boehm-gc/misc.c

   1 /*
   2  * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
   3  * Copyright (c) 1991-1994 by Xerox Corporation.  All rights reserved.
   4  * Copyright (c) 1999-2001 by Hewlett-Packard Company. All rights reserved.
   5  *
   6  * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
   7  * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
   8  *
   9  * Permission is hereby granted to use or copy this program
  10  * for any purpose,  provided the above notices are retained on all copies.
  11  * Permission to modify the code and to distribute modified code is granted,
  12  * provided the above notices are retained, and a notice that the code was
  13  * modified is included with the above copyright notice.
  14  */
  15 /* Boehm, July 31, 1995 5:02 pm PDT */
  16
  17
  18 #include <stdio.h>
  19 #include <limits.h>
  20 #ifndef _WIN32_WCE
  21 #include <signal.h>
  22 #endif
  23
  24 #define I_HIDE_POINTERS /* To make GC_call_with_alloc_lock visible */
  25 #include "private/gc_pmark.h"
  26
  27 #ifdef GC_SOLARIS_THREADS
  28 # include <sys/syscall.h>
  29 #endif
  30 #if defined(MSWIN32) || defined(MSWINCE)
  31 # define WIN32_LEAN_AND_MEAN
  32 # define NOSERVICE
  33 # include <windows.h>
  34 # include <tchar.h>
  35 #endif
  36
  37 # ifdef THREADS
  38 #   ifdef PCR
  39 #     include "il/PCR_IL.h"
  40       PCR_Th_ML GC_allocate_ml;
  41 #   else
  42 #     ifdef SRC_M3
  43         /* Critical section counter is defined in the M3 runtime        */
  44         /* That's all we use.                                           */
  45 #     else
  46 #       ifdef GC_SOLARIS_THREADS
  47           mutex_t GC_allocate_ml;       /* Implicitly initialized.      */
  48 #       else
  49 #          ifdef GC_WIN32_THREADS
  50 #             if !defined(GC_NOT_DLL) && (defined(_DLL) || defined(GC_DLL))
  51                  __declspec(dllexport) CRITICAL_SECTION GC_allocate_ml;
  52 #             else
  53                  CRITICAL_SECTION GC_allocate_ml;
  54 #             endif
  55 #          else
  56 #             if defined(GC_PTHREADS) && !defined(GC_SOLARIS_THREADS)
  57 #               if defined(USE_SPIN_LOCK)
  58                   pthread_t GC_lock_holder = NO_THREAD;
  59 #               else
  60                   pthread_mutex_t GC_allocate_ml = PTHREAD_MUTEX_INITIALIZER;
  61                   pthread_t GC_lock_holder = NO_THREAD;
  62                         /* Used only for assertions, and to prevent      */
  63                         /* recursive reentry in the system call wrapper. */
  64 #               endif
  65 #             else
  66                   --> declare allocator lock here
  67 #             endif
  68 #          endif
  69 #       endif
  70 #     endif
  71 #   endif
  72 # endif
  73
  74 #if defined(NOSYS) || defined(ECOS)
  75 #undef STACKBASE
  76 #endif
  77
  78 GC_FAR struct _GC_arrays GC_arrays /* = { 0 } */;
  79
  80
  81 GC_bool GC_debugging_started = FALSE;
  82         /* defined here so we don't have to load debug_malloc.o */
  83
  84 void (*GC_check_heap) GC_PROTO((void)) = (void (*) GC_PROTO((void)))0;
  85
  86 void (*GC_start_call_back) GC_PROTO((void)) = (void (*) GC_PROTO((void)))0;
  87
  88 ptr_t GC_stackbottom = 0;
  89
  90 #ifdef IA64
  91   ptr_t GC_register_stackbottom = 0;
  92 #endif
  93
  94 GC_bool GC_dont_gc = 0;
  95
  96 GC_bool GC_dont_precollect = 0;
  97
  98 GC_bool GC_quiet = 0;
  99
 100 GC_bool GC_print_stats = 0;
 101
 102 GC_bool GC_print_back_height = 0;
 103
 104 #ifdef FIND_LEAK
 105   int GC_find_leak = 1;
 106 #else
 107   int GC_find_leak = 0;
 108 #endif
 109
 110 #ifdef ALL_INTERIOR_POINTERS
 111   int GC_all_interior_pointers = 1;
 112 #else
 113   int GC_all_interior_pointers = 0;
 114 #endif
 115
 116 long GC_large_alloc_warn_interval = 5;
 117         /* Interval between unsuppressed warnings.      */
 118
 119 long GC_large_alloc_warn_suppressed = 0;
 120         /* Number of warnings suppressed so far.        */
 121
 122 /*ARGSUSED*/
 123 GC_PTR GC_default_oom_fn GC_PROTO((size_t bytes_requested))
 124 {
 125     return(0);
 126 }
 127
 128 GC_PTR (*GC_oom_fn) GC_PROTO((size_t bytes_requested)) = GC_default_oom_fn;
 129
 130 extern signed_word GC_mem_found;
 131
 132 # ifdef MERGE_SIZES
 133     /* Set things up so that GC_size_map[i] >= words(i),                */
 134     /* but not too much bigger                                          */
 135     /* and so that size_map contains relatively few distinct entries    */
 136     /* This is stolen from Russ Atkinson's Cedar quantization           */
