path: root/src/H5CX.c

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * Copyright by The HDF Group.                                               *
 * All rights reserved.                                                      *
 *                                                                           *
 * This file is part of HDF5.  The full HDF5 copyright notice, including     *
 * terms governing use, modification, and redistribution, is contained in    *
 * the COPYING file, which can be found at the root of the source code       *
 * distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.  *
 * If you do not have access to either file, you may request a copy from     *
 * help@hdfgroup.org.                                                        *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/*
 * Programmer:  Quincey Koziol <koziol@lbl.gov>
 *              Monday, February 19, 2018
 *
 * Purpose:
 *      Keep a set of "psuedo-global" information for an API call.  This
 *      general corresponds to the DXPL for the call, along with cached
 *      information from them.
 */

/****************/
/* Module Setup */
/****************/

#include "H5CXmodule.h"          /* This source code file is part of the H5CX module */



/***********/
/* Headers */
/***********/
#include "H5private.h"          /* Generic Functions                    */
#include "H5CXprivate.h"        /* API Contexts                         */
#include "H5Dprivate.h"		/* Datasets				*/
#include "H5Eprivate.h"         /* Error handling                       */
#include "H5FLprivate.h"        /* Free Lists                           */
#include "H5Iprivate.h"         /* IDs                                  */
#include "H5Lprivate.h"		/* Links		  		*/
#include "H5MMprivate.h"        /* Memory management                    */
#include "H5Pprivate.h"         /* Property lists                       */


/****************/
/* Local Macros */
/****************/

#ifdef H5_HAVE_THREADSAFE
/*
 * The per-thread API context. pthread_once() initializes a special
 * key that will be used by all threads to create a stack specific to
 * each thread individually. The association of contexts to threads will
 * be handled by the pthread library.
 *
 * In order for this macro to work, H5E_get_my_stack() must be preceeded
 * by "H5CX_node_t *ctx =".
 */
#define H5CX_get_my_context()  H5CX__get_context()
#else /* H5_HAVE_THREADSAFE */
/*
 * The current API context.
 */
#define H5CX_get_my_context() (H5CX_head_g)
#endif /* H5_HAVE_THREADSAFE */

/* 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") \
                                                                              \
        /* Get the property */                                                \
        if(H5P_get((*head)->ctx.PL, (PROP_NAME), &(*head)->ctx.PROP_FIELD) < 0) \
            HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "can't retrieve value from API context") \
    } /* end else */                                                          \
                                                                              \
    /* Mark the field as valid */                                             \
    (*head)->ctx.H5_GLUE(PROP_FIELD,_valid) = TRUE;

/* Macro for the duplicated code to retrieve properties from a property list */
#define H5CX_RETRIEVE_PROP_VALID(PL, DEF_PL, PROP_NAME, PROP_FIELD)           \
    /* Check if the value has been retrieved already */                       \
    if(!(*head)->ctx.H5_GLUE(PROP_FIELD,_valid)) {                            \
        H5CX_RETRIEVE_PROP_COMMON(PL, DEF_PL, PROP_NAME, PROP_FIELD)          \
    } /* end if */

#ifdef H5_HAVE_PARALLEL
/* Macro for the duplicated code to retrieve possibly set properties from a property list */
#define H5CX_RETRIEVE_PROP_VALID_SET(PL, DEF_PL, PROP_NAME, PROP_FIELD)       \
    /* Check if the value has been retrieved already */                       \
    if(!((*head)->ctx.H5_GLUE(PROP_FIELD,_valid) || (*head)->ctx.H5_GLUE(PROP_FIELD,_set))) { \
        H5CX_RETRIEVE_PROP_COMMON(PL, DEF_PL, PROP_NAME, PROP_FIELD)          \
    } /* end if */
#endif /* H5_HAVE_PARALLEL */

#ifdef H5_HAVE_PARALLEL
/* Macro for the duplicated code to test and set properties for a property list */
#define H5CX_TEST_SET_PROP(PROP_NAME, PROP_FIELD)                             \
{                                                                             \
    htri_t check_prop = 0;              /* Whether the property exists in the API context's DXPL */ \
                                                                              \
    /* 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") \
                                                                              \
        if((check_prop = H5P_exist_plist((*head)->ctx.dxpl, PROP_NAME)) < 0)  \
            HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "error checking for property") \
    } /* end if */                                                            \
                                                                              \
    /* If property was already set or exists (for first set), update it */    \
    if((*head)->ctx.H5_GLUE(PROP_FIELD,_set) || check_prop > 0) {             \
        /* Cache the value for later, marking it to set in DXPL when context popped */ \
        (*head)->ctx.PROP_FIELD = PROP_FIELD;                                 \
        (*head)->ctx.H5_GLUE(PROP_FIELD,_set) = TRUE;                         \
    } /* end if */                                                            \
}
#endif /* H5_HAVE_PARALLEL */

/* 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") \
                                                                              \
        /* Set the chunk filter mask 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") \
    } /* end if */


/******************/
/* Local Typedefs */
/******************/

/* Typedef for context about each API call, as it proceeds */
/* Fields in this struct are of several types:
 * - The DXPL & LAPL ID are either library default ones (from the API context
 *      initialization) or passed in from the application via an API call
 *      parameter.  The corresponding H5P_genplist_t* is just the underlying
 *      property list struct for the ID, to optimize retrieving properties
 *      from the list multiple times.
 *
 * - Internal fields, used and set only within the library, for managing the
 *      operation under way.  These do not correspond to properties in the
 *      DXPL or LAPL and can have any name.
 *
 * - Cached fields, which are not returned to the application, for managing
 *      the operation under way.  These correspond to properties in the DXPL
 *      or LAPL, and are retrieved either from the (global) cache for a
 *      default property list, or from the corresponding property in the
 *      application's (non-default) property list.  Getting / setting these
 *      properties within the library does _not_ affect the application's
 *      property list.  Note that the naming of these fields, <foo> and
 *      <foo>_valid, is important for the H5CX_RETRIEVE_PROP_VALID ahd
 *      H5CX_RETRIEVE_PROP_VALID_SET macros to work properly.
 *
 * - "Return-only"" properties that are returned to the application, mainly
 *      for sending out "introspection" information ("Why did collective I/O
 *      get broken for this operation?", "Which filters are set on the chunk I
 *      just directly read in?", etc) Setting these fields will cause the
 *      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.
 */
typedef struct H5CX_t {
    /* DXPL */
    hid_t dxpl_id;              /* DXPL ID for API operation */
    H5P_genplist_t *dxpl;       /* Dataset Transfer Property List */

    /* LAPL */
    hid_t lapl_id;              /* LAPL ID for API operation */
    H5P_genplist_t *lapl;       /* Link Access Property List */

    /* Internal: Object tagging info */
    haddr_t tag;                /* Current object's tag (ohdr chunk #0 address) */

    /* Internal: Metadata cache info */
    H5AC_ring_t ring;           /* Current metadata cache ring for entries */

#ifdef H5_HAVE_PARALLEL
    /* Internal: Parallel I/O settings */
    hbool_t coll_metadata_read; /* Whether to use collective I/O for metadata read */
    MPI_Datatype btype;         /* MPI datatype for buffer, when using collective I/O */
    MPI_Datatype ftype;         /* MPI datatype for file, when using collective I/O */
    hbool_t mpi_file_flushing;  /* Whether an MPI-opened file is being flushed */
#endif /* H5_HAVE_PARALLEL */

    /* Cached DXPL properties */
    size_t max_temp_buf;        /* Maximum temporary buffer size */
    hbool_t max_temp_buf_valid; /* Whether maximum temporary buffer size is valid */
    void *tconv_buf;            /* Temporary conversion buffer (H5D_XFER_TCONV_BUF_NAME) */
    hbool_t tconv_buf_valid;    /* Whether temporary conversion buffer is valid */
    void *bkgr_buf;             /* Background conversion buffer (H5D_XFER_BKGR_BUF_NAME) */
    hbool_t bkgr_buf_valid;     /* Whether background conversion buffer is valid */
    H5T_bkg_t bkgr_buf_type;    /* Background buffer type (H5D_XFER_BKGR_BUF_NAME) */
    hbool_t bkgr_buf_type_valid;/* Whether background buffer type is valid */
    double btree_split_ratio[3];        /* B-tree split ratios */
    hbool_t btree_split_ratio_valid;    /* Whether B-tree split ratios are valid */
    size_t vec_size;            /* Size of hyperslab vector (H5D_XFER_HYPER_VECTOR_SIZE_NAME) */
    hbool_t vec_size_valid;     /* Whether hyperslab vector is valid */
#ifdef H5_HAVE_PARALLEL
    H5FD_mpio_xfer_t io_xfer_mode; /* Parallel transfer mode for this request (H5D_XFER_IO_XFER_MODE_NAME) */
    hbool_t io_xfer_mode_valid; /* Whether parallel transfer mode is valid */
    H5FD_mpio_collective_opt_t mpio_coll_opt; /* Parallel transfer with independent IO or collective IO with this mode (H5D_XFER_MPIO_COLLECTIVE_OPT_NAME) */
    hbool_t mpio_coll_opt_valid; /* Whether parallel transfer option is valid */
    H5FD_mpio_chunk_opt_t mpio_chunk_opt_mode; /* Collective chunk option (H5D_XFER_MPIO_CHUNK_OPT_HARD_NAME) */
    hbool_t mpio_chunk_opt_mode_valid; /* Whether collective chunk option is valid */
    unsigned mpio_chunk_opt_num; /* Collective chunk thrreshold (H5D_XFER_MPIO_CHUNK_OPT_NUM_NAME) */
    hbool_t mpio_chunk_opt_num_valid; /* Whether collective chunk threshold is valid */
    unsigned mpio_chunk_opt_ratio; /* Collective chunk ratio (H5D_XFER_MPIO_CHUNK_OPT_RATIO_NAME) */
    hbool_t mpio_chunk_opt_ratio_valid; /* Whether collective chunk ratio is valid */
#endif /* H5_HAVE_PARALLEL */
    H5Z_EDC_t err_detect;       /* Error detection info (H5D_XFER_EDC_NAME) */
    hbool_t err_detect_valid;   /* Whether error detection info is valid */
    H5Z_cb_t filter_cb;         /* Filter callback function (H5D_XFER_FILTER_CB_NAME) */
    hbool_t filter_cb_valid;    /* Whether filter callback function is valid */
    H5Z_data_xform_t *data_transform; /* Data transform info (H5D_XFER_XFORM_NAME) */
    hbool_t data_transform_valid; /* Whether data transform info is valid */
    H5T_vlen_alloc_info_t vl_alloc_info; /* VL datatype alloc info (H5D_XFER_VLEN_*_NAME) */
    hbool_t vl_alloc_info_valid; /* Whether VL datatype alloc info is valid */
    hbool_t dcr_flag;           /* Direct chunk read flag (H5D_XFER_DIRECT_CHUNK_READ_FLAG_NAME) */
    hbool_t dcr_flag_valid;     /* Whether direct chunk read flag is valid */
    hsize_t *dcr_offset;        /* Direct chunk read offset (H5D_XFER_DIRECT_CHUNK_READ_OFFSET_NAME) */
    hbool_t dcr_offset_valid;   /* Whether direct chunk read offset is valid */
    hbool_t dcw_flag;           /* Direct chunk write flag (H5D_XFER_DIRECT_CHUNK_WRITE_FLAG_NAME) */
    hbool_t dcw_flag_valid;     /* Whether direct chunk write flag is valid */
    uint32_t dcw_filters;       /* Direct chunk write filter flags (H5D_XFER_DIRECT_CHUNK_WRITE_FILTERS_NAME) */
    hbool_t dcw_filters_valid;  /* Whether direct chunk write filter flags is valid */
    hsize_t *dcw_offset;        /* Direct chunk write offset (H5D_XFER_DIRECT_CHUNK_WRITE_OFFSET_NAME) */
    hbool_t dcw_offset_valid;   /* Whether direct chunk write offset is valid */
    uint32_t dcw_datasize;      /* Direct chunk write data size (H5D_XFER_DIRECT_CHUNK_WRITE_DATASIZE_NAME) */
    hbool_t dcw_datasize_valid; /* Whether direct chunk write data size is valid */
    H5T_conv_cb_t dt_conv_cb;   /* Datatype conversion struct (H5D_XFER_CONV_CB_NAME) */
    hbool_t dt_conv_cb_valid;   /* Whether datatype conversion struct is valid */

