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   1 /*
   2  * Copyright © 2016 Keith Packard <keithp@keithp.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  */
  14
  15 #define AO_SCHEME_CONST_BITS
  16
  17 #include "ao_scheme.h"
  18 #include <stdio.h>
  19 #include <assert.h>
  20
  21 #ifdef AO_SCHEME_MAKE_CONST
  22
  23 /*
  24  * When building the constant table, it is the
  25  * pool for allocations.
  26  */
  27
  28 #include <stdlib.h>
  29 uint8_t ao_scheme_const[AO_SCHEME_POOL_CONST] __attribute__((aligned(4)));
  30 #define ao_scheme_pool ao_scheme_const
  31 #undef AO_SCHEME_POOL
  32 #define AO_SCHEME_POOL AO_SCHEME_POOL_CONST
  33
  34 #else
  35
  36 uint8_t ao_scheme_pool[AO_SCHEME_POOL + AO_SCHEME_POOL_EXTRA] __attribute__((aligned(4)));
  37
  38 #endif
  39
  40 #ifndef DBG_MEM_STATS
  41 #define DBG_MEM_STATS   DBG_MEM
  42 #endif
  43
  44 #define DBG_MEM_STACK   0
  45 #if DBG_MEM_STACK
  46 char    *mem_collect_stack;
  47 int64_t mem_collect_max_depth;
  48
  49 static void
  50 ao_scheme_check_stack(void)
  51 {
  52         char    x;
  53         int64_t depth;
  54
  55         depth = mem_collect_stack - &x;
  56         if (depth > mem_collect_max_depth)
  57                 mem_collect_max_depth = depth;
  58 }
  59
  60 static void
  61 _ao_scheme_reset_stack(char *x)
  62 {
  63         mem_collect_stack = x;
  64 //      mem_collect_max_depth = 0;
  65 }
  66 #define ao_scheme_declare_stack char x;
  67 #define ao_scheme_reset_stack() _ao_scheme_reset_stack(&x)
  68 #else
  69 #define ao_scheme_check_stack()
  70 #define ao_scheme_declare_stack
  71 #define ao_scheme_reset_stack()
  72 #endif
  73
  74 #if DBG_MEM
  75 int dbg_move_depth;
  76 int dbg_mem = DBG_MEM_START;
  77 int dbg_validate = 0;
  78
  79 struct ao_scheme_record {
  80         struct ao_scheme_record         *next;
  81         const struct ao_scheme_type     *type;
  82         void                            *addr;
  83         int                             size;
  84 };
  85
  86 static struct ao_scheme_record  *record_head, **record_tail;
  87
  88 static void
  89 ao_scheme_record_free(struct ao_scheme_record *record)
  90 {
  91         while (record) {
  92                 struct ao_scheme_record *next = record->next;
  93                 free(record);
  94                 record = next;
  95         }
  96 }
  97
  98 static void
  99 ao_scheme_record_reset(void)
 100 {
 101         ao_scheme_record_free(record_head);
 102         record_head = NULL;
 103         record_tail = &record_head;
 104 }
 105
 106 static void
 107 ao_scheme_record(const struct ao_scheme_type    *type,
 108                void                             *addr,
 109                int                              size)
 110 {
 111         struct ao_scheme_record *r = malloc(sizeof (struct ao_scheme_record));
 112
 113         r->next = NULL;
 114         r->type = type;
 115         r->addr = addr;
 116         r->size = size;
 117         *record_tail = r;
 118         record_tail = &r->next;
 119 }
 120
 121 static struct ao_scheme_record *
 122 ao_scheme_record_save(void)
 123 {
 124         struct ao_scheme_record *r = record_head;
 125
 126         record_head = NULL;
 127         record_tail = &record_head;
 128         return r;
 129 }
 130
 131 static void
 132 ao_scheme_record_compare(char *where,
 133                        struct ao_scheme_record *a,
 134                        struct ao_scheme_record *b)
 135 {
 136         while (a && b) {
 137                 if (a->type != b->type || a->size != b->size) {
 138                         printf("%s record difers %d %s %d -> %d %s %d\n",
 139                                where,
 140                                MDBG_OFFSET(a->addr),
 141                                a->type->name,
 142                                a->size,
 143                                MDBG_OFFSET(b->addr),
 144                                b->type->name,
 145                                b->size);
 146                         ao_scheme_abort();
 147                 }
 148                 a = a->next;
 149                 b = b->next;
 150         }
 151         if (a) {
 152                 printf("%s record differs %d %s %d -> NULL\n",
 153                        where,
 154                        MDBG_OFFSET(a->addr),
 155                        a->type->name,
