space.c 34.5 KB
Newer Older
Pedro Gonnet's avatar
Pedro Gonnet committed
1
/*******************************************************************************
2
 * This file is part of SWIFT.
Pedro Gonnet's avatar
Pedro Gonnet committed
3
 * Coypright (c) 2012 Pedro Gonnet (pedro.gonnet@durham.ac.uk)
4
 *
Pedro Gonnet's avatar
Pedro Gonnet committed
5
6
7
8
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
9
 *
Pedro Gonnet's avatar
Pedro Gonnet committed
10
11
12
13
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
14
 *
Pedro Gonnet's avatar
Pedro Gonnet committed
15
16
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
17
 *
Pedro Gonnet's avatar
Pedro Gonnet committed
18
19
20
21
22
23
24
25
26
27
28
29
30
 ******************************************************************************/

/* Config parameters. */
#include "../config.h"

/* Some standard headers. */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <pthread.h>
#include <float.h>
#include <limits.h>
#include <math.h>
31
#include <omp.h>
Pedro Gonnet's avatar
Pedro Gonnet committed
32

33
34
/* MPI headers. */
#ifdef WITH_MPI
35
#include <mpi.h>
36
37
#endif

Pedro Gonnet's avatar
Pedro Gonnet committed
38
/* Local headers. */
39
#include "const.h"
Pedro Gonnet's avatar
Pedro Gonnet committed
40
#include "cycle.h"
41
#include "atomic.h"
Pedro Gonnet's avatar
Pedro Gonnet committed
42
#include "lock.h"
43
#include "task.h"
44
#include "kernel.h"
Pedro Gonnet's avatar
Pedro Gonnet committed
45
#include "space.h"
46
#include "multipole.h"
47
48
49
#include "cell.h"
#include "scheduler.h"
#include "engine.h"
Pedro Gonnet's avatar
Pedro Gonnet committed
50
#include "runner.h"
51
#include "error.h"
Pedro Gonnet's avatar
Pedro Gonnet committed
52
53
54

/* Split size. */
int space_splitsize = space_splitsize_default;
55
int space_subsize = space_subsize_default;
56
int space_maxsize = space_maxsize_default;
Pedro Gonnet's avatar
Pedro Gonnet committed
57
58
59

/* Map shift vector to sortlist. */
const int sortlistID[27] = {
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
    /* ( -1 , -1 , -1 ) */ 0,
    /* ( -1 , -1 ,  0 ) */ 1,
    /* ( -1 , -1 ,  1 ) */ 2,
    /* ( -1 ,  0 , -1 ) */ 3,
    /* ( -1 ,  0 ,  0 ) */ 4,
    /* ( -1 ,  0 ,  1 ) */ 5,
    /* ( -1 ,  1 , -1 ) */ 6,
    /* ( -1 ,  1 ,  0 ) */ 7,
    /* ( -1 ,  1 ,  1 ) */ 8,
    /* (  0 , -1 , -1 ) */ 9,
    /* (  0 , -1 ,  0 ) */ 10,
    /* (  0 , -1 ,  1 ) */ 11,
    /* (  0 ,  0 , -1 ) */ 12,
    /* (  0 ,  0 ,  0 ) */ 0,
    /* (  0 ,  0 ,  1 ) */ 12,
    /* (  0 ,  1 , -1 ) */ 11,
    /* (  0 ,  1 ,  0 ) */ 10,
    /* (  0 ,  1 ,  1 ) */ 9,
    /* (  1 , -1 , -1 ) */ 8,
    /* (  1 , -1 ,  0 ) */ 7,
    /* (  1 , -1 ,  1 ) */ 6,
    /* (  1 ,  0 , -1 ) */ 5,
    /* (  1 ,  0 ,  0 ) */ 4,
    /* (  1 ,  0 ,  1 ) */ 3,
    /* (  1 ,  1 , -1 ) */ 2,
    /* (  1 ,  1 ,  0 ) */ 1,
    /* (  1 ,  1 ,  1 ) */ 0};

88
89
90
91
92
93
94
95
96
97
98
99
/**
 * @brief Get the shift-id of the given pair of cells, swapping them
 *      if need be.
 *
 * @param s The space
 * @param ci Pointer to first #cell.
 * @param cj Pointer second #cell.
 * @param shift Vector from ci to cj.
 *
 * @return The shift ID and set shift, may or may not swap ci and cj.
 */

100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
int space_getsid(struct space *s, struct cell **ci, struct cell **cj,
                 double *shift) {

  int k, sid = 0, periodic = s->periodic;
  struct cell *temp;
  double dx[3];

