aboutsummaryrefslogtreecommitdiffstats
path: root/erts/emulator/beam/erl_goodfit_alloc.c
blob: 264561a96501ae1fbc22f9416eabbaa77d6eb4b0 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
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
88
89
90
91
92
93
94
95
96
97
98
99
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
135
136
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
162
163
164
165
166
167
168
169
170
171
172
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
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
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
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
/*
 * %CopyrightBegin%
 *
 * Copyright Ericsson AB 2003-2011. All Rights Reserved.
 *
 * The contents of this file are subject to the Erlang Public License,
 * Version 1.1, (the "License"); you may not use this file except in
 * compliance with the License. You should have received a copy of the
 * Erlang Public License along with this software. If not, it can be
 * retrieved online at http://www.erlang.org/.
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 * the License for the specific language governing rights and limitations
 * under the License.
 *
 * %CopyrightEnd%
 */


/*
 * Description:	A "good fit" allocator. Segregated free-lists with a
 *              maximum search depth are used in order to find a good
 *              fit fast. Each free-list contains blocks of sizes in a
 *              specific range. First the free-list
 *              covering the desired size is searched if it is not empty.
 *              This search is stopped when the maximum search depth has
 *              been reached. If no free block was found in the free-list
 *              covering the desired size, the next non-empty free-list
 *              covering larger sizes is searched. The maximum search
 *              depth is by default 3. The insert and delete operations
 *              are O(1) and the search operation is O(n) where n is the
 *              maximum search depth, i.e. by default the all operations
 *              are O(1).
 *
 *              This module is a callback-module for erl_alloc_util.c
 *
 * Author: 	Rickard Green
 */

#ifdef HAVE_CONFIG_H
#  include "config.h"
#endif
#include "global.h"
#define GET_ERL_GF_ALLOC_IMPL
#include "erl_goodfit_alloc.h"

#define MIN_MBC_SZ			(16*1024)
#define MIN_MBC_FIRST_FREE_SZ		(4*1024)

#define MAX_SUB_MASK_IX \
  ((((UWord)1) << (NO_OF_BKT_IX_BITS - SUB_MASK_IX_SHIFT)) - 1)
#define MAX_SUB_BKT_IX ((((UWord)1) << SUB_MASK_IX_SHIFT) - 1)
#define MAX_BKT_IX (NO_OF_BKTS - 1)

#define MIN_BLK_SZ  UNIT_CEILING(sizeof(GFFreeBlock_t) + sizeof(UWord))

#define IX2SBIX(IX) ((IX) & (~(~((UWord)0) << SUB_MASK_IX_SHIFT)))
#define IX2SMIX(IX) ((IX) >> SUB_MASK_IX_SHIFT)
#define MAKE_BKT_IX(SMIX, SBIX)	\
  ((((UWord)(SMIX)) << SUB_MASK_IX_SHIFT) | ((UWord)(SBIX)))

#define SET_BKT_MASK_IX(BM, IX)						\
do {									\
    int sub_mask_ix__ = IX2SMIX((IX));					\
    (BM).main |= (((UWord) 1) << sub_mask_ix__);				\
    (BM).sub[sub_mask_ix__] |= (((UWord)1) << IX2SBIX((IX)));		\
} while (0)

#define UNSET_BKT_MASK_IX(BM, IX)					\
do {									\
    int sub_mask_ix__ = IX2SMIX((IX));					\
    (BM).sub[sub_mask_ix__] &= ~(((UWord)1) << IX2SBIX((IX)));		\
    if (!(BM).sub[sub_mask_ix__])					\
	(BM).main &= ~(((UWord)1) << sub_mask_ix__);			\
} while (0)

/* Buckets ... */

#define BKT_INTRVL_A		(1*sizeof(Unit_t))
#define BKT_INTRVL_B		(16*sizeof(Unit_t))
#define BKT_INTRVL_C		(96*sizeof(Unit_t))

#define BKT_MIN_SIZE_A		MIN_BLK_SZ
#define BKT_MIN_SIZE_B		(BKT_MAX_SIZE_A + 1)
#define BKT_MIN_SIZE_C		(BKT_MAX_SIZE_B + 1)
#define BKT_MIN_SIZE_D		(BKT_MAX_SIZE_C + 1)

