cell.c 81.2 KB
Newer Older
1
/*******************************************************************************
2
 * This file is part of SWIFT.
3
 * Copyright (c) 2012 Pedro Gonnet (pedro.gonnet@durham.ac.uk)
4
5
6
7
 *                    Matthieu Schaller (matthieu.schaller@durham.ac.uk)
 *               2015 Peter W. Draper (p.w.draper@durham.ac.uk)
 *               2016 John A. Regan (john.a.regan@durham.ac.uk)
 *                    Tom Theuns (tom.theuns@durham.ac.uk)
8
 *
9
10
11
12
 * 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.
13
 *
14
15
16
17
 * 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.
18
 *
19
20
 * 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/>.
21
 *
22
23
24
25
26
27
28
29
30
 ******************************************************************************/

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

/* Some standard headers. */
#include <float.h>
#include <limits.h>
#include <math.h>
31
32
33
34
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
35

36
37
/* MPI headers. */
#ifdef WITH_MPI
38
#include <mpi.h>
39
40
#endif

41
42
/* Switch off timers. */
#ifdef TIMER
43
#undef TIMER
44
45
#endif

46
47
48
/* This object's header. */
#include "cell.h"

49
/* Local headers. */
50
#include "active.h"
51
#include "atomic.h"
52
#include "chemistry.h"
53
#include "drift.h"
54
#include "engine.h"
55
#include "error.h"
56
#include "gravity.h"
57
#include "hydro.h"
Matthieu Schaller's avatar
Matthieu Schaller committed
58
#include "hydro_properties.h"
Pedro Gonnet's avatar
Pedro Gonnet committed
59
#include "memswap.h"
60
#include "minmax.h"
61
#include "scheduler.h"
62
63
#include "space.h"
#include "timers.h"
64

65
66
67
/* Global variables. */
int cell_next_tag = 0;

68
69
70
71
72
/**
 * @brief Get the size of the cell subtree.
 *
 * @param c The #cell.
 */
73
int cell_getsize(struct cell *c) {
74

Pedro Gonnet's avatar
Pedro Gonnet committed
75
76
  /* Number of cells in this subtree. */
  int count = 1;
77

78
79
  /* Sum up the progeny if split. */
  if (c->split)
Pedro Gonnet's avatar
Pedro Gonnet committed
80
    for (int k = 0; k < 8; k++)
81
82
83
84
85
86
      if (c->progeny[k] != NULL) count += cell_getsize(c->progeny[k]);

  /* Return the final count. */
  return count;
}

87
/**
88
 * @brief Link the cells recursively to the given #part array.
89
90
91
92
93
94
 *
 * @param c The #cell.
 * @param parts The #part array.
 *
 * @return The number of particles linked.
 */
95
int cell_link_parts(struct cell *c, struct part *parts) {
96

97
98
99
  c->parts = parts;

  /* Fill the progeny recursively, depth-first. */
Pedro Gonnet's avatar
Pedro Gonnet committed
100
101
102
103
  if (c->split) {
    int offset = 0;
    for (int k = 0; k < 8; k++) {
      if (c->progeny[k] != NULL)
104
        offset += cell_link_parts(c->progeny[k], &parts[offset]);
Pedro Gonnet's avatar
Pedro Gonnet committed
105
106
    }
  }
107

108
  /* Return the total number of linked particles. */
109
110
  return c->count;
}
111

112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
/**
 * @brief Link the cells recursively to the given #gpart array.
 *
 * @param c The #cell.
 * @param gparts The #gpart array.
 *
 * @return The number of particles linked.
 */
int cell_link_gparts(struct cell *c, struct gpart *gparts) {

  c->gparts = gparts;

  /* Fill the progeny recursively, depth-first. */
  if (c->split) {
    int offset = 0;
    for (int k = 0; k < 8; k++) {
      if (c->progeny[k] != NULL)
        offset += cell_link_gparts(c->progeny[k], &gparts[offset]);
    }
  }

  /* Return the total number of linked particles. */
  return c->gcount;
}

137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
/**
 * @brief Link the cells recursively to the given #spart array.
 *
 * @param c The #cell.
 * @param sparts The #spart array.
 *
 * @return The number of particles linked.
 */
int cell_link_sparts(struct cell *c, struct spart *sparts) {

  c->sparts = sparts;

  /* Fill the progeny recursively, depth-first. */
  if (c->split) {
    int offset = 0;
    for (int k = 0; k < 8; k++) {
      if (c->progeny[k] != NULL)
        offset += cell_link_sparts(c->progeny[k], &sparts[offset]);
    }
  }

  /* Return the total number of linked particles. */
  return c->scount;
}

162
163
164
165
166
167
168
169
170
/**
 * @brief Pack the data of the given cell and all it's sub-cells.
 *
 * @param c The #cell.
 * @param pc Pointer to an array of packed cells in which the
 *      cells will be packed.
 *
 * @return The number of packed cells.
 */
171
int cell_pack(struct cell *restrict c, struct pcell *restrict pc) {
172

173
174
#ifdef WITH_MPI

175
176
  /* Start by packing the data of the current cell. */
  pc->h_max = c->h_max;
177
178
179
180
  pc->ti_hydro_end_min = c->ti_hydro_end_min;
  pc->ti_hydro_end_max = c->ti_hydro_end_max;
  pc->ti_gravity_end_min = c->ti_gravity_end_min;
  pc->ti_gravity_end_max = c->ti_gravity_end_max;
181
182
  pc->ti_old_part = c->ti_old_part;
  pc->ti_old_gpart = c->ti_old_gpart;
183
  pc->ti_old_multipole = c->ti_old_multipole;
184
  pc->count = c->count;
185
  pc->gcount = c->gcount;
186
  pc->scount = c->scount;
187
  c->tag = pc->tag = atomic_inc(&cell_next_tag) % cell_max_tag;
188
189
190
#ifdef SWIFT_DEBUG_CHECKS
  pc->cellID = c->cellID;
#endif
191
192

