[svn-r6379] Purpose:

    Update
Description:
    H5FP.c, H5FPclient.c, H5FPprivate.h, H5FPserver.c:
        Update. More progression towards the SAP as metadata cache. It
        only lacks the ability to take care of metadata allocations.

    H5FDfphdf5.[ch]:
        Start of a new driver for FPHDF5. Not fully implemented just
        yet...
Platforms tested:
    Linux

1 files changed, 1589 insertions, 0 deletions

diff --git a/src/H5FDfphdf5.c b/src/H5FDfphdf5.c
new file mode 100644
index 0000000..689101b
--- /dev/null
+++ b/src/H5FDfphdf5.c
@@ -0,0 +1,1589 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by the Board of Trustees of the University of Illinois.         *
+ * 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 files COPYING and Copyright.html.  COPYING can be found at the root   *
+ * of the source code distribution tree; Copyright.html can be found at the  *
+ * root level of an installed copy of the electronic HDF5 document set and   *
+ * is linked from the top-level documents page.  It can also be found at     *
+ * http://hdf.ncsa.uiuc.edu/HDF5/doc/Copyright.html.  If you do not have     *
+ * access to either file, you may request a copy from hdfhelp@ncsa.uiuc.edu. *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#include "H5private.h"      /* Library functions                            */
+#include "H5ACprivate.h"    /* Metadata cache                               */
+#include "H5Eprivate.h"     /* Error handling                               */
+#include "H5Fprivate.h"     /* Files                                        */
+#include "H5FDprivate.h"    /* File driver                                  */
+#include "H5FDfphdf5.h"     /* Flexible PHDF5 I/O file driver               */
+#include "H5Iprivate.h"     /* Object IDs                                   */
+#include "H5MMprivate.h"    /* Memory allocation                            */
+#include "H5Pprivate.h"     /* Property lists                               */
+
+#ifdef H5_HAVE_FPHDF5
+
+#include "H5FPprivate.h"    /* Flexible PHDF5                               */
+
+/*
+ * The driver identification number, initialized at runtime if
+ * H5_HAVE_FPHDF5 is defined. This allows applications to still have
+ * the H5FD_FPHDF5 "constants" in their source code (it also makes this
+ * file strictly ANSI compliant when H5_HAVE_FPHDF5 isn't defined)
+ */
+static hid_t H5FD_FPHDF5_g = 0;
+
+/*
+ * The description of a file belonging to this driver.
+ *
+ * The EOF value is only used just after the file is opened in order for
+ * the library to determine whether the file is empty, truncated, or
+ * okay. The MPIO driver doesn't bother to keep it updated since it's an
+ * expensive operation.
+ */
+typedef struct H5FP_fphdf5_t {
+    H5FD_t      pub;            /*Public stuff, must be first (ick!)    */
+    MPI_File    f;              /*MPIO file handle                      */
+    MPI_Comm    comm;           /*Communicator                          */
+    MPI_Info    info;           /*File information                      */
+    int         mpi_rank;       /*This process's rank                   */
+    int         mpi_size;       /*Total number of processes             */
+    int         mpi_round;      /*Current round robin process (for metadata I/O) */
+    haddr_t     eof;            /*End-of-file marker                    */
+    haddr_t     eoa;            /*End-of-address marker                 */
+    haddr_t     last_eoa;       /*Last known end-of-address marker      */
+} H5FP_fphdf5_t;
+
+/*
+ * Prototypes
+ */
+static haddr_t  H5FD_fphdf5_MPIOff_to_haddr(MPI_Offset mpi_off);
+static herr_t   H5FD_fphdf5_haddr_to_MPIOff(haddr_t addr, MPI_Offset *mpi_off);
+
+/*
+ * Callbacks
+ */
+static void    *H5FD_fphdf5_fapl_get(H5FD_t *_file);
+static H5FD_t  *H5FD_fphdf5_open(const char *name, unsigned flags,
+                                 hid_t fapl_id, haddr_t maxaddr);
+static herr_t   H5FD_fphdf5_close(H5FD_t *_file);
+static herr_t   H5FD_fphdf5_query(const H5FD_t *_f1, unsigned long *flags);
+static haddr_t  H5FD_fphdf5_get_eoa(H5FD_t *_file);
+static herr_t   H5FD_fphdf5_set_eoa(H5FD_t *_file, haddr_t addr);
+static haddr_t  H5FD_fphdf5_get_eof(H5FD_t *_file);
+static herr_t   H5FD_fphdf5_get_handle(H5FD_t *_file, hid_t fapl,
+                                     void **file_handle);
+static herr_t   H5FD_fphdf5_read(H5FD_t *_file, H5FD_mem_t type, hid_t dxpl_id,
+                               haddr_t addr, size_t size, void *buf);
+static herr_t   H5FD_fphdf5_write(H5FD_t *_file, H5FD_mem_t type, hid_t dxpl_id,
+                                haddr_t addr, size_t size, const void *buf);
+static herr_t   H5FD_fphdf5_flush(H5FD_t *_file, unsigned closing);
+
+/*
+ * FPHDF5-specific file access properties
+ */
+typedef struct H5FD_fphdf5_fapl_t {
+    MPI_Comm    comm;       /*communicator          */
+    MPI_Info    info;       /*file information      */
+} H5FD_fphdf5_fapl_t;
+
+/*
+ * The FPHDF5 file driver information
+ */
+static const H5FD_class_t H5FD_fphdf5_g = {
+    "fphdf5",                                   /*name                  */
+    HADDR_MAX,                                  /*maxaddr               */
+    H5F_CLOSE_SEMI,                             /*fc_degree             */
+    NULL,                                       /*sb_size               */
+    NULL,                                       /*sb_encode             */
+    NULL,                                       /*sb_decode             */
+    sizeof(H5FD_fphdf5_fapl_t),                 /*fapl_size             */
+    H5FD_fphdf5_fapl_get,                       /*fapl_get              */
+    NULL,                                       /*fapl_copy             */
+    NULL,                                       /*fapl_free             */
+    0,                                          /*dxpl_size             */
+    NULL,                                       /*dxpl_copy             */
+    NULL,                                       /*dxpl_free             */
+    H5FD_fphdf5_open,                           /*open                  */
+    H5FD_fphdf5_close,                          /*close                 */
+    NULL,                                       /*cmp                   */
+    H5FD_fphdf5_query,                          /*query                 */
+    NULL,                                       /*alloc                 */
+    NULL,                                       /*free                  */
+    H5FD_fphdf5_get_eoa,                        /*get_eoa               */
+    H5FD_fphdf5_set_eoa,                        /*set_eoa               */
+    H5FD_fphdf5_get_eof,                        /*get_eof               */
+    H5FD_fphdf5_get_handle,                     /*get_handle            */
+    H5FD_fphdf5_read,                           /*read                  */
+    H5FD_fphdf5_write,                          /*write                 */
+    H5FD_fphdf5_flush,                          /*flush                 */
+    H5FD_FLMAP_SINGLE,                          /*fl_map                */
+};
+
+/*
+ * Global var to allow elimination of redundant metadata writes to be
+ * controlled by the value of an environment variable.
+ *
+ * Use the elimination by default unless this is the Intel Red machine
+ */
+#ifndef __PUMAGON__
+hbool_t	H5_fphdf5_1_metawrite_g = TRUE;
+#else
+hbool_t	H5_fphdf5_1_metawrite_g = FALSE;
+#endif
+
+/* Interface initialization */
+#define PABLO_MASK          H5FD_fphdf5_mask
+#define INTERFACE_INIT      H5FD_fphdf5_init
+
+static int interface_initialize_g = 0;
+
+/* ======== Temporary, Local data transfer properties ======== */
+/*
+ * Definitions for memory MPI type property
+ */
+#define H5FD_FPHDF5_XFER_MEM_MPI_TYPE_NAME      "H5FD_fphdf5_mem_mpi_type"
+#define H5FD_FPHDF5_XFER_MEM_MPI_TYPE_SIZE      sizeof(MPI_Datatype)
+
+/*
+ * Definitions for file MPI type property
+ */
+#define H5FD_FPHDF5_XFER_FILE_MPI_TYPE_NAME     "H5FD_fphdf5_file_mpi_type"
+#define H5FD_FPHDF5_XFER_FILE_MPI_TYPE_SIZE     sizeof(MPI_Datatype)
+
+/*
+ * Definitions for whether to use MPI types property
+ */
+#define H5FD_FPHDF5_XFER_USE_VIEW_NAME          "H5FD_fphdf5_use_view"
+#define H5FD_FPHDF5_XFER_USE_VIEW_SIZE          sizeof(unsigned)
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5FD_fphdf5_init
+ * Purpose:	Initialize this driver by registering the driver with the
+ *		library.
