codes-darshan-io-wrkld.c 58 KB
Newer Older
1 2 3 4 5 6 7
/*
 * Copyright (C) 2013 University of Chicago.
 * See COPYRIGHT notice in top-level directory.
 *
 */

#include "codes/codes-workload.h"
8
#include "codes/quickhash.h"
9
#include "codes-workload-method.h"
10

11
#include "darshan-logutils.h"
12

13 14 15
#define DEF_INTER_IO_DELAY_PCT 0.2
#define DEF_INTER_CYC_DELAY_PCT 0.4

16 17 18 19
#define DARSHAN_NEGLIGIBLE_DELAY .001

#define RANK_HASH_TABLE_SIZE 397

20 21 22 23 24
#define IO_IS_IN_SIZE_BIN_RANGE(size, bin_ndx, bin_min_sizes)                       \
        ((bin_ndx == 9) ?                                                           \
        (size >= bin_min_sizes[bin_ndx]) :                                          \
        ((size >= bin_min_sizes[bin_ndx]) && (size < bin_min_sizes[bin_ndx + 1])))

25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42
/* 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 */
43 44
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);
45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61
static void *darshan_io_workload_get_info(int rank);
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);

/* Helper functions for implementing the (complex, nonfactored) Darshan workload generator */
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);
62
static double generate_psx_open_event(struct darshan_file *file, int create_flag,
63 64
                                      double meta_op_time, double cur_time,
                                      struct rank_io_context *io_context);
65
static double generate_psx_close_event(struct darshan_file *file, double meta_op_time,
66 67 68
                                       double cur_time, struct rank_io_context *io_context);
static double generate_barrier_event(struct darshan_file *file, int64_t root, double cur_time,
                                     struct rank_io_context *io_context);
69 70
static double generate_psx_ind_io_events(struct darshan_file *file, int64_t io_ops_this_cycle,
                                         int64_t open_ndx, double inter_io_delay, 
71 72 73 74 75 76 77
                                         double meta_op_time, double cur_time,
                                         struct rank_io_context *io_context);
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,
                                          int64_t aggregator_cnt, int64_t open_ndx,
                                          double inter_io_delay, double meta_op_time, double cur_time,
                                          struct rank_io_context *io_context);
78 79 80 81 82 83 84
static void determine_io_params(struct darshan_file *file, int write_flag, int coll_flag,
                                int64_t io_cycles, size_t *io_sz, off_t *io_off);
static void calc_io_delays(struct darshan_file *file, int64_t num_opens, int64_t num_io_ops,
                           double delay_per_cycle, double *first_io_delay, double *close_delay,
                           double *inter_open_delay, double *inter_io_delay);
static void file_sanity_check(struct darshan_file *file, struct darshan_job *job);

85 86 87 88 89 90 91 92
/* 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,
};

93
/* info about this darshan workload group needed by bgp model */
94 95
/* TODO: is this needed for darshan workloads? */
/* TODO: does this need to be stored in the rank context to support multiple workloads? */
96

97
/* hash table to store per-rank workload contexts */
98
static struct qhash_table *rank_tbl = NULL;
99

100 101 102
/* load the workload generator for this rank, given input params */
static int darshan_io_workload_load(const char *params, int rank)
{
103 104
    darshan_params *d_params = (darshan_params *)params;
    darshan_fd logfile_fd;
105 106
    struct darshan_job job;
    struct darshan_file next_file;
107
    struct rank_io_context *my_ctx;
108
    int ret;
109

110
    if (!d_params)
111 112
        return -1;

113 114
    /* (re)seed the random number generator */
    srand(time(NULL));
115

116
    /* open the darshan log to begin reading in file i/o info */
117 118
    logfile_fd = darshan_log_open(d_params->log_file_path, "r");
    if (logfile_fd < 0)
119
        return -1;
120

121 122 123 124 125 126 127 128
    /* 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;
    }

129 130 131 132 133 134 135 136 137 138 139
    /* 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();

140 141 142 143 144 145 146 147 148 149
    /* 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 */
150
            generate_psx_ind_file_events(&next_file, my_ctx);
151 152 153 154 155 156
        }
        /* 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);
157 158 159

            /* 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);
160 161 162 163 164
        }
    }
    if (ret < 0)
        return -1;

165
    darshan_log_close(logfile_fd);
166

167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189
    /* 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));

    /* fill out the info required for this workload group */
    if (darshan_workload_info.group_id == -1)
    {
        darshan_workload_info.group_id = 1;
        darshan_workload_info.min_rank = 0;
        darshan_workload_info.max_rank = job.nprocs - 1;
        darshan_workload_info.num_lrank = job.nprocs;
    }

190 191 192 193 194 195
    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)
{
196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231
    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;

    /* 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);
    }
    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;
232 233 234 235

    return;
}

236 237 238
/* return the workload info needed by the bgp model */
/* TODO: do we really need this? */
static void *darshan_io_workload_get_info(int rank)
239
{
240
    return &(darshan_workload_info);
241
}
242

