libgc/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 #          if defined(GC_WIN32_THREADS)
  50 #             if defined(GC_PTHREADS)
  51                   pthread_mutex_t GC_allocate_ml = PTHREAD_MUTEX_INITIALIZER;
  52 #             elif defined(GC_DLL)
  53                  __declspec(dllexport) CRITICAL_SECTION GC_allocate_ml;
  54 #             else
  55                  CRITICAL_SECTION GC_allocate_ml;
  56 #             endif
  57 #          else
  58 #             if defined(GC_PTHREADS) && !defined(GC_SOLARIS_THREADS)
  59 #               if defined(USE_SPIN_LOCK)
  60                   pthread_t GC_lock_holder = NO_THREAD;
  61 #               else
  62                   pthread_mutex_t GC_allocate_ml = PTHREAD_MUTEX_INITIALIZER;
  63                   pthread_t GC_lock_holder = NO_THREAD;
  64                         /* Used only for assertions, and to prevent      */
  65                         /* recursive reentry in the system call wrapper. */
  66 #               endif
  67 #             else
  68                   --> declare allocator lock here
  69 #             endif
  70 #          endif
  71 #       endif
  72 #     endif
  73 #   endif
  74 # endif
  75
  76 #if defined(NOSYS) || defined(ECOS)
  77 #undef STACKBASE
  78 #endif
  79
  80 /* Dont unnecessarily call GC_register_main_static_data() in case       */
  81 /* dyn_load.c isn't linked in.                                          */
  82 #ifdef DYNAMIC_LOADING
  83 # define GC_REGISTER_MAIN_STATIC_DATA() GC_register_main_static_data()
  84 #elif defined(GC_DONT_REGISTER_MAIN_STATIC_DATA)
  85 # define GC_REGISTER_MAIN_STATIC_DATA() FALSE
  86 #else
  87 # define GC_REGISTER_MAIN_STATIC_DATA() TRUE
  88 #endif
  89
  90 GC_FAR struct _GC_arrays GC_arrays /* = { 0 } */;
  91
  92
  93 GC_bool GC_debugging_started = FALSE;
  94         /* defined here so we don't have to load debug_malloc.o */
  95
  96 void (*GC_check_heap) GC_PROTO((void)) = (void (*) GC_PROTO((void)))0;
  97 void (*GC_print_all_smashed) GC_PROTO((void)) = (void (*) GC_PROTO((void)))0;
  98
  99 void (*GC_start_call_back) GC_PROTO((void)) = (void (*) GC_PROTO((void)))0;
 100
 101 ptr_t GC_stackbottom = 0;
 102
 103 #ifdef IA64
 104   ptr_t GC_register_stackbottom = 0;
 105 #endif
 106
 107 GC_bool GC_dont_gc = 0;
 108
 109 GC_bool GC_dont_precollect = 0;
 110
 111 GC_bool GC_quiet = 0;
 112
 113 GC_bool GC_print_stats = 0;
 114
 115 GC_bool GC_print_back_height = 0;
 116
 117 #ifndef NO_DEBUGGING
 118   GC_bool GC_dump_regularly = 0;  /* Generate regular debugging dumps. */
 119 #endif
 120
 121 #ifdef KEEP_BACK_PTRS
 122   long GC_backtraces = 0;       /* Number of random backtraces to       */
 123                                 /* generate for each GC.                */
 124 #endif
 125
 126 #ifdef FIND_LEAK
 127   int GC_find_leak = 1;
 128 #else
 129   int GC_find_leak = 0;
 130 #endif
 131
 132 #ifdef ALL_INTERIOR_POINTERS
 133   int GC_all_interior_pointers = 1;
 134 #else
 135   int GC_all_interior_pointers = 0;
 136 #endif
 137
 138 long GC_large_alloc_warn_interval = 5;
 139         /* Interval between unsuppressed warnings.      */
 140
 141 long GC_large_alloc_warn_suppressed = 0;
 142         /* Number of warnings suppressed so far.        */
 143
 144 /*ARGSUSED*/
 145 GC_PTR GC_default_oom_fn GC_PROTO((size_t bytes_requested))
 146 {
 147     return(0);
 148 }
 149
 150 GC_PTR (*GC_oom_fn) GC_PROTO((size_t bytes_requested)) = GC_default_oom_fn;
 151