 137     /* alogrithm (but we precompute it).                                */
 138
 139
 140     void GC_init_size_map()
 141     {
 142         register unsigned i;
 143
 144         /* Map size 0 to something bigger.                      */
 145         /* This avoids problems at lower levels.                */
 146         /* One word objects don't have to be 2 word aligned,    */
 147         /* unless we're using mark bytes.                       */
 148           for (i = 0; i < sizeof(word); i++) {
 149               GC_size_map[i] = MIN_WORDS;
 150           }
 151 #         if MIN_WORDS > 1
 152             GC_size_map[sizeof(word)] = MIN_WORDS;
 153 #         else
 154             GC_size_map[sizeof(word)] = ROUNDED_UP_WORDS(sizeof(word));
 155 #         endif
 156         for (i = sizeof(word) + 1; i <= 8 * sizeof(word); i++) {
 157             GC_size_map[i] = ALIGNED_WORDS(i);
 158         }
 159         for (i = 8*sizeof(word) + 1; i <= 16 * sizeof(word); i++) {
 160               GC_size_map[i] = (ROUNDED_UP_WORDS(i) + 1) & (~1);
 161         }
 162 #       ifdef GC_GCJ_SUPPORT
 163            /* Make all sizes up to 32 words predictable, so that a      */
 164            /* compiler can statically perform the same computation,     */
 165            /* or at least a computation that results in similar size    */
 166            /* classes.                                                  */
 167            for (i = 16*sizeof(word) + 1; i <= 32 * sizeof(word); i++) {
 168               GC_size_map[i] = (ROUNDED_UP_WORDS(i) + 3) & (~3);
 169            }
 170 #       endif
 171         /* We leave the rest of the array to be filled in on demand. */
 172     }
 173
 174     /* Fill in additional entries in GC_size_map, including the ith one */
 175     /* We assume the ith entry is currently 0.                          */
 176     /* Note that a filled in section of the array ending at n always    */
 177     /* has length at least n/4.                                         */
 178     void GC_extend_size_map(i)
 179     word i;
 180     {
 181         word orig_word_sz = ROUNDED_UP_WORDS(i);
 182         word word_sz = orig_word_sz;
 183         register word byte_sz = WORDS_TO_BYTES(word_sz);
 184                                 /* The size we try to preserve.         */
 185                                 /* Close to to i, unless this would     */
 186                                 /* introduce too many distinct sizes.   */
 187         word smaller_than_i = byte_sz - (byte_sz >> 3);
 188         word much_smaller_than_i = byte_sz - (byte_sz >> 2);
 189         register word low_limit;        /* The lowest indexed entry we  */
 190                                         /* initialize.                  */
 191         register word j;
 192
 193         if (GC_size_map[smaller_than_i] == 0) {
 194             low_limit = much_smaller_than_i;
 195             while (GC_size_map[low_limit] != 0) low_limit++;
 196         } else {
 197             low_limit = smaller_than_i + 1;
 198             while (GC_size_map[low_limit] != 0) low_limit++;
 199             word_sz = ROUNDED_UP_WORDS(low_limit);
 200             word_sz += word_sz >> 3;
 201             if (word_sz < orig_word_sz) word_sz = orig_word_sz;
 202         }
 203 #       ifdef ALIGN_DOUBLE
 204             word_sz += 1;
 205             word_sz &= ~1;
 206 #       endif
 207         if (word_sz > MAXOBJSZ) {
 208             word_sz = MAXOBJSZ;
 209         }
 210         /* If we can fit the same number of larger objects in a block,  */
 211         /* do so.                                                       */
 212         {
 213             size_t number_of_objs = BODY_SZ/word_sz;
 214             word_sz = BODY_SZ/number_of_objs;
 215 #           ifdef ALIGN_DOUBLE
 216                 word_sz &= ~1;
 217 #           endif
 218         }
 219         byte_sz = WORDS_TO_BYTES(word_sz);
 220         if (GC_all_interior_pointers) {
 221             /* We need one extra byte; don't fill in GC_size_map[byte_sz] */
 222             byte_sz--;
 223         }
 224
 225         for (j = low_limit; j <= byte_sz; j++) GC_size_map[j] = word_sz;
 226     }
 227 # endif
 228
 229
 230 /*
 231  * The following is a gross hack to deal with a problem that can occur
 232  * on machines that are sloppy about stack frame sizes, notably SPARC.
 233  * Bogus pointers may be written to the stack and not cleared for
 234  * a LONG time, because they always fall into holes in stack frames
 235  * that are not written.  We partially address this by clearing
 236  * sections of the stack whenever we get control.