243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384
/* 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;

        /* free data structures */
        free(array->op_array);
        free(array);
    }
    else
    {
        struct darshan_io_op *tmp = &(array->op_array[array->op_arr_ndx]);

        if ((tmp->start_time - last_op_time) < DARSHAN_NEGLIGIBLE_DELAY)
        {
            /* 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;
        }
    }
}

/* 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 */
/*                                       */
/*****************************************/
385 386 387

/* generate events for an independently opened file, and store these events */
static void generate_psx_ind_file_events(
388
    struct darshan_file *file, struct rank_io_context *io_context)
389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420
{
    int64_t io_ops_this_cycle;
    double cur_time = file->fcounters[CP_F_OPEN_TIMESTAMP];
    double delay_per_open;
    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 */
    delay_per_open = (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]) / file->counters[CP_POSIX_OPENS];

    /* calculate synthetic delay values */
    calc_io_delays(file, file->counters[CP_POSIX_OPENS],
                   file->counters[CP_POSIX_READS] + file->counters[CP_POSIX_WRITES],
                   delay_per_open, &first_io_delay, &close_delay,
                   &inter_open_delay, &inter_io_delay);

    /* calculate average meta op time (for i/o and opens/closes) */
    /* TODO: this needs to be updated when we add in stat, seek, etc. */
    meta_op_time = file->fcounters[CP_F_POSIX_META_TIME] / ((2 * file->counters[CP_POSIX_OPENS]) +
                   file->counters[CP_POSIX_READS] + file->counters[CP_POSIX_WRITES]);

421 422 423 424 425
    /* set the create flag if the file was written to */
    if (file->counters[CP_BYTES_WRITTEN])
    {
        create_flag = 1;
    }
426 427 428 429 430 431

    /* 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 */
432
        cur_time = generate_psx_open_event(file, create_flag, meta_op_time, cur_time, io_context);
433 434 435 436 437 438 439 440 441 442 443
        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 */
        cur_time = generate_psx_ind_io_events(file, io_ops_this_cycle, i, inter_io_delay,
444
                                              meta_op_time, cur_time, io_context);
445 446 447 448 449

        /* 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 */
450
        cur_time = generate_psx_close_event(file, meta_op_time, cur_time, io_context);
451 452 453 454 455 456 457

        /* account for potential interopen delay if more than one open */
        if (file->counters[CP_POSIX_OPENS] > 1)
        {
            cur_time += inter_open_delay;
        }
    }
458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731

    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)
{
    int64_t total_io_ops = file->counters[CP_POSIX_READS] + file->counters[CP_POSIX_WRITES];
    int64_t extra_opens = 0;
    int64_t extra_open_stride = 0;
    int64_t extra_io_ops = 0;
    int64_t ind_open_stride = 0;
    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;
    int64_t rank_cnt;
    int64_t aggregator_cnt;
    int create_flag = 0;
    double cur_time = file->fcounters[CP_F_OPEN_TIMESTAMP];
    double delay_per_cycle;
    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;
    int64_t i, j;

    /* 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);

    /* determine delay information */
    delay_per_cycle = (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)) /
                      (file->counters[CP_POSIX_OPENS] / nprocs);

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

    /* TODO TIMING */ 
    calc_io_delays(file, (file->counters[CP_POSIX_OPENS] / nprocs),
                   round((double)total_io_ops / nprocs), delay_per_cycle,
                   &first_io_delay, &close_delay, &inter_cycle_delay, &inter_io_delay);

    if (file->counters[CP_COLL_OPENS] && file->counters[CP_INDEP_OPENS])
    {
        if (((file->counters[CP_COLL_OPENS] / nprocs) % file->counters[CP_INDEP_OPENS]) == 0)
        {        
            ind_open_stride = (file->counters[CP_COLL_OPENS] / nprocs) /
                              file->counters[CP_INDEP_OPENS];
        }
        else
        {
            ind_open_stride = 1;
        }
    }

    if (file->counters[CP_COLL_OPENS] || file->counters[CP_INDEP_OPENS])
    {
        extra_opens = file->counters[CP_POSIX_OPENS] - file->counters[CP_COLL_OPENS] -
                      file->counters[CP_INDEP_OPENS];
        assert(extra_opens <= ((file->counters[CP_COLL_OPENS] / nprocs) +
               file->counters[CP_INDEP_OPENS]));
        if (extra_opens)
        {
            if ((((file->counters[CP_COLL_OPENS] / nprocs) + file->counters[CP_INDEP_OPENS]) %
                extra_opens) == 0)
            {
                extra_open_stride = ((file->counters[CP_COLL_OPENS] / nprocs) +
                                    file->counters[CP_INDEP_OPENS]) / extra_opens;
            }
            else
            {
                extra_open_stride = 1;
            }
            extra_io_ops = 0;
        }