 152 extern signed_word GC_mem_found;
 153
 154 void * GC_project2(arg1, arg2)
 155 void *arg1;
 156 void *arg2;
 157 {
 158   return arg2;
 159 }
 160
 161 # ifdef MERGE_SIZES
 162     /* Set things up so that GC_size_map[i] >= words(i),                */
 163     /* but not too much bigger                                          */
 164     /* and so that size_map contains relatively few distinct entries    */
 165     /* This is stolen from Russ Atkinson's Cedar quantization           */
 166     /* alogrithm (but we precompute it).                                */
 167
 168
 169     void GC_init_size_map()
 170     {
 171         register unsigned i;
 172
 173         /* Map size 0 to something bigger.                      */
 174         /* This avoids problems at lower levels.                */
 175         /* One word objects don't have to be 2 word aligned,    */
 176         /* unless we're using mark bytes.                       */
 177           for (i = 0; i < sizeof(word); i++) {
 178               GC_size_map[i] = MIN_WORDS;
 179           }
 180 #         if MIN_WORDS > 1
 181             GC_size_map[sizeof(word)] = MIN_WORDS;
 182 #         else
 183             GC_size_map[sizeof(word)] = ROUNDED_UP_WORDS(sizeof(word));
 184 #         endif
 185         for (i = sizeof(word) + 1; i <= 8 * sizeof(word); i++) {
 186             GC_size_map[i] = ALIGNED_WORDS(i);
 187         }
 188         for (i = 8*sizeof(word) + 1; i <= 16 * sizeof(word); i++) {
 189               GC_size_map[i] = (ROUNDED_UP_WORDS(i) + 1) & (~1);
 190         }
 191 #       ifdef GC_GCJ_SUPPORT
 192            /* Make all sizes up to 32 words predictable, so that a      */
 193            /* compiler can statically perform the same computation,     */
 194            /* or at least a computation that results in similar size    */
 195            /* classes.                                                  */
 196            for (i = 16*sizeof(word) + 1; i <= 32 * sizeof(word); i++) {
 197               GC_size_map[i] = (ROUNDED_UP_WORDS(i) + 3) & (~3);
 198            }
 199 #       endif
 200         /* We leave the rest of the array to be filled in on demand. */
 201     }
 202
 203     /* Fill in additional entries in GC_size_map, including the ith one */
 204     /* We assume the ith entry is currently 0.                          */
 205     /* Note that a filled in section of the array ending at n always    */
 206     /* has length at least n/4.                                         */
 207     void GC_extend_size_map(i)
 208     word i;
 209     {
 210         word orig_word_sz = ROUNDED_UP_WORDS(i);
 211         word word_sz = orig_word_sz;
 212         register word byte_sz = WORDS_TO_BYTES(word_sz);
 213                                 /* The size we try to preserve.         */
 214                                 /* Close to to i, unless this would     */
 215                                 /* introduce too many distinct sizes.   */
 216         word smaller_than_i = byte_sz - (byte_sz >> 3);
 217         word much_smaller_than_i = byte_sz - (byte_sz >> 2);
 218         register word low_limit;        /* The lowest indexed entry we  */
 219                                         /* initialize.                  */
 220         register word j;
 221
 222         if (GC_size_map[smaller_than_i] == 0) {
 223             low_limit = much_smaller_than_i;
 224             while (GC_size_map[low_limit] != 0) low_limit++;
 225         } else {