+ * Return:	Success:    The driver ID for the FPHDF5 driver.
+ *		Failure:    FAIL
+ * Programmer:	Bill Wendling
+ *              30. January 2003
+ * Modifications:
+ *-------------------------------------------------------------------------
+ */
+hid_t
+H5FD_fphdf5_init(void)
+{
+    hid_t   ret_value;
+
+    FUNC_ENTER_NOAPI(H5FD_fphdf5_init, FAIL);
+
+    if (H5Iget_type(H5FD_FPHDF5_g) != H5I_VFL)
+        H5FD_FPHDF5_g = H5FDregister(&H5FD_fphdf5_g);
+
+    /* Set return value */
+    ret_value = H5FD_FPHDF5_g;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5Pset_fapl_fphdf5
+ * Purpose:	Store the user supplied MPIO communicator COMM and INFO
+ *              in the file access property list FAPL_ID which can then
+ *              be used to create and/or open the file. This function is
+ *              available only in the parallel HDF5 library and is not
+ *              collective.
+ *
+ *		COMM is the MPI communicator to be used for file open as
+ *		defined in MPI_FILE_OPEN of MPI-2. This function does not
+ *		make a duplicated communicator. Any modification to COMM
+ *		after this function call returns may have an indeterminate
+ *		effect on the access property list. Users should not
+ *		modify the communicator while it is defined in a property
+ *		list.
+ *
+ *		INFO is the MPI info object to be used for file open as
+ *		defined in MPI_FILE_OPEN of MPI-2. This function does not
+ *		make a duplicated info. Any modification to info after
+ *		this function call returns may have an indeterminate effect
+ *		on the access property list. Users should not modify the
+ *		info while it is defined in a property list.
+ * Return:	Success:    SUCCEED
+ * 		Failure:    FAIL
+ * Programmer:	Bill Wendling
+ *		30. January 2003
+ * Modifications:
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Pset_fapl_fphdf5(hid_t fapl_id, MPI_Comm comm, MPI_Info info)
+{
+    H5FD_fphdf5_fapl_t  fa;
+    H5P_genplist_t     *plist;
+    herr_t              ret_value;
+    
+    FUNC_ENTER_API(H5Pset_fapl_fphdf5, FAIL);
+    H5TRACE3("e","iMcMi",fapl_id,comm,info);
+
+    if (fapl_id == H5P_DEFAULT)
+        HGOTO_ERROR(H5E_PLIST, H5E_BADVALUE, FAIL,
+                    "can't set values in default property list");
+
+    /* Check arguments */
+    if ((plist = H5P_object_verify(fapl_id,H5P_FILE_ACCESS)) == NULL)
+        HGOTO_ERROR(H5E_PLIST, H5E_BADTYPE, FAIL, "not a file access list");
+
+    /* Initialize driver specific properties */
+    fa.comm = comm;
+    fa.info = info;
+
+    ret_value = H5P_set_driver(plist, H5FD_FPHDF5, &fa);
+
+done:
+    FUNC_LEAVE_API(ret_value);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5Pget_fapl_fphdf5
+ * Purpose:     If the file access property list is set to the
+ *              H5FD_FPHDF5 driver then this function returns the MPI
+ *              communicator and information through the COMM and INFO
+ *              pointers.
+ * Return:      Success:    SUCCEED with the communicator and information
+ *                          returned through the COMM and INFO arguments
+ *                          if non-null. Neither piece of information is
+ *                          copied and they are therefore valid only
+ *                          until the file access property list is
+ *                          modified or closed.
+ *              Failure:    FAIL
+ * Programmer:  Bill Wendling
+ *              30. January 2003
+ * Modifications:
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Pget_fapl_fphdf5(hid_t fapl_id, MPI_Comm *comm /*out*/, MPI_Info *info /*out*/)
+{
+    H5FD_fphdf5_fapl_t *fa;
+    H5P_genplist_t     *plist;
+    herr_t              ret_value = SUCCEED;
+    
+    FUNC_ENTER_API(H5Pget_fapl_fphdf5, FAIL);
+    H5TRACE3("e","ixx",fapl_id,comm,info);
+
+    if ((plist = H5P_object_verify(fapl_id, H5P_FILE_ACCESS)) == NULL)
+        HGOTO_ERROR(H5E_PLIST, H5E_BADTYPE, FAIL, "not a file access list");
+
+    if (H5P_get_driver(plist) != H5FD_FPHDF5)
+        HGOTO_ERROR(H5E_PLIST, H5E_BADVALUE, FAIL, "incorrect VFL driver");
+
+    if ((fa = H5P_get_driver_info(plist)) == NULL)
+        HGOTO_ERROR(H5E_PLIST, H5E_BADVALUE, FAIL, "bad VFL driver info");
+
+    if (comm)
+        *comm = fa->comm;
+
+    if (info)
+        *info = fa->info;
+
+done:
+    FUNC_LEAVE_API(ret_value);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5FD_fphdf5_communicator
+ * Purpose:     Returns the MPI communicator for the file.
+ * Return:      Success:    The communicator
+ *              Failure:    NULL
+ * Programmer:  Bill Wendling
+ *              30. January 2003
+ * Modifications:
+ *-------------------------------------------------------------------------
+ */
+MPI_Comm
+H5FD_fphdf5_communicator(H5FD_t *_file)
+{
+    H5FP_fphdf5_t  *file = (H5FP_fphdf5_t*)_file;
+    MPI_Comm        ret_value;
+
+    FUNC_ENTER_NOAPI(H5FD_fphdf5_communicator, MPI_COMM_NULL);
+
+    /* check args */
+    assert(file);
+    assert(file->pub.driver_id == H5FD_FPHDF5);
+
+    /* Set return value */
+    ret_value = file->comm;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5FD_fphdf5_mpi_rank
+ * Purpose:     Returns the MPI rank for a process
+ * Return:      Success:    MPI rank
+ *              Failure:    FAIL
+ * Programmer:  Bill Wendling
+ *              30. January 2003
+ * Modifications:
+ *-------------------------------------------------------------------------
+ */
+int
+H5FD_fphdf5_mpi_rank(H5FD_t *_file)
+{
+    H5FP_fphdf5_t  *file = (H5FP_fphdf5_t*)_file;
+    int             ret_value;
+
+    FUNC_ENTER_NOAPI(H5FD_fphdf5_mpi_rank, FAIL);
+
+    /* check args */
+    assert(file);
+    assert(file->pub.driver_id == H5FD_FPHDF5);
+
+    /* Set return value */
+    ret_value = file->mpi_rank;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5FD_fphdf5_mpi_size
+ * Purpose:     Returns the number of MPI processes
+ * Return:      Success:    Number of MPI processes
+ *              Failure:    FAIL
+ * Programmer:  Bill Wendling
+ *              30. January 2003
+ * Modifications:
+ *-------------------------------------------------------------------------
+ */
+int
+H5FD_fphdf5_mpi_size(H5FD_t *_file)
+{
+    H5FP_fphdf5_t  *file = (H5FP_fphdf5_t*)_file;
+    int             ret_value; 
+
+    FUNC_ENTER_NOAPI(H5FD_fphdf5_mpi_size, FAIL);
+
+    /* check args */
+    assert(file);
+    assert(file->pub.driver_id == H5FD_FPHDF5);
+
+    /* Set return value */
+    ret_value = file->mpi_size;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5FD_fphdf5_setup
+ * Purpose:     Set the buffer type BTYPE, file type FTYPE for a data
+ *              transfer. Also request an MPI type transfer.
