text: /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
   * 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, H5CX_get_my_context() 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 retrieving the pointer to a property list */
  #define H5CX_RETRIEVE_PLIST(PL, FAILVAL)                                      \
      /* Check if the property list is already available */                     \
      if(NULL == (*head)->ctx.PL)                                               \
          /* Get the property list pointer */                                   \
          if(NULL == ((*head)->ctx.PL = (H5P_genplist_t *)H5I_object((*head)->ctx.H5_GLUE(PL,_id)))) \
              HGOTO_ERROR(H5E_CONTEXT, H5E_BADTYPE, (FAILVAL), "can't get property list")
  
  /* Common macro for the duplicated code to retrieve properties from a property list */
  #define H5CX_RETRIEVE_PROP_COMMON(PL, DEF_PL, PROP_NAME, PROP_FIELD)          \
      /* Check for default property list */                                     \
      if((*head)->ctx.H5_GLUE(PL,_id) == (DEF_PL))                              \
          H5MM_memcpy(&(*head)->ctx.PROP_FIELD, &H5_GLUE3(H5CX_def_,PL,_cache).PROP_FIELD, sizeof(H5_GLUE3(H5CX_def_,PL,_cache).PROP_FIELD)); \
      else {                                                                    \
          /* Retrieve the property list */                                      \
          H5CX_RETRIEVE_PLIST(PL, FAIL)                                         \
                                                                                \
          /* Get the property */                                                \
          if(H5P_get((*head)->ctx.PL, (PROP_NAME), &(*head)->ctx.PROP_FIELD) < 0) \
              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 */
  
  #if defined(H5_HAVE_PARALLEL) && defined(H5_HAVE_INSTRUMENTED_LIBRARY)
  /* 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)) {                              \
          /* Retrieve the dataset transfer property list */                     \
          H5CX_RETRIEVE_PLIST(dxpl, FAIL)                                       \
                                                                                \
          if((check_prop = H5P_exist_plist((*head)->ctx.dxpl, PROP_NAME)) < 0)  \
              HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "error checking for property") \
      } /* 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 /* defined(H5_HAVE_PARALLEL) && defined(H5_HAVE_INSTRUMENTED_LIBRARY) */
  
  #ifdef 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)) {                               \
          /* Retrieve the dataset transfer property list */                     \
          H5CX_RETRIEVE_PLIST(dxpl, NULL)                                       \
                                                                                \
          /* Set the property */                              		      \
          if(H5P_set((*head)->ctx.dxpl, PROP_NAME, &(*head)->ctx.PROP_FIELD) < 0) \
              HGOTO_ERROR(H5E_CONTEXT, H5E_CANTSET, NULL, "error setting data xfer property") \
      } /* end if */
  #endif /* H5_HAVE_PARALLEL */
  
  
  /******************/
  /* 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 */
  
      /* LCPL */
      hid_t lcpl_id;              /* LCPL ID for API operation */
      H5P_genplist_t *lcpl;       /* Link Creation Property List */
  
      /* LAPL */
      hid_t lapl_id;              /* LAPL ID for API operation */
      H5P_genplist_t *lapl;       /* Link Access Property List */
  
      /* DCPL */
      hid_t dcpl_id;              /* DCPL ID for API operation */
      H5P_genplist_t *dcpl;       /* Dataset Creation Property List */
  
      /* DAPL */
      hid_t dapl_id;              /* DAPL ID for API operation */
      H5P_genplist_t *dapl;       /* Dataset Access Property List */
  
      /* FAPL */
      hid_t fapl_id;              /* FAPL ID for API operation */
      H5P_genplist_t *fapl;       /* File 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 */
      hbool_t rank0_bcast;        /* Whether a dataset meets read-with-rank0-and-bcast requirements */
  #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 */
      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 */
  #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 */
      hbool_t mpio_coll_rank0_bcast;  /* Instrumented "collective chunk multi ratio ind" value (H5D_XFER_COLL_CHUNK_MULTI_RATIO_IND_NAME) */
      hbool_t mpio_coll_rank0_bcast_set; /* Whether instrumented "collective chunk multi ratio ind" value is set */
  #endif /* H5_HAVE_INSTRUMENTED_LIBRARY */
  #endif /* H5_HAVE_PARALLEL */
  
      /* Cached LCPL properties */
      H5T_cset_t encoding;     /* Link name character encoding */
      hbool_t encoding_valid;  /* Whether link name character encoding is valid */
      unsigned intermediate_group;       /* Whether to create intermediate groups */
      hbool_t intermediate_group_valid;  /* Whether create intermediate group flag is valid */
  
      /* 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 */
  
      /* Cached DCPL properties */
      hbool_t do_min_dset_ohdr;   /* Whether to minimize dataset object header */
      hbool_t do_min_dset_ohdr_valid;   /* Whether minimize dataset object header flag is valid */
      uint8_t ohdr_flags;  /* Object header flags */
      hbool_t ohdr_flags_valid;  /* Whether the object headers flags are valid */
  
      /* Cached DAPL properties */
      const char *extfile_prefix;         /* Prefix for external file                      */
      hbool_t extfile_prefix_valid;       /* Whether the prefix for external file is valid */
      const char *vds_prefix;             /* Prefix for VDS                                */
      hbool_t vds_prefix_valid;           /* Whether the prefix for VDS is valid           */
  
      /* Cached FAPL properties */
      H5F_libver_t low_bound;     /* low_bound property for H5Pset_libver_bounds() */
      hbool_t low_bound_valid;    /* Whether low_bound property is valid */
      H5F_libver_t high_bound;    /* high_bound property for H5Pset_libver_bounds */
      hbool_t high_bound_valid;   /* Whether high_bound property is valid */
  
