codes-darshan-io-wrkld.c 55.8 KB
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/*
 * Copyright (C) 2013 University of Chicago.
 * See COPYRIGHT notice in top-level directory.
 *
 */
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#include <assert.h>
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#include <math.h>
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#include "codes/codes-workload.h"
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#include "codes/quickhash.h"
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#include "codes-workload-method.h"
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#include "darshan-logutils.h"
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#define DEF_INTER_IO_DELAY_PCT 0.4
#define DEF_INTER_CYC_DELAY_PCT 0.2
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#define DARSHAN_NEGLIGIBLE_DELAY 0.001
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#define RANK_HASH_TABLE_SIZE 397

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#define MIN(a, b) (((a) < (b)) ? (a) : (b))
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#define ALIGN_BY_8(x) ((x) + ((x) % 8))

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/* structure for storing a darshan workload operation (a codes op with 2 timestamps) */
struct darshan_io_op
{
    struct codes_workload_op codes_op;
    double start_time;
    double end_time;
};

/* I/O context structure managed by each rank in the darshan workload */
struct rank_io_context
{
    int64_t my_rank;
    double last_op_time;
    void *io_op_dat;
    struct qhash_head hash_link;
};

/* Darshan workload generator's implementation of the CODES workload API */
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static int darshan_io_workload_load(const char *params, int rank);
static void darshan_io_workload_get_next(int rank, struct codes_workload_op *op);
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static int darshan_io_workload_get_rank_cnt(const char *params);
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static int darshan_rank_hash_compare(void *key, struct qhash_head *link);

/* Darshan I/O op data structure access (insert, remove) abstraction */
static void *darshan_init_io_op_dat(void);
static void darshan_insert_next_io_op(void *io_op_dat, struct darshan_io_op *io_op);
static void darshan_remove_next_io_op(void *io_op_dat, struct darshan_io_op *io_op,
                                      double last_op_time);
static void darshan_finalize_io_op_dat(void *io_op_dat);
static int darshan_io_op_compare(const void *p1, const void *p2);

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/* Helper functions for implementing the Darshan workload generator */
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static void generate_psx_ind_file_events(struct darshan_file *file,
                                         struct rank_io_context *io_context);
static void generate_psx_coll_file_events(struct darshan_file *file,
                                          struct rank_io_context *io_context,
                                          int64_t nprocs, int64_t aggregator_cnt);
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static double generate_psx_open_event(struct darshan_file *file, int create_flag,
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                                      double meta_op_time, double cur_time,
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                                      struct rank_io_context *io_context, int insert_flag);
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static double generate_psx_close_event(struct darshan_file *file, double meta_op_time,
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                                       double cur_time, struct rank_io_context *io_context,
                                       int insert_flag);
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static double generate_barrier_event(struct darshan_file *file, int64_t root, double cur_time,
                                     struct rank_io_context *io_context);
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static double generate_psx_ind_io_events(struct darshan_file *file, int64_t io_ops_this_cycle,
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                                         double inter_io_delay, double cur_time,
                                         struct rank_io_context *io_context);
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static double generate_psx_coll_io_events(struct darshan_file *file, int64_t ind_io_ops_this_cycle,
                                          int64_t coll_io_ops_this_cycle, int64_t nprocs,
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                                          int64_t aggregator_cnt, double inter_io_delay,
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                                          double cur_time, struct rank_io_context *io_context);
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static void determine_io_params(struct darshan_file *file, int write_flag, int64_t io_this_op,
                                int64_t proc_count, size_t *io_sz, off_t *io_off);
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static void calc_io_delays(struct darshan_file *file, int64_t num_opens, int64_t num_io_ops,
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                           double total_delay, double *first_io_delay, double *close_delay,
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                           double *inter_open_delay, double *inter_io_delay);
static void file_sanity_check(struct darshan_file *file, struct darshan_job *job);

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/* workload method name and function pointers for the CODES workload API */
struct codes_workload_method darshan_io_workload_method =
{
    .method_name = "darshan_io_workload",
    .codes_workload_load = darshan_io_workload_load,
    .codes_workload_get_next = darshan_io_workload_get_next,
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    .codes_workload_get_rank_cnt = darshan_io_workload_get_rank_cnt,
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};

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static int total_rank_cnt = 0;

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/* hash table to store per-rank workload contexts */
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static struct qhash_table *rank_tbl = NULL;
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static int rank_tbl_pop = 0;
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/* load the workload generator for this rank, given input params */
static int darshan_io_workload_load(const char *params, int rank)
{
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    darshan_params *d_params = (darshan_params *)params;
    darshan_fd logfile_fd;
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    struct darshan_job job;
    struct darshan_file next_file;
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    struct rank_io_context *my_ctx;
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    struct darshan_io_op end_op;
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    int ret;
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    if (!d_params)
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        return -1;

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    /* open the darshan log to begin reading in file i/o info */
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    logfile_fd = darshan_log_open(d_params->log_file_path, "r");
    if (logfile_fd < 0)
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        return -1;
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    /* get the per-job stats from the log */
    ret = darshan_log_getjob(logfile_fd, &job);
    if (ret < 0)
    {
        darshan_log_close(logfile_fd);
        return -1;
    }
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    if (!total_rank_cnt)
    {
        total_rank_cnt = job.nprocs;
    }
    assert(rank < total_rank_cnt);
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    /* allocate the i/o context needed by this rank */
    my_ctx = malloc(sizeof(struct rank_io_context));
    if (!my_ctx)
    {
        darshan_log_close(logfile_fd);
        return -1;
    }
    my_ctx->my_rank = (int64_t)rank;
    my_ctx->last_op_time = 0.0;
    my_ctx->io_op_dat = darshan_init_io_op_dat();

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    /* loop over all files contained in the log file */
    while ((ret = darshan_log_getfile(logfile_fd, &job, &next_file)) > 0)
    {
        /* generate all i/o events contained in this independent file */
        if (next_file.rank == rank)
        {
            /* make sure the file i/o counters are valid */
            file_sanity_check(&next_file, &job);

            /* generate i/o events and store them in this rank's workload context */
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            generate_psx_ind_file_events(&next_file, my_ctx);
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        }
        /* generate all i/o events involving this rank in this collective file */
        else if (next_file.rank == -1)
        {
            /* make sure the file i/o counters are valid */
            file_sanity_check(&next_file, &job);
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            /* generate collective i/o events and store them in the rank context */
            generate_psx_coll_file_events(&next_file, my_ctx, job.nprocs, d_params->aggregator_cnt);
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        }
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        else if (next_file.rank < rank)
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            continue;
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        else
            break;
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        assert(next_file.counters[CP_POSIX_OPENS] == 0);
        assert(next_file.counters[CP_POSIX_READS] == 0);
        assert(next_file.counters[CP_POSIX_WRITES] == 0);
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    }
    if (ret < 0)
        return -1;

