/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil -*- */
/*
 * Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
 *                         University Research and Technology
 *                         Corporation.  All rights reserved.
 * Copyright (c) 2004-2017 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 (c) 2015-2017 Research Organization for Information Science
 *                         and Technology (RIST). All rights reserved.
 * Copyright (c) 2015-2016 Los Alamos National Security, LLC. All rights
 *                         reserved.
 * $COPYRIGHT$
 *
 * Additional copyrights may follow
 *
 * $HEADER$
 */

#include "ompi_config.h"
#include "fcoll_two_phase.h"

#include "mpi.h"
#include "ompi/constants.h"
#include "ompi/communicator/communicator.h"
#include "ompi/mca/fcoll/fcoll.h"
#include "ompi/mca/io/ompio/io_ompio.h"
#include "ompi/mca/io/io.h"
#include "opal/mca/base/base.h"
#include "math.h"
#include "ompi/mca/pml/pml.h"
#include <unistd.h>

#define DEBUG_ON 0

/* Two Phase implementation from ROMIO ported to OMPIO infrastructure
 * This is pretty much the same as ROMIO's two_phase and based on ROMIO's code
 * base
 */


/* Datastructure to support specifying the flat-list. */
typedef struct flat_list_node {
    MPI_Datatype type;
    int count;
    OMPI_MPI_OFFSET_TYPE *blocklens;
    OMPI_MPI_OFFSET_TYPE *indices;
    struct flat_list_node *next;
} Flatlist_node;



/* local function declarations  */
static int two_phase_exch_and_write(mca_io_ompio_file_t *fh,
				    const void *buf,
				    MPI_Datatype datatype,
				    mca_io_ompio_access_array_t *others_req,
				    struct iovec *offset_len,
				    int contig_access_count,
				    OMPI_MPI_OFFSET_TYPE min_st_offset,
				    OMPI_MPI_OFFSET_TYPE fd_size,
				    OMPI_MPI_OFFSET_TYPE *fd_start,
				    OMPI_MPI_OFFSET_TYPE *fd_end,
				    Flatlist_node *flat_buf,
				    size_t *buf_idx, int striping_unit,
				    int num_io_procs, int *aggregator_list);



static int  two_phase_exchage_data(mca_io_ompio_file_t *fh,
				   const void *buf,
				   char *write_buf,
				   struct iovec *offset_length,
				   int *send_size, int *start_pos,
				   int *recv_size,
				   OMPI_MPI_OFFSET_TYPE off,
				   OMPI_MPI_OFFSET_TYPE size, int *count,
				   int *partial_recv, int *sent_to_proc,
				   int contig_access_count,
				   OMPI_MPI_OFFSET_TYPE min_st_offset,
				   OMPI_MPI_OFFSET_TYPE fd_size,
				   OMPI_MPI_OFFSET_TYPE *fd_start,
				   OMPI_MPI_OFFSET_TYPE *fd_end,
				   Flatlist_node *flat_buf,
				   mca_io_ompio_access_array_t *others_req,
				   int *send_buf_idx, int *curr_to_proc,
				   int *done_to_proc, int iter,
				   size_t *buf_idx, MPI_Aint buftype_extent,
				   int striping_unit, int num_io_procs,
				   int *aggregator_list,  int *hole);


static int two_phase_fill_send_buffer(mca_io_ompio_file_t *fh,
				      const void *buf,
				      Flatlist_node *flat_buf,
				      char **send_buf,
				      struct iovec *offset_length,
				      int *send_size,
				      MPI_Request *send_req,
				      int *sent_to_proc,
				      int contig_access_count,
				      OMPI_MPI_OFFSET_TYPE min_st_offset,
				      OMPI_MPI_OFFSET_TYPE fd_size,
				      OMPI_MPI_OFFSET_TYPE *fd_start,
				      OMPI_MPI_OFFSET_TYPE *fd_end,
				      int *send_buf_idx,
				      int *curr_to_proc,
				      int *done_to_proc,
				      int iter, MPI_Aint buftype_extent,
				      int striping_unit,
				      int num_io_procs, int *aggregator_list);
#if OMPIO_FCOLL_WANT_TIME_BREAKDOWN
static int is_aggregator(int rank,
			 int nprocs_for_coll,
			 int *aggregator_list);
#endif

void two_phase_heap_merge(mca_io_ompio_access_array_t *others_req,
			  int *count,
			  OMPI_MPI_OFFSET_TYPE *srt_off,
			  int *srt_len,
			  int *start_pos,
			  int myrank,
			  int nprocs,
			  int nprocs_recv,
			  int total_elements);


/* local function declarations  ends here!*/


#if OMPIO_FCOLL_WANT_TIME_BREAKDOWN
double write_time = 0.0, start_write_time = 0.0, end_write_time = 0.0;
double comm_time = 0.0, start_comm_time = 0.0, end_comm_time = 0.0;
double exch_write = 0.0, start_exch = 0.0, end_exch = 0.0;
#endif

int
mca_fcoll_two_phase_file_write_all (mca_io_ompio_file_t *fh,
                                    const void *buf,
                                    int count,
                                    struct ompi_datatype_t *datatype,
                                    ompi_status_public_t *status)
{



    int i, j,interleave_count=0, striping_unit=0;
    uint32_t iov_count=0,ti;
    struct iovec *decoded_iov=NULL, *temp_iov=NULL;
    size_t max_data = 0, total_bytes = 0;
    long long_max_data = 0, long_total_bytes = 0;
    int domain_size=0, *count_my_req_per_proc=NULL, count_my_req_procs;
    int count_other_req_procs,  ret=OMPI_SUCCESS;
    int two_phase_num_io_procs=1;
    size_t *buf_indices=NULL;
    int local_count = 0, local_size=0,*aggregator_list = NULL;
    struct iovec *iov = NULL;

    OMPI_MPI_OFFSET_TYPE start_offset, end_offset, fd_size;
    OMPI_MPI_OFFSET_TYPE *start_offsets=NULL, *end_offsets=NULL;
    OMPI_MPI_OFFSET_TYPE *fd_start=NULL, *fd_end=NULL, min_st_offset;
    Flatlist_node *flat_buf=NULL;
    mca_io_ompio_access_array_t *my_req=NULL, *others_req=NULL;
    MPI_Aint send_buf_addr;
#if OMPIO_FCOLL_WANT_TIME_BREAKDOWN
    mca_common_ompio_print_entry nentry;
#endif