    /* Return-only DXPL properties to return to application */
    uint32_t dcr_filters;       /* Direct chunk read filter flags (H5D_XFER_DIRECT_CHUNK_READ_FILTERS_NAME) */
    hbool_t dcr_filters_set;    /* Whether direct chunk read filter flags are set */
#ifdef H5_HAVE_PARALLEL
    H5D_mpio_actual_chunk_opt_mode_t mpio_actual_chunk_opt; /* Chunk optimization mode used for parallel I/O (H5D_MPIO_ACTUAL_CHUNK_OPT_MODE_NAME) */
    hbool_t mpio_actual_chunk_opt_set; /* Whether chunk optimization mode used for parallel I/O is set */
    H5D_mpio_actual_io_mode_t mpio_actual_io_mode; /* Actual I/O mode used for parallel I/O (H5D_MPIO_ACTUAL_IO_MODE_NAME) */
    hbool_t mpio_actual_io_mode_set; /* Whether actual I/O mode used for parallel I/O is set */
    uint32_t mpio_local_no_coll_cause; /* Local reason for breaking collective I/O (H5D_MPIO_LOCAL_NO_COLLECTIVE_CAUSE_NAME) */
    hbool_t mpio_local_no_coll_cause_set; /* Whether local reason for breaking collective I/O is set */
    hbool_t mpio_local_no_coll_cause_valid; /* Whether local reason for breaking collective I/O is valid */
    uint32_t mpio_global_no_coll_cause; /* Global reason for breaking collective I/O (H5D_MPIO_GLOBAL_NO_COLLECTIVE_CAUSE_NAME) */
    hbool_t mpio_global_no_coll_cause_set; /* Whether global reason for breaking collective I/O is set */
    hbool_t mpio_global_no_coll_cause_valid; /* Whether global reason for breaking collective I/O is valid */
#ifdef H5_HAVE_INSTRUMENTED_LIBRARY
    int mpio_coll_chunk_link_hard;  /* Instrumented "collective chunk link hard" value (H5D_XFER_COLL_CHUNK_LINK_HARD_NAME) */
    hbool_t mpio_coll_chunk_link_hard_set; /* Whether instrumented "collective chunk link hard" value is set */
    int mpio_coll_chunk_multi_hard;  /* Instrumented "collective chunk multi hard" value (H5D_XFER_COLL_CHUNK_MULTI_HARD_NAME) */
    hbool_t mpio_coll_chunk_multi_hard_set; /* Whether instrumented "collective chunk multi hard" value is set */
    int mpio_coll_chunk_link_num_true;  /* Instrumented "collective chunk link num true" value (H5D_XFER_COLL_CHUNK_LINK_NUM_TRUE_NAME) */
    hbool_t mpio_coll_chunk_link_num_true_set; /* Whether instrumented "collective chunk link num true" value is set */
    int mpio_coll_chunk_link_num_false;  /* Instrumented "collective chunk link num false" value (H5D_XFER_COLL_CHUNK_LINK_NUM_FALSE_NAME) */
    hbool_t mpio_coll_chunk_link_num_false_set; /* Whether instrumented "collective chunk link num false" value is set */
    int mpio_coll_chunk_multi_ratio_coll;  /* Instrumented "collective chunk multi ratio coll" value (H5D_XFER_COLL_CHUNK_MULTI_RATIO_COLL_NAME) */
    hbool_t mpio_coll_chunk_multi_ratio_coll_set; /* Whether instrumented "collective chunk multi ratio coll" value is set */
    int mpio_coll_chunk_multi_ratio_ind;  /* Instrumented "collective chunk multi ratio ind" value (H5D_XFER_COLL_CHUNK_MULTI_RATIO_IND_NAME) */
    hbool_t mpio_coll_chunk_multi_ratio_ind_set; /* Whether instrumented "collective chunk multi ratio ind" value is set */
#endif /* H5_HAVE_INSTRUMENTED_LIBRARY */
#endif /* H5_HAVE_PARALLEL */

    /* Cached LAPL properties */
    size_t nlinks;              /* Number of soft / UD links to traverse (H5L_ACS_NLINKS_NAME) */
    hbool_t nlinks_valid;       /* Whether number of soft / UD links to traverse is valid */
} H5CX_t;

/* Typedef for nodes on the API context stack */
/* Each entry into the library through an API routine invokes H5CX_push()
 * in a FUNC_ENTER_API* macro, which pushes an H5CX_node_t on the API
 * context [thread-local] stack, after initializing it with default values
 * in H5CX__push_common().
 */
typedef struct H5CX_node_t {
    H5CX_t ctx;                 /* Context for current API call */
    struct H5CX_node_t *next;   /* Pointer to previous context, on stack */
} H5CX_node_t;

/* Typedef for cached default dataset transfer property list information */
/* This is initialized to the values in the default DXPL during package
 * initialization and then remains constant for the rest of the library's
 * operation.  When a field in H5CX_t is retrieved from an API context that
 * uses a default DXPL, this value is copied instead of spending time looking
 * up the property in the DXPL.
 */
typedef struct H5CX_dxpl_cache_t {
    size_t max_temp_buf;            /* Maximum temporary buffer size (H5D_XFER_MAX_TEMP_BUF_NAME) */
    void *tconv_buf;                /* Temporary conversion buffer (H5D_XFER_TCONV_BUF_NAME) */
    void *bkgr_buf;                 /* Background conversion buffer (H5D_XFER_BKGR_BUF_NAME) */
    H5T_bkg_t bkgr_buf_type;        /* Background buffer type (H5D_XFER_BKGR_BUF_NAME) */
    double btree_split_ratio[3];    /* B-tree split ratios (H5D_XFER_BTREE_SPLIT_RATIO_NAME) */
    size_t vec_size;                /* Size of hyperslab vector (H5D_XFER_HYPER_VECTOR_SIZE_NAME) */
#ifdef H5_HAVE_PARALLEL
    H5FD_mpio_xfer_t io_xfer_mode;  /* Parallel transfer mode for this request (H5D_XFER_IO_XFER_MODE_NAME) */
    H5FD_mpio_collective_opt_t mpio_coll_opt; /* Parallel transfer with independent IO or collective IO with this mode (H5D_XFER_MPIO_COLLECTIVE_OPT_NAME) */
    uint32_t mpio_local_no_coll_cause; /* Local reason for breaking collective I/O (H5D_MPIO_LOCAL_NO_COLLECTIVE_CAUSE_NAME) */
    uint32_t mpio_global_no_coll_cause; /* Global reason for breaking collective I/O (H5D_MPIO_GLOBAL_NO_COLLECTIVE_CAUSE_NAME) */
    H5FD_mpio_chunk_opt_t mpio_chunk_opt_mode; /* Collective chunk option (H5D_XFER_MPIO_CHUNK_OPT_HARD_NAME) */
    unsigned mpio_chunk_opt_num;    /* Collective chunk thrreshold (H5D_XFER_MPIO_CHUNK_OPT_NUM_NAME) */
    unsigned mpio_chunk_opt_ratio;  /* Collective chunk ratio (H5D_XFER_MPIO_CHUNK_OPT_RATIO_NAME) */
#endif /* H5_HAVE_PARALLEL */
    H5Z_EDC_t err_detect;           /* Error detection info (H5D_XFER_EDC_NAME) */
    H5Z_cb_t filter_cb;             /* Filter callback function (H5D_XFER_FILTER_CB_NAME) */
    H5Z_data_xform_t *data_transform; /* Data transform info (H5D_XFER_XFORM_NAME) */
    H5T_vlen_alloc_info_t vl_alloc_info; /* VL datatype alloc info (H5D_XFER_VLEN_*_NAME) */
    hbool_t dcr_flag;               /* Direct chunk read flag (H5D_XFER_DIRECT_CHUNK_READ_FLAG_NAME) */
    hsize_t *dcr_offset;            /* Direct chunk read offset (H5D_XFER_DIRECT_CHUNK_READ_OFFSET_NAME) */
    hbool_t dcw_flag;               /* Direct chunk write flag (H5D_XFER_DIRECT_CHUNK_WRITE_FLAG_NAME) */
    uint32_t dcw_datasize;          /* Direct chunk write data size (H5D_XFER_DIRECT_CHUNK_WRITE_DATASIZE_NAME) */
    hsize_t *dcw_offset;            /* Direct chunk write offset (H5D_XFER_DIRECT_CHUNK_WRITE_OFFSET_NAME) */
    uint32_t dcw_filters;           /* Direct chunk write filter flags (H5D_XFER_DIRECT_CHUNK_WRITE_FILTERS_NAME) */
    H5T_conv_cb_t dt_conv_cb;       /* Datatype conversion struct (H5D_XFER_CONV_CB_NAME) */
} H5CX_dxpl_cache_t;