  /* Get the relative distance between the pairs, wrapping. */
  for (k = 0; k < 3; k++) {
    dx[k] = (*cj)->loc[k] - (*ci)->loc[k];
    if (periodic && dx[k] < -s->dim[k] / 2)
      shift[k] = s->dim[k];
    else if (periodic && dx[k] > s->dim[k] / 2)
      shift[k] = -s->dim[k];
    else
      shift[k] = 0.0;
    dx[k] += shift[k];
  }

  /* Get the sorting index. */
  for (k = 0; k < 3; k++)
    sid = 3 * sid + ((dx[k] < 0.0) ? 0 : ((dx[k] > 0.0) ? 2 : 1));

  /* Switch the cells around? */
  if (runner_flip[sid]) {
    temp = *ci;
    *ci = *cj;
    *cj = temp;
    for (k = 0; k < 3; k++) shift[k] = -shift[k];
  }
  sid = sortlistID[sid];

  /* Return the sort ID. */
  return sid;
}
135

136
/**
137
 * @brief Recursively dismantle a cell tree.
138
139
 *
 */
140
141
142
143
144
145
146
147
148
149
150
151
152
153

void space_rebuild_recycle(struct space *s, struct cell *c) {

  int k;

  if (c->split)
    for (k = 0; k < 8; k++)
      if (c->progeny[k] != NULL) {
        space_rebuild_recycle(s, c->progeny[k]);
        space_recycle(s, c->progeny[k]);
        c->progeny[k] = NULL;
      }
}

154
/**
155
 * @brief Re-build the cell grid.
156
 *
157
158
 * @param s The #space.
 * @param cell_max Maximum cell edge length.
159
 */
160
161
162
163
164
165
166
167
168
169
170
171
172

void space_regrid(struct space *s, double cell_max) {

  float h_max = s->cell_min / kernel_gamma / space_stretch, dmin;
  int i, j, k, cdim[3], nr_parts = s->nr_parts;
  struct cell *restrict c;
  // ticks tic;

  /* Run through the parts and get the current h_max. */
  // tic = getticks();
  if (s->cells != NULL) {
    for (k = 0; k < s->nr_cells; k++) {
      if (s->cells[k].h_max > h_max) h_max = s->cells[k].h_max;
173
    }
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
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
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
  } else {
    for (k = 0; k < nr_parts; k++) {
      if (s->parts[k].h > h_max) h_max = s->parts[k].h;
    }
    s->h_max = h_max;
  }

/* If we are running in parallel, make sure everybody agrees on
   how large the largest cell should be. */
#ifdef WITH_MPI
  {
    float buff;
    if (MPI_Allreduce(&h_max, &buff, 1, MPI_FLOAT, MPI_MAX, MPI_COMM_WORLD) !=
        MPI_SUCCESS)
      error("Failed to aggreggate the rebuild flag accross nodes.");
    h_max = buff;
  }
#endif
  message("h_max is %.3e (cell_max=%.3e).", h_max, cell_max);

  /* Get the new putative cell dimensions. */
  for (k = 0; k < 3; k++)
    cdim[k] =
        floor(s->dim[k] / fmax(h_max * kernel_gamma * space_stretch, cell_max));

  /* Check if we have enough cells for periodicity. */
  if (s->periodic && (cdim[0] < 3 || cdim[1] < 3 || cdim[2] < 3))
    error(
        "Must have at least 3 cells in each spatial dimension when periodicity "
        "is switched on.");

/* In MPI-Land, we're not allowed to change the top-level cell size. */
#ifdef WITH_MPI
  if (cdim[0] < s->cdim[0] || cdim[1] < s->cdim[1] || cdim[2] < s->cdim[2])
    error("Root-level change of cell size not allowed.");
#endif

  /* Do we need to re-build the upper-level cells? */
  // tic = getticks();
  if (s->cells == NULL || cdim[0] < s->cdim[0] || cdim[1] < s->cdim[1] ||
      cdim[2] < s->cdim[2]) {

    /* Free the old cells, if they were allocated. */
    if (s->cells != NULL) {
      for (k = 0; k < s->nr_cells; k++) {
        space_rebuild_recycle(s, &s->cells[k]);
        if (s->cells[k].sort != NULL) free(s->cells[k].sort);
      }
      free(s->cells);
      s->maxdepth = 0;
    }

    /* Set the new cell dimensions only if smaller. */
    for (k = 0; k < 3; k++) {
      s->cdim[k] = cdim[k];
      s->h[k] = s->dim[k] / cdim[k];
      s->ih[k] = 1.0 / s->h[k];
    }
    dmin = fminf(s->h[0], fminf(s->h[1], s->h[2]));