//    if (opal_datatype_is_predefined(&datatype->super)) {
//	fh->f_flags = fh->f_flags |  OMPIO_CONTIGUOUS_MEMORY;
//    }


    if (! (fh->f_flags & OMPIO_CONTIGUOUS_MEMORY)) {

	ret =   fh->f_decode_datatype ((struct mca_io_ompio_file_t *)fh,
				       datatype,
				       count,
				       buf,
				       &max_data,
				       &temp_iov,
				       &iov_count);
	if (OMPI_SUCCESS != ret ){
	    goto exit;
	}

	send_buf_addr = (ptrdiff_t)buf;
	if ( 0 < iov_count ) {
	    decoded_iov = (struct iovec *)malloc
		(iov_count * sizeof(struct iovec));
            if (NULL == decoded_iov) {
                ret = OMPI_ERR_OUT_OF_RESOURCE;
                goto exit;
            }
	}
	for (ti = 0; ti < iov_count; ti ++){
	    decoded_iov[ti].iov_base = (IOVBASE_TYPE *)(
		(ptrdiff_t)temp_iov[ti].iov_base -
		send_buf_addr);
	    decoded_iov[ti].iov_len =
		temp_iov[ti].iov_len ;
#if DEBUG_ON
	    printf("d_offset[%d]: %ld, d_len[%d]: %ld\n",
		   ti, (ptrdiff_t)decoded_iov[ti].iov_base,
		   ti, decoded_iov[ti].iov_len);
#endif
	}

    }
    else{
	max_data = count * datatype->super.size;
    }

    if ( MPI_STATUS_IGNORE != status ) {
	status->_ucount = max_data;
    }

    fh->f_get_num_aggregators ( &two_phase_num_io_procs );
    if(-1 == two_phase_num_io_procs){
	ret = fh->f_set_aggregator_props ((struct mca_io_ompio_file_t *)fh,
					  two_phase_num_io_procs,
					  max_data);
	if ( OMPI_SUCCESS != ret){
            goto exit;
	}

	two_phase_num_io_procs = fh->f_final_num_aggrs;

    }

    if (two_phase_num_io_procs > fh->f_size){
        two_phase_num_io_procs = fh->f_size;
    }


#if DEBUG_ON
    printf("Number of aggregators : %ld\n", two_phase_num_io_procs);
#endif

    aggregator_list = (int *) malloc (two_phase_num_io_procs *sizeof(int));
    if ( NULL == aggregator_list ) {
        ret = OMPI_ERR_OUT_OF_RESOURCE;
        goto exit;
    }

    if ( OMPI_COMM_IS_MAPBY_NODE (&ompi_mpi_comm_world.comm) ) {
        for (i =0; i< two_phase_num_io_procs; i++){
            aggregator_list[i] = i;
        }
    }
    else {
        for (i =0; i< two_phase_num_io_procs; i++){
            aggregator_list[i] = i * fh->f_size / two_phase_num_io_procs;
        }
    }        

    ret = fh->f_generate_current_file_view ((struct mca_io_ompio_file_t*)fh,
					    max_data,
					    &iov,
					    &local_count);


    if ( OMPI_SUCCESS != ret ){
	goto exit;
    }

    long_max_data = (long) max_data;
    ret = fh->f_comm->c_coll->coll_allreduce (&long_max_data,
					     &long_total_bytes,
					     1,
					     MPI_LONG,
					     MPI_SUM,
					     fh->f_comm,
					     fh->f_comm->c_coll->coll_allreduce_module);

    if ( OMPI_SUCCESS != ret ) {
	goto exit;
    }
    total_bytes = (size_t) long_total_bytes;

    if ( 0 == total_bytes ) {
        ret = OMPI_SUCCESS;
        goto exit;
    }

    if (!(fh->f_flags & OMPIO_CONTIGUOUS_MEMORY)) {

	/* This datastructre translates between OMPIO->ROMIO its a little hacky!*/
	/* But helps to re-use romio's code for handling non-contiguous file-type*/
	flat_buf = (Flatlist_node *)malloc(sizeof(Flatlist_node));
	if ( NULL == flat_buf ){
	    ret = OMPI_ERR_OUT_OF_RESOURCE;
	    goto exit;
	}

	flat_buf->type = datatype;
	flat_buf->next = NULL;
	flat_buf->count = 0;
	flat_buf->indices = NULL;
	flat_buf->blocklens = NULL;

	if ( 0 < count ) {
	    local_size = OMPIO_MAX(1,iov_count/count);
	}
	else {
	    local_size = 0;
	}

	if ( 0 < local_size ) {
	    flat_buf->indices =
		(OMPI_MPI_OFFSET_TYPE *)malloc(local_size *
					       sizeof(OMPI_MPI_OFFSET_TYPE));
	    if ( NULL == flat_buf->indices ){
		ret = OMPI_ERR_OUT_OF_RESOURCE;
		goto exit;

	    }

	    flat_buf->blocklens =
		(OMPI_MPI_OFFSET_TYPE *)malloc(local_size *
					       sizeof(OMPI_MPI_OFFSET_TYPE));
	    if ( NULL == flat_buf->blocklens ){
		ret = OMPI_ERR_OUT_OF_RESOURCE;
		goto exit;
	    }
	}
	flat_buf->count = local_size;
        for (j = 0 ; j < local_size ; ++j) {
	    if ( 0 < max_data  ) {
		flat_buf->indices[j] = (OMPI_MPI_OFFSET_TYPE)(intptr_t)decoded_iov[j].iov_base;
		flat_buf->blocklens[j] = decoded_iov[j].iov_len;
	    }
	    else {
		flat_buf->indices[j] = 0;
		flat_buf->blocklens[j] = 0;
	    }
	}

#if DEBUG_ON
	printf("flat_buf_count : %d\n", flat_buf->count);
	for(i=0;i<flat_buf->count;i++){
	    printf("%d: blocklen[%d] : %lld, indices[%d]: %lld \n",
		   fh->f_rank, i, flat_buf->blocklens[i], i ,flat_buf->indices[i]);