/* Typedef for cached default link access property list information */
/* (Same as the cached DXPL struct, above, except for the default LAPL) */
typedef struct H5CX_lapl_cache_t {
    size_t nlinks;                  /* Number of soft / UD links to traverse (H5L_ACS_NLINKS_NAME) */
} H5CX_lapl_cache_t;


/********************/
/* Local Prototypes */
/********************/
static H5CX_node_t **H5CX__get_context(void);
static void H5CX__push_common(H5CX_node_t *cnode);
static H5CX_node_t *H5CX__pop_common(void);


/*********************/
/* Package Variables */
/*********************/

/* Package initialization variable */
hbool_t H5_PKG_INIT_VAR = FALSE;


/*******************/
/* Local Variables */
/*******************/

#ifndef H5_HAVE_THREADSAFE
static H5CX_node_t **H5CX_head_g = NULL;         /* Pointer to head of context stack */
#endif /* H5_HAVE_THREADSAFE */

/* Define a "default" dataset transfer property list cache structure to use for default DXPLs */
static H5CX_dxpl_cache_t H5CX_def_dxpl_cache;

/* Define a "default" link access property list cache structure to use for default LAPLs */
static H5CX_lapl_cache_t H5CX_def_lapl_cache;

/* Declare a static free list to manage H5CX_node_t structs */
H5FL_DEFINE_STATIC(H5CX_node_t);



/*--------------------------------------------------------------------------
NAME
    H5CX__init_package -- Initialize interface-specific information
USAGE
    herr_t H5CX__init_package()
RETURNS
    Non-negative on success/Negative on failure
DESCRIPTION
    Initializes any interface-specific data or routines.
--------------------------------------------------------------------------*/
herr_t
H5CX__init_package(void)
{
    H5P_genplist_t *dx_plist;           /* Data transfer property list */
    H5P_genplist_t *la_plist;           /* Link access property list */
    herr_t ret_value = SUCCEED;         /* Return value */

    FUNC_ENTER_STATIC

#ifndef H5_HAVE_THREADSAFE
    /* Allocate the context stack head pointer */
    if(NULL == (H5CX_head_g = (H5CX_node_t **)HDmalloc(sizeof(H5CX_node_t *))))
        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTALLOC, FAIL, "can't allocate pointer to head of context stack")
    *H5CX_head_g = NULL;
#endif /* H5_HAVE_THREADSAFE */

    /* Reset the "default DXPL cache" information */
    HDmemset(&H5CX_def_dxpl_cache, 0, sizeof(H5CX_dxpl_cache_t));

    /* Get the default DXPL cache information */

    /* Get the default dataset transfer property list */
    if(NULL == (dx_plist = (H5P_genplist_t *)H5I_object(H5P_DATASET_XFER_DEFAULT)))
        HGOTO_ERROR(H5E_CONTEXT, H5E_BADTYPE, FAIL, "not a dataset transfer property list")

    /* Get B-tree split ratios */
    if(H5P_get(dx_plist, H5D_XFER_BTREE_SPLIT_RATIO_NAME, &H5CX_def_dxpl_cache.btree_split_ratio) < 0)
        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve B-tree split ratios")

    /* Get maximum temporary buffer size value */
    if(H5P_get(dx_plist, H5D_XFER_MAX_TEMP_BUF_NAME, &H5CX_def_dxpl_cache.max_temp_buf) < 0)
        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve maximum temporary buffer size")

    /* Get temporary buffer pointer */
    if(H5P_get(dx_plist, H5D_XFER_TCONV_BUF_NAME, &H5CX_def_dxpl_cache.tconv_buf) < 0)
        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve temporary buffer pointer")

    /* Get background buffer pointer */
    if(H5P_get(dx_plist, H5D_XFER_BKGR_BUF_NAME, &H5CX_def_dxpl_cache.bkgr_buf) < 0)
        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve background buffer pointer")

    /* Get background buffer type */
    if(H5P_get(dx_plist, H5D_XFER_BKGR_BUF_TYPE_NAME, &H5CX_def_dxpl_cache.bkgr_buf_type) < 0)
        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve background buffer type")

    /* Get I/O vector size */
    if(H5P_get(dx_plist, H5D_XFER_HYPER_VECTOR_SIZE_NAME, &H5CX_def_dxpl_cache.vec_size) < 0)
        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve I/O vector size")

#ifdef H5_HAVE_PARALLEL
    /* Collect Parallel I/O information for possible later use */
    if(H5P_get(dx_plist, H5D_XFER_IO_XFER_MODE_NAME, &H5CX_def_dxpl_cache.io_xfer_mode) < 0)
        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve parallel transfer method")
    if(H5P_get(dx_plist, H5D_XFER_MPIO_COLLECTIVE_OPT_NAME, &H5CX_def_dxpl_cache.mpio_coll_opt) < 0)
        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve collective transfer option")
    if(H5P_get(dx_plist, H5D_XFER_MPIO_CHUNK_OPT_HARD_NAME, &H5CX_def_dxpl_cache.mpio_chunk_opt_mode) < 0)
        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve chunk optimization option")
    if(H5P_get(dx_plist, H5D_XFER_MPIO_CHUNK_OPT_NUM_NAME, &H5CX_def_dxpl_cache.mpio_chunk_opt_num) < 0)
        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve chunk optimization threshold")
    if(H5P_get(dx_plist, H5D_XFER_MPIO_CHUNK_OPT_RATIO_NAME, &H5CX_def_dxpl_cache.mpio_chunk_opt_ratio) < 0)
        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve chunk optimization ratio")

    /* Get the local & global reasons for breaking collective I/O values */
    if(H5P_get(dx_plist, H5D_MPIO_LOCAL_NO_COLLECTIVE_CAUSE_NAME, &H5CX_def_dxpl_cache.mpio_local_no_coll_cause) < 0)
        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve local cause for breaking collective I/O")
    if(H5P_get(dx_plist, H5D_MPIO_GLOBAL_NO_COLLECTIVE_CAUSE_NAME, &H5CX_def_dxpl_cache.mpio_global_no_coll_cause) < 0)
        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve global cause for breaking collective I/O")
#endif /* H5_HAVE_PARALLEL */

    /* Get error detection properties */
    if(H5P_get(dx_plist, H5D_XFER_EDC_NAME, &H5CX_def_dxpl_cache.err_detect) < 0)
        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve error detection info")

    /* Get filter callback function */
    if(H5P_get(dx_plist, H5D_XFER_FILTER_CB_NAME, &H5CX_def_dxpl_cache.filter_cb) < 0)
        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve filter callback function")

    /* Look at the data transform property */
    /* (Note: 'peek', not 'get' - if this turns out to be a problem, we may need
     *          to copy it and free this in the H5CX terminate routine. -QAK)
     */
    if(H5P_peek(dx_plist, H5D_XFER_XFORM_NAME, &H5CX_def_dxpl_cache.data_transform) < 0)
        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve data transform info")

    /* Get VL datatype alloc info */
    if(H5P_get(dx_plist, H5D_XFER_VLEN_ALLOC_NAME, &H5CX_def_dxpl_cache.vl_alloc_info.alloc_func) < 0)
        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve VL datatype alloc info")
    if(H5P_get(dx_plist, H5D_XFER_VLEN_ALLOC_INFO_NAME, &H5CX_def_dxpl_cache.vl_alloc_info.alloc_info) < 0)
        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve VL datatype alloc info")
    if(H5P_get(dx_plist, H5D_XFER_VLEN_FREE_NAME, &H5CX_def_dxpl_cache.vl_alloc_info.free_func) < 0)
        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve VL datatype alloc info")
    if(H5P_get(dx_plist, H5D_XFER_VLEN_FREE_INFO_NAME, &H5CX_def_dxpl_cache.vl_alloc_info.free_info) < 0)
        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve VL datatype alloc info")

    /* Get direct chunk read info */
    if(H5P_get(dx_plist, H5D_XFER_DIRECT_CHUNK_READ_FLAG_NAME, &H5CX_def_dxpl_cache.dcr_flag) < 0)
        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve direct chunk read flag")
    if(H5P_get(dx_plist, H5D_XFER_DIRECT_CHUNK_READ_OFFSET_NAME, &H5CX_def_dxpl_cache.dcr_offset) < 0)
        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve direct chunk read offset")

    /* Get direct chunk write info */
    if(H5P_get(dx_plist, H5D_XFER_DIRECT_CHUNK_WRITE_FLAG_NAME, &H5CX_def_dxpl_cache.dcw_flag) < 0)
        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve direct chunk write flag")
    if(H5P_get(dx_plist, H5D_XFER_DIRECT_CHUNK_WRITE_FILTERS_NAME, &H5CX_def_dxpl_cache.dcw_filters) < 0)
        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve direct chunk write filter mask")
    if(H5P_get(dx_plist, H5D_XFER_DIRECT_CHUNK_WRITE_OFFSET_NAME, &H5CX_def_dxpl_cache.dcw_offset) < 0)
        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve direct chunk write offset")
    if(H5P_get(dx_plist, H5D_XFER_DIRECT_CHUNK_WRITE_DATASIZE_NAME, &H5CX_def_dxpl_cache.dcw_datasize) < 0)
        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve direct chunk write data size")

    /* Get datatype conversion struct */
    if(H5P_get(dx_plist, H5D_XFER_CONV_CB_NAME, &H5CX_def_dxpl_cache.dt_conv_cb) < 0)
        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve datatype conversion exception callback")


    /* Reset the "default LAPL cache" information */
    HDmemset(&H5CX_def_lapl_cache, 0, sizeof(H5CX_lapl_cache_t));

    /* Get the default LAPL cache information */

    /* Get the default link access property list */
    if(NULL == (la_plist = (H5P_genplist_t *)H5I_object(H5P_LINK_ACCESS_DEFAULT)))
        HGOTO_ERROR(H5E_CONTEXT, H5E_BADTYPE, FAIL, "not a link access property list")

    /* Get number of soft / UD links to traverse */
    if(H5P_get(la_plist, H5L_ACS_NLINKS_NAME, &H5CX_def_lapl_cache.nlinks) < 0)
        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve number of soft / UD links to traverse")