 156                        a->size);
 157                 ao_scheme_abort();
 158         }
 159         if (b) {
 160                 printf("%s record differs NULL -> %d %s %d\n",
 161                        where,
 162                        MDBG_OFFSET(b->addr),
 163                        b->type->name,
 164                        b->size);
 165                 ao_scheme_abort();
 166         }
 167 }
 168
 169 #else
 170 #define ao_scheme_record_reset()
 171 #endif
 172
 173 uint8_t ao_scheme_exception;
 174
 175 struct ao_scheme_root {
 176         const struct ao_scheme_type     *type;
 177         void                            **addr;
 178 };
 179
 180 static struct ao_scheme_cons    *save_cons[2];
 181 static struct ao_scheme_string  *save_string[2];
 182 static struct ao_scheme_frame   *save_frame[1];
 183 static ao_poly                  save_poly[3];
 184
 185 static const struct ao_scheme_root      ao_scheme_root[] = {
 186         {
 187                 .type = &ao_scheme_cons_type,
 188                 .addr = (void **) &save_cons[0],
 189         },
 190         {
 191                 .type = &ao_scheme_cons_type,
 192                 .addr = (void **) &save_cons[1],
 193         },
 194         {
 195                 .type = &ao_scheme_string_type,
 196                 .addr = (void **) &save_string[0],
 197         },
 198         {
 199                 .type = &ao_scheme_string_type,
 200                 .addr = (void **) &save_string[1],
 201         },
 202         {
 203                 .type = &ao_scheme_frame_type,
 204                 .addr = (void **) &save_frame[0],
 205         },
 206         {
 207                 .type = NULL,
 208                 .addr = (void **) (void *) &save_poly[0]
 209         },
 210         {
 211                 .type = NULL,
 212                 .addr = (void **) (void *) &save_poly[1]
 213         },
 214         {
 215                 .type = NULL,
 216                 .addr = (void **) (void *) &save_poly[2]
 217         },
 218         {
 219                 .type = &ao_scheme_atom_type,
 220                 .addr = (void **) &ao_scheme_atoms
 221         },
 222         {
 223                 .type = &ao_scheme_frame_type,
 224                 .addr = (void **) &ao_scheme_frame_global,
 225         },
 226         {
 227                 .type = &ao_scheme_frame_type,
 228                 .addr = (void **) &ao_scheme_frame_current,
 229         },
 230         {
 231                 .type = &ao_scheme_stack_type,
 232                 .addr = (void **) &ao_scheme_stack,
 233         },
 234         {
 235                 .type = NULL,
 236                 .addr = (void **) (void *) &ao_scheme_v,
 237         },
 238         {
 239                 .type = &ao_scheme_cons_type,
 240                 .addr = (void **) &ao_scheme_read_cons,
 241         },
 242         {
 243                 .type = &ao_scheme_cons_type,
 244                 .addr = (void **) &ao_scheme_read_cons_tail,
 245         },
 246         {
 247                 .type = &ao_scheme_cons_type,
 248                 .addr = (void **) &ao_scheme_read_stack,
 249         },
 250 #ifdef AO_SCHEME_MAKE_CONST
 251         {
 252                 .type = &ao_scheme_bool_type,
 253                 .addr = (void **) &ao_scheme_false,
 254         },
 255         {
 256                 .type = &ao_scheme_bool_type,
 257                 .addr = (void **) &ao_scheme_true,
 258         },
 259 #endif
 260 };
 261
 262 #define AO_SCHEME_ROOT  (sizeof (ao_scheme_root) / sizeof (ao_scheme_root[0]))
 263
 264 static const void ** const ao_scheme_cache[] = {
 265         (const void **) &ao_scheme_cons_free_list,
 266         (const void **) &ao_scheme_stack_free_list,
 267         (const void **) &ao_scheme_frame_free_list[0],
 268         (const void **) &ao_scheme_frame_free_list[1],
 269         (const void **) &ao_scheme_frame_free_list[2],
 270         (const void **) &ao_scheme_frame_free_list[3],
 271         (const void **) &ao_scheme_frame_free_list[4],
 272         (const void **) &ao_scheme_frame_free_list[5],
 273 };
 274
 275 #if AO_SCHEME_FRAME_FREE != 6
 276 #error Unexpected AO_SCHEME_FRAME_FREE value
 277 #endif
 278
 279 #define AO_SCHEME_CACHE (sizeof (ao_scheme_cache) / sizeof (ao_scheme_cache[0]))
 280
 281 #define AO_SCHEME_BUSY_SIZE     ((AO_SCHEME_POOL + 31) / 32)
 282
 283 static int      ao_scheme_printing, ao_scheme_print_cleared;