#define BKT_MAX_SIZE_A		((NO_OF_BKTS/4)*BKT_INTRVL_A+BKT_MIN_SIZE_A-1)
#define BKT_MAX_SIZE_B		((NO_OF_BKTS/4)*BKT_INTRVL_B+BKT_MIN_SIZE_B-1)
#define BKT_MAX_SIZE_C		((NO_OF_BKTS/4)*BKT_INTRVL_C+BKT_MIN_SIZE_C-1)


#define BKT_MAX_IX_A		((NO_OF_BKTS*1)/4 - 1)
#define BKT_MAX_IX_B		((NO_OF_BKTS*2)/4 - 1)
#define BKT_MAX_IX_C		((NO_OF_BKTS*3)/4 - 1)
#define BKT_MAX_IX_D		((NO_OF_BKTS*4)/4 - 1)

#define BKT_MIN_IX_A		(0)
#define BKT_MIN_IX_B		(BKT_MAX_IX_A + 1)
#define BKT_MIN_IX_C		(BKT_MAX_IX_B + 1)
#define BKT_MIN_IX_D		(BKT_MAX_IX_C + 1)


#define BKT_IX_(BAP, SZ)						\
  ((SZ) <= BKT_MAX_SIZE_A						\
   ? (((SZ) - BKT_MIN_SIZE_A)/BKT_INTRVL_A + BKT_MIN_IX_A)		\
   : ((SZ) <= BKT_MAX_SIZE_B						\
      ? (((SZ) - BKT_MIN_SIZE_B)/BKT_INTRVL_B + BKT_MIN_IX_B)		\
      : ((SZ) <= BKT_MAX_SIZE_C						\
	 ? (((SZ) - BKT_MIN_SIZE_C)/BKT_INTRVL_C + BKT_MIN_IX_C)	\
	 : ((SZ) <= (BAP)->bkt_max_size_d				\
	    ? (((SZ) - BKT_MIN_SIZE_D)/(BAP)->bkt_intrvl_d + BKT_MIN_IX_D)\
	    : (NO_OF_BKTS - 1)))))

#define BKT_MIN_SZ_(BAP, IX)						\
  ((IX) <= BKT_MAX_IX_A							\
   ? (((IX) - BKT_MIN_IX_A)*BKT_INTRVL_A + BKT_MIN_SIZE_A)		\
   : ((IX) <= BKT_MAX_IX_B						\
      ? (((IX) - BKT_MIN_IX_B)*BKT_INTRVL_B + BKT_MIN_SIZE_B)		\
      : ((IX) <= BKT_MAX_IX_C						\
	 ? (((IX) - BKT_MIN_IX_C)*BKT_INTRVL_C + BKT_MIN_SIZE_C)	\
	 : (((IX) - BKT_MIN_IX_D)*(BAP)->bkt_intrvl_d + BKT_MIN_SIZE_D))))

#ifdef DEBUG

static int
BKT_IX(GFAllctr_t *gfallctr, Uint size)
{
    int ix;
    ASSERT(size >= MIN_BLK_SZ);

    ix = BKT_IX_(gfallctr, size);

    ASSERT(0 <= ix && ix <= BKT_MAX_IX_D);

    return ix;
}

static Uint
BKT_MIN_SZ(GFAllctr_t *gfallctr, int ix)
{
    Uint size;
    ASSERT(0 <= ix && ix <= BKT_MAX_IX_D);

    size = BKT_MIN_SZ_(gfallctr, ix);

#ifdef ERTS_ALLOC_UTIL_HARD_DEBUG
    ASSERT(ix == BKT_IX(gfallctr, size));
    ASSERT(size == MIN_BLK_SZ || ix - 1 == BKT_IX(gfallctr, size - 1));
#endif

    return size;
}

#else

#define BKT_IX BKT_IX_
#define BKT_MIN_SZ BKT_MIN_SZ_

#endif


/* Prototypes of callback functions */
static Block_t *	get_free_block		(Allctr_t *, Uint,
						 Block_t *, Uint, Uint32);
static void		link_free_block		(Allctr_t *, Block_t *, Uint32);
static void		unlink_free_block	(Allctr_t *, Block_t *, Uint32);
static void		update_last_aux_mbc	(Allctr_t *, Carrier_t *, Uint32);
static Eterm		info_options		(Allctr_t *, char *, int *,
						 void *, Uint **, Uint *);
static void		init_atoms		(void);