        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;
    }
    else 
    {
        extra_opens = file->counters[CP_POSIX_OPENS] % nprocs;
        if (extra_opens && (((file->counters[CP_POSIX_OPENS] / nprocs) % extra_opens) == 0))
        {
            extra_open_stride = (file->counters[CP_POSIX_OPENS] / nprocs) / extra_opens;
            extra_io_ops = total_io_ops % nprocs;
        }
        else
        {
            extra_opens = 0;
        }

        total_ind_io_ops = total_io_ops - extra_io_ops;
        total_coll_io_ops = 0;
    }

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

    /* generate all events for this collectively opened file */
    for (i = 0; file->counters[CP_POSIX_OPENS]; i++)
    {
        if (file->counters[CP_COLL_OPENS])
            aggregator_cnt = in_agg_cnt;
        else
            aggregator_cnt = nprocs;

        /* assign any determined 'extra' opens to rank 0 at the beginning of the cycle */
        if (extra_opens && !(i % extra_open_stride))
        {
            assert(create_flag);

            /* generate the open/close events for creating the collective file */
            file->rank = 0;
            cur_time = generate_psx_open_event(file, create_flag, meta_op_time, cur_time, io_context);

            ind_io_ops_this_cycle = ceil((double)extra_io_ops / extra_opens);

            cur_time = generate_psx_coll_io_events(file, ind_io_ops_this_cycle, 0, nprocs,
                                                   aggregator_cnt, i, 0.0, meta_op_time,
                                                   cur_time, io_context);
            extra_io_ops -= ind_io_ops_this_cycle;

            cur_time = generate_psx_close_event(file, meta_op_time, cur_time, io_context);
            create_flag = 0;
            file->rank = -1;
            file->counters[CP_POSIX_OPENS]--;
            extra_opens--;
        }

        if (file->counters[CP_POSIX_OPENS] >= nprocs)
        {
            if (file->counters[CP_COLL_OPENS])
            {
                if (file->counters[CP_INDEP_OPENS] && !(i % ind_open_stride))
                {
                    rank_cnt = ceil((double)file->counters[CP_INDEP_OPENS] /
                                    (file->counters[CP_COLL_OPENS] / nprocs));
                    for (j = 0; j < rank_cnt; j++)
                    {
                        file->rank = j;
                        if (j != (rank_cnt - 1))
                            generate_psx_open_event(file, 0, meta_op_time, cur_time, io_context);
                        else
                            cur_time = generate_psx_open_event(file, 0, meta_op_time,
                                                               cur_time, io_context);
                    }

                    ind_io_ops_this_cycle = ceil(((double)total_ind_io_ops /
                                            file->counters[CP_INDEP_OPENS]) * rank_cnt);

                    cur_time = generate_psx_coll_io_events(file, ind_io_ops_this_cycle, 0,
                                                           nprocs, aggregator_cnt, i, 0.0,
                                                           meta_op_time, cur_time, io_context);
                    total_ind_io_ops -= ind_io_ops_this_cycle;

                    for (j = 0; j < rank_cnt; j++)
                    {
                        file->rank = j;
                        if (j != (rank_cnt - 1))
                            generate_psx_close_event(file, meta_op_time, cur_time, io_context);
                        else
                            cur_time = generate_psx_close_event(file, meta_op_time,
                                                                cur_time, io_context);
                    }
                    file->rank = -1;
                    file->counters[CP_INDEP_OPENS] -= rank_cnt;
                    file->counters[CP_POSIX_OPENS] -= rank_cnt;
                }

                cur_time = generate_barrier_event(file, 0, cur_time, io_context);

                coll_io_ops_this_cycle = ceil((double)total_coll_io_ops /
                                         (file->counters[CP_COLL_OPENS] / nprocs));
                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_POSIX_OPENS] / nprocs));
            }
            else
            {
                coll_io_ops_this_cycle = 0;
                ind_io_ops_this_cycle = ceil((double)total_ind_io_ops /
                                        (file->counters[CP_POSIX_OPENS] / nprocs));
            }

            /* perform an open across all ranks (rank == -1) */
            cur_time = generate_psx_open_event(file, create_flag, meta_op_time,
                                               cur_time, io_context);
            create_flag = 0;

            /* account for potential delay between the open and first i/o */
            cur_time += first_io_delay;

            /* generate the io events */
            cur_time = generate_psx_coll_io_events(file, ind_io_ops_this_cycle,
                                                   coll_io_ops_this_cycle, nprocs, aggregator_cnt,
                                                   i, inter_io_delay, meta_op_time,
                                                   cur_time, io_context);
            total_ind_io_ops -= ind_io_ops_this_cycle;
            total_coll_io_ops -= coll_io_ops_this_cycle;

            /* account for potential delay between last i/o operation and file close */
            cur_time += close_delay;
            