 237  */
 238 word GC_stack_last_cleared = 0; /* GC_no when we last did this */
 239 # ifdef THREADS
 240 #   define BIG_CLEAR_SIZE 2048  /* Clear this much now and then.        */
 241 #   define SMALL_CLEAR_SIZE 256 /* Clear this much every time.          */
 242 # endif
 243 # define CLEAR_SIZE 213  /* Granularity for GC_clear_stack_inner */
 244 # define DEGRADE_RATE 50
 245
 246 word GC_min_sp;         /* Coolest stack pointer value from which we've */
 247                         /* already cleared the stack.                   */
 248
 249 word GC_high_water;
 250                         /* "hottest" stack pointer value we have seen   */
 251                         /* recently.  Degrades over time.               */
 252
 253 word GC_words_allocd_at_reset;
 254
 255 #if defined(ASM_CLEAR_CODE)
 256   extern ptr_t GC_clear_stack_inner();
 257 #else
 258 /* Clear the stack up to about limit.  Return arg. */
 259 /*ARGSUSED*/
 260 ptr_t GC_clear_stack_inner(arg, limit)
 261 ptr_t arg;
 262 word limit;
 263 {
 264     word dummy[CLEAR_SIZE];
 265
 266     BZERO(dummy, CLEAR_SIZE*sizeof(word));
 267     if ((word)(dummy) COOLER_THAN limit) {
 268         (void) GC_clear_stack_inner(arg, limit);
 269     }
 270     /* Make sure the recursive call is not a tail call, and the bzero   */
 271     /* call is not recognized as dead code.                             */
 272     GC_noop1((word)dummy);
 273     return(arg);
 274 }
 275 #endif
 276
 277 /* Clear some of the inaccessible part of the stack.  Returns its       */
 278 /* argument, so it can be used in a tail call position, hence clearing  */
 279 /* another frame.                                                       */
 280 ptr_t GC_clear_stack(arg)
 281 ptr_t arg;
 282 {
 283     register word sp = (word)GC_approx_sp();  /* Hotter than actual sp */
 284 #   ifdef THREADS
 285         word dummy[SMALL_CLEAR_SIZE];
 286         static unsigned random_no = 0;
 287                                  /* Should be more random than it is ... */
 288                                  /* Used to occasionally clear a bigger  */
 289                                  /* chunk.                               */
 290 #   endif
 291     register word limit;
 292
 293 #   define SLOP 400
 294         /* Extra bytes we clear every time.  This clears our own        */
 295         /* activation record, and should cause more frequent            */
 296         /* clearing near the cold end of the stack, a good thing.       */
 297 #   define GC_SLOP 4000
 298         /* We make GC_high_water this much hotter than we really saw    */
 299         /* saw it, to cover for GC noise etc. above our current frame.  */
 300 #   define CLEAR_THRESHOLD 100000
 301         /* We restart the clearing process after this many bytes of     */
 302         /* allocation.  Otherwise very heavily recursive programs       */
 303         /* with sparse stacks may result in heaps that grow almost      */
 304         /* without bounds.  As the heap gets larger, collection         */
 305         /* frequency decreases, thus clearing frequency would decrease, */
 306         /* thus more junk remains accessible, thus the heap gets        */
 307         /* larger ...                                                   */
 308 # ifdef THREADS
 309     if (++random_no % 13 == 0) {
 310         limit = sp;
 311         MAKE_HOTTER(limit, BIG_CLEAR_SIZE*sizeof(word));
 312         limit &= ~0xf;  /* Make it sufficiently aligned for assembly    */
 313                         /* implementations of GC_clear_stack_inner.     */
 314         return GC_clear_stack_inner(arg, limit);
 315     } else {
 316         BZERO(dummy, SMALL_CLEAR_SIZE*sizeof(word));
 317         return arg;
 318     }
 319 # else
 320     if (GC_gc_no > GC_stack_last_cleared) {
 321         /* Start things over, so we clear the entire stack again */
 322         if (GC_stack_last_cleared == 0) GC_high_water = (word) GC_stackbottom;
 323         GC_min_sp = GC_high_water;
 324         GC_stack_last_cleared = GC_gc_no;
 325         GC_words_allocd_at_reset = GC_words_allocd;
 326     }
 327     /* Adjust GC_high_water */
 328         MAKE_COOLER(GC_high_water, WORDS_TO_BYTES(DEGRADE_RATE) + GC_SLOP);
 329         if (sp HOTTER_THAN GC_high_water) {
 330             GC_high_water = sp;
 331         }
 332         MAKE_HOTTER(GC_high_water, GC_SLOP);
 333     limit = GC_min_sp;
 334     MAKE_HOTTER(limit, SLOP);
 335     if (sp COOLER_THAN limit) {
 336         limit &= ~0xf;  /* Make it sufficiently aligned for assembly    */
 337                         /* implementations of GC_clear_stack_inner.     */
 338         GC_min_sp = sp;
 339         return(GC_clear_stack_inner(arg, limit));
 340     } else if (WORDS_TO_BYTES(GC_words_allocd - GC_words_allocd_at_reset)
 341                > CLEAR_THRESHOLD) {
 342         /* Restart clearing process, but limit how much clearing we do. */
 343         GC_min_sp = sp;