  /* Fill in the progeny, depth-first recursion. */
Pedro Gonnet's avatar
Pedro Gonnet committed
193
194
  int count = 1;
  for (int k = 0; k < 8; k++)
195
196
197
198
199
200
201
    if (c->progeny[k] != NULL) {
      pc->progeny[k] = count;
      count += cell_pack(c->progeny[k], &pc[count]);
    } else
      pc->progeny[k] = -1;

  /* Return the number of packed cells used. */
202
203
  c->pcell_size = count;
  return count;
204
205
206
207
208

#else
  error("SWIFT was not compiled with MPI support.");
  return 0;
#endif
209
210
}

211
212
213
214
215
216
217
218
219
/**
 * @brief Unpack the data of a given cell and its sub-cells.
 *
 * @param pc An array of packed #pcell.
 * @param c The #cell in which to unpack the #pcell.
 * @param s The #space in which the cells are created.
 *
 * @return The number of cells created.
 */
Matthieu Schaller's avatar
Matthieu Schaller committed
220
221
int cell_unpack(struct pcell *restrict pc, struct cell *restrict c,
                struct space *restrict s) {
222
223
224
225
226

#ifdef WITH_MPI

  /* Unpack the current pcell. */
  c->h_max = pc->h_max;
227
228
229
230
  c->ti_hydro_end_min = pc->ti_hydro_end_min;
  c->ti_hydro_end_max = pc->ti_hydro_end_max;
  c->ti_gravity_end_min = pc->ti_gravity_end_min;
  c->ti_gravity_end_max = pc->ti_gravity_end_max;
231
232
  c->ti_old_part = pc->ti_old_part;
  c->ti_old_gpart = pc->ti_old_gpart;
233
  c->ti_old_multipole = pc->ti_old_multipole;
234
235
236
237
  c->count = pc->count;
  c->gcount = pc->gcount;
  c->scount = pc->scount;
  c->tag = pc->tag;
238
239
240
#ifdef SWIFT_DEBUG_CHECKS
  c->cellID = pc->cellID;
#endif
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

  /* Number of new cells created. */
  int count = 1;

  /* Fill the progeny recursively, depth-first. */
  for (int k = 0; k < 8; k++)
    if (pc->progeny[k] >= 0) {
      struct cell *temp;
      space_getcells(s, 1, &temp);
      temp->count = 0;
      temp->gcount = 0;
      temp->scount = 0;
      temp->loc[0] = c->loc[0];
      temp->loc[1] = c->loc[1];
      temp->loc[2] = c->loc[2];
      temp->width[0] = c->width[0] / 2;
      temp->width[1] = c->width[1] / 2;
      temp->width[2] = c->width[2] / 2;
      temp->dmin = c->dmin / 2;
      if (k & 4) temp->loc[0] += temp->width[0];
      if (k & 2) temp->loc[1] += temp->width[1];
      if (k & 1) temp->loc[2] += temp->width[2];
      temp->depth = c->depth + 1;
      temp->split = 0;
      temp->dx_max_part = 0.f;
      temp->dx_max_gpart = 0.f;
      temp->dx_max_sort = 0.f;
      temp->nodeID = c->nodeID;
      temp->parent = c;
      c->progeny[k] = temp;
      c->split = 1;
      count += cell_unpack(&pc[pc->progeny[k]], temp, s);
    }

  /* Return the total number of unpacked cells. */
  c->pcell_size = count;
  return count;

#else
  error("SWIFT was not compiled with MPI support.");
  return 0;
#endif
}

285
286
287
288
/**
 * @brief Pack the time information of the given cell and all it's sub-cells.
 *
 * @param c The #cell.
289
 * @param pcells (output) The end-of-timestep information we pack into
290
291
292
 *
 * @return The number of packed cells.
 */
Matthieu Schaller's avatar
Matthieu Schaller committed
293
294
int cell_pack_end_step(struct cell *restrict c,
                       struct pcell_step *restrict pcells) {
295

296
297
#ifdef WITH_MPI

298
  /* Pack this cell's data. */
299
  pcells[0].ti_hydro_end_min = c->ti_hydro_end_min;
300
  pcells[0].ti_hydro_end_max = c->ti_hydro_end_max;
301
  pcells[0].ti_gravity_end_min = c->ti_gravity_end_min;
302
  pcells[0].ti_gravity_end_max = c->ti_gravity_end_max;
303
304
  pcells[0].dx_max_part = c->dx_max_part;
  pcells[0].dx_max_gpart = c->dx_max_gpart;
305

306
307
308
309
  /* Fill in the progeny, depth-first recursion. */
  int count = 1;
  for (int k = 0; k < 8; k++)
    if (c->progeny[k] != NULL) {
310
      count += cell_pack_end_step(c->progeny[k], &pcells[count]);
311
312
313
314
    }

  /* Return the number of packed values. */
  return count;
315
316
317
318
319

#else
  error("SWIFT was not compiled with MPI support.");
  return 0;
#endif
320
321
}

322
323
324
325
/**
 * @brief Unpack the time information of a given cell and its sub-cells.
 *
 * @param c The #cell
326
 * @param pcells The end-of-timestep information to unpack
327
328
329
 *
 * @return The number of cells created.
 */
Matthieu Schaller's avatar
Matthieu Schaller committed
330
331
int cell_unpack_end_step(struct cell *restrict c,
                         struct pcell_step *restrict pcells) {
332

333
334
#ifdef WITH_MPI

335
  /* Unpack this cell's data. */
336
  c->ti_hydro_end_min = pcells[0].ti_hydro_end_min;
337
  c->ti_hydro_end_max = pcells[0].ti_hydro_end_max;
338
  c->ti_gravity_end_min = pcells[0].ti_gravity_end_min;
339
  c->ti_gravity_end_max = pcells[0].ti_gravity_end_max;
340
341
  c->dx_max_part = pcells[0].dx_max_part;
  c->dx_max_gpart = pcells[0].dx_max_gpart;
342