#ifdef ERTS_ALLOC_UTIL_HARD_DEBUG
static void		check_block		(Allctr_t *, Block_t *,  int);
static void		check_mbc		(Allctr_t *, Carrier_t *);
#endif

static int atoms_initialized = 0;

void
erts_gfalc_init(void)
{
    atoms_initialized = 0;
}


Allctr_t *
erts_gfalc_start(GFAllctr_t *gfallctr,
		 GFAllctrInit_t *gfinit,
		 AllctrInit_t *init)
{
    struct {
	int dummy;
	GFAllctr_t allctr;
    } zero = {0};
    /* The struct with a dummy element first is used in order to avoid (an
       incorrect) gcc warning. gcc warns if {0} is used as initializer of
       a struct when the first member is a struct (not if, for example,
       the third member is a struct). */

    Allctr_t *allctr = (Allctr_t *) gfallctr;

    sys_memcpy((void *) gfallctr, (void *) &zero.allctr, sizeof(GFAllctr_t));

    init->sbmbct = 0; /* Small mbc not yet supported by goodfit */

    allctr->mbc_header_size		= sizeof(Carrier_t);
    allctr->min_mbc_size		= MIN_MBC_SZ;
    allctr->min_mbc_first_free_size	= MIN_MBC_FIRST_FREE_SZ;
    allctr->min_block_size		= sizeof(GFFreeBlock_t);


    allctr->vsn_str = ERTS_ALC_GF_ALLOC_VSN_STR;

    /* Callback functions */

    allctr->get_free_block		= get_free_block;
    allctr->link_free_block		= link_free_block;
    allctr->unlink_free_block		= unlink_free_block;
    allctr->info_options		= info_options;

    allctr->get_next_mbc_size		= NULL;
    allctr->creating_mbc		= update_last_aux_mbc;
    allctr->destroying_mbc		= update_last_aux_mbc;

    allctr->init_atoms			= init_atoms;

#ifdef ERTS_ALLOC_UTIL_HARD_DEBUG
    allctr->check_block			= check_block;
    allctr->check_mbc			= check_mbc;
#endif

    allctr->atoms_initialized		= 0;

    if (init->sbct > BKT_MIN_SIZE_D-1)
	gfallctr->bkt_intrvl_d =
	    UNIT_CEILING(((3*(init->sbct - BKT_MIN_SIZE_D - 1)
			   /(NO_OF_BKTS/4 - 1)) + 1)
			 / 2);
    if (gfallctr->bkt_intrvl_d < BKT_INTRVL_C)
	gfallctr->bkt_intrvl_d = BKT_INTRVL_C;
    gfallctr->bkt_max_size_d = ((NO_OF_BKTS/4)*gfallctr->bkt_intrvl_d
				+ BKT_MIN_SIZE_D
				- 1);

    gfallctr->max_blk_search		= (Uint) MAX(1, gfinit->mbsd);

    if (!erts_alcu_start(allctr, init))
	return NULL;

    if (allctr->min_block_size != MIN_BLK_SZ)
	return NULL;

    return allctr;
}

static int
find_bucket(BucketMask_t *bmask, int min_index)
{
    int min, mid, max;
    int sub_mask_ix, sub_bkt_ix;
    int ix = -1;

#undef  GET_MIN_BIT
#define GET_MIN_BIT(MinBit, BitMask, Min, Max)		\
    min = (Min);					\
    max = (Max);					\
    while(max != min) {					\
	mid = ((max - min) >> 1) + min;			\
	if((BitMask)					\
	   & (~(~((UWord) 0) << (mid + 1)))		\
	   & (~((UWord) 0) << min))			\
	    max = mid;					\
	else						\
	    min = mid + 1;				\
    }							\
    (MinBit) = min


    ASSERT(bmask->main < (((UWord) 1) << (MAX_SUB_MASK_IX+1)));

    sub_mask_ix = IX2SMIX(min_index);

    if ((bmask->main & (~((UWord) 0) << sub_mask_ix)) == 0)
	return -1;