 344         MAKE_HOTTER(GC_min_sp, CLEAR_THRESHOLD/4);
 345         if (GC_min_sp HOTTER_THAN GC_high_water) GC_min_sp = GC_high_water;
 346         GC_words_allocd_at_reset = GC_words_allocd;
 347     }
 348     return(arg);
 349 # endif
 350 }
 351
 352
 353 /* Return a pointer to the base address of p, given a pointer to a      */
 354 /* an address within an object.  Return 0 o.w.                          */
 355 # ifdef __STDC__
 356     GC_PTR GC_base(GC_PTR p)
 357 # else
 358     GC_PTR GC_base(p)
 359     GC_PTR p;
 360 # endif
 361 {
 362     register word r;
 363     register struct hblk *h;
 364     register bottom_index *bi;
 365     register hdr *candidate_hdr;
 366     register word limit;
 367
 368     r = (word)p;
 369     if (!GC_is_initialized) return 0;
 370     h = HBLKPTR(r);
 371     GET_BI(r, bi);
 372     candidate_hdr = HDR_FROM_BI(bi, r);
 373     if (candidate_hdr == 0) return(0);
 374     /* If it's a pointer to the middle of a large object, move it       */
 375     /* to the beginning.                                                */
 376         while (IS_FORWARDING_ADDR_OR_NIL(candidate_hdr)) {
 377            h = FORWARDED_ADDR(h,candidate_hdr);
 378            r = (word)h;
 379            candidate_hdr = HDR(h);
 380         }
 381     if (candidate_hdr -> hb_map == GC_invalid_map) return(0);
 382     /* Make sure r points to the beginning of the object */
 383         r &= ~(WORDS_TO_BYTES(1) - 1);
 384         {
 385             register int offset = HBLKDISPL(r);
 386             register signed_word sz = candidate_hdr -> hb_sz;
 387             register signed_word map_entry;
 388
 389             map_entry = MAP_ENTRY((candidate_hdr -> hb_map), offset);
 390             if (map_entry > CPP_MAX_OFFSET) {
 391                 map_entry = (signed_word)(BYTES_TO_WORDS(offset)) % sz;
 392             }
 393             r -= WORDS_TO_BYTES(map_entry);
 394             limit = r + WORDS_TO_BYTES(sz);
 395             if (limit > (word)(h + 1)
 396                 && sz <= BYTES_TO_WORDS(HBLKSIZE)) {
 397                 return(0);
 398             }
 399             if ((word)p >= limit) return(0);
 400         }
 401     return((GC_PTR)r);
 402 }
 403
 404
 405 /* Return the size of an object, given a pointer to its base.           */
 406 /* (For small obects this also happens to work from interior pointers,  */
 407 /* but that shouldn't be relied upon.)                                  */
 408 # ifdef __STDC__
 409     size_t GC_size(GC_PTR p)
 410 # else
 411     size_t GC_size(p)
 412     GC_PTR p;
 413 # endif
 414 {
 415     register int sz;
 416     register hdr * hhdr = HDR(p);
 417
 418     sz = WORDS_TO_BYTES(hhdr -> hb_sz);
 419     return(sz);
 420 }
 421
 422 size_t GC_get_heap_size GC_PROTO(())
 423 {
 424     return ((size_t) GC_heapsize);
 425 }
 426
 427 size_t GC_get_free_bytes GC_PROTO(())
 428 {
 429     return ((size_t) GC_large_free_bytes);
 430 }
 431
 432 size_t GC_get_bytes_since_gc GC_PROTO(())
 433 {
 434     return ((size_t) WORDS_TO_BYTES(GC_words_allocd));
 435 }
 436
 437 size_t GC_get_total_bytes GC_PROTO(())
 438 {
 439     return ((size_t) WORDS_TO_BYTES(GC_words_allocd+GC_words_allocd_before_gc));
 440 }
 441
 442 GC_bool GC_is_initialized = FALSE;
 443
 444 void GC_init()
 445 {
 446     DCL_LOCK_STATE;
 447
 448     DISABLE_SIGNALS();
 449
 450 #ifdef MSWIN32
 451     if (!GC_is_initialized) InitializeCriticalSection(&GC_allocate_ml);
 452 #endif /* MSWIN32 */
 453
 454     LOCK();
 455     GC_init_inner();
 456     UNLOCK();
 457     ENABLE_SIGNALS();
 458
 459 #   if defined(PARALLEL_MARK) || defined(THREAD_LOCAL_ALLOC)
 460         /* Make sure marker threads and started and thread local */
 461         /* allocation is initialized, in case we didn't get      */
 462         /* called from GC_init_parallel();                       */
 463         {
 464           extern void GC_init_parallel(void);
 465           GC_init_parallel();
 466         }
 467 #   endif /* PARALLEL_MARK || THREAD_LOCAL_ALLOC */
 468 }
 469
 470 #if defined(MSWIN32) || defined(MSWINCE)
 471     CRITICAL_SECTION GC_write_cs;
 472 #endif
 473
 474 #ifdef MSWIN32
 475     extern void GC_init_win32 GC_PROTO((void));
 476 #endif
 477
 478 extern void GC_setpagesize();
 479
 480 #ifdef UNIX_LIKE
 481
 482 extern void GC_set_and_save_fault_handler GC_PROTO((void (*handler)(int)));
 483
 484 static void looping_handler(sig)
 485 int sig;
 486 {
 487     GC_err_printf1("Caught signal %d: looping in handler\n", sig);
 488     for(;;);
 489 }
 490 #endif
 491
 492 #ifdef MSWIN32
 493 extern GC_bool GC_no_win32_dlls;
 494 #else
 495 # define GC_no_win32_dlls FALSE
 496 #endif
 497
 498 void GC_init_inner()
 499 {
 500 #   if !defined(THREADS) && defined(GC_ASSERTIONS)
 501         word dummy;
 502 #   endif
 503     word initial_heap_sz = (word)MINHINCR;
 504
 505     if (GC_is_initialized) return;
 506 #   ifdef PRINTSTATS
 507       GC_print_stats = 1;
 508 #   endif
 509 #   if defined(MSWIN32) || defined(MSWINCE)