343
344
345
346
  /* Fill in the progeny, depth-first recursion. */
  int count = 1;
  for (int k = 0; k < 8; k++)
    if (c->progeny[k] != NULL) {
347
      count += cell_unpack_end_step(c->progeny[k], &pcells[count]);
348
349
350
    }

  /* Return the number of packed values. */
351
  return count;
352
353
354
355
356

#else
  error("SWIFT was not compiled with MPI support.");
  return 0;
#endif
357
}
358

359
/**
Matthieu Schaller's avatar
Matthieu Schaller committed
360
361
 * @brief Pack the multipole information of the given cell and all it's
 * sub-cells.
362
363
364
365
366
367
368
 *
 * @param c The #cell.
 * @param pcells (output) The multipole information we pack into
 *
 * @return The number of packed cells.
 */
int cell_pack_multipoles(struct cell *restrict c,
Matthieu Schaller's avatar
Matthieu Schaller committed
369
                         struct gravity_tensors *restrict pcells) {
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

#ifdef WITH_MPI

  /* Pack this cell's data. */
  pcells[0] = *c->multipole;

  /* Fill in the progeny, depth-first recursion. */
  int count = 1;
  for (int k = 0; k < 8; k++)
    if (c->progeny[k] != NULL) {
      count += cell_pack_multipoles(c->progeny[k], &pcells[count]);
    }

  /* Return the number of packed values. */
  return count;

#else
  error("SWIFT was not compiled with MPI support.");
  return 0;
#endif
}

/**
 * @brief Unpack the multipole information of a given cell and its sub-cells.
 *
 * @param c The #cell
 * @param pcells The multipole information to unpack
 *
 * @return The number of cells created.
 */
int cell_unpack_multipoles(struct cell *restrict c,
Matthieu Schaller's avatar
Matthieu Schaller committed
401
                           struct gravity_tensors *restrict pcells) {
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423

#ifdef WITH_MPI

  /* Unpack this cell's data. */
  *c->multipole = pcells[0];

  /* Fill in the progeny, depth-first recursion. */
  int count = 1;
  for (int k = 0; k < 8; k++)
    if (c->progeny[k] != NULL) {
      count += cell_unpack_multipoles(c->progeny[k], &pcells[count]);
    }

  /* Return the number of packed values. */
  return count;

#else
  error("SWIFT was not compiled with MPI support.");
  return 0;
#endif
}

424
/**
425
 * @brief Lock a cell for access to its array of #part and hold its parents.
426
427
 *
 * @param c The #cell.
428
 * @return 0 on success, 1 on failure
429
 */
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
int cell_locktree(struct cell *c) {

  TIMER_TIC

  /* First of all, try to lock this cell. */
  if (c->hold || lock_trylock(&c->lock) != 0) {
    TIMER_TOC(timer_locktree);
    return 1;
  }

  /* Did somebody hold this cell in the meantime? */
  if (c->hold) {

    /* Unlock this cell. */
    if (lock_unlock(&c->lock) != 0) error("Failed to unlock cell.");

    /* Admit defeat. */
    TIMER_TOC(timer_locktree);
    return 1;
  }

  /* Climb up the tree and lock/hold/unlock. */
Pedro Gonnet's avatar
Pedro Gonnet committed
452
  struct cell *finger;
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
  for (finger = c->parent; finger != NULL; finger = finger->parent) {

    /* Lock this cell. */
    if (lock_trylock(&finger->lock) != 0) break;

    /* Increment the hold. */
    atomic_inc(&finger->hold);

    /* Unlock the cell. */
    if (lock_unlock(&finger->lock) != 0) error("Failed to unlock cell.");
  }

  /* If we reached the top of the tree, we're done. */
  if (finger == NULL) {
    TIMER_TOC(timer_locktree);
    return 0;
  }

  /* Otherwise, we hit a snag. */
  else {

    /* Undo the holds up to finger. */
Pedro Gonnet's avatar
Pedro Gonnet committed
475
476
    for (struct cell *finger2 = c->parent; finger2 != finger;
         finger2 = finger2->parent)
477
      atomic_dec(&finger2->hold);
478
479
480
481
482
483
484
485
486
487

    /* Unlock this cell. */
    if (lock_unlock(&c->lock) != 0) error("Failed to unlock cell.");

    /* Admit defeat. */
    TIMER_TOC(timer_locktree);
    return 1;
  }
}

488
489
490
491
492
493
/**
 * @brief Lock a cell for access to its array of #gpart and hold its parents.
 *
 * @param c The #cell.
 * @return 0 on success, 1 on failure
 */
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
int cell_glocktree(struct cell *c) {

  TIMER_TIC

  /* First of all, try to lock this cell. */
  if (c->ghold || lock_trylock(&c->glock) != 0) {
    TIMER_TOC(timer_locktree);
    return 1;
  }

  /* Did somebody hold this cell in the meantime? */
  if (c->ghold) {

    /* Unlock this cell. */
    if (lock_unlock(&c->glock) != 0) error("Failed to unlock cell.");

    /* Admit defeat. */
    TIMER_TOC(timer_locktree);
    return 1;
  }

  /* Climb up the tree and lock/hold/unlock. */
Pedro Gonnet's avatar
Pedro Gonnet committed
516
  struct cell *finger;
517
518
519
520
521
522
  for (finger = c->parent; finger != NULL; finger = finger->parent) {

    /* Lock this cell. */
    if (lock_trylock(&finger->glock) != 0) break;

    /* Increment the hold. */
523
    atomic_inc(&finger->ghold);
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538

    /* Unlock the cell. */
    if (lock_unlock(&finger->glock) != 0) error("Failed to unlock cell.");
  }

  /* If we reached the top of the tree, we're done. */
  if (finger == NULL) {
    TIMER_TOC(timer_locktree);
    return 0;
  }

  /* Otherwise, we hit a snag. */
  else {

    /* Undo the holds up to finger. */
Pedro Gonnet's avatar
Pedro Gonnet committed
539
540
    for (struct cell *finger2 = c->parent; finger2 != finger;
         finger2 = finger2->parent)
541
      atomic_dec(&finger2->ghold);
542
543
544
545
546
547
548
549
550