    /* Allocate the highest level of cells. */
    s->tot_cells = s->nr_cells = cdim[0] * cdim[1] * cdim[2];
    if (posix_memalign((void *)&s->cells, 64,
                       s->nr_cells * sizeof(struct cell)) != 0)
      error("Failed to allocate cells.");
    bzero(s->cells, s->nr_cells * sizeof(struct cell));
    for (k = 0; k < s->nr_cells; k++)
      if (lock_init(&s->cells[k].lock) != 0) error("Failed to init spinlock.");

    /* Set the cell location and sizes. */
    for (i = 0; i < cdim[0]; i++)
      for (j = 0; j < cdim[1]; j++)
        for (k = 0; k < cdim[2]; k++) {
          c = &s->cells[cell_getid(cdim, i, j, k)];
          c->loc[0] = i * s->h[0];
          c->loc[1] = j * s->h[1];
          c->loc[2] = k * s->h[2];
          c->h[0] = s->h[0];
          c->h[1] = s->h[1];
          c->h[2] = s->h[2];
          c->dmin = dmin;
          c->depth = 0;
          c->count = 0;
          c->gcount = 0;
          c->super = c;
          lock_init(&c->lock);
Pedro Gonnet's avatar
Pedro Gonnet committed
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

    /* Be verbose about the change. */
    message("set cell dimensions to [ %i %i %i ].", cdim[0], cdim[1], cdim[2]);
    fflush(stdout);

  } /* re-build upper-level cells? */
  // message( "rebuilding upper-level cells took %.3f ms." , (double)(getticks()
  // - tic) / CPU_TPS * 1000 );

  /* Otherwise, just clean up the cells. */
  else {

    /* Free the old cells, if they were allocated. */
    for (k = 0; k < s->nr_cells; k++) {
      space_rebuild_recycle(s, &s->cells[k]);
      s->cells[k].sorts = NULL;
      s->cells[k].nr_tasks = 0;
      s->cells[k].nr_density = 0;
      s->cells[k].nr_force = 0;
      s->cells[k].density = NULL;
      s->cells[k].force = NULL;
      s->cells[k].dx_max = 0.0f;
      s->cells[k].sorted = 0;
      s->cells[k].count = 0;
      s->cells[k].gcount = 0;
      s->cells[k].kick1 = NULL;
      s->cells[k].kick2 = NULL;
      s->cells[k].super = &s->cells[k];
289
    }
290
291
292
    s->maxdepth = 0;
  }
}
293
294
295
296
297
298
299
300

/**
 * @brief Re-build the cells as well as the tasks.
 *
 * @param s The #space in which to update the cells.
 * @param cell_max Maximal cell size.
 *
 */
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

void space_rebuild(struct space *s, double cell_max) {

  int j, k, cdim[3], nr_gparts = s->nr_gparts;
  struct cell *restrict c, *restrict cells;
  struct part *restrict finger, *restrict p, *parts = s->parts;
  struct xpart *xfinger, *xparts = s->xparts;
  struct gpart *gp, *gparts = s->gparts, *gfinger;
  int *cell_id;
  double ih[3], dim[3];
  // ticks tic;

  /* Be verbose about this. */
  // message( "re)building space..." ); fflush(stdout);

  /* Re-grid if necessary, or just re-set the cell data. */
  space_regrid(s, cell_max);
  cells = s->cells;

  /* Run through the particles and get their cell index. */
  // tic = getticks();
  const int cell_id_size = s->nr_parts;
  if ((cell_id = (int *)malloc(sizeof(int) * cell_id_size)) == NULL)
    error("Failed to allocate temporary particle indices.");
  ih[0] = s->ih[0];
  ih[1] = s->ih[1];
  ih[2] = s->ih[2];
  dim[0] = s->dim[0];
  dim[1] = s->dim[1];
  dim[2] = s->dim[2];
  cdim[0] = s->cdim[0];
  cdim[1] = s->cdim[1];
  cdim[2] = s->cdim[2];
  for (k = 0; k < s->nr_parts; k++) {
    p = &parts[k];
    for (j = 0; j < 3; j++)
      if (p->x[j] < 0.0)
        p->x[j] += dim[j];
      else if (p->x[j] >= dim[j])
        p->x[j] -= dim[j];
    cell_id[k] =
        cell_getid(cdim, p->x[0] * ih[0], p->x[1] * ih[1], p->x[2] * ih[2]);
    if (cell_id[k] < 0 || cell_id[k] >= s->nr_cells)
      error("Bad cell id %i.", cell_id[k]);
    atomic_inc(&cells[cell_id[k]].count);
  }
// message( "getting particle indices took %.3f ms." , (double)(getticks() -
// tic) / CPU_TPS * 1000 );