 510         InitializeCriticalSection(&GC_write_cs);
 511 #   endif
 512
 513     if (0 != GETENV("GC_PRINT_STATS")) {
 514       GC_print_stats = 1;
 515     }
 516     if (0 != GETENV("GC_FIND_LEAK")) {
 517       GC_find_leak = 1;
 518     }
 519     if (0 != GETENV("GC_ALL_INTERIOR_POINTERS")) {
 520       GC_all_interior_pointers = 1;
 521     }
 522     if (0 != GETENV("GC_DONT_GC")) {
 523       GC_dont_gc = 1;
 524     }
 525     if (0 != GETENV("GC_PRINT_BACK_HEIGHT")) {
 526       GC_print_back_height = 1;
 527     }
 528     if (0 != GETENV("GC_NO_BLACKLIST_WARNING")) {
 529       GC_large_alloc_warn_interval = LONG_MAX;
 530     }
 531     {
 532       char * time_limit_string = GETENV("GC_PAUSE_TIME_TARGET");
 533       if (0 != time_limit_string) {
 534         long time_limit = atol(time_limit_string);
 535         if (time_limit < 5) {
 536           WARN("GC_PAUSE_TIME_TARGET environment variable value too small "
 537                "or bad syntax: Ignoring\n", 0);
 538         } else {
 539           GC_time_limit = time_limit;
 540         }
 541       }
 542     }
 543     {
 544       char * interval_string = GETENV("GC_LARGE_ALLOC_WARN_INTERVAL");
 545       if (0 != interval_string) {
 546         long interval = atol(interval_string);
 547         if (interval <= 0) {
 548           WARN("GC_LARGE_ALLOC_WARN_INTERVAL environment variable has "
 549                "bad value: Ignoring\n", 0);
 550         } else {
 551           GC_large_alloc_warn_interval = interval;
 552         }
 553       }
 554     }
 555 #   ifdef UNIX_LIKE
 556       if (0 != GETENV("GC_LOOP_ON_ABORT")) {
 557         GC_set_and_save_fault_handler(looping_handler);
 558       }
 559 #   endif
 560     /* Adjust normal object descriptor for extra allocation.    */
 561     if (ALIGNMENT > GC_DS_TAGS && EXTRA_BYTES != 0) {
 562       GC_obj_kinds[NORMAL].ok_descriptor = ((word)(-ALIGNMENT) | GC_DS_LENGTH);
 563     }
 564     GC_setpagesize();
 565     GC_exclude_static_roots(beginGC_arrays, endGC_arrays);
 566     GC_exclude_static_roots(beginGC_obj_kinds, endGC_obj_kinds);
 567 #   ifdef SEPARATE_GLOBALS
 568       GC_exclude_static_roots(beginGC_objfreelist, endGC_objfreelist);
 569       GC_exclude_static_roots(beginGC_aobjfreelist, endGC_aobjfreelist);
 570 #   endif
 571 #   ifdef MSWIN32
 572         GC_init_win32();
 573 #   endif
 574 #   if defined(SEARCH_FOR_DATA_START)
 575         GC_init_linux_data_start();
 576 #   endif
 577 #   if (defined(NETBSD) || defined(OPENBSD)) && defined(__ELF__)
 578         GC_init_netbsd_elf();
 579 #   endif
 580 #   if defined(GC_PTHREADS) || defined(GC_SOLARIS_THREADS)
 581         GC_thr_init();
 582 #   endif
 583 #   ifdef GC_SOLARIS_THREADS
 584         /* We need dirty bits in order to find live stack sections.     */
 585         GC_dirty_init();
 586 #   endif
 587 #   if !defined(THREADS) || defined(GC_PTHREADS) || defined(GC_WIN32_THREADS) \
 588         || defined(GC_SOLARIS_THREADS)
 589       if (GC_stackbottom == 0) {
 590         GC_stackbottom = GC_get_stack_base();
 591 #       if defined(LINUX) && defined(IA64)
 592           GC_register_stackbottom = GC_get_register_stack_base();
 593 #       endif
 594       }
 595 #   endif
 596     GC_ASSERT(sizeof (ptr_t) == sizeof(word));
 597     GC_ASSERT(sizeof (signed_word) == sizeof(word));
 598     GC_ASSERT(sizeof (struct hblk) == HBLKSIZE);
 599 #   ifndef THREADS
 600 #     if defined(STACK_GROWS_UP) && defined(STACK_GROWS_DOWN)
 601         ABORT(
 602           "Only one of STACK_GROWS_UP and STACK_GROWS_DOWN should be defd\n");
 603 #     endif
 604 #     if !defined(STACK_GROWS_UP) && !defined(STACK_GROWS_DOWN)
 605         ABORT(
 606           "One of STACK_GROWS_UP and STACK_GROWS_DOWN should be defd\n");
 607 #     endif
 608 #     ifdef STACK_GROWS_DOWN
 609         GC_ASSERT((word)(&dummy) <= (word)GC_stackbottom);
 610 #     else
 611         GC_ASSERT((word)(&dummy) >= (word)GC_stackbottom);
 612 #     endif
 613 #   endif
 614 #   if !defined(_AUX_SOURCE) || defined(__GNUC__)
 615       GC_ASSERT((word)(-1) > (word)0);
 616       /* word should be unsigned */
 617 #   endif
 618     GC_ASSERT((signed_word)(-1) < (signed_word)0);
 619
 620     /* Add initial guess of root sets.  Do this first, since sbrk(0)    */
 621     /* might be used.                                                   */
 622       GC_register_data_segments();
 623     GC_init_headers();
 624     GC_bl_init();
 625     GC_mark_init();
 626     {
 627         char * sz_str = GETENV("GC_INITIAL_HEAP_SIZE");
 628         if (sz_str != NULL) {
 629           initial_heap_sz = atoi(sz_str);
 630           if (initial_heap_sz <= MINHINCR * HBLKSIZE) {
 631             WARN("Bad initial heap size %s - ignoring it.\n",
 632                  sz_str);
 633           }
 634           initial_heap_sz = divHBLKSZ(initial_heap_sz);
 635         }
 636     }
 637     if (!GC_expand_hp_inner(initial_heap_sz)) {