            /* generate the corresponding close event for the open at the start of the loop */
            cur_time = generate_psx_close_event(file, meta_op_time, cur_time, io_context);

            file->counters[CP_POSIX_OPENS] -= nprocs;
            if (file->counters[CP_COLL_OPENS])
                file->counters[CP_COLL_OPENS] -= nprocs;

            /* account for any delay between open-close cycles */
            if (file->counters[CP_POSIX_OPENS])
                cur_time += inter_cycle_delay;
        }
        else
        {
            /* open the file across participating ranks */
            rank_cnt = file->counters[CP_POSIX_OPENS];
            for (j = 0; j < rank_cnt; j++)
            {
                file->rank = j;
                if (j != (rank_cnt - 1))
                    generate_psx_open_event(file, 0, meta_op_time, cur_time, io_context);
                else
                    cur_time = generate_psx_open_event(file, 0, meta_op_time, cur_time, io_context);
            }

            /* account for potential delay between the open and first i/o */
            cur_time += first_io_delay;

            ind_io_ops_this_cycle = ceil((double)total_ind_io_ops /
                                         (file->counters[CP_POSIX_OPENS] / nprocs));

            cur_time = generate_psx_coll_io_events(file, ind_io_ops_this_cycle, 0, nprocs,
                                                   rank_cnt, i, inter_io_delay, meta_op_time,
                                                   cur_time, io_context);
            total_ind_io_ops -= ind_io_ops_this_cycle;

            /* account for potential delay between last i/o operation and file close */
            cur_time += close_delay;

            /* close the file across participating ranks */
            for (j = 0; j < rank_cnt; j++)
            {
                file->rank = j;
                if (j != (rank_cnt - 1))
                    generate_psx_close_event(file, meta_op_time, cur_time, io_context);
                else
                    cur_time = generate_psx_close_event(file, meta_op_time, cur_time, io_context);
            }
            file->rank = -1;
            file->counters[CP_POSIX_OPENS] -= rank_cnt;
        }
    }
732 733 734 735 736 737

    return;
}

/* fill in an open event structure and store it with the rank context */
static double generate_psx_open_event(
738 739
    struct darshan_file *file, int create_flag, double meta_op_time,
    double cur_time, struct rank_io_context *io_context)
740
{
741 742 743 744 745 746 747
    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
    };
748 749 750

    /* set the end time of the event based on time spent in POSIX meta operations */
    cur_time += meta_op_time;
751
    next_io_op.end_time = cur_time;
752

753 754 755
    /* store the open event (if this rank performed it) */
    if ((file->rank == io_context->my_rank) || (file->rank == -1))
        darshan_insert_next_io_op(io_context->io_op_dat, &next_io_op);
756 757 758 759 760 761

    return cur_time;
}

/* fill in a close event structure and store it with the rank context */
static double generate_psx_close_event(
762 763
    struct darshan_file *file, double meta_op_time, double cur_time,
    struct rank_io_context *io_context)
764
{
765 766 767 768 769 770
    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
    };
771 772 773

    /* set the end time of the event based on time spent in POSIX meta operations */
    cur_time += meta_op_time;
774
    next_io_op.end_time = cur_time;
775

776 777 778
    /* store the close event (if this rank performed it) */
    if ((file->rank == io_context->my_rank) || (file->rank == -1))
        darshan_insert_next_io_op(io_context->io_op_dat, &next_io_op);
779 780 781 782 783 784

    return cur_time;
}

/* fill in a barrier event structure and store it with the rank context */
static double generate_barrier_event(
785
    struct darshan_file *file, int64_t root, double cur_time, struct rank_io_context *io_context)
786
{
787 788 789 790 791 792 793
    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
    };
794 795

    cur_time += .000001; /* small synthetic delay representing time to barrier */
796
    next_io_op.end_time = cur_time;
797

798 799 800
    /* store the barrier event */
    if ((file->rank == -1) || (file->rank == io_context->my_rank))
        darshan_insert_next_io_op(io_context->io_op_dat, &next_io_op);
801 802 803 804 805 806 807

    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(
    struct darshan_file *file, int64_t io_ops_this_cycle, int64_t open_ndx,
808
    double inter_io_delay, double meta_op_time, double cur_time, struct rank_io_context *io_context)
809 810 811 812 813 814 815 816 817
{
    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;
818
    struct darshan_io_op next_io_op;
819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858

    /* 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 */
        determine_io_params(file, rw, 0, file->counters[CP_POSIX_OPENS], &io_sz, &io_off);
        if (!rw)
        {
            /* generate a read event */
859 860 861 862 863
            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;
864 865 866 867 868

            /* set the end time based on observed bandwidth and io size */
            if (rd_bw == 0.0)
                io_op_time = 0.0;
            else
869
                io_op_time = (io_sz / rd_bw);
870 871 872