	}
#endif
    }

#if DEBUG_ON
    printf("%d: fcoll:two_phase:write_all->total_bytes:%ld, local_count: %d\n",
	   fh->f_rank,total_bytes, local_count);
    for (i=0 ; i<local_count ; i++) {
	printf("%d: fcoll:two_phase:write_all:OFFSET:%ld,LENGTH:%ld\n",
	       fh->f_rank,
	       (size_t)iov[i].iov_base,
	       (size_t)iov[i].iov_len);
    }


#endif

    start_offset = (OMPI_MPI_OFFSET_TYPE)(uintptr_t)iov[0].iov_base;
    if ( 0 < local_count ) {
	end_offset = (OMPI_MPI_OFFSET_TYPE)(uintptr_t)iov[local_count-1].iov_base +
	    (OMPI_MPI_OFFSET_TYPE)iov[local_count-1].iov_len - 1;
    }
    else {
	end_offset = 0;
    }

#if DEBUG_ON
    printf("%d: fcoll:two_phase:write_all:START OFFSET:%ld,END OFFSET:%ld\n",
	   fh->f_rank,
	   (size_t)start_offset,
	   (size_t)end_offset);

#endif

    start_offsets = (OMPI_MPI_OFFSET_TYPE *)malloc
	(fh->f_size*sizeof(OMPI_MPI_OFFSET_TYPE));

    if ( NULL == start_offsets ){
	ret = OMPI_ERR_OUT_OF_RESOURCE;
	goto exit;
    }

    end_offsets = (OMPI_MPI_OFFSET_TYPE *)malloc
	(fh->f_size*sizeof(OMPI_MPI_OFFSET_TYPE));

    if ( NULL == end_offsets ){
	ret =  OMPI_ERR_OUT_OF_RESOURCE;
	goto exit;
    }


    ret = fh->f_comm->c_coll->coll_allgather(&start_offset,
					    1,
					    OMPI_OFFSET_DATATYPE,
					    start_offsets,
					    1,
					    OMPI_OFFSET_DATATYPE,
					    fh->f_comm,
					    fh->f_comm->c_coll->coll_allgather_module);

    if ( OMPI_SUCCESS != ret ){
	goto exit;
    }


    ret = fh->f_comm->c_coll->coll_allgather(&end_offset,
					    1,
					    OMPI_OFFSET_DATATYPE,
					    end_offsets,
					    1,
					    OMPI_OFFSET_DATATYPE,
					    fh->f_comm,
					    fh->f_comm->c_coll->coll_allgather_module);


    if ( OMPI_SUCCESS != ret ){
	goto exit;
    }

#if DEBUG_ON
    for (i=0;i<fh->f_size;i++){
	printf("%d: fcoll:two_phase:write_all:start[%d]:%ld,end[%d]:%ld\n",
	       fh->f_rank,i,
	       (size_t)start_offsets[i],i,
	       (size_t)end_offsets[i]);
    }
#endif



    for (i=1; i<fh->f_size; i++){
	if ((start_offsets[i] < end_offsets[i-1]) &&
	    (start_offsets[i] <= end_offsets[i])){
	    interleave_count++;
	}
    }

#if DEBUG_ON
    printf("%d: fcoll:two_phase:write_all:interleave_count:%d\n",
	   fh->f_rank,interleave_count);
#endif


    ret = mca_fcoll_two_phase_domain_partition(fh,
					       start_offsets,
					       end_offsets,
					       &min_st_offset,
					       &fd_start,
					       &fd_end,
					       domain_size,
					       &fd_size,
					       striping_unit,
					       two_phase_num_io_procs);
    if ( OMPI_SUCCESS != ret ){
	goto exit;
    }


#if  DEBUG_ON
    for (i=0;i<two_phase_num_io_procs;i++){
	printf("fd_start[%d] : %lld, fd_end[%d] : %lld, local_count: %d\n",
	       i, fd_start[i], i, fd_end[i], local_count);
    }
#endif


    ret = mca_fcoll_two_phase_calc_my_requests (fh,
						iov,
						local_count,
						min_st_offset,
						fd_start,
						fd_end,
						fd_size,
						&count_my_req_procs,
						&count_my_req_per_proc,
						&my_req,
						&buf_indices,
						striping_unit,
						two_phase_num_io_procs,
						aggregator_list);
    if ( OMPI_SUCCESS != ret ){
	goto exit;
    }



    ret = mca_fcoll_two_phase_calc_others_requests(fh,
						   count_my_req_procs,
						   count_my_req_per_proc,
						   my_req,
						   &count_other_req_procs,
						   &others_req);
    if (OMPI_SUCCESS != ret ){
	goto exit;
    }


#if DEBUG_ON
    printf("count_other_req_procs : %d\n", count_other_req_procs);
#endif

#if OMPIO_FCOLL_WANT_TIME_BREAKDOWN
    start_exch = MPI_Wtime();
#endif

    ret = two_phase_exch_and_write(fh,
				   buf,
				   datatype,
				   others_req,
				   iov,
				   local_count,
				   min_st_offset,
				   fd_size,
				   fd_start,
				   fd_end,
				   flat_buf,
				   buf_indices,
				   striping_unit,
				   two_phase_num_io_procs,
				   aggregator_list);

    if (OMPI_SUCCESS != ret){
	goto exit;
    }


#if OMPIO_FCOLL_WANT_TIME_BREAKDOWN
    end_exch = MPI_Wtime();
    exch_write += (end_exch - start_exch);

    nentry.time[0] = write_time;
    nentry.time[1] = comm_time;
    nentry.time[2] = exch_write;
    if (is_aggregator(fh->f_rank,
		      two_phase_num_io_procs,
		      aggregator_list)){
	nentry.aggregator = 1;
    }
    else{
	nentry.aggregator = 0;
    }
    nentry.nprocs_for_coll = two_phase_num_io_procs;
    if (!mca_common_ompio_full_print_queue(fh->f_coll_write_time)){
	mca_common_ompio_register_print_entry(fh->f_coll_write_time,
                                              nentry);
    }
#endif

exit :
    if (flat_buf != NULL) {

	if (flat_buf->blocklens != NULL) {
	    free (flat_buf->blocklens);
	}

	if (flat_buf->indices != NULL) {
	    free (flat_buf->indices);
	}
	free (flat_buf);