 284 #if DBG_MEM
 285 static int      ao_scheme_collecting;
 286 #endif
 287 static uint8_t  ao_scheme_busy[AO_SCHEME_BUSY_SIZE];
 288 static uint8_t  ao_scheme_cons_note[AO_SCHEME_BUSY_SIZE];
 289 static uint8_t  ao_scheme_cons_last[AO_SCHEME_BUSY_SIZE];
 290 static uint8_t  ao_scheme_cons_noted;
 291
 292 uint16_t        ao_scheme_top;
 293
 294 struct ao_scheme_chunk {
 295         uint16_t                old_offset;
 296         union {
 297                 uint16_t        size;
 298                 uint16_t        new_offset;
 299         };
 300 };
 301
 302 #define AO_SCHEME_NCHUNK        64
 303
 304 static struct ao_scheme_chunk ao_scheme_chunk[AO_SCHEME_NCHUNK];
 305
 306 /* Offset of an address within the pool. */
 307 static inline uint16_t pool_offset(void *addr) {
 308 #if DBG_MEM
 309         if (!AO_SCHEME_IS_POOL(addr))
 310                 ao_scheme_abort();
 311 #endif
 312         return ((uint8_t *) addr) - ao_scheme_pool;
 313 }
 314
 315 static inline void mark(uint8_t *tag, int offset) {
 316         int     byte = offset >> 5;
 317         int     bit = (offset >> 2) & 7;
 318         ao_scheme_check_stack();
 319         tag[byte] |= (1 << bit);
 320 }
 321
 322 static inline void clear(uint8_t *tag, int offset) {
 323         int     byte = offset >> 5;
 324         int     bit = (offset >> 2) & 7;
 325         tag[byte] &= ~(1 << bit);
 326 }
 327
 328 static inline int busy(uint8_t *tag, int offset) {
 329         int     byte = offset >> 5;
 330         int     bit = (offset >> 2) & 7;
 331         return (tag[byte] >> bit) & 1;
 332 }
 333
 334 static inline int min(int a, int b) { return a < b ? a : b; }
 335 static inline int max(int a, int b) { return a > b ? a : b; }
 336
 337 static inline int limit(int offset) {
 338         return min(AO_SCHEME_POOL, max(offset, 0));
 339 }
 340
 341 static inline void
 342 note_cons(uint16_t offset)
 343 {
 344         MDBG_MOVE("note cons %d\n", offset);
 345         ao_scheme_cons_noted = 1;
 346         mark(ao_scheme_cons_note, offset);
 347 }
 348
 349 static uint16_t chunk_low, chunk_high;
 350 static uint16_t chunk_first, chunk_last;
 351
 352 static int
 353 find_chunk(uint16_t offset)
 354 {
 355         int l, r;
 356         /* Binary search for the location */
 357         l = chunk_first;
 358         r = chunk_last - 1;
 359         while (l <= r) {
 360                 int m = (l + r) >> 1;
 361                 if (ao_scheme_chunk[m].old_offset < offset)
 362                         l = m + 1;
 363                 else
 364                         r = m - 1;
 365         }
 366         return l;
 367 }
 368
 369 static void
 370 note_chunk(uint16_t offset, uint16_t size)
 371 {
 372         int l;
 373         int end;
 374
 375         if (offset < chunk_low || chunk_high <= offset)
 376                 return;
 377
 378         l = find_chunk(offset);
 379
 380         /*
 381          * The correct location is always in 'l', with r = l-1 being
 382          * the entry before the right one
 383          */
 384
 385 #if DBG_MEM
 386         /* Off the right side */
 387         if (l >= AO_SCHEME_NCHUNK)
 388                 ao_scheme_abort();
 389
 390         /* Off the left side */
 391         if (l == 0 && chunk_last && offset > ao_scheme_chunk[0].old_offset)
 392                 ao_scheme_abort();
 393 #endif
 394
 395         /* Shuffle existing entries right */
 396         end = min(AO_SCHEME_NCHUNK, chunk_last + 1);
 397
 398         memmove(&ao_scheme_chunk[l+1],
 399                 &ao_scheme_chunk[l],
 400                 (end - (l+1)) * sizeof (struct ao_scheme_chunk));
 401
 402         /* Add new entry */
 403         ao_scheme_chunk[l].old_offset = offset;
 404         ao_scheme_chunk[l].size = size;
 405
 406         /* Increment the number of elements up to the size of the array */
 407         if (chunk_last < AO_SCHEME_NCHUNK)
 408                 chunk_last++;
 409
 410         /* Set the top address if the array is full */
 411         if (chunk_last == AO_SCHEME_NCHUNK)
 412                 chunk_high = ao_scheme_chunk[AO_SCHEME_NCHUNK-1].old_offset +
 413                         ao_scheme_chunk[AO_SCHEME_NCHUNK-1].size;
 414 }
 415
 416 static void
 417 reset_chunks(void)
 418 {
 419         chunk_high = ao_scheme_top;
 420         chunk_last = 0;
 421         chunk_first = 0;
 422 }
 423