    /* There exists a non empty bucket; find it... */

    if (bmask->main & (((UWord) 1) << sub_mask_ix)) {
	sub_bkt_ix = IX2SBIX(min_index);
	if ((bmask->sub[sub_mask_ix] & (~((UWord) 0) << sub_bkt_ix)) == 0) {
	    sub_mask_ix++;
	    sub_bkt_ix = 0;
	    if ((bmask->main & (~((UWord) 0)<< sub_mask_ix)) == 0)
		return -1;
	}
	else
	    goto find_sub_bkt_ix;
    }
    else {
	sub_mask_ix++;
	sub_bkt_ix = 0;
    }

    ASSERT(sub_mask_ix <= MAX_SUB_MASK_IX);
    /* Has to be a bit > sub_mask_ix */
    ASSERT(bmask->main & (~((UWord) 0) << (sub_mask_ix)));
    GET_MIN_BIT(sub_mask_ix, bmask->main, sub_mask_ix, MAX_SUB_MASK_IX);

 find_sub_bkt_ix:
    ASSERT(sub_mask_ix <= MAX_SUB_MASK_IX);
    ASSERT(sub_bkt_ix <= MAX_SUB_BKT_IX);

    if ((bmask->sub[sub_mask_ix] & (((UWord) 1) << sub_bkt_ix)) == 0) {
	ASSERT(sub_mask_ix + 1 <= MAX_SUB_BKT_IX);
	/* Has to be a bit > sub_bkt_ix */
	ASSERT(bmask->sub[sub_mask_ix] & (~((UWord) 0) << sub_bkt_ix));

	GET_MIN_BIT(sub_bkt_ix,
		    bmask->sub[sub_mask_ix],
		    sub_bkt_ix+1,
		    MAX_SUB_BKT_IX);

	ASSERT(sub_bkt_ix <= MAX_SUB_BKT_IX);
    }

    ix = MAKE_BKT_IX(sub_mask_ix, sub_bkt_ix);

    ASSERT(0 <= ix && ix < NO_OF_BKTS); 

    return ix;

#undef  GET_MIN_BIT

}

static Block_t *
search_bucket(Allctr_t *allctr, int ix, Uint size)
{
    int i;
    Uint min_sz;
    Uint blk_sz;
    Uint cand_sz = 0;
    UWord max_blk_search;
    GFFreeBlock_t *blk;
    GFFreeBlock_t *cand = NULL;
    int blk_on_lambc;
    int cand_on_lambc = 0;
    GFAllctr_t *gfallctr = (GFAllctr_t *) allctr;

    ASSERT(0 <= ix && ix <= NO_OF_BKTS - 1);

    if (!gfallctr->buckets[ix])
	return NULL;

    min_sz = BKT_MIN_SZ(gfallctr, ix);
    if (min_sz < size)
	min_sz = size;

    max_blk_search = gfallctr->max_blk_search;
    for (blk = gfallctr->buckets[ix], i = 0;
	 blk && i < max_blk_search;
	 blk = blk->next, i++) {

	blk_sz = MBC_FBLK_SZ(&blk->block_head);
	blk_on_lambc = (((char *) blk) < gfallctr->last_aux_mbc_end
			&& gfallctr->last_aux_mbc_start <= ((char *) blk));

	if (blk_sz == min_sz && !blk_on_lambc)
	    return (Block_t *) blk;

	if (blk_sz >= min_sz
	    && (!cand
		|| (!blk_on_lambc && (cand_on_lambc || blk_sz < cand_sz))
		|| (blk_on_lambc && cand_on_lambc && blk_sz < cand_sz))) {
	    cand_sz = blk_sz;
	    cand = blk;
	    cand_on_lambc = blk_on_lambc;
	}

    }
    return (Block_t *) cand;
}

static Block_t *
get_free_block(Allctr_t *allctr, Uint size,
	       Block_t *cand_blk, Uint cand_size, Uint32 flags)
{
    GFAllctr_t *gfallctr = (GFAllctr_t *) allctr;
    int unsafe_bi, min_bi;
    Block_t *blk;

    ASSERT(!cand_blk || cand_size >= size);

    unsafe_bi = BKT_IX(gfallctr, size);
    
    min_bi = find_bucket(&gfallctr->bucket_mask, unsafe_bi);
    if (min_bi < 0)
	return NULL;

    if (min_bi == unsafe_bi) {
	blk = search_bucket(allctr, min_bi, size);
	if (blk) {
	    if (cand_blk && cand_size <= MBC_FBLK_SZ(blk))
		return NULL; /* cand_blk was better */
	    unlink_free_block(allctr, blk, flags);
	    return blk;
	}
	if (min_bi < NO_OF_BKTS - 1) {
	    min_bi = find_bucket(&gfallctr->bucket_mask, min_bi + 1);
	    if (min_bi < 0)
		return NULL;
	}
	else
	    return NULL;
    }
    else {
	ASSERT(min_bi > unsafe_bi);
    }