#ifdef WITH_MPI
  /* Move non-local parts to the end of the list. */
  int nodeID = s->e->nodeID;
  int nr_local_parts = s->nr_parts;
  for (k = 0; k < nr_local_parts; k++)
    if (cells[cell_id[k]].nodeID != nodeID) {
      cells[cell_id[k]].count -= 1;
      nr_local_parts -= 1;
      struct part tp = parts[k];
      parts[k] = parts[nr_local_parts];
      parts[nr_local_parts] = tp;
      struct xpart txp = xparts[k];
      xparts[k] = xparts[nr_local_parts];
      xparts[nr_local_parts] = txp;
      int t = cell_id[k];
      cell_id[k] = cell_id[nr_local_parts];
      cell_id[nr_local_parts] = t;
367
368
    }

369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
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
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
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
  /* Exchange the strays, note that this potentially re-allocates
     the parts arrays. */
  s->nr_parts =
      nr_local_parts + engine_exchange_strays(s->e, nr_local_parts,
                                              &cell_id[nr_local_parts],
                                              s->nr_parts - nr_local_parts);
  parts = s->parts;
  xparts = s->xparts;

  /* Re-allocate the index array if needed.. */
  if (s->nr_parts > cell_id_size) {
    int *cell_id_new;
    if ((cell_id_new = (int *)malloc(sizeof(int) * s->nr_parts)) == NULL)
      error("Failed to allocate temporary particle indices.");
    memcpy(cell_id_new, cell_id, sizeof(int) * nr_local_parts);
    free(cell_id);
    cell_id = cell_id_new;
  }

  /* Assign each particle to its cell. */
  for (k = nr_local_parts; k < s->nr_parts; k++) {
    p = &parts[k];
    cell_id[k] =
        cell_getid(cdim, p->x[0] * ih[0], p->x[1] * ih[1], p->x[2] * ih[2]);
    cells[cell_id[k]].count += 1;
    if (cells[cell_id[k]].nodeID != nodeID)
      error(
          "Received part that does not belong to me (nodeID=%i, x=[%e,%e,%e]).",
          cells[cell_id[k]].nodeID, p->x[0], p->x[1], p->x[2]);
  }
#endif

  /* Sort the parts according to their cells. */
  // tic = getticks();
  parts_sort(parts, xparts, cell_id, s->nr_parts, 0, s->nr_cells - 1);
  // message( "parts_sort took %.3f ms." , (double)(getticks() - tic) / CPU_TPS
  // * 1000 );

  /* Re-link the gparts. */
  for (k = 0; k < s->nr_parts; k++)
    if (parts[k].gpart != NULL) parts[k].gpart->part = &parts[k];

  /* Verify sort. */
  /* for ( k = 1 ; k < nr_parts ; k++ ) {
      if ( cell_id[k-1] > cell_id[k] ) {
          error( "Sort failed!" );
          }
      else if ( cell_id[k] != cell_getid( cdim , parts[k].x[0]*ih[0] ,
     parts[k].x[1]*ih[1] , parts[k].x[2]*ih[2] ) )
          error( "Incorrect indices!" );
      } */

  /* We no longer need the indices as of here. */
  free(cell_id);

  /* Run through the gravity particles and get their cell index. */
  // tic = getticks();
  if ((cell_id = (int *)malloc(sizeof(int) * s->size_gparts)) == NULL)
    error("Failed to allocate temporary particle indices.");
  for (k = 0; k < nr_gparts; k++) {
    gp = &gparts[k];
    for (j = 0; j < 3; j++)
      if (gp->x[j] < 0.0)
        gp->x[j] += dim[j];
      else if (gp->x[j] >= dim[j])
        gp->x[j] -= dim[j];
    cell_id[k] =
        cell_getid(cdim, gp->x[0] * ih[0], gp->x[1] * ih[1], gp->x[2] * ih[2]);
    atomic_inc(&cells[cell_id[k]].gcount);
  }
  // message( "getting particle indices took %.3f ms." , (double)(getticks() -
  // tic) / CPU_TPS * 1000 );

  /* TODO: Here we should exchange the gparts as well! */

  /* Sort the parts according to their cells. */
  // tic = getticks();
  gparts_sort(gparts, cell_id, nr_gparts, 0, s->nr_cells - 1);
  // message( "gparts_sort took %.3f ms." , (double)(getticks() - tic) / CPU_TPS
  // * 1000 );