 424 /*
 425  * Walk all referenced objects calling functions on each one
 426  */
 427
 428 static void
 429 walk(int (*visit_addr)(const struct ao_scheme_type *type, void **addr),
 430      int (*visit_poly)(ao_poly *p, uint8_t do_note_cons))
 431 {
 432         int i;
 433
 434         ao_scheme_record_reset();
 435         memset(ao_scheme_busy, '\0', sizeof (ao_scheme_busy));
 436         memset(ao_scheme_cons_note, '\0', sizeof (ao_scheme_cons_note));
 437         ao_scheme_cons_noted = 0;
 438         for (i = 0; i < (int) AO_SCHEME_ROOT; i++) {
 439                 if (ao_scheme_root[i].type) {
 440                         void **a = ao_scheme_root[i].addr, *v;
 441                         if (a && (v = *a)) {
 442                                 MDBG_MOVE("root ptr %d\n", MDBG_OFFSET(v));
 443                                 visit_addr(ao_scheme_root[i].type, a);
 444                         }
 445                 } else {
 446                         ao_poly *a = (ao_poly *) ao_scheme_root[i].addr, p;
 447                         if (a && (p = *a)) {
 448                                 MDBG_MOVE("root poly %d\n", MDBG_OFFSET(ao_scheme_ref(p)));
 449                                 visit_poly(a, 0);
 450                         }
 451                 }
 452         }
 453         while (ao_scheme_cons_noted) {
 454                 memcpy(ao_scheme_cons_last, ao_scheme_cons_note, sizeof (ao_scheme_cons_note));
 455                 memset(ao_scheme_cons_note, '\0', sizeof (ao_scheme_cons_note));
 456                 ao_scheme_cons_noted = 0;
 457                 for (i = 0; i < AO_SCHEME_POOL; i += 4) {
 458                         if (busy(ao_scheme_cons_last, i)) {
 459                                 void *v = ao_scheme_pool + i;
 460                                 MDBG_MOVE("root cons %d\n", MDBG_OFFSET(v));
 461                                 visit_addr(&ao_scheme_cons_type, &v);
 462                         }
 463                 }
 464         }
 465 }
 466
 467 #if MDBG_DUMP
 468 static void
 469 dump_busy(void)
 470 {
 471         int     i;
 472         MDBG_MOVE("busy:");
 473         for (i = 0; i < ao_scheme_top; i += 4) {
 474                 if ((i & 0xff) == 0) {
 475                         MDBG_MORE("\n");
 476                         MDBG_MOVE("%s", "");
 477                 }
 478                 else if ((i & 0x1f) == 0)
 479                         MDBG_MORE(" ");
 480                 if (busy(ao_scheme_busy, i))
 481                         MDBG_MORE("*");
 482                 else
 483                         MDBG_MORE("-");
 484         }
 485         MDBG_MORE ("\n");
 486 }
 487 #define DUMP_BUSY()     dump_busy()
 488 #else
 489 #define DUMP_BUSY()
 490 #endif
 491
 492 static const struct ao_scheme_type * const ao_scheme_types[AO_SCHEME_NUM_TYPE] = {
 493         [AO_SCHEME_CONS] = &ao_scheme_cons_type,
 494         [AO_SCHEME_INT] = NULL,
 495 #ifdef AO_SCHEME_FEATURE_BIGINT
 496         [AO_SCHEME_BIGINT] = &ao_scheme_bigint_type,
 497 #endif
 498         [AO_SCHEME_OTHER] = (void *) 0x1,
 499         [AO_SCHEME_ATOM] = &ao_scheme_atom_type,
 500         [AO_SCHEME_BUILTIN] = &ao_scheme_builtin_type,
 501         [AO_SCHEME_FRAME] = &ao_scheme_frame_type,
 502         [AO_SCHEME_FRAME_VALS] = &ao_scheme_frame_vals_type,
 503         [AO_SCHEME_LAMBDA] = &ao_scheme_lambda_type,
 504         [AO_SCHEME_STACK] = &ao_scheme_stack_type,
 505         [AO_SCHEME_BOOL] = &ao_scheme_bool_type,
 506         [AO_SCHEME_STRING] = &ao_scheme_string_type,
 507 #ifdef AO_SCHEME_FEATURE_FLOAT
 508         [AO_SCHEME_FLOAT] = &ao_scheme_float_type,
 509 #endif
 510 #ifdef AO_SCHEME_FEATURE_VECTOR
 511         [AO_SCHEME_VECTOR] = &ao_scheme_vector_type,
 512 #endif
 513 };
 514
 515 static int
 516 ao_scheme_mark(const struct ao_scheme_type *type, void *addr);
 517
 518 static int
 519 ao_scheme_move(const struct ao_scheme_type *type, void **ref);
 520
 521 static int
 522 ao_scheme_mark_ref(const struct ao_scheme_type *type, void **ref)
 523 {
 524         return ao_scheme_mark(type, *ref);
 525 }
 526
 527 static int
 528 ao_scheme_poly_mark_ref(ao_poly *p, uint8_t do_note_cons)
 529 {
 530         return ao_scheme_poly_mark(*p, do_note_cons);
 531 }
 532
 533 #if DBG_MEM_STATS
 534 uint64_t ao_scheme_collects[2];
 535 uint64_t ao_scheme_freed[2];
 536 uint64_t ao_scheme_loops[2];
 537 #endif
 538