    /* We are guaranteed to find a block that fits in this bucket */
    blk = search_bucket(allctr, min_bi, size);
    ASSERT(blk);
    if (cand_blk && cand_size <= MBC_FBLK_SZ(blk))
	return NULL; /* cand_blk was better */
    unlink_free_block(allctr, blk, flags);
    return blk;
}



static void
link_free_block(Allctr_t *allctr, Block_t *block, Uint32 flags)
{
    GFAllctr_t *gfallctr = (GFAllctr_t *) allctr;
    GFFreeBlock_t *blk = (GFFreeBlock_t *) block;
    Uint sz = MBC_FBLK_SZ(&blk->block_head);
    int i = BKT_IX(gfallctr, sz);

    ASSERT(sz >= MIN_BLK_SZ);

    SET_BKT_MASK_IX(gfallctr->bucket_mask, i);

    blk->prev = NULL;
    blk->next = gfallctr->buckets[i];
    if (blk->next) {
	ASSERT(!blk->next->prev);
	blk->next->prev = blk;
    }
    gfallctr->buckets[i] = blk;
}

static void
unlink_free_block(Allctr_t *allctr, Block_t *block, Uint32 flags)
{
    GFAllctr_t *gfallctr = (GFAllctr_t *) allctr;
    GFFreeBlock_t *blk = (GFFreeBlock_t *) block;
    Uint sz = MBC_FBLK_SZ(&blk->block_head);
    int i = BKT_IX(gfallctr, sz);

    if (!blk->prev) {
	ASSERT(gfallctr->buckets[i] == blk);
	gfallctr->buckets[i] = blk->next;
    }
    else
	blk->prev->next = blk->next;
    if (blk->next)
	blk->next->prev = blk->prev;

    if (!gfallctr->buckets[i])
	UNSET_BKT_MASK_IX(gfallctr->bucket_mask, i);
}

static void
update_last_aux_mbc(Allctr_t *allctr, Carrier_t *mbc, Uint32 flags)
{
    GFAllctr_t *gfallctr = (GFAllctr_t *) allctr;

    if (gfallctr->last_aux_mbc_start != (char *) allctr->mbc_list.last) {

	if (allctr->mbc_list.last
	    && allctr->main_carrier != allctr->mbc_list.last) {
	    gfallctr->last_aux_mbc_start = (char *) allctr->mbc_list.last;
	    gfallctr->last_aux_mbc_end = (((char *) allctr->mbc_list.last)
					  + CARRIER_SZ(allctr->mbc_list.last));
	}
	else {
	    gfallctr->last_aux_mbc_start = NULL;
	    gfallctr->last_aux_mbc_end = NULL;
	}

    }
}

static struct {
    Eterm mbsd;
    Eterm as;
    Eterm gf;
#ifdef DEBUG
    Eterm end_of_atoms;
#endif
} am;

static void ERTS_INLINE atom_init(Eterm *atom, char *name)
{
    *atom = am_atom_put(name, strlen(name));
}
#define AM_INIT(AM) atom_init(&am.AM, #AM)

static void
init_atoms(void)
{
#ifdef DEBUG
    Eterm *atom;
#endif

    if (atoms_initialized)
	return;

#ifdef DEBUG
    for (atom = (Eterm *) &am; atom <= &am.end_of_atoms; atom++) {
	*atom = THE_NON_VALUE;
    }
#endif

    AM_INIT(mbsd);
    AM_INIT(as);
    AM_INIT(gf);