+ * Return:      Success:    SUCCEED
+ *              Failure:    FAIL
+ * Programmer:  Bill Wendling
+ *              30. January 2003
+ * Modifications:
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5FD_fphdf5_setup(hid_t dxpl_id, MPI_Datatype btype,
+                  MPI_Datatype ftype, unsigned use_view)
+{
+    H5P_genplist_t *plist;
+    herr_t          ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI(H5FD_fphdf5_setup, FAIL);
+
+    /* Check arguments */
+    if ((plist = H5P_object_verify(dxpl_id, H5P_DATASET_XFER)) == NULL)
+        HGOTO_ERROR(H5E_PLIST, H5E_BADTYPE, FAIL, "not a dataset transfer list");
+
+    /* Set buffer MPI type */
+    if (H5P_insert(plist, H5FD_FPHDF5_XFER_MEM_MPI_TYPE_NAME,
+                   H5FD_FPHDF5_XFER_MEM_MPI_TYPE_SIZE, &btype,
+                   NULL, NULL, NULL, NULL, NULL) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't insert MPI-I/O property");
+
+    /* Set file MPI type */
+    if (H5P_insert(plist, H5FD_FPHDF5_XFER_FILE_MPI_TYPE_NAME,
+                   H5FD_FPHDF5_XFER_FILE_MPI_TYPE_SIZE, &ftype,
+                   NULL, NULL, NULL, NULL, NULL) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't insert MPI-I/O property");
+
+    /* Set 'use view' property */
+    if (H5P_insert(plist, H5FD_FPHDF5_XFER_USE_VIEW_NAME,
+                   H5FD_FPHDF5_XFER_USE_VIEW_SIZE, &use_view,
+                   NULL, NULL, NULL, NULL, NULL) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't insert MPI-I/O property");
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5FD_fphdf5_teardown
+ * Purpose:     Remove the temporary MPI-I/O properties from dxpl.
+ * Return:      Success:    SUCCEED
+ *              Failure:    FAIL
+ * Programmer:  Bill Wendling
+ *              30. January 2003
+ * Modifications:
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5FD_fphdf5_teardown(hid_t dxpl_id)
+{
+    H5P_genplist_t *plist;
+    herr_t          ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI(H5FD_fphdf5_teardown, FAIL);
+
+    /* Check arguments */
+    if ((plist = H5P_object_verify(dxpl_id, H5P_DATASET_XFER)) == NULL)
+        HGOTO_ERROR(H5E_PLIST, H5E_BADTYPE, FAIL, "not a dataset transfer list");
+
+    /* Remove buffer MPI type */
+    if (H5P_remove(dxpl_id, plist, H5FD_FPHDF5_XFER_MEM_MPI_TYPE_NAME) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTDELETE, FAIL, "can't remove MPI-I/O property");
+
+    /* Remove file MPI type */
+    if (H5P_remove(dxpl_id, plist, H5FD_FPHDF5_XFER_FILE_MPI_TYPE_NAME) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTDELETE, FAIL, "can't remove MPI-I/O property");
+
+    /* Remove 'use view' property */
+    if (H5P_remove(dxpl_id, plist, H5FD_FPHDF5_XFER_USE_VIEW_NAME) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTDELETE, FAIL, "can't remove MPI-I/O property");
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5FD_fphdf5_fapl_get
+ *
+ * Purpose:	Returns a file access property list which could be used to
+ *		create another file the same as this one.
+ *
+ * Return:	Success:	Ptr to new file access property list with all
+ *				fields copied from the file pointer.
+ *
+ *		Failure:	NULL
+ *
+ * Programmer:	Robb Matzke
+ *              Friday, August 13, 1999
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static void *
+H5FD_fphdf5_fapl_get(H5FD_t *_file)
+{
+    H5FP_fphdf5_t      *file = (H5FP_fphdf5_t*)_file;
+    H5FD_fphdf5_fapl_t *fa = NULL;
+    void               *ret_value;
+
+    FUNC_ENTER_NOAPI(H5FD_fphdf5_fapl_get, NULL);
+
+    /* check args */
+    assert(file);
+    assert(file->pub.driver_id == H5FD_FPHDF5);
+
+    if ((fa = H5MM_calloc(sizeof(H5FD_fphdf5_fapl_t))) == NULL)
+        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");
+
+    /* These should both be copied. --rpm, 1999-08-13 */
+    fa->comm = file->comm;
+    fa->info = file->info;
+
+    /* Set return value */
+    ret_value = fa;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5FD_fphdf5_open
+ * Purpose:     Opens a file with name NAME. The FLAGS are a bit field with
+ *              purpose similar to the second argument of open(2) and
+ *              which are defined in H5Fpublic.h. The file access
+ *              property list FAPL_ID contains the properties driver
+ *              properties and MAXADDR is the largest address which this
+ *              file will be expected to access.  This is collective.
+ * Return:      Success:    A new file pointer.
+ *              Failure:    NULL
+ * Programmer:  Bill Wendling
+ *              05. February 2003
+ * Modifications:
+ *-------------------------------------------------------------------------
+ */
+static H5FD_t *
+H5FD_fphdf5_open(const char *name, unsigned flags, hid_t fapl_id, haddr_t maxaddr)
+{
+    H5FP_fphdf5_t              *file = NULL;
+    MPI_File                    fh;
+    int                         mpi_amode;
+    int                         mrc;
+    MPI_Offset                  size;
+    const H5FD_fphdf5_fapl_t   *fa = NULL;
+    H5FD_fphdf5_fapl_t          _fa;
+    H5P_genplist_t             *plist;
+    H5FD_t                     *ret_value = NULL;
+    unsigned                    file_id;
+    unsigned                    req_id;
+    MPI_Status status;
+
+    /* Flag to indicate that the file was successfully opened */
+    unsigned                    file_opened = FALSE;
+
+    FUNC_ENTER_NOAPI(H5FD_fphdf5_open, NULL);
+
+    /* check args */
+    assert(name);
+
+    /* Obtain a pointer to mpio-specific file access properties */
+    if ((plist = H5P_object_verify(fapl_id, H5P_FILE_ACCESS)) == NULL)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not a file access property list");
+
+    if (fapl_id == H5P_FILE_ACCESS_DEFAULT || H5P_get_driver(plist) != H5FD_FPHDF5) {
+        _fa.comm = MPI_COMM_SELF; /*default*/
+        _fa.info = MPI_INFO_NULL; /*default*/
+        fa = &_fa;
+    } else {
+        fa = H5P_get_driver_info(plist);
+        assert(fa);
+    }
+
+    /*
+     * Convert HDF5 flags to MPI-IO flags. Some combinations are illegal;
+     * let MPI-IO figure it out
+     */
+    mpi_amode = (flags & H5F_ACC_RDWR) ? MPI_MODE_RDWR : MPI_MODE_RDONLY;
+
+    if (flags & H5F_ACC_CREAT)  mpi_amode |= MPI_MODE_CREATE;
+    if (flags & H5F_ACC_EXCL)   mpi_amode |= MPI_MODE_EXCL;
+
+    /* OKAY: CAST DISCARDS CONST */
+    if ((mrc = MPI_File_open(H5FP_SAP_COMM, (char *)name, mpi_amode,
+                             fa->info, &fh)) != MPI_SUCCESS)
+        HMPI_GOTO_ERROR(NULL, "MPI_File_open failed", mrc);
+
+    file_opened = TRUE;
+
+    if (H5FP_request_open(name, (int)strlen(name), H5FP_OBJ_FILE, maxaddr,
+                          &file_id, &req_id) == FAIL)
+        HGOTO_ERROR(H5E_IO, H5E_CANTOPENFILE, NULL,
+                    "can't inform SAP of file open");
+
+    HDmemset(&status, 0, sizeof(status));
+
+    /* Get the file ID from the SAP */
+    if (H5FP_my_rank == H5FP_capt_rank)
+        if ((mrc = MPI_Recv(&file_id, 1, MPI_UNSIGNED, (int)H5FP_sap_rank,
+                            H5FP_TAG_FILE_ID, H5FP_SAP_COMM,
+                            &status)) != MPI_SUCCESS)
+            HMPI_GOTO_ERROR(NULL, "MPI_Recv failed", mrc);
+
+    /* Broadcast the file ID */
+    if ((mrc = MPI_Bcast(&file_id, 1, MPI_UNSIGNED,
+                         0, H5FP_SAP_BARRIER_COMM)) != MPI_SUCCESS)
+        HMPI_GOTO_ERROR(NULL, "MPI_Bcast failed", mrc);
+
+    /* The captain rank will get the filesize and broadcast it. */
+    if (H5FP_my_rank == H5FP_capt_rank)
+        /* Get current file size */
+        if ((mrc = MPI_File_get_size(fh, &size)) != MPI_SUCCESS)
+            HMPI_GOTO_ERROR(NULL, "MPI_File_get_size failed", mrc);
+
+    /* Broadcast file-size */
+    if ((mrc = MPI_Bcast(&size, sizeof(MPI_Offset), MPI_BYTE,
+                         0, H5FP_SAP_BARRIER_COMM)) != MPI_SUCCESS)
+        HMPI_GOTO_ERROR(NULL, "MPI_Bcast failed", mrc);
+
+    /* Only if size > 0, truncate the file - if requested */
+    if (size && (flags & H5F_ACC_TRUNC)) {
+        if ((mrc = MPI_File_set_size(fh, (MPI_Offset)0)) != MPI_SUCCESS)
+            HMPI_GOTO_ERROR(NULL, "MPI_File_set_size (file truncation) failed", mrc);
+
+        /* Don't let any proc return until all have truncated the file. */
+        if ((mrc = MPI_Barrier(H5FP_SAP_BARRIER_COMM)) != MPI_SUCCESS)
+            HMPI_GOTO_ERROR(NULL, "MPI_Barrier failed", mrc);
+
+        size = 0;
+    }
+
+    /* Build the return value and initialize it */
+    if ((file = H5MM_calloc(sizeof(H5FP_fphdf5_t))) == NULL)
+        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");
+
+    file->f = fh;
+    file->comm = fa->comm;
+    file->info = fa->info;
+    file->mpi_rank = H5FP_my_rank;
+    file->mpi_size = H5FP_comm_size;
+    file->eof = H5FD_fphdf5_MPIOff_to_haddr(size);
+
+    /* Set return value */
+    ret_value = (H5FD_t *)file;
+    ret_value->fphdf5_id = file_id; /* the file descriptor used in FPHDF5 */
+
+done:
+    if (!ret_value && file_opened)
+        MPI_File_close(&fh);
+
+    FUNC_LEAVE_NOAPI(ret_value);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5FD_fphdf5_close
+ *
+ * Purpose:     Closes a file.  This is collective.