 226             low_limit = smaller_than_i + 1;
 227             while (GC_size_map[low_limit] != 0) low_limit++;
 228             word_sz = ROUNDED_UP_WORDS(low_limit);
 229             word_sz += word_sz >> 3;
 230             if (word_sz < orig_word_sz) word_sz = orig_word_sz;
 231         }
 232 #       ifdef ALIGN_DOUBLE
 233             word_sz += 1;
 234             word_sz &= ~1;
 235 #       endif
 236         if (word_sz > MAXOBJSZ) {
 237             word_sz = MAXOBJSZ;
 238         }
 239         /* If we can fit the same number of larger objects in a block,  */
 240         /* do so.                                                       */
 241         {
 242             size_t number_of_objs = BODY_SZ/word_sz;
 243             word_sz = BODY_SZ/number_of_objs;
 244 #           ifdef ALIGN_DOUBLE
 245                 word_sz &= ~1;
 246 #           endif
 247         }
 248         byte_sz = WORDS_TO_BYTES(word_sz);
 249         if (GC_all_interior_pointers) {
 250             /* We need one extra byte; don't fill in GC_size_map[byte_sz] */
 251             byte_sz -= EXTRA_BYTES;
 252         }
 253
 254         for (j = low_limit; j <= byte_sz; j++) GC_size_map[j] = word_sz;
 255     }
 256 # endif
 257
 258
 259 /*
 260  * The following is a gross hack to deal with a problem that can occur
 261  * on machines that are sloppy about stack frame sizes, notably SPARC.
 262  * Bogus pointers may be written to the stack and not cleared for
 263  * a LONG time, because they always fall into holes in stack frames
 264  * that are not written.  We partially address this by clearing
 265  * sections of the stack whenever we get control.
 266  */
 267 word GC_stack_last_cleared = 0; /* GC_no when we last did this */
 268 # ifdef THREADS
 269 #   define BIG_CLEAR_SIZE 2048  /* Clear this much now and then.        */
 270 #   define SMALL_CLEAR_SIZE 256 /* Clear this much every time.          */
 271 # endif
 272 # define CLEAR_SIZE 213  /* Granularity for GC_clear_stack_inner */
 273 # define DEGRADE_RATE 50
 274
 275 word GC_min_sp;         /* Coolest stack pointer value from which we've */
 276                         /* already cleared the stack.                   */
 277
 278 word GC_high_water;
 279                         /* "hottest" stack pointer value we have seen   */
 280                         /* recently.  Degrades over time.               */
 281
 282 word GC_words_allocd_at_reset;
 283
 284 #if defined(ASM_CLEAR_CODE)
 285   extern ptr_t GC_clear_stack_inner();
 286 #else
 287 /* Clear the stack up to about limit.  Return arg. */
 288 /*ARGSUSED*/
 289 ptr_t GC_clear_stack_inner(arg, limit)
 290 ptr_t arg;
 291 word limit;
 292 {
 293     word dummy[CLEAR_SIZE];
 294
 295     BZERO(dummy, CLEAR_SIZE*sizeof(word));
 296     if ((word)(dummy) COOLER_THAN limit) {
 297         (void) GC_clear_stack_inner(arg, limit);
 298     }
 299     /* Make sure the recursive call is not a tail call, and the bzero   */
 300     /* call is not recognized as dead code.                             */
 301     GC_noop1((word)dummy);
 302     return(arg);
 303 }
 304 #endif
 305
 306 /* Clear some of the inaccessible part of the stack.  Returns its       */
 307 /* argument, so it can be used in a tail call position, hence clearing  */
 308 /* another frame.                                                       */
 309 ptr_t GC_clear_stack(arg)
 310 ptr_t arg;
 311 {
 312     register word sp = (word)GC_approx_sp();  /* Hotter than actual sp */