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX__init_package() */


/*-------------------------------------------------------------------------
 * Function: H5CX_term_package
 *
 * Purpose:  Terminate this interface.
 *
 * Return:   Success:    Positive if anything was done that might
 *                affect other interfaces; zero otherwise.
 *            Failure:    Negative.
 *
 * Programmer:  Quincey Koziol
 *              Februrary 22, 2018
 *
 *-------------------------------------------------------------------------
 */
int
H5CX_term_package(void)
{
    FUNC_ENTER_NOAPI_NOINIT_NOERR

    if(H5_PKG_INIT_VAR) {
        H5CX_node_t *cnode;         /* Context node */

        /* Pop the top context node from the stack */
        /* (Can't check for errors, as rest of library is shut down) */
        cnode = H5CX__pop_common();

        /* Free the context node */
        /* (Allocated with HDmalloc() in H5CX_push_special() ) */
        HDfree(cnode);

#ifndef H5_HAVE_THREADSAFE
        /* Release pointer to head of API context stack */
        HDfree(H5CX_head_g);
        H5CX_head_g = NULL;
#endif /* H5_HAVE_THREADSAFE */

        H5_PKG_INIT_VAR = FALSE;
    } /* end if */

    FUNC_LEAVE_NOAPI(0)
} /* end H5CX_term_package() */


#ifdef H5_HAVE_THREADSAFE
/*-------------------------------------------------------------------------
 * Function:	H5CX__get_context
 *
 * Purpose:	Support function for H5CX_get_my_context() to initialize and
 *              acquire per-thread API context stack.
 *
 * Return:	Success: Non-NULL pointer to head pointer of API context stack for thread
 *		Failure: NULL
 *
 * Programmer:	Quincey Koziol
 *              March 12, 2018
 *
 *-------------------------------------------------------------------------
 */
static H5CX_node_t **
H5CX__get_context(void)
{
    H5CX_node_t **ctx = NULL;

    FUNC_ENTER_STATIC_NOERR

    ctx = (H5CX_node_t **)H5TS_get_thread_local_value(H5TS_apictx_key_g);

    if(!ctx) {
        /* No associated value with current thread - create one */
#ifdef H5_HAVE_WIN_THREADS
        /* Win32 has to use LocalAlloc to match the LocalFree in DllMain */
        ctx = (H5CX_node_t **)LocalAlloc(LPTR, sizeof(H5CX_node_t *)); 
#else
        /* Use HDmalloc here since this has to match the HDfree in the
         * destructor and we want to avoid the codestack there.
         */
        ctx = (H5CX_node_t **)HDmalloc(sizeof(H5CX_node_t *));
#endif /* H5_HAVE_WIN_THREADS */
        HDassert(ctx);

        /* Reset the thread-specific info */
        *ctx = NULL;

        /* (It's not necessary to release this in this API, it is
         *      released by the "key destructor" set up in the H5TS
         *      routines.  See calls to pthread_key_create() in H5TS.c -QAK)
         */
        H5TS_set_thread_local_value(H5TS_apictx_key_g, (void *)ctx);
    } /* end if */

    /* Set return value */
    FUNC_LEAVE_NOAPI(ctx)
} /* end H5CX__get_context() */
#endif  /* H5_HAVE_THREADSAFE */


/*-------------------------------------------------------------------------
 * Function:    H5CX__push_common
 *
 * Purpose:     Internal routine to push a context for an API call.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              Februrary 22, 2018
 *
 *-------------------------------------------------------------------------
 */
static void
H5CX__push_common(H5CX_node_t *cnode)
{
    H5CX_node_t **head = H5CX_get_my_context();  /* Get the pointer to the head of the API context, for this thread */

    FUNC_ENTER_STATIC_NOERR

    /* Sanity check */
    HDassert(cnode);

    /* Set non-zero context info */
    cnode->ctx.dxpl_id = H5P_DATASET_XFER_DEFAULT;
    cnode->ctx.lapl_id = H5P_LINK_ACCESS_DEFAULT;
    cnode->ctx.tag = H5AC__INVALID_TAG;
    cnode->ctx.ring = H5AC_RING_USER;

    /* Push context node onto stack */
    cnode->next = *head;
    *head = cnode;

    FUNC_LEAVE_NOAPI_VOID
} /* end H5CX__push_common() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_push
 *
 * Purpose:     Pushes a context for an API call.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              Februrary 19, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_push(void)
{
    H5CX_node_t *cnode = NULL;          /* Context node */
    herr_t ret_value = SUCCEED;         /* Return value */

    FUNC_ENTER_NOAPI(FAIL)

    /* Allocate & clear API context node */
    if(NULL == (cnode = H5FL_CALLOC(H5CX_node_t)))
        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTALLOC, FAIL, "unable to allocate new struct")

    /* Set context info */
    H5CX__push_common(cnode);

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_push() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_push_special
 *
 * Purpose:     Pushes a context for an API call, without using library routines.
 *
 * Note:	This should only be called in special circumstances, like H5close.
 *
 * Return:      <none>
 *
 * Programmer:  Quincey Koziol
 *              Februrary 22, 2018
 *
 *-------------------------------------------------------------------------
 */
void
H5CX_push_special(void)
{
    H5CX_node_t *cnode;         /* Context node */

    FUNC_ENTER_NOAPI_NOINIT_NOERR

    /* Allocate & clear API context node, without using library API routines */
    cnode = (H5CX_node_t *)HDcalloc(1, sizeof(H5CX_node_t));
    HDassert(cnode);

    /* Set context info */
    H5CX__push_common(cnode);

    FUNC_LEAVE_NOAPI_VOID
} /* end H5CX_push_special() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_is_def_dxpl
 *
 * Purpose:     Checks if the API context is using the library's default DXPL
 *
 * Return:      TRUE / FALSE (can't fail)
 *
 * Programmer:  Quincey Koziol
 *              March 6, 2018
 *
 *-------------------------------------------------------------------------
 */
hbool_t
H5CX_is_def_dxpl(void)
{
    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);

    FUNC_LEAVE_NOAPI((*head)->ctx.dxpl_id == H5P_DATASET_XFER_DEFAULT);
} /* end H5CX_is_def_dxpl() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_set_dxpl
 *
 * Purpose:     Sets the DXPL for the current API call context.
 *
 * Return:      <none>
 *
 * Programmer:  Quincey Koziol
 *              March 8, 2018
 *
 *-------------------------------------------------------------------------
 */
void
H5CX_set_dxpl(hid_t dxpl_id)
{
    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);

    /* Set the API context's DXPL to a new value */
    (*head)->ctx.dxpl_id = dxpl_id;

    FUNC_LEAVE_NOAPI_VOID
} /* end H5CX_set_dxpl() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_set_lapl
 *
 * Purpose:     Sets the LAPL for the current API call context.
 *
 * Return:      <none>
 *
 * Programmer:  Quincey Koziol
 *              March 10, 2018
 *
 *-------------------------------------------------------------------------
 */
void
H5CX_set_lapl(hid_t lapl_id)
{
    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);

    /* Set the API context's LAPL to a new value */
    (*head)->ctx.lapl_id = lapl_id;

    FUNC_LEAVE_NOAPI_VOID
} /* end H5CX_set_lapl() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_set_apl
 *
 * Purpose:     Validaties an access property list, and sanity checking &
 *              setting up collective operations.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              Februrary 19, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_set_apl(hid_t *acspl_id, const H5P_libclass_t *libclass,
    hid_t
#ifndef H5_HAVE_PARALLEL
   H5_ATTR_UNUSED
#endif /* H5_HAVE_PARALLEL */
   loc_id, hbool_t
#ifndef H5_HAVE_PARALLEL
   H5_ATTR_UNUSED
#endif /* H5_HAVE_PARALLEL */
   is_collective)
{
    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 checks */
    HDassert(acspl_id);
    HDassert(libclass);
    HDassert(head && *head);

    /* Set access plist to the default property list of the appropriate class if it's the generic default */
    if(H5P_DEFAULT == *acspl_id)
        *acspl_id = *libclass->def_plist_id;
    else {
        htri_t is_lapl;         /* Whether the access property list is (or is derived from) a link access property list */

#ifdef H5CX_DEBUG
        /* Sanity check the access property list class */
        if(TRUE != H5P_isa_class(*acspl_id, *libclass->class_id))
            HGOTO_ERROR(H5E_CONTEXT, H5E_BADTYPE, FAIL, "not the required access property list")
#endif /* H5CX_DEBUG*/

        /* Check for link access property and set API context if so */
        if((is_lapl = H5P_class_isa(*libclass->pclass, *H5P_CLS_LACC->pclass)) < 0)
            HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "can't check for link access class")
        else if(is_lapl)
            (*head)->ctx.lapl_id = *acspl_id;

#ifdef H5_HAVE_PARALLEL
        /* If this routine is not guaranteed to be collective (i.e. it doesn't
         * modify the structural metadata in a file), check if we should use
         * a collective metadata read.
         */
        if(!is_collective) {
            H5P_genplist_t *plist;                  /* Property list pointer */
            H5P_coll_md_read_flag_t md_coll_read;   /* Collective metadata read flag */

            /* Get the plist structure for the access property list */
            if(NULL == (plist = (H5P_genplist_t *)H5I_object(*acspl_id)))
                HGOTO_ERROR(H5E_CONTEXT, H5E_BADATOM, FAIL, "can't find object for ID")

            /* Get the collective metadata read flag */
            if(H5P_peek(plist, H5_COLL_MD_READ_FLAG_NAME, &md_coll_read) < 0)
                HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "can't get core collective metadata read flag")

            /* If collective metadata read requested, set collective metadata read flag */
            if(H5P_USER_TRUE == md_coll_read)
                is_collective = TRUE;
        } /* end if */
#endif /* H5_HAVE_PARALLEL */
    } /* end else */

#ifdef H5_HAVE_PARALLEL
    /* Check for collective operation */
    if(is_collective) {
        /* Set collective metadata read flag */
        (*head)->ctx.coll_metadata_read = TRUE;

        /* If parallel is enabled and the file driver used is the MPI-IO
         * VFD, issue an MPI barrier for easier debugging if the API function
         * calling this is supposed to be called collectively. Note that this
         * happens only when the environment variable H5_COLL_BARRIER is set
         * to non 0.
         */
        if(H5_coll_api_sanity_check_g) {
            MPI_Comm mpi_comm;      /* File communicator */

            /* Retrieve the MPI communicator from the loc_id or the fapl_id */
            if(H5F_mpi_retrieve_comm(loc_id, *acspl_id, &mpi_comm) < 0)
                HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "can't get MPI communicator")

            /* issue the barrier */
            if(mpi_comm != MPI_COMM_NULL)
                MPI_Barrier(mpi_comm);
        } /* end if */
    } /* end if */
#endif /* H5_HAVE_PARALLEL */