    /* Unlock this cell. */
    if (lock_unlock(&c->glock) != 0) error("Failed to unlock cell.");

    /* Admit defeat. */
    TIMER_TOC(timer_locktree);
    return 1;
  }
}
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
/**
 * @brief Lock a cell for access to its #multipole and hold its parents.
 *
 * @param c The #cell.
 * @return 0 on success, 1 on failure
 */
int cell_mlocktree(struct cell *c) {

  TIMER_TIC

  /* First of all, try to lock this cell. */
  if (c->mhold || lock_trylock(&c->mlock) != 0) {
    TIMER_TOC(timer_locktree);
    return 1;
  }

  /* Did somebody hold this cell in the meantime? */
  if (c->mhold) {

    /* Unlock this cell. */
    if (lock_unlock(&c->mlock) != 0) error("Failed to unlock cell.");

    /* Admit defeat. */
    TIMER_TOC(timer_locktree);
    return 1;
  }

  /* Climb up the tree and lock/hold/unlock. */
  struct cell *finger;
  for (finger = c->parent; finger != NULL; finger = finger->parent) {

    /* Lock this cell. */
    if (lock_trylock(&finger->mlock) != 0) break;

    /* Increment the hold. */
    atomic_inc(&finger->mhold);

    /* Unlock the cell. */
    if (lock_unlock(&finger->mlock) != 0) error("Failed to unlock cell.");
  }

  /* If we reached the top of the tree, we're done. */
  if (finger == NULL) {
    TIMER_TOC(timer_locktree);
    return 0;
  }

  /* Otherwise, we hit a snag. */
  else {

    /* Undo the holds up to finger. */
    for (struct cell *finger2 = c->parent; finger2 != finger;
         finger2 = finger2->parent)
      atomic_dec(&finger2->mhold);

    /* Unlock this cell. */
    if (lock_unlock(&c->mlock) != 0) error("Failed to unlock cell.");

    /* Admit defeat. */
    TIMER_TOC(timer_locktree);
    return 1;
  }
}

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
/**
 * @brief Lock a cell for access to its array of #spart and hold its parents.
 *
 * @param c The #cell.
 * @return 0 on success, 1 on failure
 */
int cell_slocktree(struct cell *c) {

  TIMER_TIC

  /* First of all, try to lock this cell. */
  if (c->shold || lock_trylock(&c->slock) != 0) {
    TIMER_TOC(timer_locktree);
    return 1;
  }

  /* Did somebody hold this cell in the meantime? */
  if (c->shold) {

    /* Unlock this cell. */
    if (lock_unlock(&c->slock) != 0) error("Failed to unlock cell.");

    /* Admit defeat. */
    TIMER_TOC(timer_locktree);
    return 1;
  }

  /* Climb up the tree and lock/hold/unlock. */
  struct cell *finger;
  for (finger = c->parent; finger != NULL; finger = finger->parent) {

    /* Lock this cell. */
    if (lock_trylock(&finger->slock) != 0) break;

    /* Increment the hold. */
    atomic_inc(&finger->shold);

    /* Unlock the cell. */
    if (lock_unlock(&finger->slock) != 0) error("Failed to unlock cell.");
  }

  /* If we reached the top of the tree, we're done. */
  if (finger == NULL) {
    TIMER_TOC(timer_locktree);
    return 0;
  }

  /* Otherwise, we hit a snag. */
  else {

    /* Undo the holds up to finger. */
    for (struct cell *finger2 = c->parent; finger2 != finger;
         finger2 = finger2->parent)
      atomic_dec(&finger2->shold);

    /* Unlock this cell. */
    if (lock_unlock(&c->slock) != 0) error("Failed to unlock cell.");

    /* Admit defeat. */
    TIMER_TOC(timer_locktree);
    return 1;
  }
}

680
/**
681
 * @brief Unlock a cell's parents for access to #part array.
682
683
684
 *
 * @param c The #cell.
 */
685
686
687
688
689
690
691
692
void cell_unlocktree(struct cell *c) {

  TIMER_TIC

  /* First of all, try to unlock this cell. */
  if (lock_unlock(&c->lock) != 0) error("Failed to unlock cell.");

  /* Climb up the tree and unhold the parents. */
Pedro Gonnet's avatar
Pedro Gonnet committed
693
  for (struct cell *finger = c->parent; finger != NULL; finger = finger->parent)
694
    atomic_dec(&finger->hold);
695
696
697
698

  TIMER_TOC(timer_locktree);
}

699
700
701
702
703
/**
 * @brief Unlock a cell's parents for access to #gpart array.
 *
 * @param c The #cell.
 */
704
705
706
707
708
709
710
711
void cell_gunlocktree(struct cell *c) {

  TIMER_TIC

  /* First of all, try to unlock this cell. */
  if (lock_unlock(&c->glock) != 0) error("Failed to unlock cell.");

  /* Climb up the tree and unhold the parents. */
Pedro Gonnet's avatar
Pedro Gonnet committed
712
  for (struct cell *finger = c->parent; finger != NULL; finger = finger->parent)
713
    atomic_dec(&finger->ghold);
714
715
716
717

  TIMER_TOC(timer_locktree);
}

718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
/**
 * @brief Unlock a cell's parents for access to its #multipole.
 *
 * @param c The #cell.
 */
void cell_munlocktree(struct cell *c) {

  TIMER_TIC

  /* First of all, try to unlock this cell. */
  if (lock_unlock(&c->mlock) != 0) error("Failed to unlock cell.");

  /* Climb up the tree and unhold the parents. */
  for (struct cell *finger = c->parent; finger != NULL; finger = finger->parent)
    atomic_dec(&finger->mhold);

  TIMER_TOC(timer_locktree);
}

737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
/**
 * @brief Unlock a cell's parents for access to #spart array.
 *
 * @param c The #cell.
 */
void cell_sunlocktree(struct cell *c) {

  TIMER_TIC

  /* First of all, try to unlock this cell. */
  if (lock_unlock(&c->slock) != 0) error("Failed to unlock cell.");