  /* Re-link the parts. */
  for (k = 0; k < nr_gparts; k++)
    if (gparts[k].id > 0) gparts[k].part->gpart = &gparts[k];

  /* We no longer need the indices as of here. */
  free(cell_id);

  /* Hook the cells up to the parts. */
  // tic = getticks();
  finger = parts;
  xfinger = xparts;
  gfinger = gparts;
  for (k = 0; k < s->nr_cells; k++) {
    c = &cells[k];
    c->parts = finger;
    c->xparts = xfinger;
    c->gparts = gfinger;
    finger = &finger[c->count];
    xfinger = &xfinger[c->count];
    gfinger = &gfinger[c->gcount];
  }
  // message( "hooking up cells took %.3f ms." , (double)(getticks() - tic) /
  // CPU_TPS * 1000 );

  /* At this point, we have the upper-level cells, old or new. Now make
     sure that the parts in each cell are ok. */
  // tic = getticks();
  k = 0;
  {
    if (omp_get_thread_num() < 8)
      while (1) {
        int myk = atomic_inc(&k);
        if (myk < s->nr_cells)
          space_split(s, &cells[myk]);
        else
          break;
      }
  }
  // message( "space_split took %.3f ms." , (double)(getticks() - tic) / CPU_TPS
  // * 1000 );
}
491

492
/**
493
494
 * @brief Sort the particles and condensed particles according to the given
 *indices.
495
496
 *
 * @param parts The list of #part
497
 * @param xparts The list of reduced particles
498
499
500
501
502
 * @param ind The indices with respect to which the parts are sorted.
 * @param N The number of parts
 * @param min Lowest index.
 * @param max highest index.
 */
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
void parts_sort(struct part *parts, struct xpart *xparts, int *ind, int N,
                int min, int max) {

  struct qstack {
    volatile int i, j, min, max;
    volatile int ready;
  };
  struct qstack *qstack;
  int qstack_size = 2 * (max - min) + 10;
  volatile unsigned int first, last, waiting;

  int pivot;
  int i, ii, j, jj, temp_i, qid;
  struct part temp_p;
  struct xpart temp_xp;

  /* for ( int k = 0 ; k < N ; k++ )
      if ( ind[k] > max || ind[k] < min )
          error( "ind[%i]=%i is not in [%i,%i]." , k , ind[k] , min , max ); */

  /* Allocate the stack. */
  if ((qstack = malloc(sizeof(struct qstack) * qstack_size)) == NULL)
    error("Failed to allocate qstack.");

  /* Init the interval stack. */
  qstack[0].i = 0;
  qstack[0].j = N - 1;
  qstack[0].min = min;
  qstack[0].max = max;
  qstack[0].ready = 1;
  for (i = 1; i < qstack_size; i++) qstack[i].ready = 0;
  first = 0;
  last = 1;
  waiting = 1;

/* Parallel bit. */
#pragma omp parallel default(shared)                                           \
    shared(N, first, last, waiting, qstack, parts, xparts, ind, qstack_size,   \
           stderr, engine_rank) private(pivot, i, ii, j, jj, min, max, temp_i, \
                                        qid, temp_xp, temp_p)
  {

    /* Main loop. */
    if (omp_get_thread_num() < 8)
      while (waiting > 0) {

        /* Grab an interval off the queue. */
        qid = atomic_inc(&first) % qstack_size;

        /* Wait for the interval to be ready. */
        while (waiting > 0 && atomic_cas(&qstack[qid].ready, 1, 1) != 1)
          ;

        /* Broke loop for all the wrong reasons? */
        if (waiting == 0) break;

        /* Get the stack entry. */
        i = qstack[qid].i;
        j = qstack[qid].j;
        min = qstack[qid].min;
        max = qstack[qid].max;
        qstack[qid].ready = 0;
        // message( "thread %i got interval [%i,%i] with values in [%i,%i]." ,
        // omp_get_thread_num() , i , j , min , max );

        /* Loop over sub-intervals. */
        while (1) {

          /* Bring beer. */
          pivot = (min + max) / 2;

          /* One pass of QuickSort's partitioning. */
          ii = i;
          jj = j;
          while (ii < jj) {
            while (ii <= j && ind[ii] <= pivot) ii++;
            while (jj >= i && ind[jj] > pivot) jj--;
            if (ii < jj) {
              temp_i = ind[ii];
              ind[ii] = ind[jj];
              ind[jj] = temp_i;
              temp_p = parts[ii];
              parts[ii] = parts[jj];
              parts[jj] = temp_p;
              temp_xp = xparts[ii];
              xparts[ii] = xparts[jj];
              xparts[jj] = temp_xp;
            }
          }