    }


    free (start_offsets);
    free (end_offsets);
    free (aggregator_list);
    free (decoded_iov);
    free (fd_start);
    free (fd_end);
    free (others_req);
    free (my_req);
    free (buf_indices);
    free (count_my_req_per_proc);

    return ret;
}


static int two_phase_exch_and_write(mca_io_ompio_file_t *fh,
				    const void *buf,
				    MPI_Datatype datatype,
				    mca_io_ompio_access_array_t *others_req,
				    struct iovec *offset_len,
				    int contig_access_count,
				    OMPI_MPI_OFFSET_TYPE min_st_offset,
				    OMPI_MPI_OFFSET_TYPE fd_size,
				    OMPI_MPI_OFFSET_TYPE *fd_start,
				    OMPI_MPI_OFFSET_TYPE *fd_end,
				    Flatlist_node *flat_buf,
				    size_t *buf_idx, int striping_unit,
				    int two_phase_num_io_procs,
				    int *aggregator_list)

{


    int i, j, ntimes, max_ntimes, m;
    int *curr_offlen_ptr=NULL, *count=NULL, *send_size=NULL, *recv_size=NULL;
    int *partial_recv=NULL, *start_pos=NULL, req_len, flag;
    int *sent_to_proc=NULL, ret = OMPI_SUCCESS;
    int *send_buf_idx=NULL, *curr_to_proc=NULL, *done_to_proc=NULL;
    OMPI_MPI_OFFSET_TYPE st_loc=-1, end_loc=-1, off, done;
    OMPI_MPI_OFFSET_TYPE size=0, req_off, len;
    MPI_Aint buftype_extent;
    int  hole;
    int two_phase_cycle_buffer_size;
    size_t byte_size;
    MPI_Datatype byte = MPI_BYTE;
#if DEBUG_ON
    int ii,jj;
#endif

    char *write_buf=NULL;


    opal_datatype_type_size(&byte->super,
			    &byte_size);

    for (i = 0; i < fh->f_size; i++){
	if (others_req[i].count) {
	    st_loc = others_req[i].offsets[0];
	    end_loc = others_req[i].offsets[0];
	    break;
	}
    }

    for (i=0;i<fh->f_size;i++){
	for(j=0;j< others_req[i].count; j++){
	    st_loc = OMPIO_MIN(st_loc, others_req[i].offsets[j]);
	    end_loc = OMPIO_MAX(end_loc, (others_req[i].offsets[j] + others_req[i].lens[j] - 1));

	}
    }

    fh->f_get_bytes_per_agg ( &two_phase_cycle_buffer_size );
    ntimes = (int) ((end_loc - st_loc + two_phase_cycle_buffer_size)/two_phase_cycle_buffer_size);

    if ((st_loc == -1) && (end_loc == -1)) {
	ntimes = 0;
    }

    fh->f_comm->c_coll->coll_allreduce (&ntimes,
				       &max_ntimes,
				       1,
				       MPI_INT,
				       MPI_MAX,
				       fh->f_comm,
				       fh->f_comm->c_coll->coll_allreduce_module);

    if (ntimes){
	write_buf = (char *) malloc (two_phase_cycle_buffer_size);
	if ( NULL == write_buf ){
	    return OMPI_ERR_OUT_OF_RESOURCE;
	}
    }

    curr_offlen_ptr = (int *) calloc(fh->f_size, sizeof(int));

    if ( NULL == curr_offlen_ptr ){
        ret = OMPI_ERR_OUT_OF_RESOURCE;
        goto exit;
    }

    count = (int *) malloc(fh->f_size*sizeof(int));

    if ( NULL == count ){
        ret = OMPI_ERR_OUT_OF_RESOURCE;
        goto exit;
    }

    partial_recv = (int *)calloc(fh->f_size, sizeof(int));

    if ( NULL == partial_recv ){
        ret = OMPI_ERR_OUT_OF_RESOURCE;
        goto exit;
    }

    send_size = (int *) calloc(fh->f_size,sizeof(int));

    if ( NULL == send_size ){
        ret = OMPI_ERR_OUT_OF_RESOURCE;
        goto exit;
    }

    recv_size = (int *) calloc(fh->f_size,sizeof(int));

    if ( NULL == recv_size ){
        ret = OMPI_ERR_OUT_OF_RESOURCE;
        goto exit;
    }

    send_buf_idx = (int *) malloc(fh->f_size*sizeof(int));

    if ( NULL == send_buf_idx ){
        ret = OMPI_ERR_OUT_OF_RESOURCE;
        goto exit;
    }

    sent_to_proc = (int *) calloc(fh->f_size, sizeof(int));

    if ( NULL == sent_to_proc){
        ret = OMPI_ERR_OUT_OF_RESOURCE;
        goto exit;
    }

    curr_to_proc = (int *) malloc(fh->f_size*sizeof(int));

    if ( NULL == curr_to_proc ){
        ret = OMPI_ERR_OUT_OF_RESOURCE;
        goto exit;
    }

    done_to_proc = (int *) malloc(fh->f_size*sizeof(int));

    if ( NULL == done_to_proc ){
        ret = OMPI_ERR_OUT_OF_RESOURCE;
        goto exit;
    }

    start_pos = (int *) malloc(fh->f_size*sizeof(int));

    if ( NULL == start_pos ){
      ret = OMPI_ERR_OUT_OF_RESOURCE;
      goto exit;
    }


    done = 0;
    off = st_loc;

    ompi_datatype_type_extent(datatype, &buftype_extent);
    for (m=0;m <ntimes; m++){
	for (i=0; i< fh->f_size; i++) count[i] = recv_size[i] = 0;