  /* Climb up the tree and unhold the parents. */
  for (struct cell *finger = c->parent; finger != NULL; finger = finger->parent)
    atomic_dec(&finger->shold);

  TIMER_TOC(timer_locktree);
}

756
/**
757
758
759
760
 * @brief Sort the part buffers into eight bins along the given pivots.
 *
 * Assumes the #cell has all its progeny and sets the parts and counts
 * in each sub-cell.
761
762
 *
 * @param c The #cell array to be sorted.
763
764
 * @param buff A buffer with at least max(c->count, c->gcount) entries,
 *        used for sorting indices.
765
766
 * @param sbuff A buffer with at least max(c->scount, c->gcount) entries,
 *        used for sorting indices for the sparts.
Peter W. Draper's avatar
Peter W. Draper committed
767
768
 * @param gbuff A buffer with at least max(c->count, c->gcount) entries,
 *        used for sorting indices for the gparts.
769
 */
770
void cell_split(struct cell *c, struct cell_buff *buff, struct cell_buff *sbuff,
771
                struct cell_buff *gbuff) {
772

773
  const int count = c->count, gcount = c->gcount, scount = c->scount;
774
775
776
777
778
779
780
781
  const double pivot[3] = {c->loc[0] + c->width[0] / 2,
                           c->loc[1] + c->width[1] / 2,
                           c->loc[2] + c->width[2] / 2};
  int bucket_count[8] = {0, 0, 0, 0, 0, 0, 0, 0};
  int bucket_offset[9];

  /* Fill the buffer with the indices. */
  for (int k = 0; k < count; k++) {
782
783
    const int bid = (buff[k].x[0] >= pivot[0]) * 4 +
                    (buff[k].x[1] >= pivot[1]) * 2 + (buff[k].x[2] >= pivot[2]);
784
    bucket_count[bid]++;
Matthieu Schaller's avatar
Matthieu Schaller committed
785
    buff[k].ind = bid;
786
  }
787

788
789
790
791
792
  /* Set the buffer offsets. */
  bucket_offset[0] = 0;
  for (int k = 1; k <= 8; k++) {
    bucket_offset[k] = bucket_offset[k - 1] + bucket_count[k - 1];
    bucket_count[k - 1] = 0;
793
794
  }

795
796
797
798
  /* Run through the buckets, and swap particles to their correct spot. */
  for (int bucket = 0; bucket < 8; bucket++) {
    for (int k = bucket_offset[bucket] + bucket_count[bucket];
         k < bucket_offset[bucket + 1]; k++) {
Matthieu Schaller's avatar
Matthieu Schaller committed
799
      int bid = buff[k].ind;
800
      if (bid != bucket) {
801
        struct cell_buff temp_buff = buff[k];
802
803
        while (bid != bucket) {
          int j = bucket_offset[bid] + bucket_count[bid]++;
Matthieu Schaller's avatar
Matthieu Schaller committed
804
          while (buff[j].ind == bid) {
805
806
807
            j++;
            bucket_count[bid]++;
          }
808
809
          memswap(&buff[j], &temp_buff, sizeof(struct cell_buff));
          bid = temp_buff.ind;
810
        }
811
        buff[k] = temp_buff;
812
      }
813
      bucket_count[bid]++;
814
815
816
817
    }
  }

  /* Store the counts and offsets. */
Pedro Gonnet's avatar
Pedro Gonnet committed
818
  for (int k = 0; k < 8; k++) {
819
820
821
    c->progeny[k]->count = bucket_count[k];
    c->progeny[k]->parts = &c->parts[bucket_offset[k]];
    c->progeny[k]->xparts = &c->xparts[bucket_offset[k]];
822
823
  }

824
#ifdef SWIFT_DEBUG_CHECKS
825
826
827
828
829
  /* Check that the buffs are OK. */
  for (int k = 1; k < count; k++) {
    if (buff[k].ind < buff[k - 1].ind) error("Buff not sorted.");
  }

830
  /* Verify that _all_ the parts have been assigned to a cell. */
831
832
833
834
835
836
837
838
  for (int k = 1; k < 8; k++)
    if (&c->progeny[k - 1]->parts[c->progeny[k - 1]->count] !=
        c->progeny[k]->parts)
      error("Particle sorting failed (internal consistency).");
  if (c->progeny[0]->parts != c->parts)
    error("Particle sorting failed (left edge).");
  if (&c->progeny[7]->parts[c->progeny[7]->count] != &c->parts[count])
    error("Particle sorting failed (right edge).");
839
840

  /* Verify a few sub-cells. */
841
  for (int k = 0; k < c->progeny[0]->count; k++)
842
843
    if (buff[k].x[0] >= pivot[0] || buff[k].x[1] >= pivot[1] ||
        buff[k].x[2] >= pivot[2])
844
      error("Sorting failed (progeny=0).");
845
846
847
  for (int k = bucket_offset[1]; k < bucket_offset[2]; k++)
    if (buff[k].x[0] >= pivot[0] || buff[k].x[1] >= pivot[1] ||
        buff[k].x[2] < pivot[2])
848
      error("Sorting failed (progeny=1).");
849
850
851
  for (int k = bucket_offset[2]; k < bucket_offset[3]; k++)
    if (buff[k].x[0] >= pivot[0] || buff[k].x[1] < pivot[1] ||
        buff[k].x[2] >= pivot[2])
852
      error("Sorting failed (progeny=2).");
853
854
855
  for (int k = bucket_offset[3]; k < bucket_offset[4]; k++)
    if (buff[k].x[0] >= pivot[0] || buff[k].x[1] < pivot[1] ||
        buff[k].x[2] < pivot[2])
856
      error("Sorting failed (progeny=3).");
857
858
859
  for (int k = bucket_offset[4]; k < bucket_offset[5]; k++)
    if (buff[k].x[0] < pivot[0] || buff[k].x[1] >= pivot[1] ||
        buff[k].x[2] >= pivot[2])
860
      error("Sorting failed (progeny=4).");
861
862
863
  for (int k = bucket_offset[5]; k < bucket_offset[6]; k++)
    if (buff[k].x[0] < pivot[0] || buff[k].x[1] >= pivot[1] ||
        buff[k].x[2] < pivot[2])
864
      error("Sorting failed (progeny=5).");
865
866
867
  for (int k = bucket_offset[6]; k < bucket_offset[7]; k++)
    if (buff[k].x[0] < pivot[0] || buff[k].x[1] < pivot[1] ||
        buff[k].x[2] >= pivot[2])
868
      error("Sorting failed (progeny=6).");
869
870
871
  for (int k = bucket_offset[7]; k < c->count; k++)
    if (buff[k].x[0] < pivot[0] || buff[k].x[1] < pivot[1] ||
        buff[k].x[2] < pivot[2])
872
      error("Sorting failed (progeny=7).");
873
#endif
874