 313 #   ifdef THREADS
 314         word dummy[SMALL_CLEAR_SIZE];
 315         static unsigned random_no = 0;
 316                                  /* Should be more random than it is ... */
 317                                  /* Used to occasionally clear a bigger  */
 318                                  /* chunk.                               */
 319 #   endif
 320     register word limit;
 321
 322 #   define SLOP 400
 323         /* Extra bytes we clear every time.  This clears our own        */
 324         /* activation record, and should cause more frequent            */
 325         /* clearing near the cold end of the stack, a good thing.       */
 326 #   define GC_SLOP 4000
 327         /* We make GC_high_water this much hotter than we really saw    */
 328         /* saw it, to cover for GC noise etc. above our current frame.  */
 329 #   define CLEAR_THRESHOLD 100000
 330         /* We restart the clearing process after this many bytes of     */
 331         /* allocation.  Otherwise very heavily recursive programs       */
 332         /* with sparse stacks may result in heaps that grow almost      */
 333         /* without bounds.  As the heap gets larger, collection         */
 334         /* frequency decreases, thus clearing frequency would decrease, */
 335         /* thus more junk remains accessible, thus the heap gets        */
 336         /* larger ...                                                   */
 337 # ifdef THREADS
 338     if (++random_no % 13 == 0) {
 339         limit = sp;
 340         MAKE_HOTTER(limit, BIG_CLEAR_SIZE*sizeof(word));
 341         limit &= ~0xf;  /* Make it sufficiently aligned for assembly    */
 342                         /* implementations of GC_clear_stack_inner.     */
 343         return GC_clear_stack_inner(arg, limit);
 344     } else {
 345         BZERO(dummy, SMALL_CLEAR_SIZE*sizeof(word));
 346         return arg;
 347     }
 348 # else
 349     if (GC_gc_no > GC_stack_last_cleared) {
 350         /* Start things over, so we clear the entire stack again */
 351         if (GC_stack_last_cleared == 0) GC_high_water = (word) GC_stackbottom;
 352         GC_min_sp = GC_high_water;
 353         GC_stack_last_cleared = GC_gc_no;
 354         GC_words_allocd_at_reset = GC_words_allocd;
 355     }
 356     /* Adjust GC_high_water */
 357         MAKE_COOLER(GC_high_water, WORDS_TO_BYTES(DEGRADE_RATE) + GC_SLOP);
 358         if (sp HOTTER_THAN GC_high_water) {
 359             GC_high_water = sp;
 360         }
 361         MAKE_HOTTER(GC_high_water, GC_SLOP);
 362     limit = GC_min_sp;
 363     MAKE_HOTTER(limit, SLOP);
 364     if (sp COOLER_THAN limit) {
 365         limit &= ~0xf;  /* Make it sufficiently aligned for assembly    */
 366                         /* implementations of GC_clear_stack_inner.     */
 367         GC_min_sp = sp;
 368         return(GC_clear_stack_inner(arg, limit));
 369     } else if (WORDS_TO_BYTES(GC_words_allocd - GC_words_allocd_at_reset)
 370                > CLEAR_THRESHOLD) {
 371         /* Restart clearing process, but limit how much clearing we do. */
 372         GC_min_sp = sp;
 373         MAKE_HOTTER(GC_min_sp, CLEAR_THRESHOLD/4);
 374         if (GC_min_sp HOTTER_THAN GC_high_water) GC_min_sp = GC_high_water;
 375         GC_words_allocd_at_reset = GC_words_allocd;
 376     }
 377     return(arg);
 378 # endif
 379 }
 380
 381
 382 /* Return a pointer to the base address of p, given a pointer to a      */