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    darshan_log_close(logfile_fd);
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    /* tack a workload end file on the end of the events list */
    /* NOTE: this helps us generate a delay from the last close to program termination */
    end_op.codes_op.op_type = CODES_WK_END;
    end_op.start_time = end_op.end_time = job.end_time - job.start_time + 1;
    darshan_insert_next_io_op(my_ctx->io_op_dat, &end_op);

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    /* finalize the rank's i/o context so i/o ops may be retrieved later (in order) */
    darshan_finalize_io_op_dat(my_ctx->io_op_dat);

    /* initialize the hash table of rank contexts, if it has not been initialized */
    if (!rank_tbl)
    {
        rank_tbl = qhash_init(darshan_rank_hash_compare, quickhash_64bit_hash, RANK_HASH_TABLE_SIZE);
        if (!rank_tbl)
            return -1;
    }

    /* add this rank context to the hash table */
    qhash_add(rank_tbl, &(my_ctx->my_rank), &(my_ctx->hash_link));
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    rank_tbl_pop++;
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    return 0;
}

/* pull the next event (independent or collective) for this rank from its event context */
static void darshan_io_workload_get_next(int rank, struct codes_workload_op *op)
{
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    int64_t my_rank = (int64_t)rank;
    struct qhash_head *hash_link = NULL;
    struct rank_io_context *tmp = NULL;
    struct darshan_io_op next_io_op;

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    assert(rank < total_rank_cnt);

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    /* find i/o context for this rank in the rank hash table */
    hash_link = qhash_search(rank_tbl, &my_rank);

    /* terminate the workload if there is no valid rank context */
    if (!hash_link)
    {
        op->op_type = CODES_WK_END;
        return;
    }

    /* get access to the rank's io_context data */
    tmp = qhash_entry(hash_link, struct rank_io_context, hash_link);
    assert(tmp->my_rank == my_rank);

    /* get the next darshan i/o op out of this rank's context */
    darshan_remove_next_io_op(tmp->io_op_dat, &next_io_op, tmp->last_op_time);

    /* free the rank's i/o context if this is the last i/o op */
    if (next_io_op.codes_op.op_type == CODES_WK_END)
    {
        qhash_del(hash_link);
        free(tmp);
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        rank_tbl_pop--;
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        if (!rank_tbl_pop){
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            qhash_finalize(rank_tbl);
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            rank_tbl = NULL;
        }
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    }
    else
    {
        /* else, set the last op time to be the end of the returned op */
        tmp->last_op_time = next_io_op.end_time;
    }

    /* return the codes op contained in the darshan i/o op */
    *op = next_io_op.codes_op;
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    return;
}

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static int darshan_io_workload_get_rank_cnt(const char *params)
{
    darshan_params *d_params = (darshan_params *)params;
    darshan_fd logfile_fd;
    struct darshan_job job;
    int ret;

    if (!d_params)
        return -1;

    /* open the darshan log to begin reading in file i/o info */
    logfile_fd = darshan_log_open(d_params->log_file_path, "r");
    if (logfile_fd < 0)
        return -1;

    /* get the per-job stats from the log */
    ret = darshan_log_getjob(logfile_fd, &job);
    if (ret < 0)
    {
        darshan_log_close(logfile_fd);
        return -1;
    }

    darshan_log_close(logfile_fd);

    return job.nprocs;
}

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/* comparison function for comparing two hash keys (used for storing multiple io contexts) */
static int darshan_rank_hash_compare(
    void *key, struct qhash_head *link)
{
    int64_t *in_rank = (int64_t *)key;
    struct rank_io_context *tmp;

    tmp = qhash_entry(link, struct rank_io_context, hash_link);
    if (tmp->my_rank == *in_rank)
        return 1;

    return 0;
}

/*****************************************/
/*                                       */
/*   Darshan I/O op storage abstraction  */
/*                                       */
/*****************************************/

#define DARSHAN_IO_OP_INC_CNT 100000

/* dynamically allocated array data structure for storing darshan i/o events */
struct darshan_io_dat_array
{
    struct darshan_io_op *op_array;
    int64_t op_arr_ndx;
    int64_t op_arr_cnt;
};

/* initialize the dynamic array data structure */
static void *darshan_init_io_op_dat()
{
    struct darshan_io_dat_array *tmp;

    /* initialize the array data structure */
    tmp = malloc(sizeof(struct darshan_io_dat_array));
    assert(tmp);
    tmp->op_array = malloc(DARSHAN_IO_OP_INC_CNT * sizeof(struct darshan_io_op));
    assert(tmp->op_array);
    tmp->op_arr_ndx = 0;
    tmp->op_arr_cnt = DARSHAN_IO_OP_INC_CNT;

    /* return the array info for this rank's i/o context */
    return (void *)tmp;
}

/* store the i/o event in this rank's i/o context */
static void darshan_insert_next_io_op(
    void *io_op_dat, struct darshan_io_op *io_op)
{
    struct darshan_io_dat_array *array = (struct darshan_io_dat_array *)io_op_dat;
    struct darshan_io_op *tmp;

    /* realloc array if it is already full */
    if (array->op_arr_ndx == array->op_arr_cnt)
    {
        tmp = malloc((array->op_arr_cnt + DARSHAN_IO_OP_INC_CNT) * sizeof(struct darshan_io_op));
        assert(tmp);
        memcpy(tmp, array->op_array, array->op_arr_cnt * sizeof(struct darshan_io_op));
        free(array->op_array);
        array->op_array = tmp;
        array->op_arr_cnt += DARSHAN_IO_OP_INC_CNT;
    }

    /* add the darshan i/o op to the array */
    array->op_array[array->op_arr_ndx++] = *io_op;

    return;
}

/* pull the next i/o event out of this rank's i/o context */
static void darshan_remove_next_io_op(
    void *io_op_dat, struct darshan_io_op *io_op, double last_op_time)
{
    struct darshan_io_dat_array *array = (struct darshan_io_dat_array *)io_op_dat;

    /* if the array has been scanned completely already */
    if (array->op_arr_ndx == array->op_arr_cnt)
    {
        /* no more events just end the workload */
        io_op->codes_op.op_type = CODES_WK_END;
    }
    else
    {
        struct darshan_io_op *tmp = &(array->op_array[array->op_arr_ndx]);