+ *
+ * Return:      Success:	Non-negative
+ *
+ * 		Failure:	Negative
+ *
+ * Programmer:  Unknown
+ *              January 30, 1998
+ *
+ * Modifications:
+ * 		Robb Matzke, 1998-02-18
+ *		Added the ACCESS_PARMS argument.
+ *
+ * 		Robb Matzke, 1999-08-06
+ *		Modified to work with the virtual file layer.
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5FD_fphdf5_close(H5FD_t *_file)
+{
+    H5FP_fphdf5_t	*file = (H5FP_fphdf5_t*)_file;
+    int				mpi_code;	/* mpi return code */
+    herr_t      ret_value=SUCCEED;       /* Return value */
+
+    FUNC_ENTER_NOAPI(H5FD_fphdf5_close, FAIL);
+
+    assert(file);
+    assert(H5FD_FPHDF5==file->pub.driver_id);
+
+    /* MPI_File_close sets argument to MPI_FILE_NULL */
+    if (MPI_SUCCESS != (mpi_code=MPI_File_close(&(file->f)/*in,out*/)))
+        HMPI_GOTO_ERROR(FAIL, "MPI_File_close failed", mpi_code);
+
+    /* Clean up other stuff */
+    H5MM_xfree(file);
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5FD_fphdf5_query
+ *
+ * Purpose:	Set the flags that this VFL driver is capable of supporting.
+ *              (listed in H5FDpublic.h)
+ *
+ * Return:	Success:	non-negative
+ *
+ *		Failure:	negative
+ *
+ * Programmer:	Quincey Koziol
+ *              Friday, August 25, 2000
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5FD_fphdf5_query(const H5FD_t UNUSED *_file, unsigned long *flags /* out */)
+{
+    herr_t ret_value=SUCCEED;
+
+    FUNC_ENTER_NOAPI(H5FD_fphdf5_query, FAIL);
+
+    /* Set the VFL feature flags that this driver supports */
+    if(flags) {
+        *flags=0;
+        *flags|=H5FD_FEAT_AGGREGATE_METADATA; /* OK to aggregate metadata allocations */
+
+        /* Distinguish between updating the metadata accumulator on writes and
+         * reads.  This is particularly (perhaps only, even) important for MPI-I/O
+         * where we guarantee that writes are collective, but reads may not be.
+         * If we were to allow the metadata accumulator to be written during a
+         * read operation, the application would hang.
+         */
+        *flags|=H5FD_FEAT_ACCUMULATE_METADATA_WRITE; /* OK to accumulate metadata for faster writes */
+
+        *flags|=H5FD_FEAT_AGGREGATE_SMALLDATA; /* OK to aggregate "small" raw data allocations */
+    } /* end if */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5FD_fphdf5_get_eoa
+ *
+ * Purpose:	Gets the end-of-address marker for the file. The EOA marker
+ *		is the first address past the last byte allocated in the
+ *		format address space.
+ *
+ * Return:	Success:	The end-of-address marker.
+ *
+ *		Failure:	HADDR_UNDEF
+ *
+ * Programmer:	Robb Matzke
+ *              Friday, August  6, 1999
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static haddr_t
+H5FD_fphdf5_get_eoa(H5FD_t *_file)
+{
+    H5FP_fphdf5_t	*file = (H5FP_fphdf5_t*)_file;
+    haddr_t ret_value;          /* Return value */
+
+    FUNC_ENTER_NOAPI(H5FD_fphdf5_get_eoa, HADDR_UNDEF);
+
+    assert(file);
+    assert(H5FD_FPHDF5==file->pub.driver_id);
+
+    /* Set return value */
+    ret_value=file->eoa;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5FD_fphdf5_set_eoa
+ *
+ * Purpose:	Set the end-of-address marker for the file. This function is
+ *		called shortly after an existing HDF5 file is opened in order
+ *		to tell the driver where the end of the HDF5 data is located.
+ *
+ * Return:	Success:	0
+ *
+ *		Failure:	-1
+ *
+ * Programmer:	Robb Matzke
+ *              Friday, August 6, 1999
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5FD_fphdf5_set_eoa(H5FD_t *_file, haddr_t addr)
+{
+    H5FP_fphdf5_t	*file = (H5FP_fphdf5_t*)_file;
+    herr_t ret_value=SUCCEED;   /* Return value */
+
+    FUNC_ENTER_NOAPI(H5FD_fphdf5_set_eoa, FAIL);
+
+    assert(file);
+    assert(H5FD_FPHDF5==file->pub.driver_id);
+
+    file->eoa = addr;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5FD_fphdf5_get_eof
+ *
+ * Purpose:	Gets the end-of-file marker for the file. The EOF marker
+ *		is the real size of the file.
+ *
+ *		The MPIO driver doesn't bother keeping this field updated
+ *		since that's a relatively expensive operation. Fortunately
+ *		the library only needs the EOF just after the file is opened
+ *		in order to determine whether the file is empty, truncated,
+ *		or okay.  Therefore, any MPIO I/O function will set its value
+ *		to HADDR_UNDEF which is the error return value of this
+ *		function.
+ *
+ * Return:	Success:	The end-of-address marker.
+ *
+ *		Failure:	HADDR_UNDEF
+ *
+ * Programmer:	Robb Matzke
+ *              Friday, August  6, 1999
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static haddr_t
+H5FD_fphdf5_get_eof(H5FD_t *_file)
+{
+    H5FP_fphdf5_t	*file = (H5FP_fphdf5_t*)_file;
+    haddr_t ret_value;          /* Return value */
+
+    FUNC_ENTER_NOAPI(H5FD_fphdf5_get_eof, HADDR_UNDEF);
+
+    assert(file);
+    assert(H5FD_FPHDF5==file->pub.driver_id);
+
+    /* Set return value */
+    ret_value=file->eof;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:       H5FD_fphdf5_get_handle
+ * 
+ * Purpose:        Returns the file handle of MPIO file driver.
+ * 
+ * Returns:        Non-negative if succeed or negative if fails.