      /* Cached VOL settings */
      H5VL_connector_prop_t vol_connector_prop;  /* Property for VOL connector ID & info */
      hbool_t vol_connector_prop_valid; /* Whether property for VOL connector ID & info is valid */
      void *vol_wrap_ctx;         /* VOL connector's "wrap context" for creating IDs */
      hbool_t vol_wrap_ctx_valid; /* Whether VOL connector's "wrap context" for creating IDs 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) */
      H5T_conv_cb_t dt_conv_cb;       /* Datatype conversion struct (H5D_XFER_CONV_CB_NAME) */
  } H5CX_dxpl_cache_t;
  
  /* Typedef for cached default link creation property list information */
  /* (Same as the cached DXPL struct, above, except for the default LCPL) */
  typedef struct H5CX_lcpl_cache_t {
      H5T_cset_t encoding;         /* Link name character encoding */
      unsigned intermediate_group; /* Whether to create intermediate groups  */
  } H5CX_lcpl_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;
  
  /* Typedef for cached default dataset creation property list information */
  /* (Same as the cached DXPL struct, above, except for the default DCPL) */
  typedef struct H5CX_dcpl_cache_t {
      hbool_t do_min_dset_ohdr;   /* Whether to minimize dataset object header */
      uint8_t ohdr_flags;  /* Object header flags */
  } H5CX_dcpl_cache_t;
  
  /* Typedef for cached default dataset access property list information */
  /* (Same as the cached DXPL struct, above, except for the default DXPL) */
  typedef struct H5CX_dapl_cache_t {
      const char *extfile_prefix; /* Prefix for external file */
      const char *vds_prefix;     /* Prefix for VDS           */
  } H5CX_dapl_cache_t;
  
  /* Typedef for cached default file access property list information */
  /* (Same as the cached DXPL struct, above, except for the default DCPL) */
  typedef struct H5CX_fapl_cache_t {
      H5F_libver_t low_bound;     /* low_bound property for H5Pset_libver_bounds() */
      H5F_libver_t high_bound;    /* high_bound property for H5Pset_libver_bounds */
  } H5CX_fapl_cache_t;
  
  /********************/
  /* Local Prototypes */
  /********************/
  #ifdef H5_HAVE_THREADSAFE
  static H5CX_node_t **H5CX__get_context(void);
  #endif /* H5_HAVE_THREADSAFE */
  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 creation property list cache structure to use for default LCPLs */
  static H5CX_lcpl_cache_t H5CX_def_lcpl_cache;
  
  /* Define a "default" link access property list cache structure to use for default LAPLs */
  static H5CX_lapl_cache_t H5CX_def_lapl_cache;
  
  /* Define a "default" dataset creation property list cache structure to use for default DCPLs */
  static H5CX_dcpl_cache_t H5CX_def_dcpl_cache;
  
  /* Define a "default" dataset access property list cache structure to use for default DAPLs */
  static H5CX_dapl_cache_t H5CX_def_dapl_cache;
  
  /* Define a "default" file access property list cache structure to use for default FAPLs */
  static H5CX_fapl_cache_t H5CX_def_fapl_cache;
  
  /* Declare a static free list to manage H5CX_node_t structs */
  H5FL_DEFINE_STATIC(H5CX_node_t);
  
  /* Declare a static free list to manage H5CX_state_t structs */
  H5FL_DEFINE_STATIC(H5CX_state_t);
  
  
  
  /*--------------------------------------------------------------------------
  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 *lc_plist;           /* Link creation property list */
      H5P_genplist_t *la_plist;           /* Link access property list */
      H5P_genplist_t *dc_plist;           /* Dataset creation property list */
      H5P_genplist_t *da_plist;           /* Dataset access property list */
      H5P_genplist_t *fa_plist;           /* File access property list */
      herr_t ret_value = SUCCEED;         /* Return value */
  
      FUNC_ENTER_STATIC
  
      /* 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 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 LCPL cache" information */
      HDmemset(&H5CX_def_lcpl_cache, 0, sizeof(H5CX_lcpl_cache_t));
  
      /* Get the default LCPL cache information */
  
      /* Get the default link creation property list */
      if(NULL == (lc_plist = (H5P_genplist_t *)H5I_object(H5P_LINK_CREATE_DEFAULT)))
          HGOTO_ERROR(H5E_CONTEXT, H5E_BADTYPE, FAIL, "not a link creation property list")
  
      /* Get link name character encoding */
      if(H5P_get(lc_plist, H5P_STRCRT_CHAR_ENCODING_NAME, &H5CX_def_lcpl_cache.encoding) < 0)
          HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve link name encoding")
  
      /* Get flag whether to create intermediate groups */
      if(H5P_get(lc_plist, H5L_CRT_INTERMEDIATE_GROUP_NAME, &H5CX_def_lcpl_cache.intermediate_group) < 0)
          HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve intermediate group creation flag")
  
      /* 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")
  
      /* Reset the "default DCPL cache" information */
      HDmemset(&H5CX_def_dcpl_cache, 0, sizeof(H5CX_dcpl_cache_t));
  
      /* Get the default DCPL cache information */
  
      /* Get the default dataset creation property list */
      if(NULL == (dc_plist = (H5P_genplist_t *)H5I_object(H5P_DATASET_CREATE_DEFAULT)))
          HGOTO_ERROR(H5E_CONTEXT, H5E_BADTYPE, FAIL, "not a dataset create property list")
  
      /* Get flag to indicate whether to minimize dataset object header */
      if(H5P_get(dc_plist, H5D_CRT_MIN_DSET_HDR_SIZE_NAME, &H5CX_def_dcpl_cache.do_min_dset_ohdr) < 0)
          HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve dataset minimize flag")
  
      /* Get object header flags */
      if(H5P_get(dc_plist, H5O_CRT_OHDR_FLAGS_NAME, &H5CX_def_dcpl_cache.ohdr_flags) < 0)
          HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve object header flags")
  