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        if ((tmp->start_time - last_op_time) <= DARSHAN_NEGLIGIBLE_DELAY)
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        {
            /* there is no delay, just return the next op in the array */
            *io_op = *tmp;
            array->op_arr_ndx++;
        }
        else
        {
            /* there is a nonnegligible delay, so generate and return a delay event */
            io_op->codes_op.op_type = CODES_WK_DELAY;
            io_op->codes_op.u.delay.seconds = tmp->start_time - last_op_time;
            io_op->start_time = last_op_time;
            io_op->end_time = tmp->start_time;
        }
    }
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    /* if this is the end op, free data structures */
    if (io_op->codes_op.op_type == CODES_WK_END)
    {
        free(array->op_array);
        free(array);
    }

    return;
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}

/* sort the dynamic array in order of i/o op start time */
static void darshan_finalize_io_op_dat(
    void *io_op_dat)
{
    struct darshan_io_dat_array *array = (struct darshan_io_dat_array *)io_op_dat;

    /* sort this rank's i/o op list */
    qsort(array->op_array, array->op_arr_ndx, sizeof(struct darshan_io_op), darshan_io_op_compare);
    array->op_arr_cnt = array->op_arr_ndx;
    array->op_arr_ndx = 0;

    return;
}

/* comparison function for sorting darshan_io_ops in order of start timestamps */
static int darshan_io_op_compare(
    const void *p1, const void *p2)
{
    struct darshan_io_op *a = (struct darshan_io_op *)p1;
    struct darshan_io_op *b = (struct darshan_io_op *)p2;

    if (a->start_time < b->start_time)
        return -1;
    else if (a->start_time > b->start_time)
        return 1;
    else
        return 0;
}

/*****************************************/
/*                                       */
/* Darshan workload generation functions */
/*                                       */
/*****************************************/
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/* generate events for an independently opened file, and store these events */
static void generate_psx_ind_file_events(
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    struct darshan_file *file, struct rank_io_context *io_context)
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{
    int64_t io_ops_this_cycle;
    double cur_time = file->fcounters[CP_F_OPEN_TIMESTAMP];
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    double total_delay;
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    double first_io_delay = 0.0;
    double close_delay = 0.0;
    double inter_open_delay = 0.0;
    double inter_io_delay = 0.0;
    double meta_op_time;
    int create_flag;
    int64_t i;

    /* if the file was never really opened, just return because we have no timing info */
    if (file->counters[CP_POSIX_OPENS] == 0)
        return;

    /* determine delay available per open-io-close cycle */
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    total_delay = file->fcounters[CP_F_CLOSE_TIMESTAMP] - file->fcounters[CP_F_OPEN_TIMESTAMP] -
                  file->fcounters[CP_F_POSIX_READ_TIME] - file->fcounters[CP_F_POSIX_WRITE_TIME] -
                  file->fcounters[CP_F_POSIX_META_TIME];
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    /* calculate synthetic delay values */
    calc_io_delays(file, file->counters[CP_POSIX_OPENS],
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                   file->counters[CP_POSIX_READS] + file->counters[CP_POSIX_WRITES], total_delay,
                   &first_io_delay, &close_delay, &inter_open_delay, &inter_io_delay);
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    /* calculate average meta op time (for i/o and opens/closes) */
    /* TODO: this needs to be updated when we add in stat, seek, etc. */
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    meta_op_time = file->fcounters[CP_F_POSIX_META_TIME] / (2 * file->counters[CP_POSIX_OPENS]);
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    /* set the create flag if the file was written to */
    if (file->counters[CP_BYTES_WRITTEN])
    {
        create_flag = 1;
    }
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    /* generate open/io/close events for all cycles */
    /* TODO: add stats */
    for (i = 0; file->counters[CP_POSIX_OPENS]; i++, file->counters[CP_POSIX_OPENS]--)
    {
        /* generate an open event */
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        cur_time = generate_psx_open_event(file, create_flag, meta_op_time, cur_time,
                                           io_context, 1);
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        create_flag = 0;

        /* account for potential delay from first open to first io */
        cur_time += first_io_delay;

        io_ops_this_cycle = ceil((double)(file->counters[CP_POSIX_READS] +
                                 file->counters[CP_POSIX_WRITES]) /
                                 file->counters[CP_POSIX_OPENS]);

        /* perform the calculated number of i/o operations for this file open */
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        cur_time = generate_psx_ind_io_events(file, io_ops_this_cycle, inter_io_delay,
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                                              cur_time, io_context);
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        /* account for potential delay from last io to close */
        cur_time += close_delay;

        /* generate a close for the open event at the start of the loop */
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        cur_time = generate_psx_close_event(file, meta_op_time, cur_time, io_context, 1);
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        /* account for potential interopen delay if more than one open */
        if (file->counters[CP_POSIX_OPENS] > 1)
        {
            cur_time += inter_open_delay;
        }
    }
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    return;
}

/* generate events for the i/o ops stored in a collectively opened file for this rank */
void generate_psx_coll_file_events(
    struct darshan_file *file, struct rank_io_context *io_context,
    int64_t nprocs, int64_t in_agg_cnt)
{
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    int64_t open_cycles;
    int64_t total_ind_opens;
    int64_t total_coll_opens;
    int64_t ind_opens_this_cycle;
    int64_t coll_opens_this_cycle;
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    int64_t extra_opens = 0;
    int64_t extra_io_ops = 0;
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    int64_t total_io_ops = file->counters[CP_POSIX_READS] + file->counters[CP_POSIX_WRITES];
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    int64_t total_ind_io_ops;
    int64_t total_coll_io_ops;
    int64_t ind_io_ops_this_cycle;
    int64_t coll_io_ops_this_cycle;
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    int64_t rank_cnt;
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    int create_flag = 0;
    double cur_time = file->fcounters[CP_F_OPEN_TIMESTAMP];
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    double total_delay;
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    double first_io_delay = 0.0;
    double close_delay = 0.0;
    double inter_cycle_delay = 0.0;
    double inter_io_delay = 0.0;
    double meta_op_time;
530
    int64_t i;
531
532
533
534
535
536
537
538
539
540

    /* the collective file was never opened (i.e., just stat-ed), so return */
    if (!(file->counters[CP_POSIX_OPENS]))
        return;

    /*  in this case, posix opens are less than mpi opens...
     *  this is probably a mpi deferred open -- assume app will not use this, currently.
     */
    assert(file->counters[CP_POSIX_OPENS] >= nprocs);

541
542
    if (file->counters[CP_COLL_OPENS] || file->counters[CP_INDEP_OPENS])
    {
543
544
        extra_opens = file->counters[CP_POSIX_OPENS] - file->counters[CP_COLL_OPENS] -
                      file->counters[CP_INDEP_OPENS];
545