+ * 
+ * Programmer:     Raymond Lu
+ *                 Sept. 16, 2002
+ * 
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+*/
+static herr_t  
+H5FD_fphdf5_get_handle(H5FD_t *_file, hid_t UNUSED fapl, void** file_handle)
+{   
+    H5FP_fphdf5_t         *file = (H5FP_fphdf5_t *)_file;
+    herr_t              ret_value = SUCCEED;
+                            
+    FUNC_ENTER_NOAPI(H5FD_fphdf5_get_handle, FAIL);
+                                    
+    if(!file_handle)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "file handle not valid");
+
+    *file_handle = &(file->f);
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value);
+}
+             
+
+/*-------------------------------------------------------------------------
+ * Function:	H5FD_fphdf5_read
+ *
+ * Purpose:	Reads SIZE bytes of data from FILE beginning at address ADDR
+ *		into buffer BUF according to data transfer properties in
+ *		DXPL_ID using potentially complex file and buffer types to
+ *		effect the transfer.
+ *
+ *		Reading past the end of the MPI file returns zeros instead of
+ *		failing.  MPI is able to coalesce requests from different
+ *		processes (collective or independent).
+ *
+ * Return:	Success:	Zero. Result is stored in caller-supplied
+ *				buffer BUF.
+ *
+ *		Failure:	-1, Contents of buffer BUF are undefined.
+ *
+ * Programmer:	rky, 1998-01-30
+ *
+ * Modifications:
+ * 		Robb Matzke, 1998-02-18
+ *		Added the ACCESS_PARMS argument.
+ *
+ * 		rky, 1998-04-10
+ *		Call independent or collective MPI read, based on
+ *		ACCESS_PARMS.
+ *
+ * 		Albert Cheng, 1998-06-01
+ *		Added XFER_MODE to control independent or collective MPI
+ *		read.
+ *
+ * 		rky, 1998-08-16
+ *		Use BTYPE, FTYPE, and DISP from access parms. The guts of
+ *		H5FD_fphdf5_read and H5FD_fphdf5_write should be replaced by a
+ *		single dual-purpose routine.
+ *
+ * 		Robb Matzke, 1999-04-21
+ *		Changed XFER_MODE to XFER_PARMS for all H5F_*_read()
+ *		callbacks.
+ *
+ * 		Robb Matzke, 1999-07-28
+ *		The ADDR argument is passed by value.
+ *		
+ * 		Robb Matzke, 1999-08-06
+ *		Modified to work with the virtual file layer.
+ *
+ *		Quincey Koziol,  2002-05-14
+ *		Only call MPI_Get_count if we can use MPI_BYTE for the MPI type
+ *              for the I/O transfer.  Someday we might include code to decode
+ *              the MPI type used for more complicated transfers and call
+ *              MPI_Get_count all the time.
+ *
+ *              Quincey Koziol - 2002/06/17
+ *              Removed 'disp' parameter from H5FD_fphdf5_setup routine and use
+ *              the address of the dataset in MPI_File_set_view() calls, as
+ *              necessary.
+ *
+ *              Quincey Koziol - 2002/06/24
+ *              Removed "lazy" MPI_File_set_view() calls, since they would fail
+ *              if the first I/O was a collective I/O using MPI derived types
+ *              and the next I/O was an independent I/O.
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5FD_fphdf5_read(H5FD_t *_file, H5FD_mem_t UNUSED type, hid_t dxpl_id, haddr_t addr, size_t size,
+	       void *buf/*out*/)
+{
+#if 0
+    H5FP_fphdf5_t               *file = (H5FP_fphdf5_t*)_file;
+    const H5FD_fphdf5_dxpl_t	*dx=NULL;
+    H5FD_fphdf5_dxpl_t		_dx;
+    MPI_Offset			mpi_off, mpi_disp;
+    MPI_Status  		mpi_stat;
+    int				mpi_code;	/* mpi return code */
+    MPI_Datatype		buf_type, file_type;
+    int         		size_i, bytes_read, n;
+    unsigned			use_view_this_time=0;
+    H5P_genplist_t *plist;      /* Property list pointer */
+    herr_t              	ret_value=SUCCEED;
+
+    FUNC_ENTER_NOAPI(H5FD_fphdf5_read, FAIL);
+
+    assert(file);
+    assert(H5FD_FPHDF5==file->pub.driver_id);
+    /* Make certain we have the correct type of property list */
+    assert(H5I_GENPROP_LST==H5I_get_type(dxpl_id));
+    assert(TRUE==H5P_isa_class(dxpl_id,H5P_DATASET_XFER));
+    assert(buf);
+
+    /* Portably initialize MPI status variable */
+    HDmemset(&mpi_stat,0,sizeof(MPI_Status));
+
+    /* some numeric conversions */
+    if (H5FD_fphdf5_haddr_to_MPIOff(addr, &mpi_off/*out*/)<0)
+        HGOTO_ERROR(H5E_INTERNAL, H5E_BADRANGE, FAIL, "can't convert from haddr to MPI off");
+    size_i = (int)size;
+    if ((hsize_t)size_i != size)
+        HGOTO_ERROR(H5E_INTERNAL, H5E_BADRANGE, FAIL, "can't convert from size to size_i");
+
+    /* Obtain the data transfer properties */
+    if(NULL == (plist = H5I_object(dxpl_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file access property list");
+    if (H5FD_FPHDF5!=H5P_get_driver(plist)) {
+        _dx.xfer_mode = H5FD_FPHDF5_INDEPENDENT; /*the default*/
+        dx = &_dx;
+    } else {
+        dx = H5P_get_driver_info(plist);
+        assert(dx);
+    }
+    
+    /*
+     * Set up for a fancy xfer using complex types, or single byte block. We
+     * wouldn't need to rely on the use_view field if MPI semantics allowed
+     * us to test that btype=ftype=MPI_BYTE (or even MPI_TYPE_NULL, which
+     * could mean "use MPI_BYTE" by convention).
+     */
+    if(H5P_exist_plist(plist,H5FD_FPHDF5_XFER_USE_VIEW_NAME)>0)
+        if(H5P_get(plist,H5FD_FPHDF5_XFER_USE_VIEW_NAME,&use_view_this_time)<0)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get MPI-I/O type property");
+
+    if (use_view_this_time) {
+        /* prepare for a full-blown xfer using btype, ftype, and disp */
+        if(H5P_get(plist,H5FD_FPHDF5_XFER_MEM_MPI_TYPE_NAME,&buf_type)<0)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get MPI-I/O type property");
+        if(H5P_get(plist,H5FD_FPHDF5_XFER_FILE_MPI_TYPE_NAME,&file_type)<0)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get MPI-I/O type property");
+
+        /* When using types, use the address as the displacement for
+         * MPI_File_set_view and reset the address for the read to zero
+         */
+        mpi_disp=mpi_off;
+        mpi_off=0;
+    } /* end if */
+    else {
+        /*
+         * Prepare for a simple xfer of a contiguous block of bytes. The
+         * btype, ftype, and disp fields are not used.
+         */
+        buf_type = MPI_BYTE;
+        file_type = MPI_BYTE;
+        mpi_disp = 0;		/* mpi_off is alread set */
+    } /* end else */
+
+    /*
+     * Set the file view when we are using MPI derived types
+     */
+    if (use_view_this_time) {
+        /*OKAY: CAST DISCARDS CONST QUALIFIER*/
+        if (MPI_SUCCESS != (mpi_code=MPI_File_set_view(file->f, mpi_disp, MPI_BYTE, file_type, (char*)"native",  file->info)))
+            HMPI_GOTO_ERROR(FAIL, "MPI_File_set_view failed", mpi_code);
+    } /* end if */
+    
+    /* Read the data. */
+    assert(H5FD_FPHDF5_INDEPENDENT==dx->xfer_mode || H5FD_FPHDF5_COLLECTIVE==dx->xfer_mode);
+    if (H5FD_FPHDF5_INDEPENDENT==dx->xfer_mode) {
+        if (MPI_SUCCESS!= (mpi_code=MPI_File_read_at(file->f, mpi_off, buf, size_i, buf_type, &mpi_stat)))
+            HMPI_GOTO_ERROR(FAIL, "MPI_File_read_at failed", mpi_code);
+    } else {
+        if (MPI_SUCCESS!= (mpi_code=MPI_File_read_at_all(file->f, mpi_off, buf, size_i, buf_type, &mpi_stat )))
+            HMPI_GOTO_ERROR(FAIL, "MPI_File_read_at_all failed", mpi_code);
+    }
+
+    /* KLUDGE, Robb Matzke, 2000-12-29
+     * The LAM implementation of MPI_Get_count() says
+     *    MPI_Get_count: invalid argument (rank 0, MPI_COMM_WORLD)
+     * So I'm commenting this out until it can be investigated. The
+     * returned `bytes_written' isn't used anyway because of Kim's
+     * kludge to avoid bytes_written<0. Likewise in H5FD_fphdf5_write(). */
+
+#ifdef H5_HAVE_MPI_GET_COUNT /* Bill and Albert's kludge*/
+    /* Yet Another KLUDGE, Albert Cheng & Bill Wendling, 2001-05-11.