      /* Reset the "default DAPL cache" information */
      HDmemset(&H5CX_def_dapl_cache, 0, sizeof(H5CX_dapl_cache_t));
  
      /* Get the default DAPL cache information */
  
      /* Get the default dataset access property list */
      if(NULL == (da_plist = (H5P_genplist_t *)H5I_object(H5P_DATASET_ACCESS_DEFAULT)))
          HGOTO_ERROR(H5E_CONTEXT, H5E_BADTYPE, FAIL, "not a dataset create property list")
  
      /* Get the prefix for the external file */
      if(H5P_peek(da_plist, H5D_ACS_EFILE_PREFIX_NAME, &H5CX_def_dapl_cache.extfile_prefix) < 0)
          HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve prefix for external file")
  
      /* Get the prefix for the VDS file */
      if(H5P_peek(da_plist, H5D_ACS_VDS_PREFIX_NAME, &H5CX_def_dapl_cache.vds_prefix) < 0)
          HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve prefix for VDS")
  
      /* Reset the "default FAPL cache" information */
      HDmemset(&H5CX_def_fapl_cache, 0, sizeof(H5CX_fapl_cache_t));
  
      /* Get the default FAPL cache information */
  
      /* Get the default file access property list */
      if(NULL == (fa_plist = (H5P_genplist_t *)H5I_object(H5P_FILE_ACCESS_DEFAULT)))
          HGOTO_ERROR(H5E_CONTEXT, H5E_BADTYPE, FAIL, "not a dataset create property list")
  
      /* Get low_bound */
      if(H5P_get(fa_plist, H5F_ACS_LIBVER_LOW_BOUND_NAME, &H5CX_def_fapl_cache.low_bound) < 0)
          HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve dataset minimize flag")
  
      if(H5P_get(fa_plist, H5F_ACS_LIBVER_HIGH_BOUND_NAME, &H5CX_def_fapl_cache.high_bound) < 0)
          HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve dataset minimize flag")
  
  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
          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.dcpl_id = H5P_DATASET_CREATE_DEFAULT;
      cnode->ctx.dapl_id = H5P_DATASET_ACCESS_DEFAULT;
      cnode->ctx.lcpl_id = H5P_LINK_CREATE_DEFAULT;
      cnode->ctx.lapl_id = H5P_LINK_ACCESS_DEFAULT;
      cnode->ctx.fapl_id = H5P_FILE_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_retrieve_state
   *
   * Purpose:     Retrieve the state of an API context, for later resumption.
   *
   * Note:	This routine _only_ tracks the state of API context information
   *		set before the VOL callback is invoked, not values that are
   *		set internal to the library.  It's main purpose is to provide
   *		API context state to VOL connectors.
   *
   * Return:      Non-negative on success / Negative on failure
   *
   * Programmer:  Quincey Koziol
   *              January 8, 2019
   *
   *-------------------------------------------------------------------------
   */
  herr_t
  H5CX_retrieve_state(H5CX_state_t **api_state)
  {
      H5CX_node_t **head = H5CX_get_my_context();  /* Get the pointer to the head of the API context, for this thread */
      herr_t ret_value = SUCCEED;         /* Return value */
  
      FUNC_ENTER_NOAPI(FAIL)
  
      /* Sanity check */
      HDassert(head && *head);
      HDassert(api_state);
  
      /* Allocate & clear API context state */
      if(NULL == (*api_state = H5FL_CALLOC(H5CX_state_t)))
          HGOTO_ERROR(H5E_CONTEXT, H5E_CANTALLOC, FAIL, "unable to allocate new API context state")
  
      /* Check for non-default DCPL */
      if(H5P_DATASET_CREATE_DEFAULT != (*head)->ctx.dcpl_id) {
          /* Retrieve the DCPL property list */
          H5CX_RETRIEVE_PLIST(dcpl, FAIL)
  
          /* Copy the DCPL ID */
          if(((*api_state)->dcpl_id = H5P_copy_plist((H5P_genplist_t *)(*head)->ctx.dcpl, FALSE)) < 0)
              HGOTO_ERROR(H5E_CONTEXT, H5E_CANTCOPY, FAIL, "can't copy property list")
      } /* end if */
      else
          (*api_state)->dcpl_id = H5P_DATASET_CREATE_DEFAULT;
  
      /* Check for non-default DXPL */
      if(H5P_DATASET_XFER_DEFAULT != (*head)->ctx.dxpl_id) {
          /* Retrieve the DXPL property list */
          H5CX_RETRIEVE_PLIST(dxpl, FAIL)
  
          /* Copy the DXPL ID */
          if(((*api_state)->dxpl_id = H5P_copy_plist((H5P_genplist_t *)(*head)->ctx.dxpl, FALSE)) < 0)
              HGOTO_ERROR(H5E_CONTEXT, H5E_CANTCOPY, FAIL, "can't copy property list")
      } /* end if */
      else
          (*api_state)->dxpl_id = H5P_DATASET_XFER_DEFAULT;
  
      /* Check for non-default LAPL */
      if(H5P_LINK_ACCESS_DEFAULT != (*head)->ctx.lapl_id) {
          /* Retrieve the LAPL property list */
          H5CX_RETRIEVE_PLIST(lapl, FAIL)
  
          /* Copy the LAPL ID */
          if(((*api_state)->lapl_id = H5P_copy_plist((H5P_genplist_t *)(*head)->ctx.lapl, FALSE)) < 0)
              HGOTO_ERROR(H5E_CONTEXT, H5E_CANTCOPY, FAIL, "can't copy property list")
      } /* end if */
      else
          (*api_state)->lapl_id = H5P_LINK_ACCESS_DEFAULT;
  
      /* Check for non-default LCPL */
      if(H5P_LINK_CREATE_DEFAULT != (*head)->ctx.lcpl_id) {
          /* Retrieve the LCPL property list */
          H5CX_RETRIEVE_PLIST(lcpl, FAIL)
  
