int mca_io_ompio_file_read_at_all (ompi_file_t *fh,
OMPI_MPI_OFFSET_TYPE offset,
void *buf,
int count,
struct ompi_datatype_t *datatype,
ompi_status_public_t * status)
{
int ret = OMPI_SUCCESS;
mca_io_ompio_data_t *data;
data = (mca_io_ompio_data_t *) fh->f_io_selected_data;
ret = ompio_io_ompio_file_read_at_all(&data->ompio_fh,offset,buf,count,datatype,status);
return ret;
}
int mca_sharedfp_addproc_read_ordered (mca_io_ompio_file_t *fh,
void *buf,
int count,
struct ompi_datatype_t *datatype,
ompi_status_public_t *status)
{
int ret = OMPI_SUCCESS;
OMPI_MPI_OFFSET_TYPE offset = 0, offsetReceived = 0;
long sendBuff = 0;
long *buff=NULL;
long offsetBuff, bytesRequested = 0;
size_t numofBytes;
int rank, size, i;
struct mca_sharedfp_base_data_t *sh = NULL;
mca_sharedfp_base_module_t * shared_fp_base_module = NULL;
if(NULL == fh->f_sharedfp_data){
if ( mca_sharedfp_addproc_verbose ) {
printf("sharedfp_addproc_read_ordered: opening the shared file pointer file\n");
}
shared_fp_base_module = fh->f_sharedfp;
ret = shared_fp_base_module->sharedfp_file_open(fh->f_comm,
fh->f_filename,
fh->f_amode,
fh->f_info,
fh);
if ( OMPI_SUCCESS != ret ) {
opal_output(1,"sharedfp_addproc_read_ordered - error opening the shared file pointer\n");
return ret;
}
}
/*Retrieve the new communicator*/
sh = fh->f_sharedfp_data;
/* Calculate the number of bytes to read*/
opal_datatype_type_size ( &datatype->super, &numofBytes);
sendBuff = count * numofBytes;
/* Get the ranks in the communicator */
rank = ompi_comm_rank ( sh->comm);
size = ompi_comm_size ( sh->comm);
if ( 0 == rank ) {
buff = (long*)malloc(sizeof(long) * size);
if ( NULL == buff )
return OMPI_ERR_OUT_OF_RESOURCE;
}
ret = sh->comm->c_coll.coll_gather( &sendBuff, 1, OMPI_OFFSET_DATATYPE,
buff, 1, OMPI_OFFSET_DATATYPE, 0, sh->comm,
sh->comm->c_coll.coll_gather_module);
if ( OMPI_SUCCESS != ret ) {
goto exit;
}
/* All the counts are present now in the recvBuff.
The size of recvBuff is sizeof_newComm
*/
if ( 0 == rank ) {
for (i = 0; i < size ; i ++) {
if ( mca_sharedfp_addproc_verbose ){
printf("sharedfp_addproc_read_ordered: Buff is %ld\n",buff[i]);
}
bytesRequested += buff[i];
if ( mca_sharedfp_addproc_verbose ){
printf("sharedfp_addproc_read_ordered: Bytes requested are %ld\n",bytesRequested);
}
}
/* Request the offset to read bytesRequested bytes
** only the root process needs to do the request,
** since the root process will then tell the other
** processes at what offset they should read their
** share of the data.
*/
ret = mca_sharedfp_addproc_request_position(sh,bytesRequested,&offsetReceived);
if( OMPI_SUCCESS != ret ){
goto exit;
}
if ( mca_sharedfp_addproc_verbose ){
printf("sharedfp_addproc_read_ordered: Offset received is %lld\n",offsetReceived);
}
buff[0] += offsetReceived;
for (i = 1 ; i < size; i++) {
buff[i] += buff[i-1];
}
}
/* Scatter the results to the other processes*/
ret = sh->comm->c_coll.coll_scatter ( buff, 1, OMPI_OFFSET_DATATYPE, &offsetBuff,
1, OMPI_OFFSET_DATATYPE, 0, sh->comm,
sh->comm->c_coll.coll_scatter_module );
if ( OMPI_SUCCESS != ret ) {
goto exit;
}
/*Each process now has its own individual offset in recvBUFF*/
offset = offsetBuff - sendBuff;
if ( mca_sharedfp_addproc_verbose ){
printf("sharedfp_addproc_read_ordered: Offset returned is %lld\n",offset);
}
/* read from the file */
ret = ompio_io_ompio_file_read_at_all(sh->sharedfh,offset,buf,count,datatype,status);
exit:
if ( NULL != buff ) {
free ( buff );
}
return ret;
}