          /* Verify sort. */
          /* for ( int k = i ; k <= jj ; k++ )
              if ( ind[k] > pivot ) {
                  message( "sorting failed at k=%i, ind[k]=%i, pivot=%i, i=%i,
          j=%i, N=%i." , k , ind[k] , pivot , i , j , N );
                  error( "Partition failed (<=pivot)." );
                  }
          for ( int k = jj+1 ; k <= j ; k++ )
              if ( ind[k] <= pivot ) {
                  message( "sorting failed at k=%i, ind[k]=%i, pivot=%i, i=%i,
          j=%i, N=%i." , k , ind[k] , pivot , i , j , N );
                  error( "Partition failed (>pivot)." );
                  } */

          /* Split-off largest interval. */
          if (jj - i > j - jj + 1) {

            /* Recurse on the left? */
            if (jj > i && pivot > min) {
              qid = atomic_inc(&last) % qstack_size;
              while (atomic_cas(&qstack[qid].ready, 0, 0) != 0)
                ;
              qstack[qid].i = i;
              qstack[qid].j = jj;
              qstack[qid].min = min;
              qstack[qid].max = pivot;
              qstack[qid].ready = 1;
              if (atomic_inc(&waiting) >= qstack_size)
                error("Qstack overflow.");
            }
624

625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
            /* Recurse on the right? */
            if (jj + 1 < j && pivot + 1 < max) {
              i = jj + 1;
              min = pivot + 1;
            } else
              break;

          } else {

            /* Recurse on the right? */
            if (jj + 1 < j && pivot + 1 < max) {
              qid = atomic_inc(&last) % qstack_size;
              while (atomic_cas(&qstack[qid].ready, 0, 0) != 0)
                ;
              qstack[qid].i = jj + 1;
              qstack[qid].j = j;
              qstack[qid].min = pivot + 1;
              qstack[qid].max = max;
              qstack[qid].ready = 1;
              if (atomic_inc(&waiting) >= qstack_size)
                error("Qstack overflow.");
            }
647

648
649
650
651
652
653
654
            /* Recurse on the left? */
            if (jj > i && pivot > min) {
              j = jj;
              max = pivot;
            } else
              break;
          }
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
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
        } /* loop over sub-intervals. */

        atomic_dec(&waiting);

      } /* main loop. */

  } /* parallel bit. */

  /* Verify sort. */
  /* for ( i = 1 ; i < N ; i++ )
      if ( ind[i-1] > ind[i] )
          error( "Sorting failed (ind[%i]=%i,ind[%i]=%i)." , i-1 , ind[i-1] , i
     , ind[i] ); */

  /* Clean up. */
  free(qstack);
}

void gparts_sort(struct gpart *gparts, int *ind, int N, int min, int max) {

  struct qstack {
    volatile int i, j, min, max;
    volatile int ready;
  };
  struct qstack *qstack;
  int qstack_size = 2 * (max - min) + 10;
  volatile unsigned int first, last, waiting;

  int pivot;
  int i, ii, j, jj, temp_i, qid;
  struct gpart temp_p;

  /* for ( int k = 0 ; k < N ; k++ )
      if ( ind[k] > max || ind[k] < min )
          error( "ind[%i]=%i is not in [%i,%i]." , k , ind[k] , min , max ); */

  /* Allocate the stack. */
  if ((qstack = malloc(sizeof(struct qstack) * qstack_size)) == NULL)
    error("Failed to allocate qstack.");

  /* Init the interval stack. */
  qstack[0].i = 0;
  qstack[0].j = N - 1;
  qstack[0].min = min;
  qstack[0].max = max;
  qstack[0].ready = 1;
  for (i = 1; i < qstack_size; i++) qstack[i].ready = 0;
  first = 0;
  last = 1;
  waiting = 1;

/* Parallel bit. */
#pragma omp parallel default(shared) shared(                           \
    N, first, last, waiting, qstack, gparts, ind, qstack_size, stderr, \
    engine_rank) private(pivot, i, ii, j, jj, min, max, temp_i, qid, temp_p)
  {

    /* Main loop. */
    if (omp_get_thread_num() < 8)
      while (waiting > 0) {

        /* Grab an interval off the queue. */
        qid = atomic_inc(&first) % qstack_size;

        /* Wait for the interval to be ready. */
        while (waiting > 0 && atomic_cas(&qstack[qid].ready, 1, 1) != 1)
          ;

