root/ompi/mca/io/romio321/romio/mpi-io/read_ordb.c

DEFINITIONS

1. MPI_File_read_ordered_begin

   1 /* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil ; -*- */
   2 /* 
   3  *
   4  *   Copyright (C) 1997 University of Chicago. 
   5  *   See COPYRIGHT notice in top-level directory.
   6  */
   7 
   8 #include "mpioimpl.h"
   9 
  10 #ifdef HAVE_WEAK_SYMBOLS
  11 
  12 #if defined(HAVE_PRAGMA_WEAK)
  13 #pragma weak MPI_File_read_ordered_begin = PMPI_File_read_ordered_begin
  14 #elif defined(HAVE_PRAGMA_HP_SEC_DEF)
  15 #pragma _HP_SECONDARY_DEF PMPI_File_read_ordered_begin MPI_File_read_ordered_begin
  16 #elif defined(HAVE_PRAGMA_CRI_DUP)
  17 #pragma _CRI duplicate MPI_File_read_ordered_begin as PMPI_File_read_ordered_begin
  18 /* end of weak pragmas */
  19 #elif defined(HAVE_WEAK_ATTRIBUTE)
  20 int MPI_File_read_ordered_begin(MPI_File fh, void *buf, int count, MPI_Datatype datatype)
  21     __attribute__((weak,alias("PMPI_File_read_ordered_begin")));
  22 #endif
  23 
  24 /* Include mapping from MPI->PMPI */
  25 #define MPIO_BUILD_PROFILING
  26 #include "mpioprof.h"
  27 #endif
  28 
  29 /*@
  30     MPI_File_read_ordered_begin - Begin a split collective read using shared file pointer
  31 
  32 Input Parameters:
  33 . fh - file handle (handle)
  34 . count - number of elements in buffer (nonnegative integer)
  35 . datatype - datatype of each buffer element (handle)
  36 
  37 Output Parameters:
  38 . buf - initial address of buffer (choice)
  39 
  40 .N fortran
  41 @*/
  42 int MPI_File_read_ordered_begin(MPI_File fh, void *buf, int count,
  43                                 MPI_Datatype datatype)
  44 {
  45     int error_code,  nprocs, myrank;
  46     MPI_Count datatype_size;
  47     int source, dest;
  48     ADIO_Offset shared_fp, incr;
  49     ADIO_File adio_fh;
  50     static char myname[] = "MPI_FILE_READ_ORDERED_BEGIN";
  51     void *xbuf=NULL, *e32_buf=NULL;
  52 
  53     ROMIO_THREAD_CS_ENTER();
  54 
  55     adio_fh = MPIO_File_resolve(fh);
  56 
  57     /* --BEGIN ERROR HANDLING-- */
  58     MPIO_CHECK_FILE_HANDLE(adio_fh, myname, error_code);
  59     MPIO_CHECK_COUNT(adio_fh, count, myname, error_code);
  60     MPIO_CHECK_DATATYPE(adio_fh, datatype, myname, error_code);
  61 
  62     if (adio_fh->split_coll_count)
  63     {
  64         error_code = MPIO_Err_create_code(MPI_SUCCESS, MPIR_ERR_RECOVERABLE,
  65                                           myname, __LINE__, MPI_ERR_IO, 
  66                                           "**iosplitcoll", 0);
  67         error_code = MPIO_Err_return_file(adio_fh, error_code);
  68         goto fn_exit;
  69     }
  70     /* --END ERROR HANDLING-- */
  71 
  72     adio_fh->split_coll_count = 1;
  73 
  74 
  75     MPI_Type_size_x(datatype, &datatype_size);
  76     /* --BEGIN ERROR HANDLING-- */
  77     MPIO_CHECK_INTEGRAL_ETYPE(adio_fh, count, datatype_size, myname, error_code);
  78     MPIO_CHECK_FS_SUPPORTS_SHARED(adio_fh, myname, error_code);
  79     MPIO_CHECK_COUNT_SIZE(adio_fh, count, datatype_size, myname, error_code);
  80     /* --END ERROR HANDLING-- */
  81 
  82     ADIOI_TEST_DEFERRED(adio_fh, myname, &error_code);
  83 
  84     MPI_Comm_size(adio_fh->comm, &nprocs);
  85     MPI_Comm_rank(adio_fh->comm, &myrank);
  86 
  87     incr = (count*datatype_size)/adio_fh->etype_size;
  88     /* Use a message as a 'token' to order the operations */
  89     source = myrank - 1;
  90     dest   = myrank + 1;
  91     if (source < 0) source = MPI_PROC_NULL;
  92     if (dest >= nprocs) dest = MPI_PROC_NULL;
  93     MPI_Recv(NULL, 0, MPI_BYTE, source, 0, adio_fh->comm, MPI_STATUS_IGNORE);
  94 
  95     ADIO_Get_shared_fp(adio_fh, incr, &shared_fp, &error_code);
  96     /* --BEGIN ERROR HANDLING-- */
  97     if (error_code != MPI_SUCCESS)
  98     {
  99         error_code = MPIO_Err_return_file(adio_fh, error_code);
 100         goto fn_exit;
 101     }
 102     /* --END ERROR HANDLING-- */
 103 
 104     MPI_Send(NULL, 0, MPI_BYTE, dest, 0, adio_fh->comm);
 105 
 106     xbuf = buf;
 107     if (adio_fh->is_external32)
 108     {
 109         MPI_Aint e32_size = 0;
 110         error_code = MPIU_datatype_full_size(datatype, &e32_size);
 111         if (error_code != MPI_SUCCESS)
 112             goto fn_exit;
 113 
 114         e32_buf = ADIOI_Malloc(e32_size*count);
 115         xbuf = e32_buf;
 116     }
 117 
 118 
 119     ADIO_ReadStridedColl(adio_fh, xbuf, count, datatype, ADIO_EXPLICIT_OFFSET,
 120                          shared_fp, &adio_fh->split_status, &error_code);
 121 
 122     /* --BEGIN ERROR HANDLING-- */
 123     if (error_code != MPI_SUCCESS)
 124         error_code = MPIO_Err_return_file(adio_fh, error_code);
 125     /* --END ERROR HANDLING-- */
 126 
 127     if (e32_buf != NULL) {
 128         error_code = MPIU_read_external32_conversion_fn(buf, datatype,
 129                 count, e32_buf);
 130         ADIOI_Free(e32_buf);
 131     }
 132 
 133 fn_exit:
 134     ROMIO_THREAD_CS_EXIT();
 135 
 136     return error_code;
 137 }