 539 int ao_scheme_last_top;
 540 int ao_scheme_collect_counts;
 541
 542 int
 543 ao_scheme_collect(uint8_t style)
 544 {
 545         ao_scheme_declare_stack
 546         int     i;
 547         int     top;
 548 #if DBG_MEM_STATS
 549         int     loops = 0;
 550 #endif
 551 #if DBG_MEM
 552         struct ao_scheme_record *mark_record = NULL, *move_record = NULL;
 553
 554         MDBG_MOVE("collect %d\n", ao_scheme_collects[style]);
 555 #endif
 556         MDBG_DO(ao_scheme_frame_write(ao_scheme_frame_poly(ao_scheme_frame_global)));
 557         MDBG_DO(++ao_scheme_collecting);
 558
 559         ao_scheme_reset_stack();
 560
 561         /* The first time through, we're doing a full collect */
 562         if (ao_scheme_last_top == 0)
 563                 style = AO_SCHEME_COLLECT_FULL;
 564
 565         /* One in a while, just do a full collect */
 566
 567         if (ao_scheme_collect_counts >= 128)
 568                 style = AO_SCHEME_COLLECT_FULL;
 569
 570         if (style == AO_SCHEME_COLLECT_FULL)
 571                 ao_scheme_collect_counts = 0;
 572
 573         /* Clear references to all caches */
 574         for (i = 0; i < (int) AO_SCHEME_CACHE; i++)
 575                 *ao_scheme_cache[i] = NULL;
 576         if (style == AO_SCHEME_COLLECT_FULL) {
 577                 chunk_low = top = 0;
 578         } else {
 579                 chunk_low = top = ao_scheme_last_top;
 580         }
 581         for (;;) {
 582 #if DBG_MEM_STATS
 583                 loops++;
 584 #endif
 585                 MDBG_MOVE("move chunks from %d to %d\n", chunk_low, top);
 586                 /* Find the sizes of the first chunk of objects to move */
 587                 reset_chunks();
 588                 walk(ao_scheme_mark_ref, ao_scheme_poly_mark_ref);
 589 #if DBG_MEM
 590
 591                 ao_scheme_record_free(mark_record);
 592                 mark_record = ao_scheme_record_save();
 593                 if (mark_record && move_record)
 594                         ao_scheme_record_compare("mark", move_record, mark_record);
 595 #endif
 596
 597                 DUMP_BUSY();
 598
 599                 /* Find the first moving object */
 600                 for (i = 0; i < chunk_last; i++) {
 601                         uint16_t        size = ao_scheme_chunk[i].size;
 602
 603 #if DBG_MEM
 604                         if (!size)
 605                                 ao_scheme_abort();
 606 #endif
 607
 608                         if (ao_scheme_chunk[i].old_offset > top)
 609                                 break;
 610
 611                         MDBG_MOVE("chunk %d %d not moving\n",
 612                                   ao_scheme_chunk[i].old_offset,
 613                                   ao_scheme_chunk[i].size);
 614 #if DBG_MEM
 615                         if (ao_scheme_chunk[i].old_offset != top)
 616                                 ao_scheme_abort();
 617 #endif
 618                         top += size;
 619                 }
 620
 621                 /*
 622                  * Limit amount of chunk array used in mapping moves
 623                  * to the active region
 624                  */
 625                 chunk_first = i;
 626                 chunk_low = ao_scheme_chunk[i].old_offset;
 627
 628                 /* Copy all of the objects */
 629                 for (; i < chunk_last; i++) {
 630                         uint16_t        size = ao_scheme_chunk[i].size;
 631
 632 #if DBG_MEM
 633                         if (!size)
 634                                 ao_scheme_abort();
 635 #endif
 636
 637                         MDBG_MOVE("chunk %d %d -> %d\n",
 638                                   ao_scheme_chunk[i].old_offset,
 639                                   size,
 640                                   top);
 641                         ao_scheme_chunk[i].new_offset = top;
 642
 643                         memmove(&ao_scheme_pool[top],
 644                                 &ao_scheme_pool[ao_scheme_chunk[i].old_offset],
 645                                 size);
 646
 647                         top += size;
 648                 }
 649
 650                 if (chunk_first < chunk_last) {
 651                         /* Relocate all references to the objects */
 652                         walk(ao_scheme_move, ao_scheme_poly_move);
 653
 654 #if DBG_MEM
 655                         ao_scheme_record_free(move_record);