 638         GC_err_printf0("Can't start up: not enough memory\n");
 639         EXIT();
 640     }
 641     /* Preallocate large object map.  It's otherwise inconvenient to    */
 642     /* deal with failure.                                               */
 643       if (!GC_add_map_entry((word)0)) {
 644         GC_err_printf0("Can't start up: not enough memory\n");
 645         EXIT();
 646       }
 647     GC_register_displacement_inner(0L);
 648 #   ifdef MERGE_SIZES
 649       GC_init_size_map();
 650 #   endif
 651 #   ifdef PCR
 652       if (PCR_IL_Lock(PCR_Bool_false, PCR_allSigsBlocked, PCR_waitForever)
 653           != PCR_ERes_okay) {
 654           ABORT("Can't lock load state\n");
 655       } else if (PCR_IL_Unlock() != PCR_ERes_okay) {
 656           ABORT("Can't unlock load state\n");
 657       }
 658       PCR_IL_Unlock();
 659       GC_pcr_install();
 660 #   endif
 661 #   if !defined(SMALL_CONFIG)
 662       if (!GC_no_win32_dlls && 0 != GETENV("GC_ENABLE_INCREMENTAL")) {
 663         GC_ASSERT(!GC_incremental);
 664         GC_setpagesize();
 665 #       ifndef GC_SOLARIS_THREADS
 666           GC_dirty_init();
 667 #       endif
 668         GC_ASSERT(GC_words_allocd == 0)
 669         GC_incremental = TRUE;
 670       }
 671 #   endif /* !SMALL_CONFIG */
 672     /* Get black list set up and/or incrmental GC started */
 673       if (!GC_dont_precollect || GC_incremental) GC_gcollect_inner();
 674     GC_is_initialized = TRUE;
 675 #   ifdef STUBBORN_ALLOC
 676         GC_stubborn_init();
 677 #   endif
 678     /* Convince lint that some things are used */
 679 #   ifdef LINT
 680       {
 681           extern char * GC_copyright[];
 682           extern int GC_read();
 683           extern void GC_register_finalizer_no_order();
 684
 685           GC_noop(GC_copyright, GC_find_header,
 686                   GC_push_one, GC_call_with_alloc_lock, GC_read,
 687                   GC_dont_expand,
 688 #                 ifndef NO_DEBUGGING
 689                     GC_dump,
 690 #                 endif
 691                   GC_register_finalizer_no_order);
 692       }
 693 #   endif
 694 }
 695
 696 void GC_enable_incremental GC_PROTO(())
 697 {
 698 # if !defined(SMALL_CONFIG)
 699   if (!GC_find_leak) {
 700     DCL_LOCK_STATE;
 701
 702     DISABLE_SIGNALS();
 703     LOCK();
 704     if (GC_incremental) goto out;
 705     GC_setpagesize();
 706     if (GC_no_win32_dlls) goto out;
 707 #   ifndef GC_SOLARIS_THREADS
 708         GC_dirty_init();
 709 #   endif
 710     if (!GC_is_initialized) {
 711         GC_init_inner();
 712     }
 713     if (GC_incremental) goto out;
 714     if (GC_dont_gc) {
 715         /* Can't easily do it. */
 716         UNLOCK();
 717         ENABLE_SIGNALS();
 718         return;
 719     }
 720     if (GC_words_allocd > 0) {
 721         /* There may be unmarked reachable objects      */
 722         GC_gcollect_inner();
 723     }   /* else we're OK in assuming everything's       */
 724         /* clean since nothing can point to an          */
 725         /* unmarked object.                             */
 726     GC_read_dirty();
 727     GC_incremental = TRUE;
 728 out:
 729     UNLOCK();
 730     ENABLE_SIGNALS();
 731   }
 732 # endif
 733 }
 734
 735
 736 #if defined(MSWIN32) || defined(MSWINCE)
 737 # define LOG_FILE _T("gc.log")
 738
 739   HANDLE GC_stdout = 0;
 740
 741   void GC_deinit()
 742   {
 743       if (GC_is_initialized) {
 744         DeleteCriticalSection(&GC_write_cs);
 745       }
 746   }
 747
 748   int GC_write(buf, len)
 749   GC_CONST char * buf;
 750   size_t len;
 751   {
 752       BOOL tmp;
 753       DWORD written;
 754       if (len == 0)
 755           return 0;
 756       EnterCriticalSection(&GC_write_cs);
 757       if (GC_stdout == INVALID_HANDLE_VALUE) {
 758           return -1;
 759       } else if (GC_stdout == 0) {
 760           GC_stdout = CreateFile(LOG_FILE, GENERIC_WRITE,
 761                                  FILE_SHARE_READ | FILE_SHARE_WRITE,
 762                                  NULL, CREATE_ALWAYS, FILE_FLAG_WRITE_THROUGH,
 763                                  NULL);
 764           if (GC_stdout == INVALID_HANDLE_VALUE) ABORT("Open of log file failed");
 765       }
 766       tmp = WriteFile(GC_stdout, buf, len, &written, NULL);
 767       if (!tmp)
 768           DebugBreak();
 769       LeaveCriticalSection(&GC_write_cs);
 770       return tmp ? (int)written : -1;
 771   }
 772
 773 #endif
 774
 775 #if defined(OS2) || defined(MACOS)
 776 FILE * GC_stdout = NULL;
 777 FILE * GC_stderr = NULL;
 778 int GC_tmp;  /* Should really be local ... */
 779
 780   void GC_set_files()
 781   {
 782       if (GC_stdout == NULL) {
 783         GC_stdout = stdout;
 784     }
 785     if (GC_stderr == NULL) {
 786         GC_stderr = stderr;
 787     }
 788   }
 789 #endif
 790
 791 #if !defined(OS2) && !defined(MACOS) && !defined(MSWIN32) && !defined(MSWINCE)
 792   int GC_stdout = 1;
 793   int GC_stderr = 2;
