, sizeof(H5VL_connector_prop_t));
+
+        /* Check for actual VOL connector property */
+        if((*api_state)->vol_connector_prop.connector_id) {
+            /* Copy connector info, if it exists */
+            if((*api_state)->vol_connector_prop.connector_info) {
+                H5VL_class_t *connector;           /* Pointer to connector */
+                void *new_connector_info = NULL;    /* Copy of connector info */
+
+                /* Retrieve the connector for the ID */
+                if(NULL == (connector = (H5VL_class_t *)H5I_object((*api_state)->vol_connector_prop.connector_id)))
+                    HGOTO_ERROR(H5E_CONTEXT, H5E_BADTYPE, FAIL, "not a VOL connector ID")
+
+                /* Allocate and copy connector info */
+                if(H5VL_copy_connector_info(connector, &new_connector_info, (*api_state)->vol_connector_prop.connector_info) < 0)
+                    HGOTO_ERROR(H5E_CONTEXT, H5E_CANTCOPY, FAIL, "connector info copy failed")
+                (*api_state)->vol_connector_prop.connector_info = new_connector_info;
+            } /* end if */
+
+            /* Increment the refcount on the connector ID */
+            if(H5I_inc_ref((*api_state)->vol_connector_prop.connector_id, FALSE) < 0)
+                HGOTO_ERROR(H5E_CONTEXT, H5E_CANTINC, FAIL, "incrementing VOL connector ID failed")
+        } /* end if */
+    } /* end if */
+
+#ifdef H5_HAVE_PARALLEL
+    /* Save parallel I/O settings */
+    (*api_state)->coll_metadata_read = (*head)->ctx.coll_metadata_read;
+#endif /* H5_HAVE_PARALLEL */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5CX_retrieve_state() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5CX_restore_state
+ *
+ * Purpose:     Restore an API context, from a previously retrieved state.
+ *
+ * Note:	This routine _only_ resets the state of API context information
+ *		set before the VOL callback is invoked, not values that are
+ *		set internal to the library.  It's main purpose is to restore
+ *		API context state from VOL connectors.
+ *
+ * Return:      Non-negative on success / Negative on failure
+ *
+ * Programmer:  Quincey Koziol
+ *              January 9, 2019
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5CX_restore_state(const H5CX_state_t *api_state)
+{
+    H5CX_node_t **head = H5CX_get_my_context();  /* Get the pointer to the head of the API context, for this thread */
+
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    /* Sanity check */
+    HDassert(head && *head);
+    HDassert(api_state);
+
+    /* Restore the DXPL info */
+    (*head)->ctx.dxpl_id = api_state->dxpl_id;
+    (*head)->ctx.dxpl = NULL;
+
+    /* Restore the LAPL info */
+    (*head)->ctx.lapl_id = api_state->lapl_id;
+    (*head)->ctx.lapl = NULL;
+
+    /* Restore the VOL wrapper context */
+    (*head)->ctx.vol_wrap_ctx = api_state->vol_wrap_ctx;
+
+    /* Restore the VOL connector info */
+    if(api_state->vol_connector_prop.connector_id) {
+        HDmemcpy(&(*head)->ctx.vol_connector_prop, &api_state->vol_connector_prop, sizeof(H5VL_connector_prop_t));
+        (*head)->ctx.vol_connector_prop_valid = TRUE;
+    } /* end if */
+
+#ifdef H5_HAVE_PARALLEL
+    /* Restore parallel I/O settings */
+    (*head)->ctx.coll_metadata_read = api_state->coll_metadata_read;
+#endif /* H5_HAVE_PARALLEL */
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5CX_restore_state() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5CX_free_state
+ *
+ * Purpose:     Free a previously retrievedAPI context state
+ *
+ * Return:      Non-negative on success / Negative on failure
+ *
+ * Programmer:  Quincey Koziol
+ *              January 9, 2019
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5CX_free_state(H5CX_state_t *api_state)
+{
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity check */
+    HDassert(api_state);
+
+    /* Release the DXPL */
+    if(api_state->dxpl_id != H5P_DATASET_XFER_DEFAULT)
+        if(H5I_dec_ref(api_state->dxpl_id) < 0)
+            HGOTO_ERROR(H5E_CONTEXT, H5E_CANTDEC, FAIL, "can't decrement refcount on DXPL")
+
+    /* Release the LAPL */
+    if(api_state->lapl_id != H5P_LINK_ACCESS_DEFAULT)
+        if(H5I_dec_ref(api_state->lapl_id) < 0)
+            HGOTO_ERROR(H5E_CONTEXT, H5E_CANTDEC, FAIL, "can't decrement refcount on LAPL")
+
+    /* Release the VOL wrapper context */
+    if(api_state->vol_wrap_ctx)
+        if(H5VL_dec_vol_wrapper(api_state->vol_wrap_ctx) < 0)
+            HGOTO_ERROR(H5E_CONTEXT, H5E_CANTDEC, FAIL, "can't decrement refcount on VOL wrapping context")
+
+    /* Release the VOL connector property, if it was set */
+    if(api_state->vol_connector_prop.connector_id) {
+        /* Clean up any VOL connector info */
+        if(api_state->vol_connector_prop.connector_info) {
+            H5VL_class_t *connector;       /* Pointer to connector */
+
+            /* Retrieve the connector for the ID */
+            if(NULL == (connector = (H5VL_class_t *)H5I_object(api_state->vol_connector_prop.connector_id)))
+                HGOTO_ERROR(H5E_CONTEXT, H5E_BADTYPE, FAIL, "not a VOL connector ID")
+
+            /* Free the connector info */
+            if(H5VL_free_connector_info(connector, api_state->vol_connector_prop.connector_info) < 0)
+                HGOTO_ERROR(H5E_CONTEXT, H5E_CANTRELEASE, FAIL, "unable to release VOL connector info object")
+        } /* end if */
+
+        /* Decrement connector ID */
+        if(H5I_dec_ref(api_state->vol_connector_prop.connector_id) < 0)
+            HDONE_ERROR(H5E_CONTEXT, H5E_CANTDEC, FAIL, "can't close VOL connector ID")
+    } /* end if */
+
+    /* Free the state */
+    api_state = H5FL_FREE(H5CX_state_t, api_state);
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5CX_free_state() */
+
+
+/*-------------------------------------------------------------------------
  * Function:    H5CX_is_def_dxpl
  *
  * Purpose:     Checks if the API context is using the library's default DXPL
@@ -951,6 +1173,7 @@ H5CX_set_loc(hid_t
 #endif /* H5_HAVE_PARALLEL */
    loc_id)
 {
+#ifdef H5_HAVE_PARALLEL
     H5CX_node_t **head = H5CX_get_my_context();  /* Get the pointer to the head of the API context, for this thread */
     herr_t ret_value = SUCCEED;         /* Return value */
 
@@ -959,7 +1182,6 @@ H5CX_set_loc(hid_t
     /* Sanity check */
     HDassert(head && *head);
 
-#ifdef H5_HAVE_PARALLEL
     /* Set collective metadata read flag */
     (*head)->ctx.coll_metadata_read = TRUE;
 
@@ -980,10 +1202,14 @@ H5CX_set_loc(hid_t
         if(mpi_comm != MPI_COMM_NULL)
             MPI_Barrier(mpi_comm);
     } /* end if */
-#endif /* H5_HAVE_PARALLEL */
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
+#else /* H5_HAVE_PARALLEL */
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+#endif /* H5_HAVE_PARALLEL */
 } /* end H5CX_set_loc() */