+     * Many systems don't support MPI_Get_count so we need to do a
+     * configure thingy to fix this. */
+
+    /* Calling MPI_Get_count with "MPI_BYTE" is only valid when we actually
+     * had the 'buf_type' set to MPI_BYTE -QAK
+     */
+    if(use_view_this_time) {
+        /* Figure out the mapping from the MPI 'buf_type' to bytes, someday...
+         * If this gets fixed (and MPI_Get_count() is reliable), the
+         * kludge below where the 'bytes_read' value from MPI_Get_count() is
+         * overwritten with the 'size_i' parameter can be removed. -QAK
+         */
+    } /* end if */
+    else {
+        /* How many bytes were actually read? */
+        if (MPI_SUCCESS != (mpi_code=MPI_Get_count(&mpi_stat, MPI_BYTE, &bytes_read)))
+            HMPI_GOTO_ERROR(FAIL, "MPI_Get_count failed", mpi_code);
+    } /* end else */
+#endif /* H5_HAVE_MPI_GET_COUNT */
+
+    /*
+     * KLUGE rky 1998-02-02
+     * MPI_Get_count incorrectly returns negative count; fake a complete
+     * read.
+     */
+    bytes_read = size_i;
+
+    /* Check for read failure */
+    if (bytes_read<0 || bytes_read>size_i)
+        HGOTO_ERROR(H5E_IO, H5E_READERROR, FAIL, "file read failed");
+
+    /*
+     * Reset the file view when we used MPI derived types
+     */
+    if (use_view_this_time) {
+        /*OKAY: CAST DISCARDS CONST QUALIFIER*/
+        if (MPI_SUCCESS != (mpi_code=MPI_File_set_view(file->f, 0, MPI_BYTE, MPI_BYTE, (char*)"native",  file->info)))
+            HMPI_GOTO_ERROR(FAIL, "MPI_File_set_view failed", mpi_code);
+    } /* end if */
+    
+    /*
+     * This gives us zeroes beyond end of physical MPI file.  What about
+     * reading past logical end of HDF5 file???
+     */
+    if ((n=(size_i-bytes_read)) > 0) {
+        if (use_view_this_time) {
+            /*
+             * INCOMPLETE rky 1998-09-18
+             * Haven't implemented reading zeros beyond EOF. What to do???
+             */
+            HGOTO_ERROR(H5E_IO, H5E_READERROR, FAIL, "eof file read failed");
+        } else {
+            memset((char*)buf+bytes_read, 0, (size_t)n);
+        }
+    }
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value);
+#else
+    return SUCCEED;
+#endif
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5FD_fphdf5_write
+ *
+ * Purpose:	Writes SIZE bytes of data to FILE beginning at address ADDR
+ *		from buffer BUF according to data transfer properties in
+ *		DXPL_ID using potentially complex file and buffer types to
+ *		effect the transfer.
+ *
+ *		MPI is able to coalesce requests from different processes
+ *		(collective and independent).
+ *
+ * Return:	Success:	Zero. USE_TYPES and OLD_USE_TYPES in the
+ *				access params are altered.
+ *
+ *		Failure:	-1, USE_TYPES and OLD_USE_TYPES in the
+ *				access params may be altered.
+ *
+ * Programmer:	Unknown
+ *              January 30, 1998
+ *
+ * Modifications:
+ *		rky, 1998-08-28
+ *		If the file->allsame flag is set, we assume that all the
+ *		procs in the relevant MPI communicator will write identical
+ *		data at identical offsets in the file, so only proc 0 will
+ *		write, and all other procs will wait for p0 to finish. This
+ *		is useful for writing metadata, for example. Note that we
+ *		don't _check_ that the data is identical. Also, the mechanism
+ *		we use to eliminate the redundant writes is by requiring a
+ *		call to H5FD_fphdf5_tas_allsame before the write, which is
+ *		rather klugey. Would it be better to pass a parameter to
+ *		low-level writes like H5F_block_write and H5F_low_write,
+ *		instead?  Or...??? Also, when I created this mechanism I
+ *		wanted to minimize the difference in behavior between the old
+ *		way of doing things (i.e., all procs write) and the new way,
+ *		so the writes are eliminated at the very lowest level, here
+ *		in H5FD_fphdf5_write. It may be better to rethink that, and
+ *		short-circuit the writes at a higher level (e.g., at the
+ *		points in the code where H5FD_fphdf5_tas_allsame is called).
+ *
+ *
+ * 		Robb Matzke, 1998-02-18
+ *		Added the ACCESS_PARMS argument.
+ *
+ * 		rky, 1998-04-10
+ *		Call independent or collective MPI write, based on
+ *		ACCESS_PARMS.
+ *
+ * 		rky, 1998-04-24
+ *		Removed redundant write from H5FD_fphdf5_write.
+ *
+ * 		Albert Cheng, 1998-06-01
+ *		Added XFER_MODE to control independent or collective MPI
+ *		write.
+ *
+ * 		rky, 1998-08-16
+ *		Use BTYPE, FTYPE, and DISP from access parms. The guts of
+ *		H5FD_fphdf5_read and H5FD_fphdf5_write should be replaced by a
+ *		single dual-purpose routine.
+ *
+ * 		rky, 1998-08-28
+ *		Added ALLSAME parameter to make all but proc 0 skip the
+ *		actual write.
+ *
+ * 		Robb Matzke, 1999-04-21
+ *		Changed XFER_MODE to XFER_PARMS for all H5FD_*_write()
+ *		callbacks.
+ *
+ * 		Robb Matzke, 1999-07-28
+ *		The ADDR argument is passed by value.
+ *
+ * 		Robb Matzke, 1999-08-06
+ *		Modified to work with the virtual file layer.
+ *
+ *		Albert Cheng, 1999-12-19
+ *		When only-p0-write-allsame-data, p0 Bcasts the
+ *		ret_value to other processes.  This prevents
+ *		a racing condition (that other processes try to
+ *		read the file before p0 finishes writing) and also
+ *		allows all processes to report the same ret_value.
+ *
+ *		Kim Yates, Pat Weidhaas,  2000-09-26
+ *		Move block of coding where only p0 writes after the
+ *              MPI_File_set_view call. 
+ *
+ *		Quincey Koziol,  2002-05-10
+ *		Instead of always writing metadata from process 0, spread the
+ *              burden among all the processes by using a round-robin rotation
+ *              scheme.
+ *
+ *		Quincey Koziol,  2002-05-10
+ *		Removed allsame code, keying off the type parameter instead.
+ *
+ *		Quincey Koziol,  2002-05-14
+ *		Only call MPI_Get_count if we can use MPI_BYTE for the MPI type
+ *              for the I/O transfer.  Someday we might include code to decode
+ *              the MPI type used for more complicated transfers and call
+ *              MPI_Get_count all the time.
+ *
+ *              Quincey Koziol - 2002/06/17
+ *              Removed 'disp' parameter from H5FD_fphdf5_setup routine and use
+ *              the address of the dataset in MPI_File_set_view() calls, as
+ *              necessary.
+ *
+ *              Quincey Koziol - 2002/06/24
+ *              Removed "lazy" MPI_File_set_view() calls, since they would fail
+ *              if the first I/O was a collective I/O using MPI derived types
+ *              and the next I/O was an independent I/O.
+ *
+ *              Quincey Koziol - 2002/07/18
+ *              Added "block_before_meta_write" dataset transfer flag, which
+ *              is set during writes from a metadata cache flush and indicates
+ *              that all the processes must sync up before (one of them)
+ *              writing metadata.