 794 # if !defined(AMIGA)
 795 #   include <unistd.h>
 796 # endif
 797 #endif
 798
 799 #if !defined(MSWIN32) && !defined(MSWINCE) && !defined(OS2) \
 800     && !defined(MACOS)  && !defined(ECOS) && !defined(NOSYS)
 801 int GC_write(fd, buf, len)
 802 int fd;
 803 GC_CONST char *buf;
 804 size_t len;
 805 {
 806      register int bytes_written = 0;
 807      register int result;
 808
 809      while (bytes_written < len) {
 810 #       ifdef GC_SOLARIS_THREADS
 811             result = syscall(SYS_write, fd, buf + bytes_written,
 812                                             len - bytes_written);
 813 #       else
 814             result = write(fd, buf + bytes_written, len - bytes_written);
 815 #       endif
 816         if (-1 == result) return(result);
 817         bytes_written += result;
 818     }
 819     return(bytes_written);
 820 }
 821 #endif /* UN*X */
 822
 823 #ifdef ECOS
 824 int GC_write(fd, buf, len)
 825 {
 826   _Jv_diag_write (buf, len);
 827   return len;
 828 }
 829 #endif
 830
 831 #ifdef NOSYS
 832 int GC_write(fd, buf, len)
 833 {
 834   /* No writing.  */
 835   return len;
 836 }
 837 #endif
 838
 839
 840 #if defined(MSWIN32) || defined(MSWINCE)
 841 #   define WRITE(f, buf, len) GC_write(buf, len)
 842 #else
 843 #   if defined(OS2) || defined(MACOS)
 844 #   define WRITE(f, buf, len) (GC_set_files(), \
 845                                GC_tmp = fwrite((buf), 1, (len), (f)), \
 846                                fflush(f), GC_tmp)
 847 #   else
 848 #     define WRITE(f, buf, len) GC_write((f), (buf), (len))
 849 #   endif
 850 #endif
 851
 852 /* A version of printf that is unlikely to call malloc, and is thus safer */
 853 /* to call from the collector in case malloc has been bound to GC_malloc. */
 854 /* Assumes that no more than 1023 characters are written at once.         */
 855 /* Assumes that all arguments have been converted to something of the     */
 856 /* same size as long, and that the format conversions expect something    */
 857 /* of that size.                                                          */
 858 void GC_printf(format, a, b, c, d, e, f)
 859 GC_CONST char * format;
 860 long a, b, c, d, e, f;
 861 {
 862     char buf[1025];
 863
 864     if (GC_quiet) return;
 865     buf[1024] = 0x15;
 866     (void) sprintf(buf, format, a, b, c, d, e, f);
 867     if (buf[1024] != 0x15) ABORT("GC_printf clobbered stack");
 868     if (WRITE(GC_stdout, buf, strlen(buf)) < 0) ABORT("write to stdout failed");
 869 }
 870
 871 void GC_err_printf(format, a, b, c, d, e, f)
 872 GC_CONST char * format;
 873 long a, b, c, d, e, f;
 874 {
 875     char buf[1025];
 876
 877     buf[1024] = 0x15;
 878     (void) sprintf(buf, format, a, b, c, d, e, f);
 879     if (buf[1024] != 0x15) ABORT("GC_err_printf clobbered stack");
 880     if (WRITE(GC_stderr, buf, strlen(buf)) < 0) ABORT("write to stderr failed");
 881 }
 882
 883 void GC_err_puts(s)
 884 GC_CONST char *s;
 885 {
 886     if (WRITE(GC_stderr, s, strlen(s)) < 0) ABORT("write to stderr failed");
 887 }
 888
 889 #if defined(LINUX) && !defined(SMALL_CONFIG)
 890 void GC_err_write(buf, len)
 891 GC_CONST char *buf;
 892 size_t len;
 893 {
 894     if (WRITE(GC_stderr, buf, len) < 0) ABORT("write to stderr failed");
 895 }
 896 #endif
 897
 898 # if defined(__STDC__) || defined(__cplusplus)
 899     void GC_default_warn_proc(char *msg, GC_word arg)
 900 # else
 901     void GC_default_warn_proc(msg, arg)
 902     char *msg;
 903     GC_word arg;
 904 # endif
 905 {
 906     GC_err_printf1(msg, (unsigned long)arg);
 907 }
 908
 909 GC_warn_proc GC_current_warn_proc = GC_default_warn_proc;
 910
 911 # if defined(__STDC__) || defined(__cplusplus)
 912     GC_warn_proc GC_set_warn_proc(GC_warn_proc p)
 913 # else
 914     GC_warn_proc GC_set_warn_proc(p)
 915     GC_warn_proc p;
 916 # endif
 917 {
 918     GC_warn_proc result;
 919
 920     LOCK();
 921     result = GC_current_warn_proc;
 922     GC_current_warn_proc = p;
 923     UNLOCK();
 924     return(result);
 925 }
 926
 927
 928 #ifndef PCR
 929 void GC_abort(msg)
 930 GC_CONST char * msg;
 931 {
 932 #   if defined(MSWIN32)
 933       (void) MessageBoxA(NULL, msg, "Fatal error in gc", MB_ICONERROR|MB_OK);
 934       DebugBreak();
 935 #   else
 936       GC_err_printf1("%s\n", msg);
 937 #   endif
 938     if (GETENV("GC_LOOP_ON_ABORT") != NULL) {
 939             /* In many cases it's easier to debug a running process.    */
 940             /* It's arguably nicer to sleep, but that makes it harder   */
 941             /* to look at the thread if the debugger doesn't know much  */
 942             /* about threads.                                           */
 943             for(;;) {}
 944     }
 945 #   ifdef MSWIN32
 946         DebugBreak();
 947 #   else
 948         (void) abort();
 949 #   endif
 950 }
 951 #endif
 952
 953 #ifdef NEED_CALLINFO
 954
 955 #ifdef HAVE_BUILTIN_BACKTRACE
 956 # include <execinfo.h>
 957 # ifdef LINUX
 958 #   include <unistd.h>