        /* Broke loop for all the wrong reasons? */
        if (waiting == 0) break;

        /* Get the stack entry. */
        i = qstack[qid].i;
        j = qstack[qid].j;
        min = qstack[qid].min;
        max = qstack[qid].max;
        qstack[qid].ready = 0;
        // message( "thread %i got interval [%i,%i] with values in [%i,%i]." ,
        // omp_get_thread_num() , i , j , min , max );

        /* Loop over sub-intervals. */
        while (1) {

          /* Bring beer. */
          pivot = (min + max) / 2;

          /* One pass of QuickSort's partitioning. */
          ii = i;
          jj = j;
          while (ii < jj) {
            while (ii <= j && ind[ii] <= pivot) ii++;
            while (jj >= i && ind[jj] > pivot) jj--;
            if (ii < jj) {
              temp_i = ind[ii];
              ind[ii] = ind[jj];
              ind[jj] = temp_i;
              temp_p = gparts[ii];
              gparts[ii] = gparts[jj];
              gparts[jj] = temp_p;
            }
          }

          /* Verify sort. */
          /* for ( int k = i ; k <= jj ; k++ )
              if ( ind[k] > pivot ) {
                  message( "sorting failed at k=%i, ind[k]=%i, pivot=%i, i=%i,
          j=%i, N=%i." , k , ind[k] , pivot , i , j , N );
                  error( "Partition failed (<=pivot)." );
                  }
          for ( int k = jj+1 ; k <= j ; k++ )
              if ( ind[k] <= pivot ) {
                  message( "sorting failed at k=%i, ind[k]=%i, pivot=%i, i=%i,
          j=%i, N=%i." , k , ind[k] , pivot , i , j , N );
                  error( "Partition failed (>pivot)." );
                  } */

          /* Split-off largest interval. */
          if (jj - i > j - jj + 1) {

            /* Recurse on the left? */
            if (jj > i && pivot > min) {
              qid = atomic_inc(&last) % qstack_size;
              while (atomic_cas(&qstack[qid].ready, 0, 0) != 0)
                ;
              qstack[qid].i = i;
              qstack[qid].j = jj;
              qstack[qid].min = min;
              qstack[qid].max = pivot;
              qstack[qid].ready = 1;
              if (atomic_inc(&waiting) >= qstack_size)
                error("Qstack overflow.");
            }

            /* Recurse on the right? */
            if (jj + 1 < j && pivot + 1 < max) {
              i = jj + 1;
              min = pivot + 1;
            } else
              break;

          } else {

            /* Recurse on the right? */
            if (jj + 1 < j && pivot + 1 < max) {
              qid = atomic_inc(&last) % qstack_size;
              while (atomic_cas(&qstack[qid].ready, 0, 0) != 0)
                ;
              qstack[qid].i = jj + 1;
              qstack[qid].j = j;
              qstack[qid].min = pivot + 1;
              qstack[qid].max = max;
              qstack[qid].ready = 1;
              if (atomic_inc(&waiting) >= qstack_size)
                error("Qstack overflow.");
            }

            /* Recurse on the left? */
            if (jj > i && pivot > min) {
              j = jj;
              max = pivot;
            } else
              break;
          }

        } /* loop over sub-intervals. */

        atomic_dec(&waiting);
823

824
825
826
827
828
829
830
831
832
833
834
835
836
      } /* main loop. */

  } /* parallel bit. */

  /* Verify sort. */
  /* for ( i = 1 ; i < N ; i++ )
      if ( ind[i-1] > ind[i] )
          error( "Sorting failed (ind[%i]=%i,ind[%i]=%i)." , i-1 , ind[i-1] , i
     , ind[i] ); */

  /* Clean up. */
  free(qstack);
}
837

Pedro Gonnet's avatar
Pedro Gonnet committed
838
/**
839
 * @brief Mapping function to free the sorted indices buffers.
Pedro Gonnet's avatar
Pedro Gonnet committed
840
841
 */

842
void space_map_clearsort(struct cell *c, void *data) {
Pedro Gonnet's avatar
Pedro Gonnet committed
843

844
845
846
847
848
  if (c->sort != NULL) {
    free(c->sort);
    c->sort = NULL;
  }
}
Pedro Gonnet's avatar
Pedro Gonnet committed
849
850
851
852
853

/**
 * @brief Map a function to all particles in a aspace.
 *
 * @param s The #space we are working in.
854
855
 * @param fun Function pointer to apply on the cells.
 * @param data Data passed to the function fun.
Pedro Gonnet's avatar
Pedro Gonnet committed
856
857
 */