546
547
        total_coll_opens = file->counters[CP_COLL_OPENS];
        total_ind_opens = file->counters[CP_POSIX_OPENS] - total_coll_opens - extra_opens;
548
549
550
551

        total_ind_io_ops = file->counters[CP_INDEP_READS] + file->counters[CP_INDEP_WRITES];
        total_coll_io_ops = (file->counters[CP_COLL_READS] + file->counters[CP_COLL_WRITES]) / nprocs;

552
553
554
555
556
557
558
559
        if (file->counters[CP_COLL_OPENS])
        {
            total_delay = (file->fcounters[CP_F_CLOSE_TIMESTAMP] -
                           file->fcounters[CP_F_OPEN_TIMESTAMP] -
                           (file->fcounters[CP_F_POSIX_READ_TIME] / in_agg_cnt) -
                           (file->fcounters[CP_F_POSIX_WRITE_TIME] / in_agg_cnt) -
                           (file->fcounters[CP_F_POSIX_META_TIME] / in_agg_cnt));

560
            open_cycles = total_coll_opens / nprocs;
561
562
563
564
            calc_io_delays(file, ceil(((double)(total_coll_opens + total_ind_opens)) / nprocs),
                           total_coll_io_ops + ceil((double)total_ind_io_ops / nprocs), total_delay,
                           &first_io_delay, &close_delay, &inter_cycle_delay, &inter_io_delay);
        }
565
        else
566
567
568
569
570
571
        {
            total_delay = (file->fcounters[CP_F_CLOSE_TIMESTAMP] -
                           file->fcounters[CP_F_OPEN_TIMESTAMP] -
                           (file->fcounters[CP_F_POSIX_READ_TIME] / nprocs) -
                           (file->fcounters[CP_F_POSIX_WRITE_TIME] / nprocs) -
                           (file->fcounters[CP_F_POSIX_META_TIME] / nprocs));
572

573
574
575
576
            open_cycles = ceil((double)total_ind_opens / nprocs);
            calc_io_delays(file, open_cycles, ceil((double)total_ind_io_ops / nprocs), total_delay,
                           &first_io_delay, &close_delay, &inter_cycle_delay, &inter_io_delay);
        }
577
578
579
580
581
582
583
584
585
586
587
    }
    else
    {
        extra_opens = file->counters[CP_POSIX_OPENS] % nprocs;
        if (extra_opens && ((file->counters[CP_POSIX_OPENS] / nprocs) % extra_opens))
        {
            extra_opens = 0;
        }
        else
        {
            extra_io_ops = total_io_ops % nprocs;
588
589
590
591
592
            if (extra_io_ops != extra_opens)
            {
                extra_opens = 0;
                extra_io_ops = 0;
            }
593
594
595
        }

        total_coll_opens = 0;
596
        total_ind_opens = file->counters[CP_POSIX_OPENS] - extra_opens;
597
598
599

        total_ind_io_ops = total_io_ops - extra_io_ops;
        total_coll_io_ops = 0;
600

601
602
603
604
605
606
        total_delay = (file->fcounters[CP_F_CLOSE_TIMESTAMP] -
                       file->fcounters[CP_F_OPEN_TIMESTAMP] -
                       (file->fcounters[CP_F_POSIX_READ_TIME] / nprocs) -
                       (file->fcounters[CP_F_POSIX_WRITE_TIME] / nprocs) -
                       (file->fcounters[CP_F_POSIX_META_TIME] / nprocs));

607
608
609
        open_cycles = ceil((double)total_ind_opens / nprocs);
        calc_io_delays(file, open_cycles, ceil((double)total_ind_io_ops / nprocs), total_delay,
                       &first_io_delay, &close_delay, &inter_cycle_delay, &inter_io_delay);
610
611
612
    }
    assert(extra_opens <= open_cycles);

613
    /* calculate average meta op time (for i/o and opens/closes) */
614
    meta_op_time = file->fcounters[CP_F_POSIX_META_TIME] / (2 * file->counters[CP_POSIX_OPENS]);
615

616
617
618
619
620
    /* it is rare to overwrite existing files, so set the create flag */
    if (file->counters[CP_BYTES_WRITTEN])
    {
        create_flag = 1;
    }
621

622
623
    /* generate all events for this collectively opened file */
    for (i = 0; i < open_cycles; i++)
624
    {
625
626
        ind_opens_this_cycle = ceil((double)total_ind_opens / (open_cycles - i));
        coll_opens_this_cycle = total_coll_opens / (open_cycles - i);
627

628
629
630
        /* assign any extra opens to rank 0 (these may correspond to file creations or
         * header reads/writes)
         */
631
        if (extra_opens && !(i % (open_cycles / extra_opens)))
632
        {
633
634
            cur_time = generate_psx_open_event(file, create_flag, meta_op_time, cur_time,
                                               io_context, (io_context->my_rank == 0));
635
636
            create_flag = 0;

637
638
639
            if (!file->counters[CP_COLL_OPENS] && !file->counters[CP_INDEP_OPENS])
            {
                cur_time = generate_psx_coll_io_events(file, 1, 0, nprocs, nprocs, 0.0,
640
                                                       cur_time, io_context);
641
642
                extra_io_ops--;
            }
643

644
645
            cur_time = generate_psx_close_event(file, meta_op_time, cur_time, io_context,
                                                (io_context->my_rank == 0));
646
647
648
            file->counters[CP_POSIX_OPENS]--;
        }

649
        while (ind_opens_this_cycle)
650
        {
651
652
653
654
655
            if (ind_opens_this_cycle >= nprocs)
                rank_cnt = nprocs;
            else
                rank_cnt = ind_opens_this_cycle;

656
657
            cur_time = generate_psx_open_event(file, create_flag, meta_op_time, cur_time,
                                               io_context, (io_context->my_rank < rank_cnt));
658
659
            create_flag = 0;

660
661
662
663
            cur_time += first_io_delay;

            ind_io_ops_this_cycle = ceil(((double)total_ind_io_ops / total_ind_opens) * rank_cnt);
            cur_time = generate_psx_coll_io_events(file, ind_io_ops_this_cycle, 0, nprocs,
664
                                                   nprocs, inter_io_delay, cur_time, io_context);
665
666
667
            total_ind_io_ops -= ind_io_ops_this_cycle;

            cur_time += close_delay;
668

669
670
            cur_time = generate_psx_close_event(file, meta_op_time, cur_time, io_context,
                                                (io_context->my_rank < rank_cnt));
671

672
673
674
675
676
677
            file->counters[CP_POSIX_OPENS] -= rank_cnt;
            ind_opens_this_cycle -= rank_cnt;
            total_ind_opens -= rank_cnt;

            if (file->counters[CP_POSIX_OPENS])
                cur_time += inter_cycle_delay;
678
679
        }