 959 # endif
 960 #endif
 961
 962 void GC_print_callers (info)
 963 struct callinfo info[NFRAMES];
 964 {
 965     register int i;
 966
 967 #   if NFRAMES == 1
 968       GC_err_printf0("\tCaller at allocation:\n");
 969 #   else
 970       GC_err_printf0("\tCall chain at allocation:\n");
 971 #   endif
 972     for (i = 0; i < NFRAMES; i++) {
 973         if (info[i].ci_pc == 0) break;
 974 #       if NARGS > 0
 975         {
 976           int j;
 977
 978           GC_err_printf0("\t\targs: ");
 979           for (j = 0; j < NARGS; j++) {
 980             if (j != 0) GC_err_printf0(", ");
 981             GC_err_printf2("%d (0x%X)", ~(info[i].ci_arg[j]),
 982                                         ~(info[i].ci_arg[j]));
 983           }
 984           GC_err_printf0("\n");
 985         }
 986 #       endif
 987 #       if defined(HAVE_BUILTIN_BACKTRACE) && !defined(REDIRECT_MALLOC)
 988           /* Unfortunately backtrace_symbols calls malloc, which makes  */
 989           /* it dangersous if that has been redirected.                 */
 990           {
 991             char **sym_name =
 992               backtrace_symbols((void **)(&(info[i].ci_pc)), 1);
 993             char *name = sym_name[0];
 994             GC_bool found_it = (strchr(name, '(') != 0);
 995             FILE *pipe;
 996 #           ifdef LINUX
 997               if (!found_it) {
 998 #               define EXE_SZ 100
 999                 static char exe_name[EXE_SZ];
1000 #               define CMD_SZ 200
1001                 char cmd_buf[CMD_SZ];
1002 #               define RESULT_SZ 200
1003                 static char result_buf[RESULT_SZ];
1004                 size_t result_len;
1005                 static GC_bool found_exe_name = FALSE;
1006                 static GC_bool will_fail = FALSE;
1007                 int ret_code;
1008                 /* Unfortunately, this is the common case for the       */
1009                 /* main executable.                                     */
1010                 /* Try to get it via a hairy and expensive scheme.      */
1011                 /* First we get the name of the executable:             */
1012                 if (will_fail) goto out;
1013                 if (!found_exe_name) {
1014                   ret_code = readlink("/proc/self/exe", exe_name, EXE_SZ);
1015                   if (ret_code < 0 || ret_code >= EXE_SZ || exe_name[0] != '/') {
1016                     will_fail = TRUE;   /* Dont try again. */
1017                     goto out;
1018                   }
1019                   exe_name[ret_code] = '\0';
1020                   found_exe_name = TRUE;
1021                 }
1022                 /* Then we use popen to start addr2line -e <exe> <addr> */
1023                 /* There are faster ways to do this, but hopefully this */
1024                 /* isn't time critical.                                 */
1025                 sprintf(cmd_buf, "/usr/bin/addr2line -e %s 0x%lx", exe_name,
1026                                  (unsigned long)info[i].ci_pc);
1027                 pipe = popen(cmd_buf, "r");
1028                 if (pipe < 0 || fgets(result_buf, RESULT_SZ, pipe) == 0) {
1029                   will_fail = TRUE;
1030                   goto out;
1031                 }
1032                 result_len = strlen(result_buf);
1033                 if (result_buf[result_len - 1] == '\n') --result_len;
1034                 if (result_buf[0] == '?'
1035                     || result_buf[result_len-2] == ':'
1036                        && result_buf[result_len-1] == '0')
1037                     goto out;
1038                 if (result_len < RESULT_SZ - 25) {
1039                   /* Add in hex address */
1040                     sprintf(result_buf + result_len, " [0x%lx]",
1041                           (unsigned long)info[i].ci_pc);
1042                 }
1043                 name = result_buf;
1044                 pclose(pipe);
1045                 out:
1046               }
1047 #           endif
1048             GC_err_printf1("\t\t%s\n", name);
1049             free(sym_name);
1050           }
1051 #       else
1052           GC_err_printf1("\t\t##PC##= 0x%lx\n", info[i].ci_pc);
1053 #       endif
1054     }
1055 }
1056
1057 #endif /* SAVE_CALL_CHAIN */
1058
1059 /* Needed by SRC_M3, gcj, and should perhaps be the official interface  */
1060 /* to GC_dont_gc.                                                       */
1061 void GC_enable()
1062 {
1063     GC_dont_gc--;
1064 }
1065
1066 void GC_disable()
1067 {
1068     GC_dont_gc++;
1069 }
1070
1071 #if !defined(NO_DEBUGGING)
1072
1073 void GC_dump()
1074 {
1075     GC_printf0("***Static roots:\n");
1076     GC_print_static_roots();
1077     GC_printf0("\n***Heap sections:\n");
1078     GC_print_heap_sects();
1079     GC_printf0("\n***Free blocks:\n");
1080     GC_print_hblkfreelist();
1081     GC_printf0("\n***Blocks in use:\n");
1082     GC_print_block_list();
1083 }
1084
1085 #endif /* NO_DEBUGGING */