875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
  /* Now do the same song and dance for the sparts. */
  for (int k = 0; k < 8; k++) bucket_count[k] = 0;

  /* Fill the buffer with the indices. */
  for (int k = 0; k < scount; k++) {
    const int bid = (sbuff[k].x[0] > pivot[0]) * 4 +
                    (sbuff[k].x[1] > pivot[1]) * 2 + (sbuff[k].x[2] > pivot[2]);
    bucket_count[bid]++;
    sbuff[k].ind = bid;
  }

  /* Set the buffer offsets. */
  bucket_offset[0] = 0;
  for (int k = 1; k <= 8; k++) {
    bucket_offset[k] = bucket_offset[k - 1] + bucket_count[k - 1];
    bucket_count[k - 1] = 0;
  }

  /* Run through the buckets, and swap particles to their correct spot. */
  for (int bucket = 0; bucket < 8; bucket++) {
    for (int k = bucket_offset[bucket] + bucket_count[bucket];
         k < bucket_offset[bucket + 1]; k++) {
      int bid = sbuff[k].ind;
      if (bid != bucket) {
        struct cell_buff temp_buff = sbuff[k];
        while (bid != bucket) {
          int j = bucket_offset[bid] + bucket_count[bid]++;
          while (sbuff[j].ind == bid) {
            j++;
            bucket_count[bid]++;
          }
          memswap(&sbuff[j], &temp_buff, sizeof(struct cell_buff));
          bid = temp_buff.ind;
        }
        sbuff[k] = temp_buff;
      }
      bucket_count[bid]++;
    }
  }

  /* Store the counts and offsets. */
  for (int k = 0; k < 8; k++) {
    c->progeny[k]->scount = bucket_count[k];
    c->progeny[k]->sparts = &c->sparts[bucket_offset[k]];
  }

  /* Finally, do the same song and dance for the gparts. */
922
923
924
925
  for (int k = 0; k < 8; k++) bucket_count[k] = 0;

  /* Fill the buffer with the indices. */
  for (int k = 0; k < gcount; k++) {
926
927
    const int bid = (gbuff[k].x[0] > pivot[0]) * 4 +
                    (gbuff[k].x[1] > pivot[1]) * 2 + (gbuff[k].x[2] > pivot[2]);
928
    bucket_count[bid]++;
929
    gbuff[k].ind = bid;
930
  }
931
932
933
934
935
936

  /* Set the buffer offsets. */
  bucket_offset[0] = 0;
  for (int k = 1; k <= 8; k++) {
    bucket_offset[k] = bucket_offset[k - 1] + bucket_count[k - 1];
    bucket_count[k - 1] = 0;
937
938
  }

939
940
941
942
  /* Run through the buckets, and swap particles to their correct spot. */
  for (int bucket = 0; bucket < 8; bucket++) {
    for (int k = bucket_offset[bucket] + bucket_count[bucket];
         k < bucket_offset[bucket + 1]; k++) {
943
      int bid = gbuff[k].ind;
944
      if (bid != bucket) {
945
        struct cell_buff temp_buff = gbuff[k];
946
947
        while (bid != bucket) {
          int j = bucket_offset[bid] + bucket_count[bid]++;
948
          while (gbuff[j].ind == bid) {
949
950
951
            j++;
            bucket_count[bid]++;
          }
952
953
          memswap(&gbuff[j], &temp_buff, sizeof(struct cell_buff));
          bid = temp_buff.ind;
954
        }
955
        gbuff[k] = temp_buff;
956
      }
957
      bucket_count[bid]++;
958
959
960
961
    }
  }

  /* Store the counts and offsets. */
Pedro Gonnet's avatar
Pedro Gonnet committed
962
  for (int k = 0; k < 8; k++) {
963
964
    c->progeny[k]->gcount = bucket_count[k];
    c->progeny[k]->gparts = &c->gparts[bucket_offset[k]];
965
966
  }
}
967

968
969
970
971
/**
 * @brief Sanitizes the smoothing length values of cells by setting large
 * outliers to more sensible values.
 *
972
973
 * Each cell with <1000 part will be processed. We limit h to be the size of
 * the cell and replace 0s with a good estimate.
974
975
 *
 * @param c The cell.
976
 * @param treated Has the cell already been sanitized at this level ?
977
 */
978
void cell_sanitize(struct cell *c, int treated) {
979
980
981

  const int count = c->count;
  struct part *parts = c->parts;
982
  float h_max = 0.f;
983

984
985
  /* Treat cells will <1000 particles */
  if (count < 1000 && !treated) {
986

987
988
    /* Get an upper bound on h */
    const float upper_h_max = c->dmin / (1.2f * kernel_gamma);
989

990
991
992
993
994
995
    /* Apply it */
    for (int i = 0; i < count; ++i) {
      if (parts[i].h == 0.f || parts[i].h > upper_h_max)
        parts[i].h = upper_h_max;
    }
  }
996

997
998
  /* Recurse and gather the new h_max values */
  if (c->split) {
999

1000
1001
    for (int k = 0; k < 8; ++k) {
      if (c->progeny[k] != NULL) {
1002

1003
1004
        /* Recurse */
        cell_sanitize(c->progeny[k], (count < 1000));
1005

