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openmpi/ompi/mca/sharedfp/sm/sharedfp_sm_request_position.c
Edgar Gabriel 6e8522fec5 infuse life into the shared file pointer framework. For this:
- extend the framework API
 - remove the dummy component, not require anymore
 - add four components to perform the actual job.

This commit was SVN r28828.
2013-07-17 21:55:24 +00:00

81 строка
2.4 KiB
C

/*
* 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 University of Houston. 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 "orte/util/show_help.h"
#include "ompi/mca/sharedfp/sharedfp.h"
/*use a semaphore to lock the shared memory*/
#include <semaphore.h>
int mca_sharedfp_sm_request_position(struct mca_sharedfp_base_data_t * sh,
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 = sh->selected_module_data;
struct sm_offset * sm_offset_ptr = NULL;
int rank = ompi_comm_rank ( sh->comm);
*offset = 0;
if ( mca_sharedfp_sm_verbose ) {
printf("Aquiring lock, rank=%d...",rank);
}
sm_offset_ptr = sm_data->sm_offset_ptr;
/* Aquire an exclusive lock */
sem_wait(&sm_offset_ptr->mutex);
if ( mca_sharedfp_sm_verbose ) {
printf("Succeeded! Acquired sm lock.for rank=%d\n",rank);
}
old_offset=sm_offset_ptr->offset;
if ( mca_sharedfp_sm_verbose ) {
printf("Read last_offset=%lld!\n",old_offset);
}
position = old_offset + bytes_requested;
if ( mca_sharedfp_sm_verbose ) {
printf("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 ) {
printf("Releasing sm lock...rank=%d",rank);
}
sem_post(&sm_offset_ptr->mutex);
if ( mca_sharedfp_sm_verbose ) {
printf("Released lock! released lock.for rank=%d\n",rank);
}
*offset = old_offset;
return ret;
}