 656                         move_record = ao_scheme_record_save();
 657                         if (mark_record && move_record)
 658                                 ao_scheme_record_compare("move", mark_record, move_record);
 659 #endif
 660                 }
 661
 662                 /* If we ran into the end of the heap, then
 663                  * there's no need to keep walking
 664                  */
 665                 if (chunk_last != AO_SCHEME_NCHUNK)
 666                         break;
 667
 668                 /* Next loop starts right above this loop */
 669                 chunk_low = chunk_high;
 670         }
 671
 672 #if DBG_MEM_STATS
 673         /* Collect stats */
 674         ++ao_scheme_collects[style];
 675         ao_scheme_freed[style] += ao_scheme_top - top;
 676         ao_scheme_loops[style] += loops;
 677 #endif
 678
 679         ao_scheme_top = top;
 680         if (style == AO_SCHEME_COLLECT_FULL)
 681                 ao_scheme_last_top = top;
 682
 683         MDBG_DO(memset(ao_scheme_chunk, '\0', sizeof (ao_scheme_chunk));
 684                 walk(ao_scheme_mark_ref, ao_scheme_poly_mark_ref));
 685
 686 #if DBG_MEM_STACK
 687         fprintf(stderr, "max collect stack depth %lu\n", mem_collect_max_depth);
 688 #endif
 689         MDBG_DO(--ao_scheme_collecting);
 690         return AO_SCHEME_POOL - ao_scheme_top;
 691 }
 692
 693 #if DBG_FREE_CONS
 694 void
 695 ao_scheme_cons_check(struct ao_scheme_cons *cons)
 696 {
 697         ao_poly cdr;
 698         int offset;
 699
 700         chunk_low = 0;
 701         reset_chunks();
 702         walk(ao_scheme_mark_ref, ao_scheme_poly_mark_ref);
 703         while (cons) {
 704                 if (!AO_SCHEME_IS_POOL(cons))
 705                         break;
 706                 offset = pool_offset(cons);
 707                 if (busy(ao_scheme_busy, offset)) {
 708                         ao_scheme_printf("cons at %p offset %d poly %d is busy\n\t%v\n", cons, offset, ao_scheme_cons_poly(cons), ao_scheme_cons_poly(cons));
 709                         abort();
 710                 }
 711                 cdr = cons->cdr;
 712                 if (!ao_scheme_is_pair(cdr))
 713                         break;
 714                 cons = ao_scheme_poly_cons(cdr);
 715         }
 716 }
 717 #endif
 718
 719 /*
 720  * Mark interfaces for objects
 721  */
 722
 723
 724 /*
 725  * Note a reference to memory and collect information about a few
 726  * object sizes at a time
 727  */
 728
 729 int
 730 ao_scheme_mark_memory(const struct ao_scheme_type *type, void *addr)
 731 {
 732         int offset;
 733         if (!AO_SCHEME_IS_POOL(addr))
 734                 return 1;
 735
 736         offset = pool_offset(addr);
 737         MDBG_MOVE("mark memory %d\n", MDBG_OFFSET(addr));
 738         if (busy(ao_scheme_busy, offset)) {
 739                 MDBG_MOVE("already marked\n");
 740                 return 1;
 741         }
 742         mark(ao_scheme_busy, offset);
 743         note_chunk(offset, ao_scheme_size(type, addr));
 744         return 0;
 745 }
 746
 747 /*
 748  * Mark an object and all that it refereces
 749  */
 750 static int
 751 ao_scheme_mark(const struct ao_scheme_type *type, void *addr)
 752 {
 753         int ret;
 754         MDBG_MOVE("mark %d\n", MDBG_OFFSET(addr));
 755         MDBG_MOVE_IN();
 756         ret = ao_scheme_mark_memory(type, addr);
 757         if (!ret) {
 758                 MDBG_MOVE("mark recurse\n");
 759                 type->mark(addr);
 760         }
 761         MDBG_MOVE_OUT();
 762         return ret;
 763 }
 764
 765 /*
 766  * Mark an object, unless it is a cons cell and
 767  * do_note_cons is set. In that case, just
 768  * set a bit in the cons note array; those
 769  * will be marked in a separate pass to avoid
 770  * deep recursion in the collector
 771  */
 772 int
 773 ao_scheme_poly_mark(ao_poly p, uint8_t do_note_cons)
 774 {
 775         uint8_t type;
 776         void    *addr;
 777         int     ret;
 778
 779         type = ao_scheme_poly_base_type(p);
 780
 781         if (type == AO_SCHEME_INT)
 782                 return 1;
 783
 784         addr = ao_scheme_ref(p);
 785         if (!AO_SCHEME_IS_POOL(addr))
 786                 return 1;
 787
 788         if (type == AO_SCHEME_CONS && do_note_cons) {
 789                 note_cons(pool_offset(addr));
 790                 return 1;