	size = OMPIO_MIN((unsigned)two_phase_cycle_buffer_size,
			 end_loc-st_loc+1-done);
	for (i=0;i<fh->f_size;i++){
	    if(others_req[i].count){
		start_pos[i] = curr_offlen_ptr[i];
		for (j=curr_offlen_ptr[i]; j<others_req[i].count; j++) {
		    if (partial_recv[i]) {
			/* this request may have been partially
			   satisfied in the previous iteration. */
			req_off = others_req[i].offsets[j] +
			    partial_recv[i];
                        req_len = others_req[i].lens[j] -
			    partial_recv[i];
			partial_recv[i] = 0;
			/* modify the off-len pair to reflect this change */
			others_req[i].offsets[j] = req_off;
			others_req[i].lens[j] = req_len;
		    }
		    else {
			req_off = others_req[i].offsets[j];
                        req_len = others_req[i].lens[j];
		    }
		    if (req_off < off + size) {
			count[i]++;
#if DEBUG_ON
			printf("%d: req_off : %lld, off : %lld, size : %lld, count[%d]: %d\n", fh->f_rank,
			       req_off,
			       off,
			       size,i,
			       count[i]);
#endif
			PMPI_Address(write_buf+req_off-off,
				     &(others_req[i].mem_ptrs[j]));
#if DEBUG_ON
			printf("%d : mem_ptrs : %ld\n", fh->f_rank,
			       others_req[i].mem_ptrs[j]);
#endif
			recv_size[i] += (int) (OMPIO_MIN(off + size - req_off,
							 (unsigned)req_len));

			if (off+size-req_off < (unsigned)req_len){

			    partial_recv[i] = (int)(off + size - req_off);
			    break;
			}
		    }
		    else break;
		}
		curr_offlen_ptr[i] = j;
	    }
	}

	ret = two_phase_exchage_data(fh, buf, write_buf,
				     offset_len,send_size,
				     start_pos,recv_size,off,size,
				     count, partial_recv, sent_to_proc,
				     contig_access_count,
				     min_st_offset,
				     fd_size, fd_start,
				     fd_end, flat_buf, others_req,
				     send_buf_idx, curr_to_proc,
				     done_to_proc, m, buf_idx,
				     buftype_extent, striping_unit,
				     two_phase_num_io_procs,
				     aggregator_list, &hole);

	if ( OMPI_SUCCESS != ret ){
	    goto exit;
	}



	flag = 0;
	for (i=0; i<fh->f_size; i++)
	    if (count[i]) flag = 1;



	if (flag){

#if OMPIO_FCOLL_WANT_TIME_BREAKDOWN
	    start_write_time = MPI_Wtime();
#endif

#if DEBUG_ON
	    printf("rank : %d enters writing\n", fh->f_rank);
	    printf("size : %ld, off : %ld\n",size, off);
	    for (ii=0, jj=0;jj<size;jj+=4, ii++){
		printf("%d : write_buf[%d]: %d\n", fh->f_rank, ii,((int *)write_buf[jj]));
	    }
#endif
	    len = size * byte_size;
	    fh->f_io_array = (mca_io_ompio_io_array_t *)malloc
		(sizeof(mca_io_ompio_io_array_t));
	    if (NULL == fh->f_io_array) {
		opal_output(1, "OUT OF MEMORY\n");
		ret = OMPI_ERR_OUT_OF_RESOURCE;
                goto exit;
	    }

	    fh->f_io_array[0].offset  =(IOVBASE_TYPE *)(intptr_t) off;
	    fh->f_io_array[0].length = len;
	    fh->f_io_array[0].memory_address = write_buf;
	    fh->f_num_of_io_entries = 1;

#if DEBUG_ON
            for (i=0 ; i<fh->f_num_of_io_entries ; i++) {
                printf("%d: ADDRESS: %p  OFFSET: %ld   LENGTH: %d\n",
		       fh->f_rank,
                       fh->f_io_array[i].memory_address,
                       fh->f_io_array[i].offset,
                       fh->f_io_array[i].length);
            }
#endif

	    if (fh->f_num_of_io_entries){
		if ( 0 > fh->f_fbtl->fbtl_pwritev (fh)) {
		    opal_output(1, "WRITE FAILED\n");
                    ret = OMPI_ERROR;
                    goto exit;
		}
	    }
#if OMPIO_FCOLL_WANT_TIME_BREAKDOWN
	    end_write_time = MPI_Wtime();
	    write_time += (end_write_time - start_write_time);
#endif


	}
	/***************** DONE WRITING *****************************************/
	/****RESET **********************/
	fh->f_num_of_io_entries = 0;
	if (NULL != fh->f_io_array) {
	    free (fh->f_io_array);
	    fh->f_io_array = NULL;
	}

	off += size;
	done += size;

    }
    for (i=0; i<fh->f_size; i++) count[i] = recv_size[i] = 0;
    for (m=ntimes; m<max_ntimes; m++) {
	ret = two_phase_exchage_data(fh, buf, write_buf,
				     offset_len,send_size,
				     start_pos,recv_size,off,size,
				     count, partial_recv, sent_to_proc,
				     contig_access_count,
				     min_st_offset,
				     fd_size, fd_start,
				     fd_end, flat_buf,others_req,
				     send_buf_idx, curr_to_proc,
				     done_to_proc, m, buf_idx,
				     buftype_extent, striping_unit,
				     two_phase_num_io_procs,
				     aggregator_list, &hole);
	if ( OMPI_SUCCESS != ret ){
	    goto exit;
	}
    }

exit:

    free (write_buf);
    free (curr_offlen_ptr);
    free (count);
    free (partial_recv);
    free (send_size);
    free (recv_size);
    free (sent_to_proc);
    free (start_pos);
    free (send_buf_idx);
    free (curr_to_proc);
    free (done_to_proc);

    return ret;
}

static int two_phase_exchage_data(mca_io_ompio_file_t *fh,
				  const void *buf,
				  char *write_buf,
				  struct iovec *offset_length,
				  int *send_size,int *start_pos,
				  int *recv_size,
				  OMPI_MPI_OFFSET_TYPE off,
				  OMPI_MPI_OFFSET_TYPE size, int *count,
				  int *partial_recv, int *sent_to_proc,
				  int contig_access_count,
				  OMPI_MPI_OFFSET_TYPE min_st_offset,
				  OMPI_MPI_OFFSET_TYPE fd_size,
				  OMPI_MPI_OFFSET_TYPE *fd_start,
				  OMPI_MPI_OFFSET_TYPE *fd_end,
				  Flatlist_node *flat_buf,
				  mca_io_ompio_access_array_t *others_req,
				  int *send_buf_idx, int *curr_to_proc,
				  int *done_to_proc, int iter,
				  size_t *buf_idx,MPI_Aint buftype_extent,
				  int striping_unit, int two_phase_num_io_procs,
				  int *aggregator_list, int *hole){

    int *tmp_len=NULL, sum, *srt_len=NULL, nprocs_recv, nprocs_send,  k,i,j;
    int ret=OMPI_SUCCESS;
    MPI_Request *requests=NULL, *send_req=NULL;
    ompi_datatype_t **recv_types=NULL;
    OMPI_MPI_OFFSET_TYPE *srt_off=NULL;
    char **send_buf = NULL;