          /* Copy the LCPL ID */
          if(((*api_state)->lcpl_id = H5P_copy_plist((H5P_genplist_t *)(*head)->ctx.lcpl, FALSE)) < 0)
              HGOTO_ERROR(H5E_CONTEXT, H5E_CANTCOPY, FAIL, "can't copy property list")
      } /* end if */
      else
          (*api_state)->lcpl_id = H5P_LINK_CREATE_DEFAULT;
  
      /* Keep a reference to the current VOL wrapping context */
      (*api_state)->vol_wrap_ctx = (*head)->ctx.vol_wrap_ctx;
      if(NULL != (*api_state)->vol_wrap_ctx)
          if(H5VL_inc_vol_wrapper((*api_state)->vol_wrap_ctx) < 0)
              HGOTO_ERROR(H5E_CONTEXT, H5E_CANTINC, FAIL, "can't increment refcount on VOL wrapping context")
  
      /* Keep a copy of the VOL connector property, if there is one */
      if((*head)->ctx.vol_connector_prop_valid && (*head)->ctx.vol_connector_prop.connector_id > 0) {
          /* Get the connector property */
          H5MM_memcpy(&(*api_state)->vol_connector_prop, &(*head)->ctx.vol_connector_prop, sizeof(H5VL_connector_prop_t));
  
          /* Check for actual VOL connector property */
          if((*api_state)->vol_connector_prop.connector_id) {
              /* Copy connector info, if it exists */
              if((*api_state)->vol_connector_prop.connector_info) {
                  H5VL_class_t *connector;           /* Pointer to connector */
                  void *new_connector_info = NULL;    /* Copy of connector info */
  
                  /* Retrieve the connector for the ID */
                  if(NULL == (connector = (H5VL_class_t *)H5I_object((*api_state)->vol_connector_prop.connector_id)))
                      HGOTO_ERROR(H5E_CONTEXT, H5E_BADTYPE, FAIL, "not a VOL connector ID")
  
                  /* Allocate and copy connector info */
                  if(H5VL_copy_connector_info(connector, &new_connector_info, (*api_state)->vol_connector_prop.connector_info) < 0)
                      HGOTO_ERROR(H5E_CONTEXT, H5E_CANTCOPY, FAIL, "connector info copy failed")
                  (*api_state)->vol_connector_prop.connector_info = new_connector_info;
              } /* end if */
  
              /* Increment the refcount on the connector ID */
              if(H5I_inc_ref((*api_state)->vol_connector_prop.connector_id, FALSE) < 0)
                  HGOTO_ERROR(H5E_CONTEXT, H5E_CANTINC, FAIL, "incrementing VOL connector ID failed")
          } /* end if */
      } /* end if */
  
  #ifdef H5_HAVE_PARALLEL
      /* Save parallel I/O settings */
      (*api_state)->coll_metadata_read = (*head)->ctx.coll_metadata_read;
  #endif /* H5_HAVE_PARALLEL */
  
  done:
      FUNC_LEAVE_NOAPI(ret_value)
  } /* end H5CX_retrieve_state() */
  
  
  /*-------------------------------------------------------------------------
   * Function:    H5CX_restore_state
   *
   * Purpose:     Restore an API context, from a previously retrieved state.
   *
   * Note:	This routine _only_ resets the state of API context information
   *		set before the VOL callback is invoked, not values that are
   *		set internal to the library.  It's main purpose is to restore
   *		API context state from VOL connectors.
   *
   * Return:      Non-negative on success / Negative on failure
   *
   * Programmer:  Quincey Koziol
   *              January 9, 2019
   *
   *-------------------------------------------------------------------------
   */
  herr_t
  H5CX_restore_state(const H5CX_state_t *api_state)
  {
      H5CX_node_t **head = H5CX_get_my_context();  /* Get the pointer to the head of the API context, for this thread */
  
      FUNC_ENTER_NOAPI_NOINIT_NOERR
  
      /* Sanity check */
      HDassert(head && *head);
      HDassert(api_state);
  
      /* Restore the DCPL info */
      (*head)->ctx.dcpl_id = api_state->dcpl_id;
      (*head)->ctx.dcpl = NULL;
  
      /* Restore the DXPL info */
      (*head)->ctx.dxpl_id = api_state->dxpl_id;
      (*head)->ctx.dxpl = NULL;
  
      /* Restore the LAPL info */
      (*head)->ctx.lapl_id = api_state->lapl_id;
      (*head)->ctx.lapl = NULL;
  
      /* Restore the LCPL info */
      (*head)->ctx.lcpl_id = api_state->lcpl_id;
      (*head)->ctx.lcpl = NULL;
  
      /* Restore the VOL wrapper context */
      (*head)->ctx.vol_wrap_ctx = api_state->vol_wrap_ctx;
  
      /* Restore the VOL connector info */
      if(api_state->vol_connector_prop.connector_id) {
          H5MM_memcpy(&(*head)->ctx.vol_connector_prop, &api_state->vol_connector_prop, sizeof(H5VL_connector_prop_t));
          (*head)->ctx.vol_connector_prop_valid = TRUE;
      } /* end if */
  
  #ifdef H5_HAVE_PARALLEL
      /* Restore parallel I/O settings */
      (*head)->ctx.coll_metadata_read = api_state->coll_metadata_read;
  #endif /* H5_HAVE_PARALLEL */
  
      FUNC_LEAVE_NOAPI(SUCCEED)
  } /* end H5CX_restore_state() */
  
  
  /*-------------------------------------------------------------------------
   * Function:    H5CX_free_state
   *
   * Purpose:     Free a previously retrievedAPI context state
   *
   * Return:      Non-negative on success / Negative on failure
   *
   * Programmer:  Quincey Koziol
   *              January 9, 2019
   *
   *-------------------------------------------------------------------------
   */
  herr_t
  H5CX_free_state(H5CX_state_t *api_state)
  {
      herr_t ret_value = SUCCEED;         /* Return value */
  
