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openmpi/ompi/mca/fbtl/plfs/fbtl_plfs_preadv.c
2015-06-23 20:59:57 -07:00

132 строки
3.5 KiB
C

/*
* Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
* University Research and Technology
* Corporation. All rights reserved.
* Copyright (c) 2004-2011 The University of Tennessee and The University
* of Tennessee Research Foundation. All rights
* reserved.
* Copyright (c) 2004-2005 High Performance Computing Center Stuttgart,
* University of Stuttgart. All rights reserved.
* Copyright (c) 2004-2005 The Regents of the University of California.
* All rights reserved.
* Copyright (c) 2008-2014 University of Houston. All rights reserved.
* $COPYRIGHT$
*
* Additional copyrights may follow
*
* $HEADER$
*/
#include "ompi_config.h"
#include "fbtl_plfs.h"
#include "mpi.h"
#include <unistd.h>
#include "ompi/constants.h"
#include "ompi/mca/fbtl/fbtl.h"
ssize_t mca_fbtl_plfs_preadv (mca_io_ompio_file_t *fh )
{
Plfs_fd *pfd = NULL;
plfs_error_t plfs_ret;
pfd = fh->f_fs_ptr;
ssize_t total_bytes_read=0;
int i, block=1;
struct iovec *iov = NULL;
int iov_count = 0;
OMPI_MPI_OFFSET_TYPE iov_offset = 0;
if (NULL == fh->f_io_array) {
return OMPI_ERROR;
}
iov = (struct iovec *) malloc
(OMPIO_IOVEC_INITIAL_SIZE * sizeof (struct iovec));
if (NULL == iov) {
opal_output(1, "OUT OF MEMORY\n");
return OMPI_ERR_OUT_OF_RESOURCE;
}
for (i=0 ; i<fh->f_num_of_io_entries ; i++) {
if (0 == iov_count) {
iov[iov_count].iov_base = fh->f_io_array[i].memory_address;
iov[iov_count].iov_len = fh->f_io_array[i].length;
iov_offset = (OMPI_MPI_OFFSET_TYPE)(intptr_t)fh->f_io_array[i].offset;
iov_count ++;
}
if (OMPIO_IOVEC_INITIAL_SIZE*block <= iov_count) {
block ++;
iov = (struct iovec *)realloc
(iov, OMPIO_IOVEC_INITIAL_SIZE * block *
sizeof(struct iovec));
if (NULL == iov) {
opal_output(1, "OUT OF MEMORY\n");
return OMPI_ERR_OUT_OF_RESOURCE;
}
}
if (fh->f_num_of_io_entries != i+1) {
if (((OMPI_MPI_OFFSET_TYPE)(intptr_t)fh->f_io_array[i].offset +
(OPAL_PTRDIFF_TYPE)fh->f_io_array[i].length) ==
(OMPI_MPI_OFFSET_TYPE)(intptr_t)fh->f_io_array[i+1].offset) {
iov[iov_count].iov_base =
fh->f_io_array[i+1].memory_address;
iov[iov_count].iov_len = fh->f_io_array[i+1].length;
iov_count ++;
continue;
}
}
// Find the total number of bytes to be read.
size_t bytes = 0;
for (int i = 0; i < iov_count; ++i) {
bytes += iov[i].iov_len;
}
// Allocate a temporary buffer to hold the data
char *buffer;
buffer = (char *) malloc (bytes);
if (buffer == NULL) {
return OMPI_ERROR;
}
// Read the data
ssize_t bytes_read;
plfs_ret = plfs_read( pfd, buffer, bytes, iov_offset, &bytes_read );
if (PLFS_SUCCESS != plfs_ret) {
opal_output(0, "fbtl_plfs_preadv: Error in plfs_read:\n%s\n", strplfserr(plfs_ret));
return OMPI_ERROR;
}
if (bytes_read < 0)
return OMPI_ERROR;
total_bytes_read += bytes_read;
// Copy the data from BUFFER into the memory specified by IOV
bytes = bytes_read;
for (int i = 0; i < iov_count; ++i) {
size_t copy = MIN (iov[i].iov_len, bytes);
(void) memcpy ((void *) iov[i].iov_base, (void *) buffer, copy);
buffer += copy;
bytes -= copy;
if (bytes == 0) {
break;
}
}
iov_count = 0;
if ( NULL != buffer ) {
free (buffer);
buffer=NULL;
}
}
if (NULL != iov) {
free (iov);
iov = NULL;
}
return total_bytes_read;
}