680
        while (coll_opens_this_cycle)
681
        {
682
            assert(!create_flag);
683

684
            cur_time = generate_barrier_event(file, 0, cur_time, io_context);
685
686

            cur_time = generate_psx_open_event(file, create_flag, meta_op_time,
687
                                               cur_time, io_context, 1);
688

689
690
691
692
693
694
695
696
697
698
699
700
            cur_time += first_io_delay;

            if (file->counters[CP_INDEP_OPENS])
                ind_io_ops_this_cycle = 0;
            else
                ind_io_ops_this_cycle = ceil((double)total_ind_io_ops / 
                                             (file->counters[CP_COLL_OPENS] / nprocs));

            coll_io_ops_this_cycle = ceil((double)total_coll_io_ops / 
                                          (file->counters[CP_COLL_OPENS] / nprocs));
            cur_time = generate_psx_coll_io_events(file, ind_io_ops_this_cycle,
                                                   coll_io_ops_this_cycle, nprocs, in_agg_cnt,
701
                                                   inter_io_delay, cur_time, io_context);
702
703
704
705
            total_ind_io_ops -= ind_io_ops_this_cycle;
            total_coll_io_ops -= coll_io_ops_this_cycle;

            cur_time += close_delay;
706

707
            cur_time = generate_psx_close_event(file, meta_op_time, cur_time, io_context, 1);
708
709

            file->counters[CP_POSIX_OPENS] -= nprocs;
710
711
            file->counters[CP_COLL_OPENS] -= nprocs;
            coll_opens_this_cycle -= nprocs;
712
713
714
715
            total_coll_opens -= nprocs;

            if (file->counters[CP_POSIX_OPENS])
                cur_time += inter_cycle_delay;
716
717
        }
    }
718
719
720
721
722
723

    return;
}

/* fill in an open event structure and store it with the rank context */
static double generate_psx_open_event(
724
    struct darshan_file *file, int create_flag, double meta_op_time,
725
    double cur_time, struct rank_io_context *io_context, int insert_flag)
726
{
727
728
729
730
731
732
733
    struct darshan_io_op next_io_op = 
    {
        .codes_op.op_type = CODES_WK_OPEN,
        .codes_op.u.open.file_id = file->hash,
        .codes_op.u.open.create_flag = create_flag,
        .start_time = cur_time
    };
734
735
736

    /* set the end time of the event based on time spent in POSIX meta operations */
    cur_time += meta_op_time;
737
    next_io_op.end_time = cur_time;
738

739
    /* store the open event (if this rank performed it) */
740
    if (insert_flag)
741
        darshan_insert_next_io_op(io_context->io_op_dat, &next_io_op);
742
743
744
745
746
747

    return cur_time;
}

/* fill in a close event structure and store it with the rank context */
static double generate_psx_close_event(
748
    struct darshan_file *file, double meta_op_time, double cur_time,
749
    struct rank_io_context *io_context, int insert_flag)
750
{
751
752
753
754
755
756
    struct darshan_io_op next_io_op =
    {
        .codes_op.op_type = CODES_WK_CLOSE,
        .codes_op.u.close.file_id = file->hash,
        .start_time = cur_time
    };
757
758
759

    /* set the end time of the event based on time spent in POSIX meta operations */
    cur_time += meta_op_time;
760
    next_io_op.end_time = cur_time;
761

762
    /* store the close event (if this rank performed it) */
763
    if (insert_flag)
764
        darshan_insert_next_io_op(io_context->io_op_dat, &next_io_op);
765
766
767
768
769
770

    return cur_time;
}

/* fill in a barrier event structure and store it with the rank context */
static double generate_barrier_event(
771
    struct darshan_file *file, int64_t root, double cur_time, struct rank_io_context *io_context)
772
{
773
774
775
776
777
778
779
    struct darshan_io_op next_io_op =
    {
        .codes_op.op_type = CODES_WK_BARRIER, 
        .codes_op.u.barrier.count = -1, /* all processes */
        .codes_op.u.barrier.root = root,
        .start_time = cur_time
    };
780
781

    cur_time += .000001; /* small synthetic delay representing time to barrier */
782
    next_io_op.end_time = cur_time;
783

784
    /* store the barrier event */
785
    if (file->rank == -1)
786
        darshan_insert_next_io_op(io_context->io_op_dat, &next_io_op);
787
788
789
790
791
792

    return cur_time;
}

/* generate all i/o events for one independent file open and store them with the rank context */
static double generate_psx_ind_io_events(
793
    struct darshan_file *file, int64_t io_ops_this_cycle, double inter_io_delay,
794
    double cur_time, struct rank_io_context *io_context)
795
796
797
798
799
800
801
802
803
{
    static int rw = -1; /* rw = 1 for write, 0 for read, -1 for uninitialized */
    static int64_t io_ops_this_rw;
    static double rd_bw = 0.0, wr_bw = 0.0;
    int64_t psx_rw_ops_remaining = file->counters[CP_POSIX_READS] + file->counters[CP_POSIX_WRITES];
    double io_op_time;
    size_t io_sz;
    off_t io_off;
    int64_t i;
804
    struct darshan_io_op next_io_op;
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840

    /* if there are no i/o ops, just return immediately */
    if (!io_ops_this_cycle)
        return cur_time;

    /* initialze static variables when a new file is opened */
    if (rw == -1)
    {
        /* initialize rw to be the first i/o operation found in the log */
        if (file->fcounters[CP_F_WRITE_START_TIMESTAMP] == 0.0)
            rw = 0;
        else if (file->fcounters[CP_F_READ_START_TIMESTAMP] == 0.0)
            rw = 1;
        else
            rw = (file->fcounters[CP_F_READ_START_TIMESTAMP] <
                  file->fcounters[CP_F_WRITE_START_TIMESTAMP]) ? 0 : 1;

        /* determine how many io ops to do before next rw switch */
        if (!rw)
            io_ops_this_rw = file->counters[CP_POSIX_READS] /
                             ((file->counters[CP_RW_SWITCHES] / 2) + 1);
        else
            io_ops_this_rw = file->counters[CP_POSIX_WRITES] /
                             ((file->counters[CP_RW_SWITCHES] / 2) + 1);

        /* initialize the rd and wr bandwidth values using total io size and time */
        if (file->fcounters[CP_F_POSIX_READ_TIME])
            rd_bw = file->counters[CP_BYTES_READ] / file->fcounters[CP_F_POSIX_READ_TIME];
        if (file->fcounters[CP_F_POSIX_WRITE_TIME])
            wr_bw = file->counters[CP_BYTES_WRITTEN] / file->fcounters[CP_F_POSIX_WRITE_TIME];
    }