 383 /* an address within an object.  Return 0 o.w.                          */
 384 # ifdef __STDC__
 385     GC_PTR GC_base(GC_PTR p)
 386 # else
 387     GC_PTR GC_base(p)
 388     GC_PTR p;
 389 # endif
 390 {
 391     register word r;
 392     register struct hblk *h;
 393     register bottom_index *bi;
 394     register hdr *candidate_hdr;
 395     register word limit;
 396
 397     r = (word)p;
 398     if (!GC_is_initialized) return 0;
 399     h = HBLKPTR(r);
 400     GET_BI(r, bi);
 401     candidate_hdr = HDR_FROM_BI(bi, r);
 402     if (candidate_hdr == 0) return(0);
 403     /* If it's a pointer to the middle of a large object, move it       */
 404     /* to the beginning.                                                */
 405         while (IS_FORWARDING_ADDR_OR_NIL(candidate_hdr)) {
 406            h = FORWARDED_ADDR(h,candidate_hdr);
 407            r = (word)h;
 408            candidate_hdr = HDR(h);
 409         }
 410     if (candidate_hdr -> hb_map == GC_invalid_map) return(0);
 411     /* Make sure r points to the beginning of the object */
 412         r &= ~(WORDS_TO_BYTES(1) - 1);
 413         {
 414             register int offset = HBLKDISPL(r);
 415             register signed_word sz = candidate_hdr -> hb_sz;
 416             register signed_word map_entry;
 417
 418             map_entry = MAP_ENTRY((candidate_hdr -> hb_map), offset);
 419             if (map_entry > CPP_MAX_OFFSET) {
 420                 map_entry = (signed_word)(BYTES_TO_WORDS(offset)) % sz;
 421             }
 422             r -= WORDS_TO_BYTES(map_entry);
 423             limit = r + WORDS_TO_BYTES(sz);
 424             if (limit > (word)(h + 1)
 425                 && sz <= BYTES_TO_WORDS(HBLKSIZE)) {
 426                 return(0);
 427             }
 428             if ((word)p >= limit) return(0);
 429         }
 430     return((GC_PTR)r);
 431 }
 432
 433
 434 /* Return the size of an object, given a pointer to its base.           */
 435 /* (For small obects this also happens to work from interior pointers,  */
 436 /* but that shouldn't be relied upon.)                                  */
 437 # ifdef __STDC__
 438     size_t GC_size(GC_PTR p)
 439 # else
 440     size_t GC_size(p)
 441     GC_PTR p;
 442 # endif
 443 {
 444     register int sz;
 445     register hdr * hhdr = HDR(p);
 446
 447     sz = WORDS_TO_BYTES(hhdr -> hb_sz);
 448     return(sz);
 449 }
 450
 451 size_t GC_get_heap_size GC_PROTO(())
 452 {
 453     return ((size_t) GC_heapsize);
 454 }
 455
 456 size_t GC_get_free_bytes GC_PROTO(())
 457 {
 458     return ((size_t) GC_large_free_bytes);
 459 }
 460
 461 size_t GC_get_bytes_since_gc GC_PROTO(())
 462 {
 463     return ((size_t) WORDS_TO_BYTES(GC_words_allocd));
 464 }
 465
 466 size_t GC_get_total_bytes GC_PROTO(())
 467 {
 468     return ((size_t) WORDS_TO_BYTES(GC_words_allocd+GC_words_allocd_before_gc));
 469 }
 470
 471 GC_bool GC_is_initialized = FALSE;
 472
 473 void GC_init()
 474 {
 475     DCL_LOCK_STATE;
 476
 477     DISABLE_SIGNALS();
 478
 479 #if defined(GC_WIN32_THREADS) && !defined(GC_PTHREADS)
 480     if (!GC_is_initialized) {
 481       BOOL (WINAPI *pfn) (LPCRITICAL_SECTION, DWORD) = NULL;
 482       HMODULE hK32 = GetModuleHandle(_T("kernel32.dll"));
 483       if (hK32)
 484           pfn = GetProcAddress(hK32,
 485                           "InitializeCriticalSectionAndSpinCount");
 486       if (pfn)
 487           pfn(&GC_allocate_ml, 4000);
 488       else