1006
1007
1008
1009
        /* And collect */
        h_max = max(h_max, c->progeny[k]->h_max);
      }
    }
1010
1011
  } else {

1012
1013
    /* Get the new value of h_max */
    for (int i = 0; i < count; ++i) h_max = max(h_max, parts[i].h);
1014
  }
1015
1016
1017

  /* Record the change */
  c->h_max = h_max;
1018
1019
}

1020
/**
1021
 * @brief Converts hydro quantities to a valid state after the initial density
1022
 * calculation
1023
1024
1025
1026
1027
1028
1029
 *
 * @param c Cell to act upon
 * @param data Unused parameter
 */
void cell_convert_hydro(struct cell *c, void *data) {

  struct part *p = c->parts;
1030
  struct xpart *xp = c->xparts;
1031
1032

  for (int i = 0; i < c->count; ++i) {
1033
    hydro_convert_quantities(&p[i], &xp[i]);
1034
1035
1036
  }
}

Matthieu Schaller's avatar
Matthieu Schaller committed
1037
1038
1039
1040
1041
1042
/**
 * @brief Cleans the links in a given cell.
 *
 * @param c Cell to act upon
 * @param data Unused parameter
 */
1043
void cell_clean_links(struct cell *c, void *data) {
Matthieu Schaller's avatar
Matthieu Schaller committed
1044
  c->density = NULL;
1045
  c->gradient = NULL;
Matthieu Schaller's avatar
Matthieu Schaller committed
1046
  c->force = NULL;
1047
  c->grav = NULL;
Matthieu Schaller's avatar
Matthieu Schaller committed
1048
}
1049

1050
/**
1051
 * @brief Checks that the #part in a cell are at the
1052
 * current point in time
1053
1054
1055
1056
1057
1058
 *
 * Calls error() if the cell is not at the current time.
 *
 * @param c Cell to act upon
 * @param data The current time on the integer time-line
 */
1059
void cell_check_part_drift_point(struct cell *c, void *data) {
1060

1061
1062
#ifdef SWIFT_DEBUG_CHECKS

1063
  const integertime_t ti_drift = *(integertime_t *)data;
1064

1065
  /* Only check local cells */
1066
  if (c->nodeID != engine_rank) return;
1067

1068
1069
1070
  if (c->ti_old_part != ti_drift)
    error("Cell in an incorrect time-zone! c->ti_old_part=%lld ti_drift=%lld",
          c->ti_old_part, ti_drift);
1071

1072
1073
  for (int i = 0; i < c->count; ++i)
    if (c->parts[i].ti_drift != ti_drift)
1074
      error("part in an incorrect time-zone! p->ti_drift=%lld ti_drift=%lld",
1075
            c->parts[i].ti_drift, ti_drift);
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
#else
  error("Calling debugging code without debugging flag activated.");
#endif
}

/**
 * @brief Checks that the #gpart and #spart in a cell are at the
 * current point in time
 *
 * Calls error() if the cell is not at the current time.
 *
 * @param c Cell to act upon
 * @param data The current time on the integer time-line
 */
void cell_check_gpart_drift_point(struct cell *c, void *data) {

#ifdef SWIFT_DEBUG_CHECKS

  const integertime_t ti_drift = *(integertime_t *)data;

  /* Only check local cells */
  if (c->nodeID != engine_rank) return;

  if (c->ti_old_gpart != ti_drift)
    error("Cell in an incorrect time-zone! c->ti_old_gpart=%lld ti_drift=%lld",
          c->ti_old_gpart, ti_drift);
1102

1103
1104
  for (int i = 0; i < c->gcount; ++i)
    if (c->gparts[i].ti_drift != ti_drift)
1105
      error("g-part in an incorrect time-zone! gp->ti_drift=%lld ti_drift=%lld",
1106
            c->gparts[i].ti_drift, ti_drift);
1107

1108
1109
1110
1111
  for (int i = 0; i < c->scount; ++i)
    if (c->sparts[i].ti_drift != ti_drift)
      error("s-part in an incorrect time-zone! sp->ti_drift=%lld ti_drift=%lld",
            c->sparts[i].ti_drift, ti_drift);
1112
1113
1114
#else
  error("Calling debugging code without debugging flag activated.");
#endif
1115
1116
}

1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
/**
 * @brief Checks that the multipole of a cell is at the current point in time
 *
 * Calls error() if the cell is not at the current time.
 *
 * @param c Cell to act upon
 * @param data The current time on the integer time-line
 */
void cell_check_multipole_drift_point(struct cell *c, void *data) {

#ifdef SWIFT_DEBUG_CHECKS

  const integertime_t ti_drift = *(integertime_t *)data;

  if (c->ti_old_multipole != ti_drift)
    error(
        "Cell multipole in an incorrect time-zone! c->ti_old_multipole=%lld "
1134
1135
        "ti_drift=%lld (depth=%d)",
        c->ti_old_multipole, ti_drift, c->depth);
1136
1137
1138
1139
1140
1141

#else
  error("Calling debugging code without debugging flag activated.");
#endif
}

1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
/**
 * @brief Resets all the individual cell task counters to 0.
 *
 * Should only be used for debugging purposes.
 *
 * @param c The #cell to reset.
 */
void cell_reset_task_counters(struct cell *c) {

#ifdef SWIFT_DEBUG_CHECKS
  for (int t = 0; t < task_type_count; ++t) c->tasks_executed[t] = 0;
  for (int t = 0; t < task_subtype_count; ++t) c->subtasks_executed[t] = 0;
#else
  error("Calling debugging code without debugging flag activated.");
#endif
}

1159
1160
1161
1162
/**
 * @brief Recursively construct all the multipoles in a cell hierarchy.
 *
 * @param c The #cell.
Matthieu Schaller's avatar
Matthieu Schaller committed
1163
 * @param ti_current The current integer time.
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
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
 */
void cell_make_multipoles(struct cell *c, integertime_t ti_current) {