 791         } else {
 792                 const struct ao_scheme_type *lisp_type;
 793
 794                 if (type == AO_SCHEME_OTHER)
 795                         type = ao_scheme_other_type(addr);
 796
 797                 lisp_type = ao_scheme_types[type];
 798 #if DBG_MEM
 799                 if (!lisp_type)
 800                         ao_scheme_abort();
 801 #endif
 802
 803                 MDBG_MOVE("mark %d\n", MDBG_OFFSET(addr));
 804                 MDBG_MOVE_IN();
 805                 ret = ao_scheme_mark_memory(lisp_type, addr);
 806                 if (!ret) {
 807                         MDBG_MOVE("mark recurse\n");
 808                         lisp_type->mark(addr);
 809                 }
 810                 MDBG_MOVE_OUT();
 811                 return ret;
 812         }
 813 }
 814
 815 /*
 816  * Find the current location of an object
 817  * based on the original location. For unmoved
 818  * objects, this is simple. For moved objects,
 819  * go search for it
 820  */
 821
 822 static uint16_t
 823 move_map(uint16_t offset)
 824 {
 825         int             l;
 826
 827         if (offset < chunk_low || chunk_high <= offset)
 828                 return offset;
 829
 830         l = find_chunk(offset);
 831
 832 #if DBG_MEM
 833         if (ao_scheme_chunk[l].old_offset != offset)
 834                 ao_scheme_abort();
 835 #endif
 836         return ao_scheme_chunk[l].new_offset;
 837 }
 838
 839 int
 840 ao_scheme_move_memory(const struct ao_scheme_type *type, void **ref)
 841 {
 842         void            *addr = *ref;
 843         uint16_t        offset, orig_offset;
 844
 845         if (!AO_SCHEME_IS_POOL(addr))
 846                 return 1;
 847
 848         (void) type;
 849
 850         MDBG_MOVE("move memory %d\n", MDBG_OFFSET(addr));
 851         orig_offset = pool_offset(addr);
 852         offset = move_map(orig_offset);
 853         if (offset != orig_offset) {
 854                 MDBG_MOVE("update ref %d %d -> %d\n",
 855                           AO_SCHEME_IS_POOL(ref) ? MDBG_OFFSET(ref) : -1,
 856                           orig_offset, offset);
 857                 *ref = ao_scheme_pool + offset;
 858         }
 859         if (busy(ao_scheme_busy, offset)) {
 860                 MDBG_MOVE("already moved\n");
 861                 return 1;
 862         }
 863         mark(ao_scheme_busy, offset);
 864         MDBG_DO(ao_scheme_record(type, addr, ao_scheme_size(type, addr)));
 865         return 0;
 866 }
 867
 868 static int
 869 ao_scheme_move(const struct ao_scheme_type *type, void **ref)
 870 {
 871         int ret;
 872         MDBG_MOVE("move object %d\n", MDBG_OFFSET(*ref));
 873         MDBG_MOVE_IN();
 874         ret = ao_scheme_move_memory(type, ref);
 875         if (!ret) {
 876                 MDBG_MOVE("move recurse\n");
 877                 type->move(*ref);
 878         }
 879         MDBG_MOVE_OUT();
 880         return ret;
 881 }
 882
 883 int
 884 ao_scheme_poly_move(ao_poly *ref, uint8_t do_note_cons)
 885 {
 886         ao_poly         p = *ref;
 887         int             ret;
 888         void            *addr;
 889         uint16_t        offset, orig_offset;
 890
 891         if (ao_scheme_poly_base_type(p) == AO_SCHEME_INT)
 892                 return 1;
 893
 894         addr = ao_scheme_ref(p);
 895         if (!AO_SCHEME_IS_POOL(addr))
 896                 return 1;
 897
 898         orig_offset = pool_offset(addr);
 899         offset = move_map(orig_offset);
 900
 901         if (ao_scheme_poly_base_type(p) == AO_SCHEME_CONS && do_note_cons) {
 902                 note_cons(orig_offset);
 903                 ret = 1;
 904         } else {
 905                 uint8_t type = ao_scheme_poly_base_type(p);
 906                 const struct ao_scheme_type *lisp_type;
 907
 908                 if (type == AO_SCHEME_OTHER)
 909                         type = ao_scheme_other_type(ao_scheme_pool + offset);
 910
 911                 lisp_type = ao_scheme_types[type];
 912 #if DBG_MEM
 913                 if (!lisp_type)
 914                         ao_scheme_abort();
 915 #endif
 916                 /* inline ao_scheme_move to save stack space */
 917                 MDBG_MOVE("move object %d\n", MDBG_OFFSET(addr));
 918                 MDBG_MOVE_IN();
 919                 ret = ao_scheme_move_memory(lisp_type, &addr);
 920                 if (!ret) {