 489           InitializeCriticalSection (&GC_allocate_ml);
 490     }
 491 #endif /* MSWIN32 */
 492
 493     LOCK();
 494     GC_init_inner();
 495     UNLOCK();
 496     ENABLE_SIGNALS();
 497
 498 #   if defined(PARALLEL_MARK) || defined(THREAD_LOCAL_ALLOC)
 499         /* Make sure marker threads and started and thread local */
 500         /* allocation is initialized, in case we didn't get      */
 501         /* called from GC_init_parallel();                       */
 502         {
 503           extern void GC_init_parallel(void);
 504           GC_init_parallel();
 505         }
 506 #   endif /* PARALLEL_MARK || THREAD_LOCAL_ALLOC */
 507
 508 #   if defined(DYNAMIC_LOADING) && defined(DARWIN)
 509     {
 510         /* This must be called WITHOUT the allocation lock held
 511         and before any threads are created */
 512         extern void GC_init_dyld();
 513         GC_init_dyld();
 514     }
 515 #   endif
 516 }
 517
 518 #if defined(MSWIN32) || defined(MSWINCE)
 519     CRITICAL_SECTION GC_write_cs;
 520 #endif
 521
 522 #ifdef MSWIN32
 523     extern void GC_init_win32 GC_PROTO((void));
 524 #endif
 525
 526 extern void GC_setpagesize();
 527
 528
 529 #ifdef MSWIN32
 530 extern GC_bool GC_no_win32_dlls;
 531 #else
 532 # define GC_no_win32_dlls FALSE
 533 #endif
 534
 535 void GC_exit_check GC_PROTO((void))
 536 {
 537    GC_gcollect();
 538 }
 539
 540 #ifdef SEARCH_FOR_DATA_START
 541   extern void GC_init_linux_data_start GC_PROTO((void));
 542 #endif
 543
 544 #ifdef UNIX_LIKE
 545
 546 extern void GC_set_and_save_fault_handler GC_PROTO((void (*handler)(int)));
 547
 548 static void looping_handler(sig)
 549 int sig;
 550 {
 551     GC_err_printf1("Caught signal %d: looping in handler\n", sig);
 552     for(;;);
 553 }
 554
 555 static GC_bool installed_looping_handler = FALSE;
 556
 557 static void maybe_install_looping_handler()
 558 {
 559     /* Install looping handler before the write fault handler, so we    */
 560     /* handle write faults correctly.                                   */
 561       if (!installed_looping_handler && 0 != GETENV("GC_LOOP_ON_ABORT")) {
 562         GC_set_and_save_fault_handler(looping_handler);
 563         installed_looping_handler = TRUE;
 564       }
 565 }
 566
 567 #else /* !UNIX_LIKE */
 568
 569 # define maybe_install_looping_handler()
 570
 571 #endif
 572
 573 void GC_init_inner()
 574 {
 575 #   if !defined(THREADS) && defined(GC_ASSERTIONS)
 576         word dummy;
 577 #   endif
 578     word initial_heap_sz = (word)MINHINCR;
 579
 580     if (GC_is_initialized) return;
 581 #   ifdef PRINTSTATS
 582       GC_print_stats = 1;
 583 #   endif
 584 #   if defined(MSWIN32) || defined(MSWINCE)
 585       InitializeCriticalSection(&GC_write_cs);
 586 #   endif
 587     if (0 != GETENV("GC_PRINT_STATS")) {
 588       GC_print_stats = 1;
 589     }
 590 #   ifndef NO_DEBUGGING
 591       if (0 != GETENV("GC_DUMP_REGULARLY")) {
 592         GC_dump_regularly = 1;
 593       }
 594 #   endif
 595 #   ifdef KEEP_BACK_PTRS
 596       {
 597         char * backtraces_string = GETENV("GC_BACKTRACES");
 598         if (0 != backtraces_string) {
 599           GC_backtraces = atol(backtraces_string);
 600           if (backtraces_string[0] == '\0') GC_backtraces = 1;
 601         }
 602       }
 603 #   endif
 604     if (0 != GETENV("GC_FIND_LEAK")) {
 605       GC_find_leak = 1;
 606 #     ifdef __STDC__
 607         atexit(GC_exit_check);
 608 #     endif
 609     }