  /* Reset everything */
  gravity_reset(c->multipole);

  if (c->split) {

    /* Compute CoM of all progenies */
    double CoM[3] = {0., 0., 0.};
    double mass = 0.;

    for (int k = 0; k < 8; ++k) {
      if (c->progeny[k] != NULL) {
        const struct gravity_tensors *m = c->progeny[k]->multipole;
        CoM[0] += m->CoM[0] * m->m_pole.M_000;
        CoM[1] += m->CoM[1] * m->m_pole.M_000;
        CoM[2] += m->CoM[2] * m->m_pole.M_000;
        mass += m->m_pole.M_000;
      }
    }
    c->multipole->CoM[0] = CoM[0] / mass;
    c->multipole->CoM[1] = CoM[1] / mass;
    c->multipole->CoM[2] = CoM[2] / mass;

    /* Now shift progeny multipoles and add them up */
    struct multipole temp;
    double r_max = 0.;
    for (int k = 0; k < 8; ++k) {
      if (c->progeny[k] != NULL) {
        const struct cell *cp = c->progeny[k];
        const struct multipole *m = &cp->multipole->m_pole;

        /* Contribution to multipole */
        gravity_M2M(&temp, m, c->multipole->CoM, cp->multipole->CoM);
        gravity_multipole_add(&c->multipole->m_pole, &temp);

        /* Upper limit of max CoM<->gpart distance */
        const double dx = c->multipole->CoM[0] - cp->multipole->CoM[0];
        const double dy = c->multipole->CoM[1] - cp->multipole->CoM[1];
        const double dz = c->multipole->CoM[2] - cp->multipole->CoM[2];
        const double r2 = dx * dx + dy * dy + dz * dz;
        r_max = max(r_max, cp->multipole->r_max + sqrt(r2));
      }
    }
    /* Alternative upper limit of max CoM<->gpart distance */
    const double dx = c->multipole->CoM[0] > c->loc[0] + c->width[0] / 2.
                          ? c->multipole->CoM[0] - c->loc[0]
                          : c->loc[0] + c->width[0] - c->multipole->CoM[0];
    const double dy = c->multipole->CoM[1] > c->loc[1] + c->width[1] / 2.
                          ? c->multipole->CoM[1] - c->loc[1]
                          : c->loc[1] + c->width[1] - c->multipole->CoM[1];
    const double dz = c->multipole->CoM[2] > c->loc[2] + c->width[2] / 2.
                          ? c->multipole->CoM[2] - c->loc[2]
                          : c->loc[2] + c->width[2] - c->multipole->CoM[2];

    /* Take minimum of both limits */
    c->multipole->r_max = min(r_max, sqrt(dx * dx + dy * dy + dz * dz));

  } else {

    if (c->gcount > 0) {
      gravity_P2M(c->multipole, c->gparts, c->gcount);
      const double dx = c->multipole->CoM[0] > c->loc[0] + c->width[0] / 2.
                            ? c->multipole->CoM[0] - c->loc[0]
                            : c->loc[0] + c->width[0] - c->multipole->CoM[0];
      const double dy = c->multipole->CoM[1] > c->loc[1] + c->width[1] / 2.
                            ? c->multipole->CoM[1] - c->loc[1]
                            : c->loc[1] + c->width[1] - c->multipole->CoM[1];
      const double dz = c->multipole->CoM[2] > c->loc[2] + c->width[2] / 2.
                            ? c->multipole->CoM[2] - c->loc[2]
                            : c->loc[2] + c->width[2] - c->multipole->CoM[2];
      c->multipole->r_max = sqrt(dx * dx + dy * dy + dz * dz);
    } else {
      gravity_multipole_init(&c->multipole->m_pole);
      c->multipole->CoM[0] = c->loc[0] + c->width[0] / 2.;
      c->multipole->CoM[1] = c->loc[1] + c->width[1] / 2.;
      c->multipole->CoM[2] = c->loc[2] + c->width[2] / 2.;
      c->multipole->r_max = 0.;
    }
  }

  c->ti_old_multipole = ti_current;
}

1249
1250
1251
1252
1253
1254
1255
1256
1257
/**
 * @brief Computes the multi-pole brutally and compare to the
 * recursively computed one.
 *
 * @param c Cell to act upon
 * @param data Unused parameter
 */
void cell_check_multipole(struct cell *c, void *data) {

1258
#ifdef SWIFT_DEBUG_CHECKS
1259
  struct gravity_tensors ma;
1260
  const double tolerance = 1e-3; /* Relative */
1261

1262
1263
  return;

1264
1265
1266
1267
  /* First recurse */
  if (c->split)
    for (int k = 0; k < 8; k++)
      if (c->progeny[k] != NULL) cell_check_multipole(c->progeny[k], NULL);
1268
1269
1270
1271

  if (c->gcount > 0) {

    /* Brute-force calculation */
1272
    gravity_P2M(&ma, c->gparts, c->gcount);
1273
1274

    /* Now  compare the multipole expansion */
1275
    if (!gravity_multipole_equal(&ma, c->multipole, tolerance)) {
Matthieu Schaller's avatar
Matthieu Schaller committed
1276
1277
      message("Multipoles are not equal at depth=%d! tol=%f", c->depth,
              tolerance);
1278
      message("Correct answer:");
1279
      gravity_multipole_print(&ma.m_pole);
1280
      message("Recursive multipole:");
1281
      gravity_multipole_print(&c->multipole->m_pole);
1282
1283
      error("Aborting");
    }
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293

    /* Check that the upper limit of r_max is good enough */
    if (!(c->multipole->r_max >= ma.r_max)) {
      error("Upper-limit r_max=%e too small. Should be >=%e.",
            c->multipole->r_max, ma.r_max);
    } else if (c->multipole->r_max * c->multipole->r_max >
               3. * c->width[0] * c->width[0]) {
      error("r_max=%e larger than cell diagonal %e.", c->multipole->r_max,
            sqrt(3. * c->width[0] * c->width[0]));
    }
1294
  }
1295
1296
1297
#else
  error("Calling debugging code without debugging flag activated.");
#endif
1298
1299
}

1300
/**