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

DEFINITIONS

1. MPI_File_read_ordered

   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 = PMPI_File_read_ordered
  14 #elif defined(HAVE_PRAGMA_HP_SEC_DEF)
  15 #pragma _HP_SECONDARY_DEF PMPI_File_read_ordered MPI_File_read_ordered
  16 #elif defined(HAVE_PRAGMA_CRI_DUP)
  17 #pragma _CRI duplicate MPI_File_read_ordered as PMPI_File_read_ordered
  18 /* end of weak pragmas */
  19 #elif defined(HAVE_WEAK_ATTRIBUTE)
  20 int MPI_File_read_ordered(MPI_File fh, void *buf, int count, MPI_Datatype datatype,
  21                           MPI_Status *status) __attribute__((weak,alias("PMPI_File_read_ordered")));
  22 #endif
  23 
  24 /* Include mapping from MPI->PMPI */
  25 #define MPIO_BUILD_PROFILING
  26 #include "mpioprof.h"
  27 #endif
  28 
  29 /* status object not filled currently */
  30 
  31 /*@
  32     MPI_File_read_ordered - Collective read using shared file pointer
  33 
  34 Input Parameters:
  35 . fh - file handle (handle)
  36 . count - number of elements in buffer (nonnegative integer)
  37 . datatype - datatype of each buffer element (handle)
  38 
  39 Output Parameters:
  40 . buf - initial address of buffer (choice)
  41 . status - status object (Status)
  42 
  43 .N fortran
  44 @*/
  45 int MPI_File_read_ordered(MPI_File fh, void *buf, int count,
  46                           MPI_Datatype datatype, MPI_Status *status)
  47 {
  48     int error_code, nprocs, myrank;
  49     ADIO_Offset incr;
  50     MPI_Count datatype_size;
  51     int source, dest;
  52     static char myname[] = "MPI_FILE_READ_ORDERED";
  53     ADIO_Offset shared_fp=0;
  54     ADIO_File adio_fh;
  55 
  56     ROMIO_THREAD_CS_ENTER();
  57 
  58     adio_fh = MPIO_File_resolve(fh);
  59 
  60     /* --BEGIN ERROR HANDLING-- */
  61     MPIO_CHECK_FILE_HANDLE(adio_fh, myname, error_code);
  62     MPIO_CHECK_COUNT(adio_fh, count, myname, error_code);
  63     MPIO_CHECK_DATATYPE(adio_fh, datatype, myname, error_code);
  64     /* --END ERROR HANDLING-- */
  65 
  66     MPI_Type_size_x(datatype, &datatype_size);
  67 
  68     /* --BEGIN ERROR HANDLING-- */
  69     MPIO_CHECK_INTEGRAL_ETYPE(adio_fh, count, datatype_size, myname, error_code);
  70     MPIO_CHECK_FS_SUPPORTS_SHARED(adio_fh, myname, error_code);
  71     MPIO_CHECK_COUNT_SIZE(adio_fh, count, datatype_size, myname, error_code);
  72     /* --END ERROR HANDLING-- */
  73 
  74     ADIOI_TEST_DEFERRED(adio_fh, "MPI_File_read_ordered", &error_code);
  75 
  76     MPI_Comm_size(adio_fh->comm, &nprocs);
  77     MPI_Comm_rank(adio_fh->comm, &myrank);
  78 
  79     incr = (count*datatype_size)/adio_fh->etype_size;
  80     
  81     /* Use a message as a 'token' to order the operations */
  82     source = myrank - 1;
  83     dest   = myrank + 1;
  84     if (source < 0) source = MPI_PROC_NULL;
  85     if (dest >= nprocs) dest = MPI_PROC_NULL;
  86     MPI_Recv(NULL, 0, MPI_BYTE, source, 0, adio_fh->comm, MPI_STATUS_IGNORE);
  87 
  88     ADIO_Get_shared_fp(adio_fh, incr, &shared_fp, &error_code);
  89     /* --BEGIN ERROR HANDLING-- */
  90     if (error_code != MPI_SUCCESS) {
  91         error_code = MPIO_Err_return_file(adio_fh, error_code);
  92         goto fn_exit;
  93     }
  94     /* --END ERROR HANDLING-- */
  95 
  96     MPI_Send(NULL, 0, MPI_BYTE, dest, 0, adio_fh->comm);
  97 
  98     ADIO_ReadStridedColl(adio_fh, buf, count, datatype, ADIO_EXPLICIT_OFFSET,
  99                          shared_fp, status, &error_code);
 100 
 101     /* --BEGIN ERROR HANDLING-- */
 102     if (error_code != MPI_SUCCESS)
 103         error_code = MPIO_Err_return_file(adio_fh, error_code);
 104     /* --END ERROR HANDLING-- */
 105 
 106 fn_exit:
 107     ROMIO_THREAD_CS_EXIT();
 108 
 109     /* FIXME: Check for error code from ReadStridedColl? */
 110     return error_code;
 111 }