#if OMPIO_FCOLL_WANT_TIME_BREAKDOWN
    start_comm_time = MPI_Wtime();
#endif
    ret = fh->f_comm->c_coll->coll_alltoall (recv_size,
					    1,
					    MPI_INT,
					    send_size,
					    1,
					    MPI_INT,
					    fh->f_comm,
					    fh->f_comm->c_coll->coll_alltoall_module);

    if ( OMPI_SUCCESS != ret ){
	return ret;
    }

    nprocs_recv = 0;
    for (i=0;i<fh->f_size;i++){
	if (recv_size[i]){
	    nprocs_recv++;
	}
    }


    recv_types = (ompi_datatype_t **)
	calloc (( nprocs_recv + 1 ), sizeof(ompi_datatype_t *));

    if ( NULL == recv_types ){
	ret = OMPI_ERR_OUT_OF_RESOURCE;
	goto exit;
    }

    tmp_len = (int *) calloc(fh->f_size, sizeof(int));

    if ( NULL == tmp_len ) {
        ret = OMPI_ERR_OUT_OF_RESOURCE;
        goto exit;
    }

    j = 0;
    for (i=0;i<fh->f_size;i++){
	if (recv_size[i]) {
	    if (partial_recv[i]) {
		k = start_pos[i] + count[i] - 1;
		tmp_len[i] = others_req[i].lens[k];
		others_req[i].lens[k] = partial_recv[i];
	    }
	    ompi_datatype_create_hindexed(count[i],
					  &(others_req[i].lens[start_pos[i]]),
					  &(others_req[i].mem_ptrs[start_pos[i]]),
					  MPI_BYTE, recv_types+j);
	    ompi_datatype_commit(recv_types+j);
	    j++;
	}
    }

    sum = 0;
    for (i=0;i<fh->f_size;i++) sum += count[i];
    srt_off = (OMPI_MPI_OFFSET_TYPE *)
	malloc((sum+1)*sizeof(OMPI_MPI_OFFSET_TYPE));

    if ( NULL == srt_off ){
	ret = OMPI_ERR_OUT_OF_RESOURCE;
	goto exit;
    }

    srt_len = (int *) malloc((sum+1)*sizeof(int));

    if ( NULL == srt_len ) {
	ret = OMPI_ERR_OUT_OF_RESOURCE;
        free(srt_off);
	goto exit;
    }


    two_phase_heap_merge(others_req, count, srt_off, srt_len, start_pos, fh->f_size,fh->f_rank,  nprocs_recv, sum);


    for (i=0; i<fh->f_size; i++)
        if (partial_recv[i]) {
            k = start_pos[i] + count[i] - 1;
            others_req[i].lens[k] = tmp_len[i];
        }

    free(tmp_len);
    tmp_len = NULL;

    *hole = 0;
    if (off != srt_off[0]){
	*hole = 1;
    }
    else{
	for (i=1;i<sum;i++){
	    if (srt_off[i] <= srt_off[0] + srt_len[0]){
		int new_len = srt_off[i] + srt_len[i] - srt_off[0];
		if(new_len > srt_len[0])
		    srt_len[0] = new_len;
	    }
	    else
		break;
	}
	if (i < sum || size != srt_len[0])
	    *hole = 1;
    }


    free(srt_off);
    free(srt_len);

    if (nprocs_recv){
	if (*hole){
	    if (off >= 0){
		fh->f_io_array = (mca_io_ompio_io_array_t *)malloc
		    (sizeof(mca_io_ompio_io_array_t));
		if (NULL == fh->f_io_array) {
		    opal_output(1, "OUT OF MEMORY\n");
                    ret = OMPI_ERR_OUT_OF_RESOURCE;
                    goto exit;
		}
		fh->f_io_array[0].offset  =(IOVBASE_TYPE *)(intptr_t) off;
		fh->f_num_of_io_entries = 1;
		fh->f_io_array[0].length = size;
		fh->f_io_array[0].memory_address = write_buf;
		if (fh->f_num_of_io_entries){
		    if ( 0 >  fh->f_fbtl->fbtl_preadv (fh)) {
			opal_output(1, "READ FAILED\n");
                        ret = OMPI_ERROR;
                        goto exit;
		    }
		}

	    }
	    fh->f_num_of_io_entries = 0;
	    if (NULL != fh->f_io_array) {
		free (fh->f_io_array);
		fh->f_io_array = NULL;
	    }
	}
    }

    nprocs_send = 0;
    for (i=0; i <fh->f_size; i++) if (send_size[i]) nprocs_send++;

#if DEBUG_ON
    printf("%d : nprocs_send : %d\n", fh->f_rank,nprocs_send);
#endif

    requests = (MPI_Request *)
	malloc((nprocs_send+nprocs_recv+1)*sizeof(MPI_Request));

    if ( NULL == requests ){
        ret = OMPI_ERR_OUT_OF_RESOURCE;
        goto exit;
    }

    j = 0;
    for (i=0; i<fh->f_size; i++) {
	if (recv_size[i]) {
	    ret = MCA_PML_CALL(irecv(MPI_BOTTOM,
				     1,
				     recv_types[j],
				     i,
				     fh->f_rank+i+100*iter,
				     fh->f_comm,
				     requests+j));

	    if ( OMPI_SUCCESS != ret ){
		goto exit;
	    }
	    j++;
	}
    }
    send_req = requests + nprocs_recv;