            /* update time, accounting for metadata time */
            cur_time += (io_op_time + meta_op_time);
873
            next_io_op.end_time = cur_time;
874 875 876 877 878
            file->counters[CP_POSIX_READS]--;
        }
        else
        {
            /* generate a write event */
879 880 881 882 883
            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;
884 885 886 887 888

            /* set the end time based on observed bandwidth and io size */
            if (wr_bw == 0.0)
                io_op_time = 0.0;
            else
889
                io_op_time = (io_sz / wr_bw);
890 891 892

            /* update time, accounting for metadata time */
            cur_time += (io_op_time + meta_op_time);
893
            next_io_op.end_time = cur_time;
894 895 896 897 898 899 900
            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);

901 902
        /* store the i/o event */
        darshan_insert_next_io_op(io_context->io_op_dat, &next_io_op);
903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922

        /* 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 */
923
            cur_time += inter_io_delay;
924 925 926 927 928 929 930 931 932 933 934 935
        }
    }

    /* 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;
}

936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 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 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173
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, int64_t aggregator_cnt, int64_t open_ndx, double inter_io_delay,
    double meta_op_time, double cur_time, struct rank_io_context *io_context)
{
    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;
    int64_t ind_ops_so_far = 0;
    double ind_coll_switch;
    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;

        /* 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);
        }

        /* 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];
    }

    for (i = 0; i < total_io_ops_this_cycle; i++)
    {
        ind_coll_switch = (double)ind_io_ops_this_cycle / (total_io_ops_this_cycle - i);
        if (((double)rand() / (double)(RAND_MAX + 1.0)) < ind_coll_switch)
        {
            ind_coll = 0;
            tmp_rank = (next_ind_io_rank++) % nprocs;
            io_cnt = 1;
            if (!rw)
                file->counters[CP_INDEP_READS]--;
            else
                file->counters[CP_INDEP_WRITES]--;
            ind_io_ops_this_cycle--;
        }
        else
        {
            if (ind_ops_so_far)
            {
                cur_time = max_cur_time;
                cur_time += inter_io_delay;
                ind_ops_so_far = 0;
            }

            ind_coll = 1;
            cur_time = generate_barrier_event(file, 0, cur_time, io_context);
            tmp_rank = 0;
            if (!rw)
            {
                io_cnt = ceil((double)(file->counters[CP_POSIX_READS] -
                              file->counters[CP_INDEP_READS]) /
                              (file->counters[CP_COLL_READS] / nprocs));
                file->counters[CP_COLL_READS] -= nprocs;
            }
            else
            {
                io_cnt = ceil((double)(file->counters[CP_POSIX_WRITES] -
                              file->counters[CP_INDEP_WRITES]) /
                              (file->counters[CP_COLL_WRITES] / nprocs));
                file->counters[CP_COLL_WRITES] -= nprocs;
            }
            coll_io_ops_this_cycle--;
        }

        for (j = 0; j < io_cnt; j++)
        {
            determine_io_params(file, rw, ind_coll, (ind_coll) ? total_coll_io_ops :
                                file->counters[CP_POSIX_OPENS] / nprocs, &io_sz, &io_off);
            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);
                
                next_io_op.end_time = cur_time + io_op_time + meta_op_time;
                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);

                next_io_op.end_time = cur_time + io_op_time + meta_op_time;
                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;
            if (tmp_rank >= (ranks_per_aggregator * aggregator_cnt))
            {
                tmp_rank = 0;
                cur_time = max_cur_time;
                max_cur_time = 0.0;
            }
        }
        io_ops_this_rw--;

        /* 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);
            }
        }

        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
        {
            if (ind_ops_so_far && ((ind_ops_so_far % nprocs) == nprocs - 1))
            {
                cur_time = max_cur_time;
                if (i != (total_io_ops_this_cycle - 1))
                    cur_time += inter_io_delay;
            }
            ind_ops_so_far++;
        }
    }

    /* 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;
    }

    if (max_cur_time > cur_time)
        return max_cur_time;
    else
        return cur_time;
}

1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438
static void determine_io_params(
    struct darshan_file *file, int write_flag, int coll_flag, int64_t io_cycles, 
    size_t *io_sz, off_t *io_off)
{
    static int seq_rd_flag = -1;
    static int seq_wr_flag = -1;
    static uint64_t next_rd_off = 0;
    static uint64_t next_wr_off = 0;
    static int64_t rd_common_accesses[4] = { 0, 0, 0, 0 };
    static int64_t wr_common_accesses[4] = { 0, 0, 0, 0 };
    static int all_common_flag = -1;
    int64_t *size_bins; /* 10 size bins for io operations */
    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 */
    int64_t *total_io_size;
    int64_t last_io_byte;
    int64_t tmp_byte_counter = 0;
    int size_bin_ndx;
    int i, j = 0;
    int64_t bin_min_size[10] = { 0, 100, 1024, 10 * 1024, 100 * 1024, 1024 * 1024, 4 * 1024 * 1024,
                                 10 * 1024 * 1024, 100 * 1024 * 1024, 1024 * 1024 * 1024 };
    int64_t bin_def_size[10] = { 40, 512, 4 * 1024, 60 * 1024, 512 * 1024, 2 * 1024 * 1024,
                                 6 * 1024 * 1024, 40 * 1024 * 1024, 400 * 1024 * 1024,
                                 1 * 1024 * 1024 * 1024 };