    /* loop to generate all reads/writes for this open/close sequence */
    for (i = 0; i < io_ops_this_cycle; i++)
    {
        /* calculate what value to use for i/o size and offset */
841
        determine_io_params(file, rw, 1, 1, &io_sz, &io_off);
842
843
844
        if (!rw)
        {
            /* generate a read event */
845
846
847
848
849
            next_io_op.codes_op.op_type = CODES_WK_READ;
            next_io_op.codes_op.u.read.file_id = file->hash;
            next_io_op.codes_op.u.read.size = io_sz;
            next_io_op.codes_op.u.read.offset = io_off;
            next_io_op.start_time = cur_time;
850
851
852
853
854

            /* set the end time based on observed bandwidth and io size */
            if (rd_bw == 0.0)
                io_op_time = 0.0;
            else
855
                io_op_time = (io_sz / rd_bw);
856
857

            /* update time, accounting for metadata time */
858
            cur_time += io_op_time;
859
            next_io_op.end_time = cur_time;
860
861
862
863
864
            file->counters[CP_POSIX_READS]--;
        }
        else
        {
            /* generate a write event */
865
866
867
868
869
            next_io_op.codes_op.op_type = CODES_WK_WRITE;
            next_io_op.codes_op.u.write.file_id = file->hash;
            next_io_op.codes_op.u.write.size = io_sz;
            next_io_op.codes_op.u.write.offset = io_off;
            next_io_op.start_time = cur_time;
870
871
872
873
874

            /* set the end time based on observed bandwidth and io size */
            if (wr_bw == 0.0)
                io_op_time = 0.0;
            else
875
                io_op_time = (io_sz / wr_bw);
876
877

            /* update time, accounting for metadata time */
878
            cur_time += io_op_time;
879
            next_io_op.end_time = cur_time;
880
881
882
883
884
885
886
            file->counters[CP_POSIX_WRITES]--;
        }
        psx_rw_ops_remaining--;
        io_ops_this_rw--;
        assert(file->counters[CP_POSIX_READS] >= 0);
        assert(file->counters[CP_POSIX_WRITES] >= 0);

887
888
        /* store the i/o event */
        darshan_insert_next_io_op(io_context->io_op_dat, &next_io_op);
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908

        /* determine whether to toggle between reads and writes */
        if (!io_ops_this_rw && psx_rw_ops_remaining)
        {
            /* toggle the read/write flag */
            rw ^= 1;
            file->counters[CP_RW_SWITCHES]--;

            /* determine how many io ops to do before next rw switch */
            if (!rw)
                io_ops_this_rw = file->counters[CP_POSIX_READS] /
                                 ((file->counters[CP_RW_SWITCHES] / 2) + 1);
            else
                io_ops_this_rw = file->counters[CP_POSIX_WRITES] /
                                 ((file->counters[CP_RW_SWITCHES] / 2) + 1);
        }

        if (i != (io_ops_this_cycle - 1))
        {
            /* update current time to account for possible delay between i/o operations */
909
            cur_time += inter_io_delay;
910
911
912
913
914
915
916
917
918
919
920
921
        }
    }

    /* reset the static rw flag if this is the last open-close cycle for this file */
    if (file->counters[CP_POSIX_OPENS] == 1)
    {
        rw = -1;
    }

    return cur_time;
}

922
923
static double generate_psx_coll_io_events(
    struct darshan_file *file, int64_t ind_io_ops_this_cycle, int64_t coll_io_ops_this_cycle,
924
925
    int64_t nprocs, int64_t aggregator_cnt, double inter_io_delay, double cur_time,
    struct rank_io_context *io_context)
926
927
928
929
930
931
932
933
934
935
936
937
{
    static int rw = -1; /* rw = 1 for write, 0 for read, -1 for uninitialized */
    static int64_t io_ops_this_rw;
    static double rd_bw = 0.0, wr_bw = 0.0;
    int64_t psx_rw_ops_remaining = file->counters[CP_POSIX_READS] + file->counters[CP_POSIX_WRITES];
    int64_t total_io_ops_this_cycle = ind_io_ops_this_cycle + coll_io_ops_this_cycle;
    int64_t total_coll_io_ops =
            (file->counters[CP_COLL_READS] + file->counters[CP_COLL_WRITES]) / nprocs;
    int64_t tmp_rank;
    int64_t next_ind_io_rank = 0;
    int64_t io_cnt;
    int64_t ranks_per_aggregator = nprocs / aggregator_cnt;
938
    int64_t ind_ops_remaining = 0;
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
    double io_op_time;
    double max_cur_time = 0.0;
    int ind_coll;
    size_t io_sz;
    off_t io_off;
    int64_t i, j;
    struct darshan_io_op next_io_op;

    if (!total_io_ops_this_cycle)
        return cur_time;

    /* initialze static variables when a new file is opened */
    if (rw == -1)
    {
        /* initialize rw to be the first i/o operation found in the log */
        if (file->fcounters[CP_F_WRITE_START_TIMESTAMP] == 0.0)
            rw = 0;
        else if (file->fcounters[CP_F_READ_START_TIMESTAMP] == 0.0)
            rw = 1;
        else
            rw = (file->fcounters[CP_F_READ_START_TIMESTAMP] <
                  file->fcounters[CP_F_WRITE_START_TIMESTAMP]) ? 0 : 1;

962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
        /* determine how many io ops to do before next rw switch */
        if (!rw)
        {
            if (file->counters[CP_COLL_OPENS])
                io_ops_this_rw =
                    ((file->counters[CP_COLL_READS] / nprocs) + file->counters[CP_INDEP_READS]) /
                    ((file->counters[CP_RW_SWITCHES] / (2 * aggregator_cnt)) + 1);
            else
                io_ops_this_rw = file->counters[CP_POSIX_READS] /
                                 ((file->counters[CP_RW_SWITCHES] / (2 * aggregator_cnt)) + 1);
        }
        else
        {
            if (file->counters[CP_COLL_OPENS])
                io_ops_this_rw =
                    ((file->counters[CP_COLL_WRITES] / nprocs) + file->counters[CP_INDEP_WRITES]) /
                    ((file->counters[CP_RW_SWITCHES] / (2 * aggregator_cnt)) + 1);
            else
                io_ops_this_rw = file->counters[CP_POSIX_WRITES] /
                                 ((file->counters[CP_RW_SWITCHES] / (2 * aggregator_cnt)) + 1);
        }