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_set_apl() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_set_loc
 *
 * Purpose:     Sanity checks and sets up collective operations.
 *
 * Note:	Should be called for all API routines that modify file
 *              file metadata but don't pass in an access property list.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              March 8, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_set_loc(hid_t
#ifndef H5_HAVE_PARALLEL
   H5_ATTR_UNUSED
#endif /* H5_HAVE_PARALLEL */
   loc_id)
{
    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);

#ifdef H5_HAVE_PARALLEL
    /* Set collective metadata read flag */
    (*head)->ctx.coll_metadata_read = TRUE;

    /* If parallel is enabled and the file driver used is the MPI-IO
     * VFD, issue an MPI barrier for easier debugging if the API function
     * calling this is supposed to be called collectively. Note that this
     * happens only when the environment variable H5_COLL_BARRIER is set
     * to non 0.
     */
    if(H5_coll_api_sanity_check_g) {
        MPI_Comm mpi_comm;      /* File communicator */

        /* Retrieve the MPI communicator from the loc_id or the fapl_id */
        if(H5F_mpi_retrieve_comm(loc_id, H5P_DEFAULT, &mpi_comm) < 0)
            HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "can't get MPI communicator")

        /* issue the barrier */
        if(mpi_comm != MPI_COMM_NULL)
            MPI_Barrier(mpi_comm);
    } /* end if */
#endif /* H5_HAVE_PARALLEL */

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_set_loc() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_get_dxpl
 *
 * Purpose:     Retrieves the DXPL ID for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              Februrary 20, 2018
 *
 *-------------------------------------------------------------------------
 */
hid_t
H5CX_get_dxpl(void)
{
    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);

    FUNC_LEAVE_NOAPI((*head)->ctx.dxpl_id)
} /* end H5CX_get_dxpl() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_get_lapl
 *
 * Purpose:     Retrieves the LAPL ID for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              March 10, 2018
 *
 *-------------------------------------------------------------------------
 */
hid_t
H5CX_get_lapl(void)
{
    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);

    FUNC_LEAVE_NOAPI((*head)->ctx.lapl_id)
} /* end H5CX_get_lapl() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_get_tag
 *
 * Purpose:     Retrieves the object tag for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              Februrary 20, 2018
 *
 *-------------------------------------------------------------------------
 */
haddr_t
H5CX_get_tag(void)
{
    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);

    FUNC_LEAVE_NOAPI((*head)->ctx.tag)
} /* end H5CX_get_tag() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_get_ring
 *
 * Purpose:     Retrieves the metadata cache ring for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              Februrary 22, 2018
 *
 *-------------------------------------------------------------------------
 */
H5AC_ring_t
H5CX_get_ring(void)
{
    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);

    FUNC_LEAVE_NOAPI((*head)->ctx.ring)
} /* end H5CX_get_ring() */

#ifdef H5_HAVE_PARALLEL

/*-------------------------------------------------------------------------
 * Function:    H5CX_get_coll_metadata_read
 *
 * Purpose:     Retrieves the "do collective metadata reads" flag for the current API call context.
 *
 * Return:      TRUE / FALSE on success / <can't fail>
 *
 * Programmer:  Quincey Koziol
 *              Februrary 23, 2018
 *
 *-------------------------------------------------------------------------
 */
hbool_t
H5CX_get_coll_metadata_read(void)
{
    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);

    FUNC_LEAVE_NOAPI((*head)->ctx.coll_metadata_read)
} /* end H5CX_get_coll_metadata_read() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_get_mpi_coll_datatypes
 *
 * Purpose:     Retrieves the MPI datatypes for collective I/O for the current API call context.
 *
 * Note:	This is only a shallow copy, the datatypes are not duplicated.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              Februrary 26, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_get_mpi_coll_datatypes(MPI_Datatype *btype, MPI_Datatype *ftype)
{
    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(btype);
    HDassert(ftype);
    HDassert(head && *head);

    /* Set the API context values */
    *btype = (*head)->ctx.btype;
    *ftype = (*head)->ctx.ftype;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_get_mpi_coll_datatypes() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_get_mpi_file_flushing
 *
 * Purpose:     Retrieves the "flushing an MPI-opened file" flag for the current API call context.
 *
 * Return:      TRUE / FALSE on success / <can't fail>
 *
 * Programmer:  Quincey Koziol
 *              March 17, 2018
 *
 *-------------------------------------------------------------------------
 */
hbool_t
H5CX_get_mpi_file_flushing(void)
{
    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);

    FUNC_LEAVE_NOAPI((*head)->ctx.mpi_file_flushing)
} /* end H5CX_get_mpi_file_flushing() */
#endif /* H5_HAVE_PARALLEL */


/*-------------------------------------------------------------------------
 * Function:    H5CX_get_btree_split_ratios
 *
 * Purpose:     Retrieves the B-tree split ratios for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              Februrary 23, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_get_btree_split_ratios(double split_ratio[3])
{
    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(split_ratio);
    HDassert(head && *head);
    HDassert(H5P_DEFAULT != (*head)->ctx.dxpl_id);

    H5CX_RETRIEVE_PROP_VALID(dxpl, H5P_DATASET_XFER_DEFAULT, H5D_XFER_BTREE_SPLIT_RATIO_NAME, btree_split_ratio)

    /* Get the B-tree split ratio values */
    HDmemcpy(split_ratio, &(*head)->ctx.btree_split_ratio, sizeof((*head)->ctx.btree_split_ratio));

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_get_btree_split_ratios() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_get_max_temp_buf
 *
 * Purpose:     Retrieves the maximum temporary buffer size for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              Februrary 25, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_get_max_temp_buf(size_t *max_temp_buf)
{
    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(max_temp_buf);
    HDassert(head && *head);
    HDassert(H5P_DEFAULT != (*head)->ctx.dxpl_id);

    H5CX_RETRIEVE_PROP_VALID(dxpl, H5P_DATASET_XFER_DEFAULT, H5D_XFER_MAX_TEMP_BUF_NAME, max_temp_buf)

    /* Get the value */
    *max_temp_buf = (*head)->ctx.max_temp_buf;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_get_max_temp_buf() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_get_tconv_buf
 *
 * Purpose:     Retrieves the temporary buffer pointer for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              Februrary 25, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_get_tconv_buf(void **tconv_buf)
{
    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(tconv_buf);
    HDassert(head && *head);
    HDassert(H5P_DEFAULT != (*head)->ctx.dxpl_id);

    H5CX_RETRIEVE_PROP_VALID(dxpl, H5P_DATASET_XFER_DEFAULT, H5D_XFER_TCONV_BUF_NAME, tconv_buf)

    /* Get the value */
    *tconv_buf = (*head)->ctx.tconv_buf;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_get_tconv_buf() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_get_bkgr_buf
 *
 * Purpose:     Retrieves the background buffer pointer for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              Februrary 25, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_get_bkgr_buf(void **bkgr_buf)
{
    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(bkgr_buf);
    HDassert(head && *head);
    HDassert(H5P_DEFAULT != (*head)->ctx.dxpl_id);

    H5CX_RETRIEVE_PROP_VALID(dxpl, H5P_DATASET_XFER_DEFAULT, H5D_XFER_BKGR_BUF_NAME, bkgr_buf)

    /* Get the value */
    *bkgr_buf = (*head)->ctx.bkgr_buf;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_get_bkgr_buf() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_get_bkgr_buf_type
 *
 * Purpose:     Retrieves the background buffer type for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              Februrary 25, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_get_bkgr_buf_type(H5T_bkg_t *bkgr_buf_type)
{
    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(bkgr_buf_type);
    HDassert(head && *head);
    HDassert(H5P_DEFAULT != (*head)->ctx.dxpl_id);

    H5CX_RETRIEVE_PROP_VALID(dxpl, H5P_DATASET_XFER_DEFAULT, H5D_XFER_BKGR_BUF_TYPE_NAME, bkgr_buf_type)

    /* Get the value */
    *bkgr_buf_type = (*head)->ctx.bkgr_buf_type;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_get_bkgr_buf_type() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_get_vec_size
 *
 * Purpose:     Retrieves the hyperslab vector size for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              Februrary 25, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_get_vec_size(size_t *vec_size)
{
    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(vec_size);
    HDassert(head && *head);
    HDassert(H5P_DEFAULT != (*head)->ctx.dxpl_id);

    H5CX_RETRIEVE_PROP_VALID(dxpl, H5P_DATASET_XFER_DEFAULT, H5D_XFER_HYPER_VECTOR_SIZE_NAME, vec_size)

    /* Get the value */
    *vec_size = (*head)->ctx.vec_size;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_get_vec_size() */

#ifdef H5_HAVE_PARALLEL

/*-------------------------------------------------------------------------
 * Function:    H5CX_get_io_xfer_mode
 *
 * Purpose:     Retrieves the parallel transfer mode for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              Februrary 25, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_get_io_xfer_mode(H5FD_mpio_xfer_t *io_xfer_mode)
{
    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(io_xfer_mode);
    HDassert(head && *head);
    HDassert(H5P_DEFAULT != (*head)->ctx.dxpl_id);

    H5CX_RETRIEVE_PROP_VALID(dxpl, H5P_DATASET_XFER_DEFAULT, H5D_XFER_IO_XFER_MODE_NAME, io_xfer_mode)

    /* Get the value */
    *io_xfer_mode = (*head)->ctx.io_xfer_mode;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_get_io_xfer_mode() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_get_mpio_coll_opt
 *
 * Purpose:     Retrieves the collective / independent parallel I/O option for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              Februrary 26, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_get_mpio_coll_opt(H5FD_mpio_collective_opt_t *mpio_coll_opt)
{
    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(mpio_coll_opt);
    HDassert(head && *head);
    HDassert(H5P_DEFAULT != (*head)->ctx.dxpl_id);

    H5CX_RETRIEVE_PROP_VALID(dxpl, H5P_DATASET_XFER_DEFAULT, H5D_XFER_MPIO_COLLECTIVE_OPT_NAME, mpio_coll_opt)

    /* Get the value */
    *mpio_coll_opt = (*head)->ctx.mpio_coll_opt;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_get_mpio_coll_opt() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_get_mpio_local_no_coll_cause
 *
 * Purpose:     Retrieves the local cause for breaking collective I/O for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              March 6, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_get_mpio_local_no_coll_cause(uint32_t *mpio_local_no_coll_cause)
{
    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(mpio_local_no_coll_cause);
    HDassert(head && *head);
    HDassert(H5P_DEFAULT != (*head)->ctx.dxpl_id);

    H5CX_RETRIEVE_PROP_VALID_SET(dxpl, H5P_DATASET_XFER_DEFAULT, H5D_MPIO_LOCAL_NO_COLLECTIVE_CAUSE_NAME, mpio_local_no_coll_cause)