    /* determine how to assign common access counters to reads and/or writes */
    if (all_common_flag == -1)
    {
        for (i = 0; i < 4; i++)
        {
            tmp_byte_counter += (common_accesses[i] * common_access_counts[i]);
        }

        if (tmp_byte_counter == (file->counters[CP_BYTES_WRITTEN] + file->counters[CP_BYTES_READ]))
        {
            all_common_flag = 1;
        }
        else
        {
            all_common_flag = 0;
        }
    }

    /* assign data values depending on whether the operation is a read or write */
    if (write_flag)
    {
        size_bins = &(file->counters[CP_SIZE_WRITE_0_100]);
        total_io_size = &(file->counters[CP_BYTES_WRITTEN]);
        last_io_byte = file->counters[CP_MAX_BYTE_WRITTEN];

        if (seq_wr_flag == -1)
        {
            if ((file->counters[CP_POSIX_WRITES] -
                ((*total_io_size - last_io_byte - 1) / (last_io_byte + 1)) - 1) ==
                file->counters[CP_SEQ_WRITES])
            {
                seq_wr_flag = 1;
            }
            else
            {
                seq_wr_flag = 0;
            }
        }
    }
    else
    {
        size_bins = &(file->counters[CP_SIZE_READ_0_100]);
        total_io_size = &(file->counters[CP_BYTES_READ]);
        last_io_byte = file->counters[CP_MAX_BYTE_READ];

        if (seq_rd_flag == -1)
        {
            if ((file->counters[CP_POSIX_READS] -
                ((*total_io_size - last_io_byte - 1) / (last_io_byte + 1)) - 1) ==
                file->counters[CP_SEQ_READS])
            {
                seq_rd_flag = 1;
            }
            else
            {
                seq_rd_flag = 0;
            }
        }
    }

    *io_sz = 0;
    if ((*total_io_size ==  0) || (write_flag && (file->counters[CP_POSIX_WRITES] == 1)) ||
        (!write_flag && (file->counters[CP_POSIX_READS] == 1)))
    {
        if (*total_io_size >= 0)
            *io_sz = *total_io_size;
    }
    else if (all_common_flag)
    {
        for (i = 0; i < 4; i++)
        {
            if (!write_flag && rd_common_accesses[i])
            {
                *io_sz = common_accesses[i];
                rd_common_accesses[i]--;
                common_access_counts[i]--;
                break;
            }
            else if (write_flag && wr_common_accesses[i])
            {
                *io_sz = common_accesses[i];
                wr_common_accesses[i]--;
                common_access_counts[i]--;
                break;
            }
        }

        if (*io_sz == 0)
        {
            for (i = 0; i < 4; i++)
            {
                if (write_flag)
                {
                    wr_common_accesses[i] = (common_access_counts[i] / io_cycles);
                    if ((*io_sz == 0) && wr_common_accesses[i])
                    {
                        *io_sz = common_accesses[i];
                        wr_common_accesses[i]--;
                        common_access_counts[i]--;
                    }
                }
                else
                {
                    rd_common_accesses[i] = (common_access_counts[i] / io_cycles);
                    if ((*io_sz == 0) && rd_common_accesses[i])
                    {
                        *io_sz = common_accesses[i];
                        rd_common_accesses[i]--;
                        common_access_counts[i]--;
                    }
                }
            }
        }
        assert(*io_sz);
    }
    else
    {
        /* try to assign a common access first */
        for (i = 0; i < 10; i++)
        {
            for (j = 0; j < 4; j++)
            {
                if (size_bins[i] && common_access_counts[j] &&
                    IO_IS_IN_SIZE_BIN_RANGE(common_accesses[j], i, bin_min_size))
                {
                    *io_sz = common_accesses[j];
                    common_access_counts[j]--;
                    break;
                }
            }
            if (*io_sz)
                break;
        }

        /* if no common accesses left, then assign a random io size */
        if (*io_sz == 0)
        {
            size_bin_ndx = rand() % 10;
            for (i = 0; i <  10; i++)
            {
                if (size_bins[size_bin_ndx])
                {
                    *io_sz = bin_def_size[size_bin_ndx];
                    break;
                }
                size_bin_ndx = (size_bin_ndx + 1) % 10;
            }
        }
        assert(*io_sz);
    }

    *total_io_size -= *io_sz;
    for (i = 0; i < 10; i++)
    {
        if (IO_IS_IN_SIZE_BIN_RANGE(*io_sz, i, bin_min_size))
            size_bins[i]--;
    }