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5FD_fphdf5_write(H5FD_t *_file, H5FD_mem_t type, hid_t dxpl_id, haddr_t addr,
+		size_t size, const void *buf)
+{
+#if 0
+    H5FP_fphdf5_t			*file = (H5FP_fphdf5_t*)_file;
+    const H5FD_fphdf5_dxpl_t	*dx=NULL;
+    H5FD_fphdf5_dxpl_t		_dx;
+    MPI_Offset 		 	mpi_off, mpi_disp;
+    MPI_Status			mpi_stat;
+    MPI_Datatype		buf_type, file_type;
+    int			        mpi_code;	/* MPI return code */
+    int         		size_i, bytes_written;
+    unsigned			use_view_this_time=0;
+    unsigned		        block_before_meta_write=0;      /* Whether to block before a metadata write */
+    H5P_genplist_t *plist;      /* Property list pointer */
+    herr_t              	ret_value=SUCCEED;
+
+    FUNC_ENTER_NOAPI(H5FD_fphdf5_write, FAIL);
+
+    assert(file);
+    assert(H5FD_FPHDF5==file->pub.driver_id);
+    /* Make certain we have the correct type of property list */
+    assert(H5I_GENPROP_LST==H5I_get_type(dxpl_id));
+    assert(TRUE==H5P_isa_class(dxpl_id,H5P_DATASET_XFER));
+    assert(buf);
+
+    /* Portably initialize MPI status variable */
+    HDmemset(&mpi_stat,0,sizeof(MPI_Status));
+
+    /* some numeric conversions */
+    if (H5FD_fphdf5_haddr_to_MPIOff(addr, &mpi_off)<0)
+        HGOTO_ERROR(H5E_INTERNAL, H5E_BADRANGE, FAIL, "can't convert from haddr to MPI off");
+    size_i = (int)size;
+    if ((hsize_t)size_i != size)
+        HGOTO_ERROR(H5E_INTERNAL, H5E_BADRANGE, FAIL, "can't convert from size to size_i");
+
+    /* Obtain the data transfer properties */
+    if(NULL == (plist = H5I_object(dxpl_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file access property list");
+    if (H5FD_FPHDF5!=H5P_get_driver(plist)) {
+        _dx.xfer_mode = H5FD_FPHDF5_INDEPENDENT; /*the default*/
+        dx = &_dx;
+    } else {
+        dx = H5P_get_driver_info(plist);
+        assert(dx);
+    }
+    
+    /*
+     * Set up for a fancy xfer using complex types, or single byte block. We
+     * wouldn't need to rely on the use_view field if MPI semantics allowed
+     * us to test that btype=ftype=MPI_BYTE (or even MPI_TYPE_NULL, which
+     * could mean "use MPI_BYTE" by convention).
+     */
+    if(H5P_exist_plist(plist,H5FD_FPHDF5_XFER_USE_VIEW_NAME)>0)
+        if(H5P_get(plist,H5FD_FPHDF5_XFER_USE_VIEW_NAME,&use_view_this_time)<0)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get MPI-I/O type property");
+
+    if (use_view_this_time) {
+        /* prepare for a full-blown xfer using btype, ftype, and disp */
+        if(H5P_get(plist,H5FD_FPHDF5_XFER_MEM_MPI_TYPE_NAME,&buf_type)<0)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get MPI-I/O type property");
+        if(H5P_get(plist,H5FD_FPHDF5_XFER_FILE_MPI_TYPE_NAME,&file_type)<0)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get MPI-I/O type property");
+
+        /* When using types, use the address as the displacement for
+         * MPI_File_set_view and reset the address for the read to zero
+         */
+        mpi_disp=mpi_off;
+        mpi_off=0;
+    } /* end if */
+    else {
+        /*
+         * Prepare for a simple xfer of a contiguous block of bytes.
+         * The btype, ftype, and disp fields are not used.
+         */
+        buf_type = MPI_BYTE;
+        file_type = MPI_BYTE;
+        mpi_disp = 0;		/* mpi_off is already set */
+    } /* end else */
+
+    /*
+     * Set the file view when we are using MPI derived types
+     */
+    if (use_view_this_time) {
+        /*OKAY: CAST DISCARDS CONST QUALIFIER*/
+        if (MPI_SUCCESS != (mpi_code=MPI_File_set_view(file->f, mpi_disp, MPI_BYTE, file_type, (char*)"native", file->info)))
+            HMPI_GOTO_ERROR(FAIL, "MPI_File_set_view failed", mpi_code);
+    } /* end if */
+    
+    /* Metadata specific actions */
+    if(type!=H5FD_MEM_DRAW) {
+        /* Check if we need to syncronize all processes before attempting metadata write
+         * (Prevents race condition where the process writing the metadata goes ahead
+         * and writes the metadata to the file before all the processes have
+         * read the data, "transmitting" data from the "future" to the reading
+         * process. -QAK )
+         */
+        if(H5P_exist_plist(plist,H5AC_BLOCK_BEFORE_META_WRITE_NAME)>0)
+            if(H5P_get(plist,H5AC_BLOCK_BEFORE_META_WRITE_NAME,&block_before_meta_write)<0)
+                HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get H5AC property");
+
+        if(block_before_meta_write)
+            if (MPI_SUCCESS!= (mpi_code=MPI_Barrier(file->comm)))
+                HMPI_GOTO_ERROR(FAIL, "MPI_Barrier failed", mpi_code);
+
+        /* Only p<round> will do the actual write if all procs in comm write same metadata */
+        if (H5_fphdf5_1_metawrite_g) {
+            if (file->mpi_rank != file->mpi_round) {
+                HGOTO_DONE(SUCCEED) /* skip the actual write */
+            }
+        }
+    } /* end if */
+
+    /* Write the data. */
+    assert(H5FD_MPIO_INDEPENDENT==dx->xfer_mode || H5FD_MPIO_COLLECTIVE==dx->xfer_mode);
+    if (H5FD_MPIO_INDEPENDENT==dx->xfer_mode) {
+        /*OKAY: CAST DISCARDS CONST QUALIFIER*/
+        if (MPI_SUCCESS != (mpi_code=MPI_File_write_at(file->f, mpi_off, (void*)buf, size_i, buf_type, &mpi_stat)))
+            HMPI_GOTO_ERROR(FAIL, "MPI_File_write_at failed", mpi_code);
+    } else {
+        /*OKAY: CAST DISCARDS CONST QUALIFIER*/
+        if (MPI_SUCCESS != (mpi_code=MPI_File_write_at_all(file->f, mpi_off, (void*)buf, size_i, buf_type, &mpi_stat)))
+            HMPI_GOTO_ERROR(FAIL, "MPI_File_write_at_all failed", mpi_code);
+    }
+
+    /* KLUDGE, Robb Matzke, 2000-12-29
+     * The LAM implementation of MPI_Get_count() says
+     *    MPI_Get_count: invalid argument (rank 0, MPI_COMM_WORLD)
+     * So I'm commenting this out until it can be investigated. The
+     * returned `bytes_written' isn't used anyway because of Kim's
+     * kludge to avoid bytes_written<0. Likewise in H5FD_fphdf5_read(). */
+
+#ifdef H5_HAVE_MPI_GET_COUNT /* Bill and Albert's kludge*/
+    /* Yet Another KLUDGE, Albert Cheng & Bill Wendling, 2001-05-11.
+     * Many systems don't support MPI_Get_count so we need to do a
+     * configure thingy to fix this. */
+
+    /* Calling MPI_Get_count with "MPI_BYTE" is only valid when we actually
+     * had the 'buf_type' set to MPI_BYTE -QAK
+     */
+    if(use_view_this_time) {
+        /* Figure out the mapping from the MPI 'buf_type' to bytes, someday...
+         * If this gets fixed (and MPI_Get_count() is reliable), the
+         * kludge below where the 'bytes_written' value from MPI_Get_count() is
+         * overwritten with the 'size_i' parameter can be removed. -QAK
+         */
+    } /* end if */
+    else {
+        /* How many bytes were actually written? */
+        if (MPI_SUCCESS!= (mpi_code=MPI_Get_count(&mpi_stat, MPI_BYTE, &bytes_written)))
+            HMPI_GOTO_ERROR(FAIL, "MPI_Get_count failed", mpi_code);
+    } /* end else */
+#endif /* H5_HAVE_MPI_GET_COUNT */
+
+    /*
+     * KLUGE rky, 1998-02-02
+     * MPI_Get_count incorrectly returns negative count; fake a complete
+     * write.