858
859
860
void space_map_parts(struct space *s,
                     void (*fun)(struct part *p, struct cell *c, void *data),
                     void *data) {
Pedro Gonnet's avatar
Pedro Gonnet committed
861

862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
  int cid = 0;

  void rec_map(struct cell * c) {

    int k;

    /* No progeny? */
    if (!c->split)
      for (k = 0; k < c->count; k++) fun(&c->parts[k], c, data);

    /* Otherwise, recurse. */
    else
      for (k = 0; k < 8; k++)
        if (c->progeny[k] != NULL) rec_map(c->progeny[k]);
  }

  /* Call the recursive function on all higher-level cells. */
  {
    int mycid;
    while (1) {
      mycid = cid++;
      if (mycid < s->nr_cells)
        rec_map(&s->cells[mycid]);
      else
        break;
    }
  }
}
Pedro Gonnet's avatar
Pedro Gonnet committed
890
891

/**
892
 * @brief Map a function to all particles in a space.
Pedro Gonnet's avatar
Pedro Gonnet committed
893
894
 *
 * @param s The #space we are working in.
895
 * @param full Map to all cells, including cells with sub-cells.
896
897
 * @param fun Function pointer to apply on the cells.
 * @param data Data passed to the function fun.
Pedro Gonnet's avatar
Pedro Gonnet committed
898
 */
899

900
901
void space_map_cells_post(struct space *s, int full,
                          void (*fun)(struct cell *c, void *data), void *data) {
902

903
  int cid = 0;
904

905
906
907
  void rec_map(struct cell * c) {

    int k;
Pedro Gonnet's avatar
Pedro Gonnet committed
908

909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
    /* Recurse. */
    if (c->split)
      for (k = 0; k < 8; k++)
        if (c->progeny[k] != NULL) rec_map(c->progeny[k]);

    /* No progeny? */
    if (full || !c->split) fun(c, data);
  }

  /* Call the recursive function on all higher-level cells. */
  {
    int mycid;
    while (1) {
      mycid = cid++;
      if (mycid < s->nr_cells)
        rec_map(&s->cells[mycid]);
      else
        break;
Pedro Gonnet's avatar
Pedro Gonnet committed
927
    }
928
929
  }
}
Pedro Gonnet's avatar
Pedro Gonnet committed
930

931
932
933
934
935
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
void space_map_cells_pre(struct space *s, int full,
                         void (*fun)(struct cell *c, void *data), void *data) {

  int cid = 0;

  void rec_map(struct cell * c) {

    int k;

    /* No progeny? */
    if (full || !c->split) fun(c, data);

    /* Recurse. */
    if (c->split)
      for (k = 0; k < 8; k++)
        if (c->progeny[k] != NULL) rec_map(c->progeny[k]);
  }

  /* Call the recursive function on all higher-level cells. */
  {
    int mycid;
    while (1) {
      mycid = cid++;
      if (mycid < s->nr_cells)
        rec_map(&s->cells[mycid]);
      else
        break;
    }
  }
}
Pedro Gonnet's avatar
Pedro Gonnet committed
961
962
963
964
965
966
967

/**
 * @brief Split cells that contain too many particles.
 *
 * @param s The #space we are working in.
 * @param c The #cell under consideration.
 */
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
void space_split(struct space *s, struct cell *c) {

  int k, count = c->count, gcount = c->gcount, maxdepth = 0;
  float h, h_max = 0.0f, dt, dt_min = FLT_MAX, dt_max = FLT_MIN;
  struct cell *temp;
  struct part *p, *parts = c->parts;
  struct xpart *xp, *xparts = c->xparts;

  /* Check the depth. */
  if (c->depth > s->maxdepth) s->maxdepth = c->depth;

  /* Split or let it be? */
  if (count > space_splitsize || gcount > space_splitsize) {

    /* No longer just a leaf. */
    c->split = 1;

    /* Create the cell's progeny. */
    for (k = 0; k < 8; k++) {
      temp = space_getcell(s);
      temp->count = 0;
      temp->gcount = 0;
      temp->loc[0] = c->loc[0];
      temp->loc[1] = c->loc[1];
      temp->loc[2] = c->loc[2];
      temp->h[0] = c->h[0] / 2;
      temp->h[1] = c->h[1] / 2;
      temp->h[2] = c->h[2] / 2;
      temp->dmin = c->dmin / 2;
      if (k & 4) temp->loc[0] += temp->h[0];
      if (k & 2) temp->loc[1] += temp->h[1];
      if (k & 1) temp->loc[2] += temp->h[2];
For faster browsing, not all history is shown. View entire blame