984
985
986
987
988
989
990
        /* initialize the rd and wr bandwidth values using total io size and time */
        if (file->fcounters[CP_F_POSIX_READ_TIME])
            rd_bw = file->counters[CP_BYTES_READ] / file->fcounters[CP_F_POSIX_READ_TIME];
        if (file->fcounters[CP_F_POSIX_WRITE_TIME])
            wr_bw = file->counters[CP_BYTES_WRITTEN] / file->fcounters[CP_F_POSIX_WRITE_TIME];
    }

991
992
993
994
995
    if (coll_io_ops_this_cycle)
        ind_ops_remaining = ceil((double)ind_io_ops_this_cycle / coll_io_ops_this_cycle);
    else
        ind_ops_remaining = ind_io_ops_this_cycle;

996
997
    for (i = 0; i < total_io_ops_this_cycle; i++)
    {
998
        if (ind_ops_remaining)
999
1000
1001
1002
        {
            ind_coll = 0;
            tmp_rank = (next_ind_io_rank++) % nprocs;
            io_cnt = 1;
1003
1004
            ind_io_ops_this_cycle--;
            ind_ops_remaining--;
1005
1006
1007
1008
1009
1010
1011
1012
1013
            if (!rw)
                file->counters[CP_INDEP_READS]--;
            else
                file->counters[CP_INDEP_WRITES]--;
        }
        else
        {
            ind_coll = 1;
            tmp_rank = 0;
1014
            coll_io_ops_this_cycle--;
1015
1016
1017
            if (!rw)
            {
                io_cnt = ceil((double)(file->counters[CP_POSIX_READS] -
1018
                              file->counters[CP_INDEP_READS]) / 
1019
1020
1021
1022
1023
1024
                              (file->counters[CP_COLL_READS] / nprocs));
                file->counters[CP_COLL_READS] -= nprocs;
            }
            else
            {
                io_cnt = ceil((double)(file->counters[CP_POSIX_WRITES] -
1025
                              file->counters[CP_INDEP_WRITES]) / 
1026
1027
1028
                              (file->counters[CP_COLL_WRITES] / nprocs));
                file->counters[CP_COLL_WRITES] -= nprocs;
            }
1029
1030
1031
1032
1033
1034
1035

            if (coll_io_ops_this_cycle)
                ind_ops_remaining = ceil((double)ind_io_ops_this_cycle / coll_io_ops_this_cycle);
            else
                ind_ops_remaining = ind_io_ops_this_cycle;

            cur_time = generate_barrier_event(file, 0, cur_time, io_context);
1036
1037
1038
1039
        }

        for (j = 0; j < io_cnt; j++)
        {
1040
1041
            determine_io_params(file, rw, (ind_coll) ? io_cnt - j : ind_io_ops_this_cycle + 1,
                                aggregator_cnt, &io_sz, &io_off);
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
            if (!rw)
            {
                /* generate a read event */
                next_io_op.codes_op.op_type = CODES_WK_READ;
                next_io_op.codes_op.u.read.file_id = file->hash;
                next_io_op.codes_op.u.read.size = io_sz;
                next_io_op.codes_op.u.read.offset = io_off;
                next_io_op.start_time = cur_time;

                /* set the end time based on observed bandwidth and io size */
                if (rd_bw == 0.0)
                    io_op_time = 0.0;
                else
                    io_op_time = (io_sz / rd_bw);
                
1057
                next_io_op.end_time = cur_time + io_op_time;
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
                file->counters[CP_POSIX_READS]--;
            }
            else
            {
                /* generate a write event */
                next_io_op.codes_op.op_type = CODES_WK_WRITE;
                next_io_op.codes_op.u.write.file_id = file->hash;
                next_io_op.codes_op.u.write.size = io_sz;
                next_io_op.codes_op.u.write.offset = io_off;
                next_io_op.start_time = cur_time;

                /* set the end time based on observed bandwidth and io size */
                if (wr_bw == 0.0)
                    io_op_time = 0.0;
                else
                    io_op_time = (io_sz / wr_bw);

1075
                next_io_op.end_time = cur_time + io_op_time;
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
                file->counters[CP_POSIX_WRITES]--;
            }
            psx_rw_ops_remaining--;
            assert(file->counters[CP_POSIX_READS] >= 0);
            assert(file->counters[CP_POSIX_WRITES] >= 0);

            /*  store the i/o event */
            if (tmp_rank == io_context->my_rank)
                darshan_insert_next_io_op(io_context->io_op_dat, &next_io_op);

            if (next_io_op.end_time > max_cur_time)
                max_cur_time = next_io_op.end_time;

            tmp_rank += ranks_per_aggregator;
1090
            if (ind_coll && (tmp_rank >= (ranks_per_aggregator * aggregator_cnt)))
1091
1092
1093
            {
                tmp_rank = 0;
                cur_time = max_cur_time;
1094
                cur_time = generate_barrier_event(file, 0, cur_time, io_context);
1095
1096
1097
1098
            }
        }
        io_ops_this_rw--;

1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
        if (ind_coll)
        {
            total_coll_io_ops--;

            cur_time = max_cur_time;
            if (i != (total_io_ops_this_cycle - 1))
                cur_time += inter_io_delay;
        }
        else
        {
1109
1110
            if (tmp_rank == (nprocs - 1) || (i == (total_io_ops_this_cycle - 1)))
            {
1111
1112
                cur_time = max_cur_time;

1113
1114
1115
                if (i != (total_io_ops_this_cycle - 1))
                    cur_time += inter_io_delay;
            }
1116
1117
        }

1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
        /* determine whether to toggle between reads and writes */
        if (!io_ops_this_rw && psx_rw_ops_remaining)
        {
            /* toggle the read/write flag */
            rw ^= 1;
            file->counters[CP_RW_SWITCHES] -= aggregator_cnt;

            /* determine how many io ops to do before next rw switch */
            if (!rw)
            {
                if (file->counters[CP_COLL_OPENS])
                    io_ops_this_rw =
                        ((file->counters[CP_COLL_READS] / nprocs) +
                        file->counters[CP_INDEP_READS]) / ((file->counters[CP_RW_SWITCHES] /
                        (2 * aggregator_cnt)) + 1);
                else
                    io_ops_this_rw = file->counters[CP_POSIX_READS] /
                                     ((file->counters[CP_RW_SWITCHES] / (2 * aggregator_cnt)) + 1);
            }
            else
            {
                if (file->counters[CP_COLL_OPENS])
                    io_ops_this_rw =
                        ((file->counters[CP_COLL_WRITES] / nprocs) +
                        file->counters[CP_INDEP_WRITES]) / ((file->counters[CP_RW_SWITCHES] /
                        (2 * aggregator_cnt)) + 1);
                else
                    io_ops_this_rw = file->counters[CP_POSIX_WRITES] /
                                     ((file->counters[CP_RW_SWITCHES] / (2 * aggregator_cnt)) + 1);
            }
        }
    }