+     */
+    bytes_written = size_i;
+
+    /* Check for write failure */
+    if (bytes_written<0 || bytes_written>size_i)
+        HGOTO_ERROR(H5E_IO, H5E_READERROR, FAIL, "file write failed");
+
+    /*
+     * Reset the file view when we used MPI derived types
+     */
+    if (use_view_this_time) {
+        /*OKAY: CAST DISCARDS CONST QUALIFIER*/
+        if (MPI_SUCCESS != (mpi_code=MPI_File_set_view(file->f, 0, MPI_BYTE, MPI_BYTE, (char*)"native",  file->info)))
+            HMPI_GOTO_ERROR(FAIL, "MPI_File_set_view failed", mpi_code);
+    } /* end if */
+    
+    /* Forget the EOF value (see H5FD_fphdf5_get_eof()) --rpm 1999-08-06 */
+    file->eof = HADDR_UNDEF;
+    
+done:
+    /* Guard against getting into metadate broadcast in failure cases */
+    if(ret_value!=FAIL) {
+        /* if only p<round> writes, need to broadcast the ret_value to other processes */
+        if ((type!=H5FD_MEM_DRAW) && H5_fphdf5_1_metawrite_g) {
+            if (MPI_SUCCESS != (mpi_code=MPI_Bcast(&ret_value, sizeof(ret_value), MPI_BYTE, file->mpi_round, file->comm)))
+                HMPI_GOTO_ERROR(FAIL, "MPI_Bcast failed", mpi_code);
+
+            /* Round-robin rotate to the next process */
+            file->mpi_round = (++file->mpi_round)%file->mpi_size;
+        } /* end if */
+    } /* end if */
+
+    FUNC_LEAVE_NOAPI(ret_value);
+#else
+    return SUCCEED;
+#endif
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5FD_fphdf5_flush
+ *
+ * Purpose:     Makes sure that all data is on disk.  This is collective.
+ *
+ * Return:      Success:	Non-negative
+ *
+ * 		Failure:	Negative
+ *
+ * Programmer:  Unknown
+ *              January 30, 1998
+ *
+ * Modifications:
+ * 		Robb Matzke, 1998-02-18
+ *		Added the ACCESS_PARMS argument.
+ *
+ * 		Robb Matzke, 1999-08-06
+ *		Modified to work with the virtual file layer.
+ *
+ *              Robb Matzke, 2000-12-29
+ *              Make sure file size is at least as large as the last
+ *              allocated byte.
+ *
+ *              Quincey Koziol, 2002-06-??
+ *              Changed file extension method to use MPI_File_set_size instead 
+ *              read->write method.
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5FD_fphdf5_flush(H5FD_t *_file, unsigned closing)
+{
+#if 0
+    H5FP_fphdf5_t		*file = (H5FP_fphdf5_t*)_file;
+    int			mpi_code;	/* mpi return code */
+    MPI_Offset          mpi_off;
+    herr_t              ret_value=SUCCEED;
+#ifdef OLD_WAY
+    uint8_t             byte=0;
+    MPI_Status          mpi_stat;
+#endif  /* OLD_WAY */
+
+    FUNC_ENTER_NOAPI(H5FD_fphdf5_flush, FAIL);
+
+    assert(file);
+    assert(H5FD_FPHDF5==file->pub.driver_id);
+
+#ifdef OLD_WAY
+    /* Portably initialize MPI status variable */
+    HDmemset(&mpi_stat,0,sizeof(MPI_Status));
+#endif /* OLD_WAY */
+
+    /* Extend the file to make sure it's large enough, then sync.
+     * Unfortunately, keeping track of EOF is an expensive operation, so
+     * we can't just check whether EOF<EOA like with other drivers.
+     * Therefore we'll just read the byte at EOA-1 and then write it back. */
+    if(file->eoa>file->last_eoa) {
+#ifdef OLD_WAY
+        if (0==file->mpi_rank) {
+            if (H5FD_fphdf5_haddr_to_MPIOff(file->eoa-1, &mpi_off)<0)
+                HGOTO_ERROR(H5E_INTERNAL, H5E_BADRANGE, FAIL, "cannot convert from haddr_t to MPI_Offset");
+            if (MPI_SUCCESS != (mpi_code=MPI_File_read_at(file->f, mpi_off, &byte, 1, MPI_BYTE, &mpi_stat)))
+                HMPI_GOTO_ERROR(FAIL, "MPI_File_read_at failed", mpi_code);
+            if (MPI_SUCCESS != (mpi_code=MPI_File_write_at(file->f, mpi_off, &byte, 1, MPI_BYTE, &mpi_stat)))
+                HMPI_GOTO_ERROR(FAIL, "MPI_File_write_at failed", mpi_code);
+        } /* end if */
+#else /* OLD_WAY */
+        if (H5FD_fphdf5_haddr_to_MPIOff(file->eoa, &mpi_off)<0)
+            HGOTO_ERROR(H5E_INTERNAL, H5E_BADRANGE, FAIL, "cannot convert from haddr_t to MPI_Offset");
+
+        /* Extend the file's size */
+        if (MPI_SUCCESS != (mpi_code=MPI_File_set_size(file->f, mpi_off)))
+            HMPI_GOTO_ERROR(FAIL, "MPI_File_set_size failed", mpi_code);
+
+	/* Don't let any proc return until all have extended the file.
+         * (Prevents race condition where some processes go ahead and write
+         * more data to the file before all the processes have finished making
+         * it the shorter length, potentially truncating the file and dropping
+         * the new data written)
+         */
+        if (MPI_SUCCESS!= (mpi_code=MPI_Barrier(file->comm)))
+            HMPI_GOTO_ERROR(FAIL, "MPI_Barrier failed", mpi_code);
+#endif /* OLD_WAY */
+
+        /* Update the 'last' eoa value */
+        file->last_eoa=file->eoa;
+    } /* end if */
+
+    /* Only sync the file if we are not going to immediately close it */
+    if(!closing) {
+        if (MPI_SUCCESS != (mpi_code=MPI_File_sync(file->f)))
+            HMPI_GOTO_ERROR(FAIL, "MPI_File_sync failed", mpi_code);
+    } /* end if */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value);
+#else
+    return SUCCEED;
+#endif
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5FD_fphdf5_MPIOff_to_haddr
+ * Purpose:     Convert an MPI_Offset value to haddr_t.
+ * Return:      Success:    The haddr_t equivalent of the MPI_OFF argument.
+ *              Failure:    HADDR_UNDEF
+ * Programmer:  Bill Wendling
+ *              30. January 2003
+ * Modifications:
+ *------------------------------------------------------------------------- 
+ */
+static haddr_t
+H5FD_fphdf5_MPIOff_to_haddr(MPI_Offset mpi_off)
+{
+    haddr_t ret_value;
+
+    FUNC_ENTER_NOINIT(H5FD_fphdf5_MPIOff_to_haddr);
+    ret_value = (mpi_off != (MPI_Offset)(haddr_t)mpi_off ? HADDR_UNDEF : (haddr_t)mpi_off);
+    FUNC_LEAVE_NOAPI(ret_value);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5FD_fphdf5_haddr_to_MPIOff
+ * Purpose:     Convert an haddr_t value to MPI_Offset.
+ * Return:      Success:    Non-negative, the MPI_OFF argument contains
+ *                          the converted value.
+ *              Failure:    FAIL, MPI_OFF is undefined.
+ * Programmer:  Bill Wendling
+ *              30. January 2003
+ * Modifications:
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5FD_fphdf5_haddr_to_MPIOff(haddr_t addr, MPI_Offset *mpi_off /*out*/)
+{
+    herr_t ret_value = FAIL;
+
+    FUNC_ENTER_NOINIT(H5FD_fphdf5_haddr_to_MPIOff);
+
+    if (mpi_off)
+        *mpi_off = (MPI_Offset)addr;
+
+    ret_value = (addr != (haddr_t)(MPI_Offset)addr ? FAIL : SUCCEED);
+    FUNC_LEAVE_NOAPI(ret_value);
+}
+
+#endif  /* H5_HAVE_FPHDF5 */