      FUNC_ENTER_NOAPI(FAIL)
  
      /* Sanity check */
      HDassert(api_state);
  
      /* Release the DCPL */
      if(api_state->dcpl_id != H5P_DATASET_CREATE_DEFAULT)
          if(H5I_dec_ref(api_state->dcpl_id) < 0)
              HGOTO_ERROR(H5E_CONTEXT, H5E_CANTDEC, FAIL, "can't decrement refcount on DCPL")
  
      /* Release the DXPL */
      if(api_state->dxpl_id != H5P_DATASET_XFER_DEFAULT)
          if(H5I_dec_ref(api_state->dxpl_id) < 0)
              HGOTO_ERROR(H5E_CONTEXT, H5E_CANTDEC, FAIL, "can't decrement refcount on DXPL")
  
      /* Release the LAPL */
      if(api_state->lapl_id != H5P_LINK_ACCESS_DEFAULT)
          if(H5I_dec_ref(api_state->lapl_id) < 0)
              HGOTO_ERROR(H5E_CONTEXT, H5E_CANTDEC, FAIL, "can't decrement refcount on LAPL")
  
      /* Release the LCPL */
      if(api_state->lcpl_id != H5P_LINK_CREATE_DEFAULT)
          if(H5I_dec_ref(api_state->lcpl_id) < 0)
              HGOTO_ERROR(H5E_CONTEXT, H5E_CANTDEC, FAIL, "can't decrement refcount on LCPL")
  
      /* Release the VOL wrapper context */
      if(api_state->vol_wrap_ctx)
          if(H5VL_dec_vol_wrapper(api_state->vol_wrap_ctx) < 0)
              HGOTO_ERROR(H5E_CONTEXT, H5E_CANTDEC, FAIL, "can't decrement refcount on VOL wrapping context")
  
      /* Release the VOL connector property, if it was set */
      if(api_state->vol_connector_prop.connector_id) {
          /* Clean up any VOL connector info */
          if(api_state->vol_connector_prop.connector_info)
              if(H5VL_free_connector_info(api_state->vol_connector_prop.connector_id, api_state->vol_connector_prop.connector_info) < 0)
                  HGOTO_ERROR(H5E_CONTEXT, H5E_CANTRELEASE, FAIL, "unable to release VOL connector info object")
          /* Decrement connector ID */
          if(H5I_dec_ref(api_state->vol_connector_prop.connector_id) < 0)
              HDONE_ERROR(H5E_CONTEXT, H5E_CANTDEC, FAIL, "can't close VOL connector ID")
      } /* end if */
  
      /* Free the state */
      api_state = H5FL_FREE(H5CX_state_t, api_state);
  
  done:
      FUNC_LEAVE_NOAPI(ret_value)
  } /* end H5CX_free_state() */
  
  
  /*-------------------------------------------------------------------------
   * Function:    H5CX_is_def_dxpl
   *
   * Purpose:     Checks if the API context is using the library's default DXPL
   *
   * 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_dcpl
   *
   * Purpose:     Sets the DCPL for the current API call context.
   *
   * Return:      <none>
   *
   * Programmer:  Quincey Koziol
   *              March 6, 2019
   *
   *-------------------------------------------------------------------------
   */
  void
  H5CX_set_dcpl(hid_t dcpl_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 DCPL to a new value */
      (*head)->ctx.dcpl_id = dcpl_id;
  
      FUNC_LEAVE_NOAPI_VOID
  } /* end H5CX_set_dcpl() */
  
  
  /*-------------------------------------------------------------------------
   * Function:    H5CX_set_libver_bounds
   *
   * Purpose:     Sets the low/high bounds according to "f" for the current API call context.
   *              When "f" is NULL, the low/high bounds are set to latest format.
   *
   * Return:      Non-negative on success / Negative on failure
   *
   * Programmer:  Vailin Choi
   *              March 27, 2019
   *
   *-------------------------------------------------------------------------
   */
  herr_t
  H5CX_set_libver_bounds(H5F_t *f)
  {
      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.low_bound = (f == NULL) ? H5F_LIBVER_LATEST : H5F_LOW_BOUND(f);
      (*head)->ctx.high_bound = (f == NULL) ? H5F_LIBVER_LATEST : H5F_HIGH_BOUND(f);
  
      /* Mark the values as valid */
      (*head)->ctx.low_bound_valid = TRUE;
      (*head)->ctx.high_bound_valid = TRUE;
  
  done:
      FUNC_LEAVE_NOAPI(ret_value)
  } /* end H5CX_set_libver_bounds() */
  
  
  /*-------------------------------------------------------------------------
   * Function:    H5CX_set_lcpl
   *
   * Purpose:     Sets the LCPL for the current API call context.
   *
   * Return:      <none>
   *
   * Programmer:  Chris Hogan
   *              October 28, 2019
   *
   *-------------------------------------------------------------------------
   */
  void
  H5CX_set_lcpl(hid_t lcpl_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 LCPL to a new value */
      (*head)->ctx.lcpl_id = lcpl_id;
  
      FUNC_LEAVE_NOAPI_VOID
  } /* end H5CX_set_lcpl() */
  
  
  /*-------------------------------------------------------------------------
   * 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 */
          htri_t is_dapl;         /* Whether the access property list is (or is derived from) a dataset access property list */
          htri_t is_fapl;         /* Whether the access property list is (or is derived from) a file 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;
  
          /* Check for dataset access property and set API context if so */
          if((is_dapl = H5P_class_isa(*libclass->pclass, *H5P_CLS_DACC->pclass)) < 0)
              HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "can't check for dataset access class")
          else if(is_dapl)
              (*head)->ctx.dapl_id = *acspl_id;
  