    /* next, determine the offset to use */

    /*  for now we just assign a random offset that makes sure not to write past the recorded
     *  last byte written in the file.
     */
    if (*io_sz == 0)
    {
        *io_off = last_io_byte + 1;
    }
    else if (write_flag && seq_wr_flag)
    {
        if ((next_wr_off + *io_sz) > (last_io_byte + 1))
            next_wr_off = 0;

        *io_off = next_wr_off;
        next_wr_off += *io_sz;
    }
    else if (!write_flag && seq_rd_flag)
    {
        if ((next_rd_off + *io_sz) > (last_io_byte + 1))
            next_rd_off = 0;

        *io_off = next_rd_off;
        next_rd_off += *io_sz;
    }
    else if (*io_sz < last_io_byte)
    {
        *io_off = (off_t)rand() % (last_io_byte - *io_sz);
    }
    else
    {
        *io_off = 0;
    }

    /* reset static variable if this is the last i/o op for this file */
    if ((file->counters[CP_POSIX_READS] + file->counters[CP_POSIX_WRITES]) == 1)
    {
        next_rd_off = next_wr_off = 0;
        seq_wr_flag = seq_rd_flag = -1;
        all_common_flag = -1;
        for (i = 0; i < 4; i++)
            rd_common_accesses[i] = wr_common_accesses[i] = 0;
    }

    return;
}

/* calculate the simulated "delay" between different i/o events using delay info
 * from the file counters */
static void calc_io_delays(
    struct darshan_file *file, int64_t num_opens, int64_t num_io_ops, double delay_per_cycle,
    double *first_io_delay, double *close_delay, double *inter_open_delay, double *inter_io_delay)
{
    double first_io_time, last_io_time;
    double first_io_pct, close_pct, inter_open_pct, inter_io_pct;
    double total_delay_pct;
    double tmp_inter_io_pct, tmp_inter_open_pct;

    if (delay_per_cycle > 0.0)
    {
        /* determine the time of the first io operation */
        if (!file->fcounters[CP_F_WRITE_START_TIMESTAMP])
            first_io_time = file->fcounters[CP_F_READ_START_TIMESTAMP];
        else if (!file->fcounters[CP_F_READ_START_TIMESTAMP])
            first_io_time = file->fcounters[CP_F_WRITE_START_TIMESTAMP];
        else if (file->fcounters[CP_F_READ_START_TIMESTAMP] <
                 file->fcounters[CP_F_WRITE_START_TIMESTAMP])
            first_io_time = file->fcounters[CP_F_READ_START_TIMESTAMP];
        else
            first_io_time = file->fcounters[CP_F_WRITE_START_TIMESTAMP];

        /* determine the time of the last io operation */
        if (file->fcounters[CP_F_READ_END_TIMESTAMP] > file->fcounters[CP_F_WRITE_END_TIMESTAMP])
            last_io_time = file->fcounters[CP_F_READ_END_TIMESTAMP];
        else
            last_io_time = file->fcounters[CP_F_WRITE_END_TIMESTAMP];

        /* no delay contribution for inter-open delay if there is only a single open */
        if (num_opens > 1)
            inter_open_pct = DEF_INTER_CYC_DELAY_PCT;

        /* no delay contribution for inter-io delay if there is one or less io op */
1439
        if ((num_io_ops - num_opens) > 0)
1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475
            inter_io_pct = DEF_INTER_IO_DELAY_PCT;

        /* determine delay contribution for first io and close delays */
        if (first_io_time != 0.0)
        {
            first_io_pct = (first_io_time - file->fcounters[CP_F_OPEN_TIMESTAMP]) / delay_per_cycle;
            close_pct = (file->fcounters[CP_F_CLOSE_TIMESTAMP] - last_io_time) / delay_per_cycle;
        }
        else
        {
            first_io_pct = 0.0;
            close_pct = 1 - inter_open_pct;
        }

        /* adjust per open delay percentages using a simple heuristic */
        total_delay_pct = inter_open_pct + inter_io_pct + first_io_pct + close_pct;
        if ((total_delay_pct < 1) && (inter_open_pct || inter_io_pct))
        {
            /* only adjust inter-open and inter-io delays if we underestimate */
            tmp_inter_open_pct = (inter_open_pct / (inter_open_pct + inter_io_pct)) *
                                 (1 - first_io_pct - close_pct);
            tmp_inter_io_pct = (inter_io_pct / (inter_open_pct + inter_io_pct)) *
                               (1 - first_io_pct - close_pct);
            inter_open_pct = tmp_inter_open_pct;
            inter_io_pct = tmp_inter_io_pct;
        }
        else
        {
            inter_open_pct += (inter_open_pct / total_delay_pct) * (1 - total_delay_pct);
            inter_io_pct += (inter_io_pct / total_delay_pct) * (1 - total_delay_pct);
            first_io_pct += (first_io_pct / total_delay_pct) * (1 - total_delay_pct);
            close_pct += (close_pct / total_delay_pct) * (1 - total_delay_pct);
        }