    if (fh->f_flags & OMPIO_CONTIGUOUS_MEMORY) {
	j = 0;
	for (i=0; i <fh->f_size; i++)
	    if (send_size[i]) {
		ret = MCA_PML_CALL(isend(((char *) buf) + buf_idx[i],
					 send_size[i],
					 MPI_BYTE,
					 i,
					 fh->f_rank+i+100*iter,
					 MCA_PML_BASE_SEND_STANDARD,
					 fh->f_comm,
					 send_req+j));

		if ( OMPI_SUCCESS != ret ){
		    goto exit;
		}

		j++;
		buf_idx[i] += send_size[i];
	    }
    }
    else if(nprocs_send && (!(fh->f_flags & OMPIO_CONTIGUOUS_MEMORY))){
	send_buf = (char **) calloc (fh->f_size, sizeof(char*));
	if ( NULL == send_buf ){
	    ret = OMPI_ERR_OUT_OF_RESOURCE;
	    goto exit;
	}
	for (i=0; i < fh->f_size; i++){
	    if (send_size[i]) {
		send_buf[i] = (char *) malloc(send_size[i]);

		if ( NULL == send_buf[i] ){
		    ret = OMPI_ERR_OUT_OF_RESOURCE;
		    goto exit;
		}
	    }
	}

	ret = two_phase_fill_send_buffer(fh, buf,flat_buf, send_buf,
					 offset_length, send_size,
					 send_req,sent_to_proc,
					 contig_access_count,
					 min_st_offset, fd_size,
					 fd_start, fd_end, send_buf_idx,
					 curr_to_proc, done_to_proc,
					 iter, buftype_extent, striping_unit,
					 two_phase_num_io_procs, aggregator_list);

	if ( OMPI_SUCCESS != ret ){
	    goto exit;
	}
    }


    ret = ompi_request_wait_all (nprocs_send+nprocs_recv,
				 requests,
				 MPI_STATUS_IGNORE);


#if OMPIO_FCOLL_WANT_TIME_BREAKDOWN
    end_comm_time = MPI_Wtime();
    comm_time += (end_comm_time - start_comm_time);
#endif

exit:
    if (recv_types) {
        for (i=0; i<nprocs_recv; i++) {
            if (recv_types[i]) {
                ompi_datatype_destroy(recv_types+i);
            }
        }
    }
    free (recv_types);

    free (requests);
    if (send_buf) {
        for (i=0; i < fh->f_size; i++){
            free (send_buf[i]);
        }

        free (send_buf);
    }
    free (tmp_len);

    return ret;
}


#define TWO_PHASE_BUF_INCR			\
    {						\
	while (buf_incr) {				\
	    size_in_buf = OMPIO_MIN(buf_incr, flat_buf_sz);	\
	    user_buf_idx += size_in_buf;			\
	    flat_buf_sz -= size_in_buf;				\
	    if (!flat_buf_sz) {					      \
		if (flat_buf_idx < (flat_buf->count - 1)) flat_buf_idx++; \
		else {							\
		    flat_buf_idx = 0;					\
		    n_buftypes++;					\
		}							\
		user_buf_idx = flat_buf->indices[flat_buf_idx] +	\
		    (OMPI_MPI_OFFSET_TYPE)n_buftypes*(OMPI_MPI_OFFSET_TYPE)buftype_extent; \
		flat_buf_sz = flat_buf->blocklens[flat_buf_idx];	\
	    }								\
	    buf_incr -= size_in_buf;					\
	}								\
    }


#define TWO_PHASE_BUF_COPY			\
    {						\
	while (size) {				    \
	    size_in_buf = OMPIO_MIN(size, flat_buf_sz); \
	    memcpy(&(send_buf[p][send_buf_idx[p]]),	    \
		   ((char *) buf) + user_buf_idx, size_in_buf); \
	    send_buf_idx[p] += size_in_buf;			\
	    user_buf_idx += size_in_buf;			\
	    flat_buf_sz -= size_in_buf;				\
	    if (!flat_buf_sz) {					      \
		if (flat_buf_idx < (flat_buf->count - 1)) flat_buf_idx++; \
		else {							\
		    flat_buf_idx = 0;					\
		    n_buftypes++;					\
		}							\
		user_buf_idx = flat_buf->indices[flat_buf_idx] +	\
		    (OMPI_MPI_OFFSET_TYPE)n_buftypes*(OMPI_MPI_OFFSET_TYPE)buftype_extent; \
		flat_buf_sz = flat_buf->blocklens[flat_buf_idx];	\
	    }								\
	    size -= size_in_buf;					\
	    buf_incr -= size_in_buf;					\
	}								\
	TWO_PHASE_BUF_INCR						\
}





static int two_phase_fill_send_buffer(mca_io_ompio_file_t *fh,
				      const void *buf,
				      Flatlist_node *flat_buf,
				      char **send_buf,
				      struct iovec *offset_length,
				      int *send_size,
				      MPI_Request *requests,
				      int *sent_to_proc,
				      int contig_access_count,
				      OMPI_MPI_OFFSET_TYPE min_st_offset,
				      OMPI_MPI_OFFSET_TYPE fd_size,
				      OMPI_MPI_OFFSET_TYPE *fd_start,
				      OMPI_MPI_OFFSET_TYPE *fd_end,
				      int *send_buf_idx,
				      int *curr_to_proc,
				      int *done_to_proc,
				      int iter, MPI_Aint buftype_extent,
				      int striping_unit, int two_phase_num_io_procs,
				      int *aggregator_list)
{

    int i, p, flat_buf_idx=0;
    OMPI_MPI_OFFSET_TYPE flat_buf_sz=0, size_in_buf=0, buf_incr=0, size=0;
    int jj, n_buftypes, ret=OMPI_SUCCESS;
    OMPI_MPI_OFFSET_TYPE off=0, len=0, rem_len=0, user_buf_idx=0;

    for (i=0; i < fh->f_size; i++) {
	send_buf_idx[i] = curr_to_proc[i] = 0;
	done_to_proc[i] = sent_to_proc[i];
    }
    jj = 0;

    flat_buf_idx = 0;
    n_buftypes = 0;
    if ( flat_buf->count > 0 ) {
	user_buf_idx = flat_buf->indices[0];
	flat_buf_sz = flat_buf->blocklens[0];
    }