          /* Check for file access property and set API context if so */
          if((is_fapl = H5P_class_isa(*libclass->pclass, *H5P_CLS_FACC->pclass)) < 0)
              HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "can't check for file access class")
          else if(is_fapl)
              (*head)->ctx.fapl_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 the application
           * specified a collective metadata read for just this operation.
           */
          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)
  {
  #ifdef H5_HAVE_PARALLEL
      H5CX_node_t **head = H5CX_get_my_context();  /* Get the pointer to the head of the API context, for this thread */
      herr_t ret_value = SUCCEED;         /* Return value */
  
      FUNC_ENTER_NOAPI(FAIL)
  
      /* Sanity check */
      HDassert(head && *head);
  
      /* 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 */
  
  done:
      FUNC_LEAVE_NOAPI(ret_value)
  #else /* H5_HAVE_PARALLEL */
      FUNC_ENTER_NOAPI_NOINIT_NOERR
  
      FUNC_LEAVE_NOAPI(SUCCEED)
  #endif /* H5_HAVE_PARALLEL */
  } /* end H5CX_set_loc() */
  
  
  /*-------------------------------------------------------------------------
   * Function:    H5CX_set_vol_wrap_ctx
   *
   * Purpose:     Sets the VOL object wrapping context for an operation.
   *
   * Return:      Non-negative on success / Negative on failure
   *
   * Programmer:  Quincey Koziol
   *              October 14, 2018
   *
   *-------------------------------------------------------------------------
   */
  herr_t
  H5CX_set_vol_wrap_ctx(void *vol_wrap_ctx)
  {
      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.vol_wrap_ctx = vol_wrap_ctx;
  
      /* Mark the value as valid */
      (*head)->ctx.vol_wrap_ctx_valid = TRUE;
  
  done:
      FUNC_LEAVE_NOAPI(ret_value)
  } /* end H5CX_set_vol_wrap_ctx() */
  
  
  /*-------------------------------------------------------------------------
   * Function:    H5CX_set_vol_connector_prop
   *
   * Purpose:     Sets the VOL connector ID & info for an operation.
   *
   * Return:      Non-negative on success / Negative on failure
   *
   * Programmer:  Quincey Koziol
   *              January 3, 2019
   *
   *-------------------------------------------------------------------------
   */
  herr_t
  H5CX_set_vol_connector_prop(const H5VL_connector_prop_t *vol_connector_prop)
  {
      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 */
      H5MM_memcpy(&(*head)->ctx.vol_connector_prop, vol_connector_prop, sizeof(H5VL_connector_prop_t));
  
      /* Mark the value as valid */
      (*head)->ctx.vol_connector_prop_valid = TRUE;
  
  done:
      FUNC_LEAVE_NOAPI(ret_value)
  } /* end H5CX_set_vol_connector_prop() */
  
  
  /*-------------------------------------------------------------------------
   * 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_vol_wrap_ctx
   *
   * Purpose:     Retrieves the VOL object wrapping context for an operation.
   *
   * Return:      Non-negative on success / Negative on failure
   *
   * Programmer:  Quincey Koziol
   *              October 14, 2018
   *
   *-------------------------------------------------------------------------
   */
  herr_t
  H5CX_get_vol_wrap_ctx(void **vol_wrap_ctx)
  {
      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(vol_wrap_ctx);
      HDassert(head && *head);
  
      /* Check for value that was set */
      if((*head)->ctx.vol_wrap_ctx_valid)
          /* Get the value */
          *vol_wrap_ctx = (*head)->ctx.vol_wrap_ctx;
      else
          *vol_wrap_ctx = NULL;
  
  done:
      FUNC_LEAVE_NOAPI(ret_value)
  } /* end H5CX_get_vol_wrap_ctx() */
  
  
  /*-------------------------------------------------------------------------
   * Function:    H5CX_get_vol_connector_prop
   *
   * Purpose:     Retrieves the VOL connector ID & info for an operation.
   *
   * Return:      Non-negative on success / Negative on failure
   *
   * Programmer:  Quincey Koziol
   *              January 3, 2019
   *
   *-------------------------------------------------------------------------
   */
  herr_t
  H5CX_get_vol_connector_prop(H5VL_connector_prop_t *vol_connector_prop)
  {
      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(vol_connector_prop);
      HDassert(head && *head);
  
      /* Check for value that was set */
      if((*head)->ctx.vol_connector_prop_valid)
          /* Get the value */
          H5MM_memcpy(vol_connector_prop, &(*head)->ctx.vol_connector_prop, sizeof(H5VL_connector_prop_t));
      else
          HDmemset(vol_connector_prop, 0, sizeof(H5VL_connector_prop_t));
  
  done:
      FUNC_LEAVE_NOAPI(ret_value)
  } /* end H5CX_get_vol_connector_prop() */
  
  
  /*-------------------------------------------------------------------------
   * 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() */
  
  
  /*-------------------------------------------------------------------------
   * Function:    H5CX_get_mpio_rank0_bcast
   *
   * Purpose:     Retrieves if the dataset meets read-with-rank0-and-bcast requirements for the current API call context.
   *
   * Return:      Non-negative on success / Negative on failure
   *
   * Programmer:  M. Breitenfeld
   *              December 31, 2018
   *
   *-------------------------------------------------------------------------
   */
  hbool_t
  H5CX_get_mpio_rank0_bcast(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.rank0_bcast)
  } /* end H5CX_get_mpio_rank0_bcast() */
  #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 */
      H5MM_memcpy(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_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_encoding
   *
   * Purpose:     Retrieves the character encoding for the current API call context.
   *
   * Return:      Non-negative on success / Negative on failure
   *
   * Programmer:  Gerd Heber
   *              October 21, 2019
   *
   *-------------------------------------------------------------------------
   */
  herr_t
  H5CX_get_encoding(H5T_cset_t* encoding)
  {
      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(encoding);
      HDassert(head && *head);
      HDassert(H5P_DEFAULT != (*head)->ctx.lcpl_id);
  