    /* Get the value */
    *mpio_local_no_coll_cause = (*head)->ctx.mpio_local_no_coll_cause;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_get_mpio_local_no_coll_cause() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_get_mpio_global_no_coll_cause
 *
 * Purpose:     Retrieves the global cause for breaking collective I/O for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              March 6, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_get_mpio_global_no_coll_cause(uint32_t *mpio_global_no_coll_cause)
{
    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(mpio_global_no_coll_cause);
    HDassert(head && *head);
    HDassert(H5P_DEFAULT != (*head)->ctx.dxpl_id);

    H5CX_RETRIEVE_PROP_VALID_SET(dxpl, H5P_DATASET_XFER_DEFAULT, H5D_MPIO_GLOBAL_NO_COLLECTIVE_CAUSE_NAME, mpio_global_no_coll_cause)

    /* Get the value */
    *mpio_global_no_coll_cause = (*head)->ctx.mpio_global_no_coll_cause;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_get_mpio_global_no_coll_cause() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_get_mpio_chunk_opt_mode
 *
 * Purpose:     Retrieves the collective chunk optimization mode for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              March 6, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_get_mpio_chunk_opt_mode(H5FD_mpio_chunk_opt_t *mpio_chunk_opt_mode)
{
    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(mpio_chunk_opt_mode);
    HDassert(head && *head);
    HDassert(H5P_DEFAULT != (*head)->ctx.dxpl_id);

    H5CX_RETRIEVE_PROP_VALID(dxpl, H5P_DATASET_XFER_DEFAULT, H5D_XFER_MPIO_CHUNK_OPT_HARD_NAME, mpio_chunk_opt_mode)

    /* Get the value */
    *mpio_chunk_opt_mode = (*head)->ctx.mpio_chunk_opt_mode;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_get_mpio_chunk_opt_mode() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_get_mpio_chunk_opt_num
 *
 * Purpose:     Retrieves the collective chunk optimization threshold for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              March 6, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_get_mpio_chunk_opt_num(unsigned *mpio_chunk_opt_num)
{
    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(mpio_chunk_opt_num);
    HDassert(head && *head);
    HDassert(H5P_DEFAULT != (*head)->ctx.dxpl_id);

    H5CX_RETRIEVE_PROP_VALID(dxpl, H5P_DATASET_XFER_DEFAULT, H5D_XFER_MPIO_CHUNK_OPT_NUM_NAME, mpio_chunk_opt_num)

    /* Get the value */
    *mpio_chunk_opt_num = (*head)->ctx.mpio_chunk_opt_num;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_get_mpio_chunk_opt_num() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_get_mpio_chunk_opt_ratio
 *
 * Purpose:     Retrieves the collective chunk optimization ratio for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              March 6, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_get_mpio_chunk_opt_ratio(unsigned *mpio_chunk_opt_ratio)
{
    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(mpio_chunk_opt_ratio);
    HDassert(head && *head);
    HDassert(H5P_DEFAULT != (*head)->ctx.dxpl_id);

    H5CX_RETRIEVE_PROP_VALID(dxpl, H5P_DATASET_XFER_DEFAULT, H5D_XFER_MPIO_CHUNK_OPT_RATIO_NAME, mpio_chunk_opt_ratio)

    /* Get the value */
    *mpio_chunk_opt_ratio = (*head)->ctx.mpio_chunk_opt_ratio;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_get_mpio_chunk_opt_ratio() */
#endif /* H5_HAVE_PARALLEL */


/*-------------------------------------------------------------------------
 * Function:    H5CX_get_err_detect
 *
 * Purpose:     Retrieves the error detection info for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              Februrary 26, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_get_err_detect(H5Z_EDC_t *err_detect)
{
    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(err_detect);
    HDassert(head && *head);
    HDassert(H5P_DEFAULT != (*head)->ctx.dxpl_id);

    H5CX_RETRIEVE_PROP_VALID(dxpl, H5P_DATASET_XFER_DEFAULT, H5D_XFER_EDC_NAME, err_detect)

    /* Get the value */
    *err_detect = (*head)->ctx.err_detect;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_get_err_detect() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_get_filter_cb
 *
 * Purpose:     Retrieves the I/O filter callback function for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              Februrary 26, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_get_filter_cb(H5Z_cb_t *filter_cb)
{
    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(filter_cb);
    HDassert(head && *head);
    HDassert(H5P_DEFAULT != (*head)->ctx.dxpl_id);

    H5CX_RETRIEVE_PROP_VALID(dxpl, H5P_DATASET_XFER_DEFAULT, H5D_XFER_FILTER_CB_NAME, filter_cb)

    /* Get the value */
    *filter_cb = (*head)->ctx.filter_cb;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_get_filter_cb() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_get_data_transform
 *
 * Purpose:     Retrieves the I/O filter callback function for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              Februrary 26, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_get_data_transform(H5Z_data_xform_t **data_transform)
{
    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(data_transform);
    HDassert(head && *head);
    HDassert(H5P_DEFAULT != (*head)->ctx.dxpl_id);

    /* Check if the value has been retrieved already */
    if(!(*head)->ctx.data_transform_valid) {
        /* Check for default DXPL */
        if((*head)->ctx.dxpl_id == H5P_DATASET_XFER_DEFAULT)
            (*head)->ctx.data_transform = H5CX_def_dxpl_cache.data_transform;
        else {
            /* 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")

            /* Get data transform info value */
            /* (Note: 'peek', not 'get' - if this turns out to be a problem, we may need
             *          to copy it and free this in the H5CX pop routine. -QAK)
             */
            if(H5P_peek((*head)->ctx.dxpl, H5D_XFER_XFORM_NAME, &(*head)->ctx.data_transform) < 0)
                HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve data transform info")
        } /* end else */

        /* Mark the value as valid */
        (*head)->ctx.data_transform_valid = TRUE;
    } /* end if */

    /* Get the value */
    *data_transform = (*head)->ctx.data_transform;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_get_data_transform() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_get_vlen_alloc_info
 *
 * Purpose:     Retrieves the VL datatype alloc info for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              March 5, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_get_vlen_alloc_info(H5T_vlen_alloc_info_t *vl_alloc_info)
{
    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(vl_alloc_info);
    HDassert(head && *head);
    HDassert(H5P_DEFAULT != (*head)->ctx.dxpl_id);

    /* Check if the value has been retrieved already */
    if(!(*head)->ctx.vl_alloc_info_valid) {
        /* Check for default DXPL */
        if((*head)->ctx.dxpl_id == H5P_DATASET_XFER_DEFAULT)
            (*head)->ctx.vl_alloc_info = H5CX_def_dxpl_cache.vl_alloc_info;
        else {
            /* 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")

            /* Get VL datatype alloc info values */
            if(H5P_get((*head)->ctx.dxpl, H5D_XFER_VLEN_ALLOC_NAME, &(*head)->ctx.vl_alloc_info.alloc_func) < 0)
                HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve VL datatype alloc info")
            if(H5P_get((*head)->ctx.dxpl, H5D_XFER_VLEN_ALLOC_INFO_NAME, &(*head)->ctx.vl_alloc_info.alloc_info) < 0)
                HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve VL datatype alloc info")
            if(H5P_get((*head)->ctx.dxpl, H5D_XFER_VLEN_FREE_NAME, &(*head)->ctx.vl_alloc_info.free_func) < 0)
                HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve VL datatype alloc info")
            if(H5P_get((*head)->ctx.dxpl, H5D_XFER_VLEN_FREE_INFO_NAME, &(*head)->ctx.vl_alloc_info.free_info) < 0)
                HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve VL datatype alloc info")
        } /* end else */

        /* Mark the value as valid */
        (*head)->ctx.vl_alloc_info_valid = TRUE;
    } /* end if */

    /* Get the value */
    *vl_alloc_info = (*head)->ctx.vl_alloc_info;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_get_vlen_alloc_info() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_get_dcr_flag
 *
 * Purpose:     Retrieves the direct chunk read flag for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              March 6, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_get_dcr_flag(hbool_t *dcr_flag)
{
    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(dcr_flag);
    HDassert(head && *head);
    HDassert(H5P_DEFAULT != (*head)->ctx.dxpl_id);

    H5CX_RETRIEVE_PROP_VALID(dxpl, H5P_DATASET_XFER_DEFAULT, H5D_XFER_DIRECT_CHUNK_READ_FLAG_NAME, dcr_flag)

    /* Get the value */
    *dcr_flag = (*head)->ctx.dcr_flag;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_get_dcr_flag() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_get_dcr_offset
 *
 * Purpose:     Retrieves the direct chunk read offset for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              March 6, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_get_dcr_offset(hsize_t **dcr_offset)
{
    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(dcr_offset);
    HDassert(head && *head);
    HDassert(H5P_DEFAULT != (*head)->ctx.dxpl_id);

    H5CX_RETRIEVE_PROP_VALID(dxpl, H5P_DATASET_XFER_DEFAULT, H5D_XFER_DIRECT_CHUNK_READ_OFFSET_NAME, dcr_offset)

    /* Get the value */
    *dcr_offset = (*head)->ctx.dcr_offset;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_get_dcr_offset() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_get_dcw_flag
 *
 * Purpose:     Retrieves the direct chunk write flag for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              March 6, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_get_dcw_flag(hbool_t *dcw_flag)
{
    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(dcw_flag);
    HDassert(head && *head);
    HDassert(H5P_DEFAULT != (*head)->ctx.dxpl_id);

    H5CX_RETRIEVE_PROP_VALID(dxpl, H5P_DATASET_XFER_DEFAULT, H5D_XFER_DIRECT_CHUNK_WRITE_FLAG_NAME, dcw_flag)

    /* Get the value */
    *dcw_flag = (*head)->ctx.dcw_flag;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_get_dcw_flag() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_get_dcw_filters
 *
 * Purpose:     Retrieves the direct chunk write filter mask for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              March 6, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_get_dcw_filters(uint32_t *dcw_filters)
{
    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(dcw_filters);
    HDassert(head && *head);
    HDassert(H5P_DEFAULT != (*head)->ctx.dxpl_id);

    H5CX_RETRIEVE_PROP_VALID(dxpl, H5P_DATASET_XFER_DEFAULT, H5D_XFER_DIRECT_CHUNK_WRITE_FILTERS_NAME, dcw_filters)

    /* Get the value */
    *dcw_filters = (*head)->ctx.dcw_filters;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_get_dcw_filters() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_get_dcw_offset
 *
 * Purpose:     Retrieves the direct chunk write offset for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              March 6, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_get_dcw_offset(hsize_t **dcw_offset)
{
    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(dcw_offset);
    HDassert(head && *head);
    HDassert(H5P_DEFAULT != (*head)->ctx.dxpl_id);