        *first_io_delay = (first_io_pct * delay_per_cycle);
        *close_delay = (close_pct * delay_per_cycle);
1476 1477 1478 1479 1480 1481 1482

        if (num_opens > 1)
            *inter_open_delay = (inter_open_pct * delay_per_cycle) *
                                ((double)num_opens / (num_opens - 1));
        if ((num_io_ops - num_opens) > 0)
            *inter_io_delay = (inter_io_pct * delay_per_cycle) *
                              ((double)num_io_ops / (num_io_ops - num_opens));
1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547
    }

    return;
}

/* check to make sure file stats are valid and properly formatted */
static void file_sanity_check(
    struct darshan_file *file, struct darshan_job *job)
{
    assert(file->counters[CP_POSIX_OPENS] != -1);
    assert(file->fcounters[CP_F_OPEN_TIMESTAMP] != -1);
    assert(file->counters[CP_COLL_OPENS] != -1);
    assert(file->fcounters[CP_F_CLOSE_TIMESTAMP] != -1);
    assert(file->counters[CP_POSIX_READS] != -1);
    assert(file->counters[CP_POSIX_WRITES] != -1);
    assert(file->fcounters[CP_F_POSIX_READ_TIME] != -1);
    assert(file->fcounters[CP_F_POSIX_WRITE_TIME] != -1);
    assert(file->fcounters[CP_F_POSIX_META_TIME] != -1);
    assert(file->fcounters[CP_F_READ_START_TIMESTAMP] != -1);
    assert(file->fcounters[CP_F_WRITE_START_TIMESTAMP] != -1);
    assert(file->fcounters[CP_F_READ_END_TIMESTAMP] != -1);
    assert(file->fcounters[CP_F_WRITE_END_TIMESTAMP] != -1);
    assert(file->counters[CP_BYTES_READ] != -1);
    assert(file->counters[CP_BYTES_WRITTEN] != -1);
    assert(file->counters[CP_RW_SWITCHES] != -1);

    /* adjust timestamps if they are given in absolute unix time */
    if (file->fcounters[CP_F_OPEN_TIMESTAMP] > job->start_time)
    {
        file->fcounters[CP_F_OPEN_TIMESTAMP] -= job->start_time;
        if (file->fcounters[CP_F_OPEN_TIMESTAMP] < 0.0)
            file->fcounters[CP_F_OPEN_TIMESTAMP] = 0.0;

        file->fcounters[CP_F_READ_START_TIMESTAMP] -= job->start_time;
        if (file->fcounters[CP_F_READ_START_TIMESTAMP] < 0.0)
            file->fcounters[CP_F_READ_START_TIMESTAMP] = 0.0;

        file->fcounters[CP_F_WRITE_START_TIMESTAMP] -= job->start_time;
        if (file->fcounters[CP_F_WRITE_START_TIMESTAMP] < 0.0)
            file->fcounters[CP_F_WRITE_START_TIMESTAMP] = 0.0;

        file->fcounters[CP_F_CLOSE_TIMESTAMP] -= job->start_time;
        if (file->fcounters[CP_F_CLOSE_TIMESTAMP] < 0.0)
            file->fcounters[CP_F_CLOSE_TIMESTAMP] = 0.0;

        file->fcounters[CP_F_READ_END_TIMESTAMP] -= job->start_time;
        if (file->fcounters[CP_F_READ_END_TIMESTAMP] < 0.0)
            file->fcounters[CP_F_READ_END_TIMESTAMP] = 0.0;

        file->fcounters[CP_F_WRITE_END_TIMESTAMP] -= job->start_time;
        if (file->fcounters[CP_F_WRITE_END_TIMESTAMP] < 0.0)
            file->fcounters[CP_F_WRITE_END_TIMESTAMP] = 0.0;
    }

    /* set file close time to the end of execution if it is not given */
    if (file->fcounters[CP_F_CLOSE_TIMESTAMP] == 0.0)
        file->fcounters[CP_F_CLOSE_TIMESTAMP] = job->end_time - job->start_time + 1;

    /* collapse fopen/fread/etc. calls into the corresponding open/read/etc. counters */
    file->counters[CP_POSIX_OPENS] += file->counters[CP_POSIX_FOPENS];
    file->counters[CP_POSIX_READS] += file->counters[CP_POSIX_FREADS];
    file->counters[CP_POSIX_WRITES] += file->counters[CP_POSIX_FWRITES];

    return;
}
1548 1549 1550 1551 1552 1553 1554 1555 1556

/*
 * Local variables:
 *  c-indent-level: 4
 *  c-basic-offset: 4
 * End:
 *
 * vim: ft=c ts=8 sts=4 sw=4 expandtab
 */