      H5CX_RETRIEVE_PROP_VALID(lcpl, H5P_LINK_CREATE_DEFAULT, H5P_STRCRT_CHAR_ENCODING_NAME, encoding)
  
      /* Get the value */
      *encoding = (*head)->ctx.encoding;
  
  done:
      FUNC_LEAVE_NOAPI(ret_value)
  } /* end H5CX_get_encoding() */
  
  
  /*-------------------------------------------------------------------------
   * Function:    H5CX_get_intermediate_group
   *
   * Purpose:     Retrieves the create intermediate group flag for the current API call context.
   *
   * Return:      Non-negative on success / Negative on failure
   *
   * Programmer:  Gerd Heber
   *              October 21, 2019
   *
   *-------------------------------------------------------------------------
   */
  herr_t
  H5CX_get_intermediate_group(unsigned* crt_intermed_group)
  {
      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(crt_intermed_group);
      HDassert(head && *head);
      HDassert(H5P_DEFAULT != (*head)->ctx.lcpl_id);
  
      H5CX_RETRIEVE_PROP_VALID(lcpl, H5P_LINK_CREATE_DEFAULT, H5L_CRT_INTERMEDIATE_GROUP_NAME, intermediate_group)
  
      /* Get the value */
      *crt_intermed_group = (*head)->ctx.intermediate_group;
  
  done:
      FUNC_LEAVE_NOAPI(ret_value)
  } /* end H5CX_get_create_intermediate_group() */
  
  
  /*-------------------------------------------------------------------------
   * 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_get_libver_bounds
   *
   * Purpose:     Retrieves the low/high bounds for the current API call context.
   *
   * Return:      Non-negative on success / Negative on failure
   *
   * Programmer:  Vailin Choi
   *              March 27, 2019
   *
   *-------------------------------------------------------------------------
   */
  herr_t
  H5CX_get_libver_bounds(H5F_libver_t *low_bound, H5F_libver_t *high_bound)
  {
      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(low_bound);
      HDassert(high_bound);
      HDassert(head && *head);
      HDassert(H5P_DEFAULT != (*head)->ctx.fapl_id);
  
      H5CX_RETRIEVE_PROP_VALID(fapl, H5P_FILE_ACCESS_DEFAULT, H5F_ACS_LIBVER_LOW_BOUND_NAME, low_bound)
      H5CX_RETRIEVE_PROP_VALID(fapl, H5P_FILE_ACCESS_DEFAULT, H5F_ACS_LIBVER_HIGH_BOUND_NAME, high_bound)
  
      /* Get the values */
      *low_bound = (*head)->ctx.low_bound;
      *high_bound = (*head)->ctx.high_bound;
  
  done:
      FUNC_LEAVE_NOAPI(ret_value)
  } /* end H5CX_get_libver_bounds() */
  
  
  /*-------------------------------------------------------------------------
   * Function:    H5CX_get_dset_min_ohdr_flag
   *
   * Purpose:     Retrieves the flag that indicates whether the dataset object
   *		header should be minimized
   *
   * Return:      Non-negative on success / Negative on failure
   *
   * Programmer:  Quincey Koziol
   *              March 6, 2019
   *
   *-------------------------------------------------------------------------
   */
  herr_t
  H5CX_get_dset_min_ohdr_flag(hbool_t *dset_min_ohdr_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(dset_min_ohdr_flag);
      HDassert(head && *head);
      HDassert(H5P_DEFAULT != (*head)->ctx.dcpl_id);
  
      H5CX_RETRIEVE_PROP_VALID(dcpl, H5P_DATASET_CREATE_DEFAULT, H5D_CRT_MIN_DSET_HDR_SIZE_NAME, do_min_dset_ohdr)
  
      /* Get the value */
      *dset_min_ohdr_flag = (*head)->ctx.do_min_dset_ohdr;
  
  done:
      FUNC_LEAVE_NOAPI(ret_value)
  } /* end H5CX_get_dset_min_ohdr_flag() */
  
  
  /*-------------------------------------------------------------------------
   * Function:    H5CX_get_ext_file_prefix
   *
   * Purpose:     Retrieves the prefix for external file
   *
   * Return:      Non-negative on success / Negative on failure
   *
   * Programmer:  Raymond Lu
   *              March 6, 2019
   *
   *-------------------------------------------------------------------------
   */
  herr_t
  H5CX_get_ext_file_prefix(const char **extfile_prefix)
  {
      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(extfile_prefix);
      HDassert(head && *head);
      HDassert(H5P_DEFAULT != (*head)->ctx.dapl_id);
  
      /* Check if the value has been retrieved already */
      if(!(*head)->ctx.extfile_prefix_valid) {
          /* Check for default DAPL */
          if((*head)->ctx.dapl_id == H5P_DATASET_ACCESS_DEFAULT)
              (*head)->ctx.extfile_prefix = H5CX_def_dapl_cache.extfile_prefix;
          else {
              /* Check if the property list is already available */
              if(NULL == (*head)->ctx.dapl)
                  /* Get the dataset access property list pointer */
                  if(NULL == ((*head)->ctx.dapl = (H5P_genplist_t *)H5I_object((*head)->ctx.dapl_id)))
                      HGOTO_ERROR(H5E_CONTEXT, H5E_BADTYPE, FAIL, "can't get default dataset access property list")
  
              /* Get the prefix for the external file */
              /* (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.dapl, H5D_ACS_EFILE_PREFIX_NAME, &(*head)->ctx.extfile_prefix) < 0)
                  HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve external file prefix")
          } /* end else */
  
          /* Mark the value as valid */
          (*head)->ctx.extfile_prefix_valid = TRUE;
      } /* end if */
  