#ifdef DEBUG
    for (atom = (Eterm *) &am; atom < &am.end_of_atoms; atom++) {
	ASSERT(*atom != THE_NON_VALUE);
    }
#endif

    atoms_initialized = 1;
}

#define bld_uint	erts_bld_uint
#define bld_cons	erts_bld_cons
#define bld_tuple	erts_bld_tuple

static ERTS_INLINE void
add_2tup(Uint **hpp, Uint *szp, Eterm *lp, Eterm el1, Eterm el2)
{
    *lp = bld_cons(hpp, szp, bld_tuple(hpp, szp, 2, el1, el2), *lp);
}

static Eterm
info_options(Allctr_t *allctr,
	     char *prefix,
	     int *print_to_p,
	     void *print_to_arg,
	     Uint **hpp,
	     Uint *szp)
{
    GFAllctr_t *gfallctr = (GFAllctr_t *) allctr;
    Eterm res = THE_NON_VALUE;

    if (print_to_p) {
	erts_print(*print_to_p,
		   print_to_arg,
		   "%smbsd: %lu\n"
		   "%sas: gf\n",
		   prefix, gfallctr->max_blk_search,
		   prefix);
    }

    if (hpp || szp) {
	
	if (!atoms_initialized)
	    erl_exit(1, "%s:%d: Internal error: Atoms not initialized",
		     __FILE__, __LINE__);;

	res = NIL;
	add_2tup(hpp, szp, &res, am.as, am.gf);
	add_2tup(hpp, szp, &res,
		 am.mbsd,
		 bld_uint(hpp, szp, gfallctr->max_blk_search));
    }

    return res;
}

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *\
 * NOTE:  erts_gfalc_test() is only supposed to be used for testing.         *
 *                                                                           *
 * Keep alloc_SUITE_data/allocator_test.h updated if changes are made        *
 * to erts_gfalc_test()                                                      *
\*                                                                           */

unsigned long
erts_gfalc_test(unsigned long op, unsigned long a1, unsigned long a2)
{
    switch (op) {
    case 0x100:	return (unsigned long) BKT_IX((GFAllctr_t *) a1, (Uint) a2);
    case 0x101:	return (unsigned long) BKT_MIN_SZ((GFAllctr_t *) a1, (int) a2);
    case 0x102:	return (unsigned long) NO_OF_BKTS;
    case 0x103:	return (unsigned long)
		    find_bucket(&((GFAllctr_t *) a1)->bucket_mask, (int) a2);
    default:	ASSERT(0); return ~((unsigned long) 0);
    }
}

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *\
 * Debug functions                                                           *
\*                                                                           */

#ifdef ERTS_ALLOC_UTIL_HARD_DEBUG
void
check_block(Allctr_t *allctr, Block_t * blk, int free_block)
{
    GFAllctr_t *gfallctr = (GFAllctr_t *) allctr;
    int i;
    int bi;
    int found;
    GFFreeBlock_t *fblk;

    if(free_block) {
	Uint blk_sz = is_sbc_blk(blk) ? SBC_BLK_SZ(blk) : MBC_BLK_SZ(blk);
	bi = BKT_IX(gfallctr, blk_sz);

	ASSERT(gfallctr->bucket_mask.main & (((UWord) 1) << IX2SMIX(bi)));
	ASSERT(gfallctr->bucket_mask.sub[IX2SMIX(bi)]
	       & (((UWord) 1) << IX2SBIX(bi)));
		
	found = 0;
	for (fblk = gfallctr->buckets[bi]; fblk; fblk = fblk->next)
	    if (blk == (Block_t *) fblk)
		found++;
	ASSERT(found == 1);
    }
    else
	bi = -1;

    found = 0;
    for (i = 0; i < NO_OF_BKTS; i++) {
	if (i == bi)
	    continue; /* Already checked */
	for (fblk = gfallctr->buckets[i]; fblk; fblk = fblk->next)
	    if (blk == (Block_t *) fblk)
		found++;
    }

    ASSERT(found == 0);

}

void
check_mbc(Allctr_t *allctr, Carrier_t *mbc)
{
    GFAllctr_t *gfallctr = (GFAllctr_t *) allctr;
    int bi;

    for(bi = 0; bi < NO_OF_BKTS; bi++) {
	if ((gfallctr->bucket_mask.main & (((UWord) 1) << IX2SMIX(bi)))
	    && (gfallctr->bucket_mask.sub[IX2SMIX(bi)]
		& (((UWord) 1) << IX2SBIX(bi)))) {
	    ASSERT(gfallctr->buckets[bi] != NULL);
	}
	else {
	    ASSERT(gfallctr->buckets[bi] == NULL);
	}
    }
}

#endif