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/*
* Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
* University Research and Technology
* Corporation. All rights reserved.
* Copyright (c) 2004-2005 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) 2013-2015 University of Houston. All rights reserved.
* Copyright (c) 2015 Cisco Systems, Inc. All rights reserved.
* $COPYRIGHT$
*
* Additional copyrights may follow
*
* $HEADER$
*/
#include "ompi_config.h"
#include "sharedfp_sm.h"
#include "mpi.h"
#include "ompi/constants.h"
#include "ompi/mca/sharedfp/sharedfp.h"
#include "ompi/mca/sharedfp/base/base.h"
/*use a semaphore to lock the shared memory*/
#include <semaphore.h>
int mca_sharedfp_sm_request_position(ompio_file_t *fh,
int bytes_requested,
OMPI_MPI_OFFSET_TYPE *offset)
{
int ret = OMPI_SUCCESS;
OMPI_MPI_OFFSET_TYPE position = 0;
OMPI_MPI_OFFSET_TYPE old_offset;
struct mca_sharedfp_sm_data * sm_data = NULL;
struct mca_sharedfp_sm_offset * sm_offset_ptr = NULL;
struct mca_sharedfp_base_data_t *sh = NULL;
sh = fh->f_sharedfp_data;
sm_data = sh->selected_module_data;
*offset = 0;
if ( mca_sharedfp_sm_verbose ) {
opal_output(ompi_sharedfp_base_framework.framework_output,
"Acquiring lock, rank=%d...",fh->f_rank);
}
sm_offset_ptr = sm_data->sm_offset_ptr;
/* Acquire an exclusive lock */
sem_wait(sm_data->mutex);
if ( mca_sharedfp_sm_verbose ) {
opal_output(ompi_sharedfp_base_framework.framework_output,
"Succeeded! Acquired sm lock.for rank=%d\n",fh->f_rank);
}
old_offset=sm_offset_ptr->offset;
if ( mca_sharedfp_sm_verbose ) {
opal_output(ompi_sharedfp_base_framework.framework_output,
"Read last_offset=%lld!\n",old_offset);
}
position = old_offset + bytes_requested;
if ( mca_sharedfp_sm_verbose ) {
opal_output(ompi_sharedfp_base_framework.framework_output,
"old_offset=%lld, bytes_requested=%d, new offset=%lld!\n",old_offset,bytes_requested,position);
}
sm_offset_ptr->offset=position;
if ( mca_sharedfp_sm_verbose ) {
opal_output(ompi_sharedfp_base_framework.framework_output,
"Releasing sm lock...rank=%d",fh->f_rank);
}
sem_post(sm_data->mutex);
if ( mca_sharedfp_sm_verbose ) {
opal_output(ompi_sharedfp_base_framework.framework_output,
"Released lock! released lock.for rank=%d\n",fh->f_rank);
}
*offset = old_offset;
return ret;
}
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