    H5CX_RETRIEVE_PROP_VALID(dxpl, H5P_DATASET_XFER_DEFAULT, H5D_XFER_DIRECT_CHUNK_WRITE_OFFSET_NAME, dcw_offset)

    /* Get the value */
    *dcw_offset = (*head)->ctx.dcw_offset;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_get_dcw_offset() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_get_dcw_datasize
 *
 * Purpose:     Retrieves the direct chunk write data size for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              March 6, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_get_dcw_datasize(uint32_t *dcw_datasize)
{
    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(dcw_datasize);
    HDassert(head && *head);
    HDassert(H5P_DEFAULT != (*head)->ctx.dxpl_id);

    H5CX_RETRIEVE_PROP_VALID(dxpl, H5P_DATASET_XFER_DEFAULT, H5D_XFER_DIRECT_CHUNK_WRITE_DATASIZE_NAME, dcw_datasize)

    /* Get the value */
    *dcw_datasize = (*head)->ctx.dcw_datasize;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_get_dcw_datasize() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_get_dt_conv_cb
 *
 * Purpose:     Retrieves the datatype conversion exception callback for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              March 8, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_get_dt_conv_cb(H5T_conv_cb_t *dt_conv_cb)
{
    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(dt_conv_cb);
    HDassert(head && *head);
    HDassert(H5P_DEFAULT != (*head)->ctx.dxpl_id);

    H5CX_RETRIEVE_PROP_VALID(dxpl, H5P_DATASET_XFER_DEFAULT, H5D_XFER_CONV_CB_NAME, dt_conv_cb)

    /* Get the value */
    *dt_conv_cb = (*head)->ctx.dt_conv_cb;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_get_dt_conv_cb() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_get_nlinks
 *
 * Purpose:     Retrieves the # of soft / UD links to traverse for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              March 10, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_get_nlinks(size_t *nlinks)
{
    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(nlinks);
    HDassert(head && *head);
    HDassert(H5P_DEFAULT != (*head)->ctx.dxpl_id);

    H5CX_RETRIEVE_PROP_VALID(lapl, H5P_LINK_ACCESS_DEFAULT, H5L_ACS_NLINKS_NAME, nlinks)

    /* Get the value */
    *nlinks = (*head)->ctx.nlinks;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_get_nlinks() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_set_tag
 *
 * Purpose:     Sets the object tag for the current API call context.
 *
 * Return:      <none>
 *
 * Programmer:  Quincey Koziol
 *              Februrary 20, 2018
 *
 *-------------------------------------------------------------------------
 */
void
H5CX_set_tag(haddr_t tag)
{
    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);

    (*head)->ctx.tag = tag;

    FUNC_LEAVE_NOAPI_VOID
} /* end H5CX_set_tag() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_set_ring
 *
 * Purpose:     Sets the metadata cache ring for the current API call context.
 *
 * Return:      <none>
 *
 * Programmer:  Quincey Koziol
 *              Februrary 20, 2018
 *
 *-------------------------------------------------------------------------
 */
void
H5CX_set_ring(H5AC_ring_t ring)
{
    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);

    (*head)->ctx.ring = ring;

    FUNC_LEAVE_NOAPI_VOID
} /* end H5CX_set_ring() */

#ifdef H5_HAVE_PARALLEL

/*-------------------------------------------------------------------------
 * Function:    H5CX_set_coll_metadata_read
 *
 * Purpose:     Sets the "do collective metadata reads" flag for the current API call context.
 *
 * Return:      <none>
 *
 * Programmer:  Quincey Koziol
 *              Februrary 23, 2018
 *
 *-------------------------------------------------------------------------
 */
void
H5CX_set_coll_metadata_read(hbool_t cmdr)
{
    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);

    (*head)->ctx.coll_metadata_read = cmdr;

    FUNC_LEAVE_NOAPI_VOID
} /* end H5CX_set_coll_metadata_read() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_set_mpi_coll_datatypes
 *
 * Purpose:     Sets the MPI datatypes for collective I/O for the current API call context.
 *
 * Note:	This is only a shallow copy, the datatypes are not duplicated.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              Februrary 26, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_set_mpi_coll_datatypes(MPI_Datatype btype, MPI_Datatype ftype)
{
    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);

    /* Set the API context values */
    (*head)->ctx.btype = btype;
    (*head)->ctx.ftype = ftype;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_set_mpi_coll_datatypes() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_set_io_xfer_mode
 *
 * Purpose:     Sets the parallel transfer mode for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              Februrary 26, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_set_io_xfer_mode(H5FD_mpio_xfer_t io_xfer_mode)
{
    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);

    /* Set the API context value */
    (*head)->ctx.io_xfer_mode = io_xfer_mode;

    /* Mark the value as valid */
    (*head)->ctx.io_xfer_mode_valid = TRUE;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_set_io_xfer_mode() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_set_mpio_coll_opt
 *
 * Purpose:     Sets the parallel transfer mode for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              Februrary 26, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_set_mpio_coll_opt(H5FD_mpio_collective_opt_t mpio_coll_opt)
{
    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);

    /* Set the API context value */
    (*head)->ctx.mpio_coll_opt = mpio_coll_opt;

    /* Mark the value as valid */
    (*head)->ctx.mpio_coll_opt_valid = TRUE;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_set_mpio_coll_opt() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_set_mpi_file_flushing
 *
 * Purpose:     Sets the "flushing an MPI-opened file" flag for the current API call context.
 *
 * Return:      <none>
 *
 * Programmer:  Quincey Koziol
 *              March 170 2018
 *
 *-------------------------------------------------------------------------
 */
void
H5CX_set_mpi_file_flushing(hbool_t flushing)
{
    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);

    (*head)->ctx.mpi_file_flushing = flushing;

    FUNC_LEAVE_NOAPI_VOID
} /* end H5CX_set_mpi_file_flushing() */
#endif /* H5_HAVE_PARALLEL */


/*-------------------------------------------------------------------------
 * Function:    H5CX_set_vlen_alloc_info
 *
 * Purpose:     Sets the VL datatype alloc info for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              March 6, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_set_vlen_alloc_info(H5MM_allocate_t alloc_func,
    void *alloc_info, H5MM_free_t free_func, void *free_info)
{
    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);

    /* Set the API context value */
    (*head)->ctx.vl_alloc_info.alloc_func = alloc_func;
    (*head)->ctx.vl_alloc_info.alloc_info = alloc_info;
    (*head)->ctx.vl_alloc_info.free_func = free_func;
    (*head)->ctx.vl_alloc_info.free_info = free_info;

    /* Mark the value as valid */
    (*head)->ctx.vl_alloc_info_valid = TRUE;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_set_vlen_alloc_info() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_set_nlinks
 *
 * Purpose:     Sets the # of soft / UD links to traverse for the current API call context.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              March 10, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_set_nlinks(size_t nlinks)
{
    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);

    /* Set the API context value */
    (*head)->ctx.nlinks = nlinks;

    /* Mark the value as valid */
    (*head)->ctx.nlinks_valid = TRUE;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_set_nlinks() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_set_dcr_filters
 *
 * Purpose:     Sets the direct chunk read filter flags for the current API call context.
 *
 * Return:      <none>
 *
 * Programmer:  Quincey Koziol
 *              March 6, 2018
 *
 *-------------------------------------------------------------------------
 */
void
H5CX_set_dcr_filters(uint32_t direct_filters)
{
    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 checks */
    HDassert(head && *head);
    HDassert(!((*head)->ctx.dxpl_id == H5P_DEFAULT || 
            (*head)->ctx.dxpl_id == H5P_DATASET_XFER_DEFAULT));

    /* Cache the filter mask for later, marking it to set in DXPL when context popped */
    (*head)->ctx.dcr_filters = direct_filters;
    (*head)->ctx.dcr_filters_set = TRUE;

    FUNC_LEAVE_NOAPI_VOID
} /* end H5CX_set_dcr_filters() */

#ifdef H5_HAVE_PARALLEL

/*-------------------------------------------------------------------------
 * Function:    H5CX_set_mpio_actual_chunk_opt
 *
 * Purpose:     Sets the actual chunk optimization used for parallel I/O for the current API call context.
 *
 * Return:      <none>
 *
 * Programmer:  Quincey Koziol
 *              March 6, 2018
 *
 *-------------------------------------------------------------------------
 */
void
H5CX_set_mpio_actual_chunk_opt(H5D_mpio_actual_chunk_opt_mode_t mpio_actual_chunk_opt)
{
    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 checks */
    HDassert(head && *head);
    HDassert(!((*head)->ctx.dxpl_id == H5P_DEFAULT || 
            (*head)->ctx.dxpl_id == H5P_DATASET_XFER_DEFAULT));

    /* Cache the value for later, marking it to set in DXPL when context popped */
    (*head)->ctx.mpio_actual_chunk_opt = mpio_actual_chunk_opt;
    (*head)->ctx.mpio_actual_chunk_opt_set = TRUE;

    FUNC_LEAVE_NOAPI_VOID
} /* end H5CX_set_mpio_actual_chunk_opt() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_set_mpio_actual_io_mode
 *
 * Purpose:     Sets the actual I/O mode used for parallel I/O for the current API call context.
 *
 * Return:      <none>
 *
 * Programmer:  Quincey Koziol
 *              March 6, 2018
 *
 *-------------------------------------------------------------------------
 */
void
H5CX_set_mpio_actual_io_mode(H5D_mpio_actual_io_mode_t mpio_actual_io_mode)
{
    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 checks */
    HDassert(head && *head);
    HDassert(!((*head)->ctx.dxpl_id == H5P_DEFAULT || 
            (*head)->ctx.dxpl_id == H5P_DATASET_XFER_DEFAULT));

    /* Cache the value for later, marking it to set in DXPL when context popped */
    (*head)->ctx.mpio_actual_io_mode = mpio_actual_io_mode;
    (*head)->ctx.mpio_actual_io_mode_set = TRUE;

    FUNC_LEAVE_NOAPI_VOID
} /* end H5CX_set_mpio_actual_chunk_opt() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_set_mpio_local_no_coll_cause
 *
 * Purpose:     Sets the local reason for breaking collective I/O for the current API call context.
 *
 * Return:      <none>
 *
 * Programmer:  Quincey Koziol
 *              March 6, 2018
 *
 *-------------------------------------------------------------------------
 */
void
H5CX_set_mpio_local_no_coll_cause(uint32_t mpio_local_no_coll_cause)
{
    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 checks */
    HDassert(head && *head);
    HDassert((*head)->ctx.dxpl_id != H5P_DEFAULT);