 921                         MDBG_MOVE("move recurse\n");
 922                         lisp_type->move(addr);
 923                 }
 924                 MDBG_MOVE_OUT();
 925         }
 926
 927         /* Re-write the poly value */
 928         if (offset != orig_offset) {
 929                 ao_poly np = ao_scheme_poly(ao_scheme_pool + offset, ao_scheme_poly_base_type(p));
 930                 MDBG_MOVE("poly %d moved %d -> %d\n",
 931                           type, orig_offset, offset);
 932                 *ref = np;
 933         }
 934         return ret;
 935 }
 936
 937 #if DBG_MEM
 938 void
 939 ao_scheme_validate(void)
 940 {
 941         chunk_low = 0;
 942         memset(ao_scheme_chunk, '\0', sizeof (ao_scheme_chunk));
 943         walk(ao_scheme_mark_ref, ao_scheme_poly_mark_ref);
 944 }
 945
 946 int dbg_allocs;
 947
 948 #endif
 949
 950 void *
 951 ao_scheme_alloc(int size)
 952 {
 953         void    *addr;
 954
 955         MDBG_DO(++dbg_allocs);
 956         MDBG_DO(if (dbg_validate) ao_scheme_validate());
 957         size = ao_scheme_size_round(size);
 958         if (AO_SCHEME_POOL - ao_scheme_top < size &&
 959             ao_scheme_collect(AO_SCHEME_COLLECT_INCREMENTAL) < size &&
 960             ao_scheme_collect(AO_SCHEME_COLLECT_FULL) < size)
 961         {
 962                 ao_scheme_error(AO_SCHEME_OOM, "out of memory");
 963                 return NULL;
 964         }
 965         addr = ao_scheme_pool + ao_scheme_top;
 966         ao_scheme_top += size;
 967         MDBG_MOVE("alloc %d size %d\n", MDBG_OFFSET(addr), size);
 968         return addr;
 969 }
 970
 971 void
 972 ao_scheme_cons_stash(int id, struct ao_scheme_cons *cons)
 973 {
 974         assert(save_cons[id] == 0);
 975         save_cons[id] = cons;
 976 }
 977
 978 struct ao_scheme_cons *
 979 ao_scheme_cons_fetch(int id)
 980 {
 981         struct ao_scheme_cons *cons = save_cons[id];
 982         save_cons[id] = NULL;
 983         return cons;
 984 }
 985
 986 void
 987 ao_scheme_poly_stash(int id, ao_poly poly)
 988 {
 989         assert(save_poly[id] == AO_SCHEME_NIL);
 990         save_poly[id] = poly;
 991 }
 992
 993 ao_poly
 994 ao_scheme_poly_fetch(int id)
 995 {
 996         ao_poly poly = save_poly[id];
 997         save_poly[id] = AO_SCHEME_NIL;
 998         return poly;
 999 }
1000
1001 void
1002 ao_scheme_string_stash(int id, struct ao_scheme_string *string)
1003 {
1004         assert(save_string[id] == NULL);
1005         save_string[id] = string;
1006 }
1007
1008 struct ao_scheme_string *
1009 ao_scheme_string_fetch(int id)
1010 {
1011         struct ao_scheme_string *string = save_string[id];
1012         save_string[id] = NULL;
1013         return string;
1014 }
1015
1016 void
1017 ao_scheme_frame_stash(int id, struct ao_scheme_frame *frame)
1018 {
1019         assert(save_frame[id] == NULL);
1020         save_frame[id] = frame;
1021 }
1022
1023 struct ao_scheme_frame *
1024 ao_scheme_frame_fetch(int id)
1025 {
1026         struct ao_scheme_frame *frame = save_frame[id];
1027         save_frame[id] = NULL;
1028         return frame;
1029 }
1030
1031 int
1032 ao_scheme_print_mark_addr(void *addr)
1033 {
1034         int     offset;
1035
1036 #if DBG_MEM
1037         if (ao_scheme_collecting)
1038                 ao_scheme_abort();
1039 #endif
1040
1041         if (!AO_SCHEME_IS_POOL(addr))
1042                 return 1;
1043
1044         if (!ao_scheme_print_cleared) {
1045                 ao_scheme_print_cleared = 1;
1046                 memset(ao_scheme_busy, '\0', sizeof (ao_scheme_busy));
1047         }
1048         offset = pool_offset(addr);
1049         if (busy(ao_scheme_busy, offset))
1050                 return 1;
1051         mark(ao_scheme_busy, offset);
1052         return 0;
1053 }
1054
1055 int
1056 ao_scheme_print_mark_poly(ao_poly p)
1057 {
1058         uint8_t type = ao_scheme_poly_base_type(p);
1059
1060         if (type == AO_SCHEME_INT)
1061                 return 1;
1062         return ao_scheme_print_mark_addr(ao_scheme_ref(p));
1063 }
1064
1065 /* Notes that printing has started */
1066 void
1067 ao_scheme_print_start(void)
1068 {
1069         ao_scheme_printing++;
1070 }
1071
1072 /* Notes that printing has ended */
1073 void
1074 ao_scheme_print_stop(void)
1075 {
1076         ao_scheme_printing--;
1077         if (ao_scheme_printing == 0)
1078                 ao_scheme_print_cleared = 0;
1079 }