      /* Get the value */
      *extfile_prefix = (*head)->ctx.extfile_prefix;
  
  done:
      FUNC_LEAVE_NOAPI(ret_value)
  } /* end H5CX_get_ext_file_prefix() */
  
  
  /*-------------------------------------------------------------------------
   * Function:    H5CX_get_vds_prefix
   *
   * Purpose:     Retrieves the prefix for VDS
   *
   * Return:      Non-negative on success / Negative on failure
   *
   * Programmer:  Raymond Lu
   *              March 6, 2019
   *
   *-------------------------------------------------------------------------
   */
  herr_t
  H5CX_get_vds_prefix(const char **vds_prefix)
  {
      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(vds_prefix);
      HDassert(head && *head);
      HDassert(H5P_DEFAULT != (*head)->ctx.dapl_id);
  
      /* Check if the value has been retrieved already */
      if(!(*head)->ctx.vds_prefix_valid) {
          /* Check for default DAPL */
          if((*head)->ctx.dapl_id == H5P_DATASET_ACCESS_DEFAULT)
              (*head)->ctx.vds_prefix = H5CX_def_dapl_cache.vds_prefix;
          else {
              /* Check if the property list is already available */
              if(NULL == (*head)->ctx.dapl)
                  /* Get the dataset access property list pointer */
                  if(NULL == ((*head)->ctx.dapl = (H5P_genplist_t *)H5I_object((*head)->ctx.dapl_id)))
                      HGOTO_ERROR(H5E_CONTEXT, H5E_BADTYPE, FAIL, "can't get default dataset access property list")
  
              /* Get the prefix for the VDS */
              /* (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.dapl, H5D_ACS_VDS_PREFIX_NAME, &(*head)->ctx.vds_prefix) < 0)
                  HGOTO_ERROR(H5E_CONTEXT, H5E_CANTGET, FAIL, "Can't retrieve VDS prefix")
          } /* end else */
  
          /* Mark the value as valid */
          (*head)->ctx.vds_prefix_valid = TRUE;
      } /* end if */
  
      /* Get the value */
      *vds_prefix = (*head)->ctx.vds_prefix;
  
  done:
      FUNC_LEAVE_NOAPI(ret_value)
  } /* end H5CX_get_vds_prefix() */
  
  
  /*-------------------------------------------------------------------------
   * 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() */
  
  
  /*-------------------------------------------------------------------------
   * Function:    H5CX_set_mpio_rank0_bcast
   *
   * Purpose:     Sets the "dataset meets read-with-rank0-and-bcast requirements" flag for the current API call context.
   *
   * Return:      <none>
   *
   * Programmer:  M. Breitenfeld
   *              December 31, 2018
   *
   *-------------------------------------------------------------------------
   */
  void
  H5CX_set_mpio_rank0_bcast(hbool_t rank0_bcast)
  {
      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);
  
      (*head)->ctx.rank0_bcast = rank0_bcast;
  
      FUNC_LEAVE_NOAPI_VOID
  } /* end H5CX_set_mpio_rank0_bcast() */
  #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() */
  
  #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() */
  
  
  /*-------------------------------------------------------------------------
   * Function:    H5CX_test_set_mpio_coll_rank0_bcast
   *
   * Purpose:     Sets the instrumented "read-with-rank0-bcast" flag 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
   *              January 2, 2019
   *
   *-------------------------------------------------------------------------
   */
  herr_t
  H5CX_test_set_mpio_coll_rank0_bcast(hbool_t mpio_coll_rank0_bcast)
  {
      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_RANK0_BCAST_NAME, mpio_coll_rank0_bcast)
  
  done:
      FUNC_LEAVE_NOAPI(ret_value)
  } /* end H5CX_test_set_mpio_coll_rank0_bcast() */
  #endif /* H5_HAVE_INSTRUMENTED_LIBRARY */
  #endif /* H5_HAVE_PARALLEL */
  
  
  /*-------------------------------------------------------------------------
   * Function:    H5CX_get_ohdr_flags
   *
   * Purpose:     Retrieves the object header flags for the current API call context.
   *
   * Return:      Non-negative on success / Negative on failure
   *
   * Programmer:  Chris Hogan
   *              November 15, 2019
   *
   *-------------------------------------------------------------------------
   */
  herr_t
  H5CX_get_ohdr_flags(uint8_t *ohdr_flags)
  {
      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(ohdr_flags);
      HDassert(head && *head);
      HDassert(H5P_DEFAULT != (*head)->ctx.dcpl_id);
  
      H5CX_RETRIEVE_PROP_VALID(dcpl, H5P_DATASET_CREATE_DEFAULT, H5O_CRT_OHDR_FLAGS_NAME, ohdr_flags)
  
      /* Get the value */
      *ohdr_flags = (*head)->ctx.ohdr_flags;
  
  done:
      FUNC_LEAVE_NOAPI(ret_value)
  } /* End H5CX_get_ohdr_flags() */
  
  
  /*-------------------------------------------------------------------------
   * 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 */
  
  #ifdef H5_HAVE_PARALLEL
      FUNC_ENTER_STATIC
  #else
      FUNC_ENTER_STATIC_NOERR
  #endif
  
      /* Sanity check */
      HDassert(head && *head);
  
      /* Check for cached DXPL properties to return to application */
  #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)
      H5CX_SET_PROP(H5D_XFER_COLL_RANK0_BCAST_NAME, mpio_coll_rank0_bcast)
  #endif /* H5_HAVE_INSTRUMENTED_LIBRARY */
  #endif /* H5_HAVE_PARALLEL */
  
      /* Pop the top context node from the stack */
      ret_value = (*head);
      (*head) = (*head)->next;
  
  #ifdef H5_HAVE_PARALLEL
  done:
  #endif /* H5_HAVE_PARALLEL */
      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() */
  
  