    /* If we're using the default DXPL, don't modify it */
    if((*head)->ctx.dxpl_id != H5P_DATASET_XFER_DEFAULT) {
        /* Cache the value for later, marking it to set in DXPL when context popped */
        (*head)->ctx.mpio_local_no_coll_cause = mpio_local_no_coll_cause;
        (*head)->ctx.mpio_local_no_coll_cause_set = TRUE;
    } /* end if */

    FUNC_LEAVE_NOAPI_VOID
} /* end H5CX_set_mpio_local_no_coll_cause() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_set_mpio_global_no_coll_cause
 *
 * Purpose:     Sets the global reason for breaking collective I/O for the current API call context.
 *
 * Return:      <none>
 *
 * Programmer:  Quincey Koziol
 *              March 6, 2018
 *
 *-------------------------------------------------------------------------
 */
void
H5CX_set_mpio_global_no_coll_cause(uint32_t mpio_global_no_coll_cause)
{
    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 checks */
    HDassert(head && *head);
    HDassert((*head)->ctx.dxpl_id != H5P_DEFAULT);

    /* If we're using the default DXPL, don't modify it */
    if((*head)->ctx.dxpl_id != H5P_DATASET_XFER_DEFAULT) {
        /* Cache the value for later, marking it to set in DXPL when context popped */
        (*head)->ctx.mpio_global_no_coll_cause = mpio_global_no_coll_cause;
        (*head)->ctx.mpio_global_no_coll_cause_set = TRUE;
    } /* end if */

    FUNC_LEAVE_NOAPI_VOID
} /* end H5CX_set_mpio_global_no_coll_cause() */

#ifdef H5_HAVE_INSTRUMENTED_LIBRARY

/*-------------------------------------------------------------------------
 * Function:    H5CX_test_set_mpio_coll_chunk_link_hard
 *
 * Purpose:     Sets the instrumented "collective chunk link hard" value for the current API call context.
 *
 * Note:        Only sets value if property set in DXPL
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              March 6, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_test_set_mpio_coll_chunk_link_hard(int mpio_coll_chunk_link_hard)
{
    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_NOINIT

    /* Sanity checks */
    HDassert(head && *head);
    HDassert(!((*head)->ctx.dxpl_id == H5P_DEFAULT || 
            (*head)->ctx.dxpl_id == H5P_DATASET_XFER_DEFAULT));

    H5CX_TEST_SET_PROP(H5D_XFER_COLL_CHUNK_LINK_HARD_NAME, mpio_coll_chunk_link_hard)

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_test_set_mpio_coll_chunk_link_hard() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_test_set_mpio_coll_chunk_multi_hard
 *
 * Purpose:     Sets the instrumented "collective chunk multi hard" value for the current API call context.
 *
 * Note:        Only sets value if property set in DXPL
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              March 6, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_test_set_mpio_coll_chunk_multi_hard(int mpio_coll_chunk_multi_hard)
{
    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_NOINIT

    /* Sanity checks */
    HDassert(head && *head);
    HDassert(!((*head)->ctx.dxpl_id == H5P_DEFAULT || 
            (*head)->ctx.dxpl_id == H5P_DATASET_XFER_DEFAULT));

    H5CX_TEST_SET_PROP(H5D_XFER_COLL_CHUNK_MULTI_HARD_NAME, mpio_coll_chunk_multi_hard)

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_test_set_mpio_coll_chunk_multi_hard() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_test_set_mpio_coll_chunk_link_num_true
 *
 * Purpose:     Sets the instrumented "collective chunk link num tru" value for the current API call context.
 *
 * Note:        Only sets value if property set in DXPL
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              March 6, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_test_set_mpio_coll_chunk_link_num_true(int mpio_coll_chunk_link_num_true)
{
    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_NOINIT

    /* Sanity checks */
    HDassert(head && *head);
    HDassert(!((*head)->ctx.dxpl_id == H5P_DEFAULT || 
            (*head)->ctx.dxpl_id == H5P_DATASET_XFER_DEFAULT));

    H5CX_TEST_SET_PROP(H5D_XFER_COLL_CHUNK_LINK_NUM_TRUE_NAME, mpio_coll_chunk_link_num_true)

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_test_set_mpio_coll_chunk_link_num_true() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_test_set_mpio_coll_chunk_link_num_false
 *
 * Purpose:     Sets the instrumented "collective chunk link num false" value for the current API call context.
 *
 * Note:        Only sets value if property set in DXPL
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              March 6, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_test_set_mpio_coll_chunk_link_num_false(int mpio_coll_chunk_link_num_false)
{
    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_NOINIT

    /* Sanity checks */
    HDassert(head && *head);
    HDassert(!((*head)->ctx.dxpl_id == H5P_DEFAULT || 
            (*head)->ctx.dxpl_id == H5P_DATASET_XFER_DEFAULT));

    H5CX_TEST_SET_PROP(H5D_XFER_COLL_CHUNK_LINK_NUM_FALSE_NAME, mpio_coll_chunk_link_num_false)

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_test_set_mpio_coll_chunk_link_num_false() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_test_set_mpio_coll_chunk_multi_ratio_coll
 *
 * Purpose:     Sets the instrumented "collective chunk multi ratio coll" value for the current API call context.
 *
 * Note:        Only sets value if property set in DXPL
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              March 6, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_test_set_mpio_coll_chunk_multi_ratio_coll(int mpio_coll_chunk_multi_ratio_coll)
{
    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_NOINIT

    /* Sanity checks */
    HDassert(head && *head);
    HDassert(!((*head)->ctx.dxpl_id == H5P_DEFAULT || 
            (*head)->ctx.dxpl_id == H5P_DATASET_XFER_DEFAULT));

    H5CX_TEST_SET_PROP(H5D_XFER_COLL_CHUNK_MULTI_RATIO_COLL_NAME, mpio_coll_chunk_multi_ratio_coll)

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_test_set_mpio_coll_chunk_multi_ratio_coll() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_test_set_mpio_coll_chunk_multi_ratio_ind
 *
 * Purpose:     Sets the instrumented "collective chunk multi ratio ind" value for the current API call context.
 *
 * Note:        Only sets value if property set in DXPL
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              March 6, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_test_set_mpio_coll_chunk_multi_ratio_ind(int mpio_coll_chunk_multi_ratio_ind)
{
    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_NOINIT

    /* Sanity checks */
    HDassert(head && *head);
    HDassert(!((*head)->ctx.dxpl_id == H5P_DEFAULT || 
            (*head)->ctx.dxpl_id == H5P_DATASET_XFER_DEFAULT));

    H5CX_TEST_SET_PROP(H5D_XFER_COLL_CHUNK_MULTI_RATIO_IND_NAME, mpio_coll_chunk_multi_ratio_ind)

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_test_set_mpio_coll_chunk_multi_ratio_ind() */
#endif /* H5_HAVE_INSTRUMENTED_LIBRARY */
#endif /* H5_HAVE_PARALLEL */


/*-------------------------------------------------------------------------
 * Function:    H5CX__pop_common
 *
 * Purpose:     Common code for popping the context for an API call.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              March 6, 2018
 *
 *-------------------------------------------------------------------------
 */
static H5CX_node_t *
H5CX__pop_common(void)
{
    H5CX_node_t **head = H5CX_get_my_context();  /* Get the pointer to the head of the API context, for this thread */
    H5CX_node_t *ret_value = NULL;      /* Return value */

    FUNC_ENTER_STATIC

    /* Sanity check */
    HDassert(head && *head);

    /* Check for cached DXPL properties to return to application */
    H5CX_SET_PROP(H5D_XFER_DIRECT_CHUNK_READ_FILTERS_NAME, dcr_filters)
#ifdef H5_HAVE_PARALLEL
    H5CX_SET_PROP(H5D_MPIO_ACTUAL_CHUNK_OPT_MODE_NAME, mpio_actual_chunk_opt)
    H5CX_SET_PROP(H5D_MPIO_ACTUAL_IO_MODE_NAME, mpio_actual_io_mode)
    H5CX_SET_PROP(H5D_MPIO_LOCAL_NO_COLLECTIVE_CAUSE_NAME, mpio_local_no_coll_cause)
    H5CX_SET_PROP(H5D_MPIO_GLOBAL_NO_COLLECTIVE_CAUSE_NAME, mpio_global_no_coll_cause)
#ifdef H5_HAVE_INSTRUMENTED_LIBRARY
    H5CX_SET_PROP(H5D_XFER_COLL_CHUNK_LINK_HARD_NAME, mpio_coll_chunk_link_hard)
    H5CX_SET_PROP(H5D_XFER_COLL_CHUNK_MULTI_HARD_NAME, mpio_coll_chunk_multi_hard)
    H5CX_SET_PROP(H5D_XFER_COLL_CHUNK_LINK_NUM_TRUE_NAME, mpio_coll_chunk_link_num_true)
    H5CX_SET_PROP(H5D_XFER_COLL_CHUNK_LINK_NUM_FALSE_NAME, mpio_coll_chunk_link_num_false)
    H5CX_SET_PROP(H5D_XFER_COLL_CHUNK_MULTI_RATIO_COLL_NAME, mpio_coll_chunk_multi_ratio_coll)
    H5CX_SET_PROP(H5D_XFER_COLL_CHUNK_MULTI_RATIO_IND_NAME, mpio_coll_chunk_multi_ratio_ind)
#endif /* H5_HAVE_INSTRUMENTED_LIBRARY */
#endif /* H5_HAVE_PARALLEL */

    /* Pop the top context node from the stack */
    ret_value = (*head);
    (*head) = (*head)->next;

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX__pop_common() */


/*-------------------------------------------------------------------------
 * Function:    H5CX_pop
 *
 * Purpose:     Pops the context for an API call.
 *
 * Return:      Non-negative on success / Negative on failure
 *
 * Programmer:  Quincey Koziol
 *              Februrary 19, 2018
 *
 *-------------------------------------------------------------------------
 */
herr_t
H5CX_pop(void)
{
    H5CX_node_t *cnode;                 /* Context node */
    herr_t ret_value = SUCCEED;         /* Return value */

    FUNC_ENTER_NOAPI(FAIL)

    /* Perform common operations and get top context from stack */
    if(NULL == (cnode = H5CX__pop_common()))
        HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "error getting API context node")

    /* Free the context node */
    cnode = H5FL_FREE(H5CX_node_t, cnode);

done:
    FUNC_LEAVE_NOAPI(ret_value)
} /* end H5CX_pop() */