    for (i=0; i<contig_access_count; i++) {

	off     = (OMPI_MPI_OFFSET_TYPE) (intptr_t)offset_length[i].iov_base;
	rem_len = (OMPI_MPI_OFFSET_TYPE)offset_length[i].iov_len;


	while (rem_len != 0) {
	    len = rem_len;
	    p = mca_fcoll_two_phase_calc_aggregator(fh,
						    off,
						    min_st_offset,
						    &len,
						    fd_size,
						    fd_start,
						    fd_end,
						    striping_unit,
						    two_phase_num_io_procs,
						    aggregator_list);

	    if (send_buf_idx[p] < send_size[p]) {
		if (curr_to_proc[p]+len > done_to_proc[p]) {
		    if (done_to_proc[p] > curr_to_proc[p]) {
			size = OMPIO_MIN(curr_to_proc[p] + len -
					 done_to_proc[p], send_size[p]-send_buf_idx[p]);
			buf_incr = done_to_proc[p] - curr_to_proc[p];
			TWO_PHASE_BUF_INCR
		        buf_incr = curr_to_proc[p] + len - done_to_proc[p];
			curr_to_proc[p] = done_to_proc[p] + size;
		        TWO_PHASE_BUF_COPY
		    }
		    else {
			size = OMPIO_MIN(len,send_size[p]-send_buf_idx[p]);
			buf_incr = len;
			curr_to_proc[p] += size;
			TWO_PHASE_BUF_COPY
		    }
		    if (send_buf_idx[p] == send_size[p]) {

		      ret = MCA_PML_CALL(isend(send_buf[p],
					       send_size[p],
					       MPI_BYTE,
					       p,
					       fh->f_rank+p+100*iter,
					       MCA_PML_BASE_SEND_STANDARD,
					       fh->f_comm,
					       requests+jj));

		      if ( OMPI_SUCCESS != ret ){
			return ret;
		      }
		      jj++;
		    }
		}
		else {
		    curr_to_proc[p] += len;
		    buf_incr = len;
		    TWO_PHASE_BUF_INCR
		}
	    }
	    else {
		buf_incr = len;
		TWO_PHASE_BUF_INCR
            }
	    off     += len;
	    rem_len -= len;
	}
    }
    for (i=0; i < fh->f_size; i++) {
      if (send_size[i]){
	sent_to_proc[i] = curr_to_proc[i];
      }
    }

    return ret;
}






void two_phase_heap_merge( mca_io_ompio_access_array_t *others_req,
			   int *count,
			   OMPI_MPI_OFFSET_TYPE *srt_off,
			   int *srt_len,
			   int *start_pos,
			   int nprocs,
			   int myrank,
			   int nprocs_recv,
			   int total_elements)
{



    typedef struct {
	OMPI_MPI_OFFSET_TYPE *off_list;
	int *len_list;
	int nelem;
    } heap_struct;

    heap_struct *a, tmp;
    int i, j, heapsize, l, r, k, smallest;

    a = (heap_struct *) malloc((nprocs_recv+1)*sizeof(heap_struct));

    j = 0;
    for (i=0; i<nprocs; i++)
	if (count[i]) {
	    a[j].off_list = &(others_req[i].offsets[start_pos[i]]);
	    a[j].len_list = &(others_req[i].lens[start_pos[i]]);
	    a[j].nelem = count[i];
	    j++;
	}

    heapsize = nprocs_recv;

    for (i=heapsize/2 - 1; i>=0; i--) {
	k = i;
	for(;;) {
	    l = 2*(k+1) - 1;
	    r = 2*(k+1);
	    if ((l < heapsize) &&
		(*(a[l].off_list) < *(a[k].off_list)))
		smallest = l;
	    else smallest = k;

	    if ((r < heapsize) &&
		(*(a[r].off_list) < *(a[smallest].off_list)))
		smallest = r;

	    if (smallest != k) {
		tmp.off_list = a[k].off_list;
		tmp.len_list = a[k].len_list;
		tmp.nelem = a[k].nelem;

		a[k].off_list = a[smallest].off_list;
		a[k].len_list = a[smallest].len_list;
		a[k].nelem = a[smallest].nelem;

		a[smallest].off_list = tmp.off_list;
		a[smallest].len_list = tmp.len_list;
		a[smallest].nelem = tmp.nelem;

		k = smallest;
	    }
	    else break;
	}
    }


    for (i=0; i<total_elements; i++) {
        /* extract smallest element from heap, i.e. the root */
	srt_off[i] = *(a[0].off_list);
	srt_len[i] = *(a[0].len_list);
	(a[0].nelem)--;

	if (!a[0].nelem) {
	    a[0].off_list = a[heapsize-1].off_list;
	    a[0].len_list = a[heapsize-1].len_list;
	    a[0].nelem = a[heapsize-1].nelem;
	    heapsize--;
	}
	else {
	    (a[0].off_list)++;
	    (a[0].len_list)++;
	}

	/* Heapify(a, 0, heapsize); */
	k = 0;
	for (;;) {
	    l = 2*(k+1) - 1;
	    r = 2*(k+1);

	    if ((l < heapsize) &&
		(*(a[l].off_list) < *(a[k].off_list)))
		smallest = l;
	    else smallest = k;

	    if ((r < heapsize) &&
		(*(a[r].off_list) < *(a[smallest].off_list)))
		smallest = r;

	    if (smallest != k) {
		tmp.off_list = a[k].off_list;
		tmp.len_list = a[k].len_list;
		tmp.nelem = a[k].nelem;

		a[k].off_list = a[smallest].off_list;
		a[k].len_list = a[smallest].len_list;
		a[k].nelem = a[smallest].nelem;

		a[smallest].off_list = tmp.off_list;
		a[smallest].len_list = tmp.len_list;
		a[smallest].nelem = tmp.nelem;

		k = smallest;
	    }
	    else break;
	}
    }
    free(a);
}
#if OMPIO_FCOLL_WANT_TIME_BREAKDOWN
int is_aggregator(int rank,
		  int nprocs_for_coll,
		  int *aggregator_list){

  int i=0;
  for (i=0; i<nprocs_for_coll; i++){
    if (aggregator_list[i] == rank)
      return 1;
  }
  return 0;
}
#endif