    /* reset the static rw flag if this is the last open-close cycle for this file */
    if (file->counters[CP_POSIX_OPENS] <= nprocs)
    {
        rw = -1;
    }

1157
    return cur_time;
1158
1159
}

1160
/* WARNING: BRUTE FORCE */
1161
static void determine_io_params(
1162
    struct darshan_file *file, int write_flag, int64_t io_this_op, int64_t proc_count,
1163
1164
1165
1166
    size_t *io_sz, off_t *io_off)
{
    static uint64_t next_rd_off = 0;
    static uint64_t next_wr_off = 0;
1167
1168
1169
1170
1171
1172
    static int size_bin_ndx = -1;
    static int64_t io_this_size_bin = 0;
    static int64_t rd_common_counts[4];
    static int64_t wr_common_counts[4];
    int64_t *rd_size_bins = &(file->counters[CP_SIZE_READ_0_100]);
    int64_t *wr_size_bins = &(file->counters[CP_SIZE_WRITE_0_100]);
1173
    int64_t *size_bins = NULL;
1174
1175
    int64_t *common_accesses = &(file->counters[CP_ACCESS1_ACCESS]); /* 4 common accesses */
    int64_t *common_access_counts = &(file->counters[CP_ACCESS1_COUNT]); /* common access counts */
1176
    int64_t *total_io_size = NULL;
1177
    int64_t last_io_byte;
1178
    int look_for_small_bin = 0;
1179
    int i, j = 0;
1180
1181
1182
1183
1184
1185
    const int64_t size_bin_min_vals[10] = { 0, 100, 1024, 10 * 1024, 100 * 1024, 1024 * 1024,
                                            4 * 1024 * 1024, 10 * 1024 * 1024, 100 * 1024 * 1024,
                                            1024 * 1024 * 1024 };
    const int64_t size_bin_max_vals[10] = { 100, 1024, 10 * 1024, 100 * 1024, 1024 * 1024,
                                            4 * 1024 * 1024, 10 * 1024 * 1024, 100 * 1024 * 1024,
                                            1024 * 1024 * 1024, INT64_MAX };
1186

1187
1188
1189
    assert(io_this_op);

    if (size_bin_ndx == -1)
1190
1191
1192
    {
        for (i = 0; i < 4; i++)
        {
1193
1194
            for (j = 0; j < 10; j++)
            {
1195
1196
                if ((common_accesses[i] >= size_bin_min_vals[j]) &&
                    (common_accesses[i] <= size_bin_max_vals[j]))
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
                {
                    if (rd_size_bins[j] && wr_size_bins[j])
                    {
                        rd_common_counts[i] = MIN(common_access_counts[i] / 2, rd_size_bins[j]);
                        wr_common_counts[i] = common_access_counts[i] - rd_common_counts[i];
                    }
                    else if (rd_size_bins[j])
                    {
                        rd_common_counts[i] = common_access_counts[i];
                        wr_common_counts[i] = 0;
                    }
                    else if (wr_size_bins[j])
                    {
                        rd_common_counts[i] = 0;
                        wr_common_counts[i] = common_access_counts[i];
                    }
                    else
                    {
                        rd_common_counts[i] = wr_common_counts[i] = 0;
                    }
                    break;
                }
            }
1220
1221
1222
1223
1224
1225
1226
1227
        }
    }

    /* assign data values depending on whether the operation is a read or write */
    if (write_flag)
    {
        total_io_size = &(file->counters[CP_BYTES_WRITTEN]);
        last_io_byte = file->counters[CP_MAX_BYTE_WRITTEN];
1228
1229
        size_bins = wr_size_bins;
        common_access_counts = wr_common_counts;
1230
1231
1232
1233
1234
    }
    else
    {
        total_io_size = &(file->counters[CP_BYTES_READ]);
        last_io_byte = file->counters[CP_MAX_BYTE_READ];
1235
1236
        size_bins = rd_size_bins;
        common_access_counts = rd_common_counts;
1237
1238
    }

1239
    if (!io_this_size_bin)
1240
    {
1241
        if (io_this_op < proc_count)
1242
        {
1243
1244
            look_for_small_bin = 1;
            for (i = 0; i < 10; i++)
1245
            {
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
                if (size_bins[i] % proc_count)
                {
                    if (!io_this_size_bin)
                    {
                        size_bin_ndx = i;
                        io_this_size_bin = MIN(size_bins[i] % proc_count, io_this_op);
                    }
                    else if ((size_bins[i] % proc_count) < io_this_size_bin)
                    {
                        size_bin_ndx = i;
                        io_this_size_bin = size_bins[i] % proc_count;
                    }
                }
1259
1260
            }
        }
1261
        else
1262
        {
1263
            for (i = 0; i < 10; i++)
1264
            {
1265
                if (size_bins[i] && ((size_bins[i] % proc_count) == 0))
1266
                {
1267
1268
                    if (!io_this_size_bin ||
                        (io_this_size_bin && (size_bins[i] > size_bins[size_bin_ndx])))
1269
                    {
1270
1271
                        size_bin_ndx = i;
                        io_this_size_bin = proc_count;
1272
1273
                    }
                }
1274
1275
1276
1277
1278
1279
1280
1281
            }
        }

        if (!io_this_size_bin)
        {
            for (i = 0; i < 10; i++)
            {
                if (size_bins[i])
1282
                {
1283
1284
1285
                    size_bin_ndx = i;
                    io_this_size_bin = size_bins[i];
                    if (io_this_size_bin > io_this_op)
1286
                    {
1287
                        io_this_size_bin = io_this_op;
1288
                    }
1289
                    break;
1290
1291
1292
1293
                }
            }
        }
    }
1294
1295
1296

    *io_sz = 0;
    if (*total_io_size > 0)
1297
    {
1298
1299
1300
        if ((write_flag && (file->counters[CP_POSIX_WRITES] == 1)) ||
            (!write_flag && (file->counters[CP_POSIX_READS] == 1)))
        {
1301
            *io_sz = ALIGN_BY_8(*total_io_size);
1302
1303
        }
        else
1304
        {
1305
            /* try to assign a common access first (intelligently) */
1306
1307
            for (j = 0; j < 4; j++)
            {
1308
                if (common_access_counts[j] &&
1309
1310
                    (common_accesses[j] >= size_bin_min_vals[size_bin_ndx]) &&
                    (common_accesses[j] <= size_bin_max_vals[size_bin_ndx]))
1311
                {
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323