 610     if (0 != GETENV("GC_ALL_INTERIOR_POINTERS")) {
 611       GC_all_interior_pointers = 1;
 612     }
 613     if (0 != GETENV("GC_DONT_GC")) {
 614       GC_dont_gc = 1;
 615     }
 616     if (0 != GETENV("GC_PRINT_BACK_HEIGHT")) {
 617       GC_print_back_height = 1;
 618     }
 619     if (0 != GETENV("GC_NO_BLACKLIST_WARNING")) {
 620       GC_large_alloc_warn_interval = LONG_MAX;
 621     }
 622     {
 623       char * time_limit_string = GETENV("GC_PAUSE_TIME_TARGET");
 624       if (0 != time_limit_string) {
 625         long time_limit = atol(time_limit_string);
 626         if (time_limit < 5) {
 627           WARN("GC_PAUSE_TIME_TARGET environment variable value too small "
 628                "or bad syntax: Ignoring\n", 0);
 629         } else {
 630           GC_time_limit = time_limit;
 631         }
 632       }
 633     }
 634     {
 635       char * interval_string = GETENV("GC_LARGE_ALLOC_WARN_INTERVAL");
 636       if (0 != interval_string) {
 637         long interval = atol(interval_string);
 638         if (interval <= 0) {
 639           WARN("GC_LARGE_ALLOC_WARN_INTERVAL environment variable has "
 640                "bad value: Ignoring\n", 0);
 641         } else {
 642           GC_large_alloc_warn_interval = interval;
 643         }
 644       }
 645     }
 646     maybe_install_looping_handler();
 647     /* Adjust normal object descriptor for extra allocation.    */
 648     if (ALIGNMENT > GC_DS_TAGS && EXTRA_BYTES != 0) {
 649       GC_obj_kinds[NORMAL].ok_descriptor = ((word)(-ALIGNMENT) | GC_DS_LENGTH);
 650     }
 651     GC_setpagesize();
 652     GC_exclude_static_roots(beginGC_arrays, endGC_arrays);
 653     GC_exclude_static_roots(beginGC_obj_kinds, endGC_obj_kinds);
 654 #   ifdef SEPARATE_GLOBALS
 655       GC_exclude_static_roots(beginGC_objfreelist, endGC_objfreelist);
 656       GC_exclude_static_roots(beginGC_aobjfreelist, endGC_aobjfreelist);
 657 #   endif
 658 #   ifdef MSWIN32
 659         GC_init_win32();
 660 #   endif
 661 #   if defined(SEARCH_FOR_DATA_START)
 662         GC_init_linux_data_start();
 663 #   endif
 664 #   if (defined(NETBSD) || defined(OPENBSD)) && defined(__ELF__)
 665         GC_init_netbsd_elf();
 666 #   endif
 667 #   if defined(GC_PTHREADS) || defined(GC_SOLARIS_THREADS) \
 668        || defined(GC_WIN32_THREADS)
 669         GC_thr_init();
 670 #   endif
 671 #   ifdef GC_SOLARIS_THREADS
 672         /* We need dirty bits in order to find live stack sections.     */
 673         GC_dirty_init();
 674 #   endif
 675 #   if !defined(THREADS) || defined(GC_PTHREADS) || defined(GC_WIN32_THREADS) \
 676         || defined(GC_SOLARIS_THREADS)
 677       if (GC_stackbottom == 0) {
 678         GC_stackbottom = GC_get_stack_base();
 679 #       if (defined(LINUX) || defined(HPUX)) && defined(IA64)
 680           GC_register_stackbottom = GC_get_register_stack_base();
 681 #       endif
 682       } else {
 683 #       if (defined(LINUX) || defined(HPUX)) && defined(IA64)
 684           if (GC_register_stackbottom == 0) {
 685             WARN("GC_register_stackbottom should be set with GC_stackbottom", 0);
 686             /* The following may fail, since we may rely on             */
 687             /* alignment properties that may not hold with a user set   */
 688             /* GC_stackbottom.                                          */
 689             GC_register_stackbottom = GC_get_register_stack_base();
 690           }
 691 #       endif
 692       }
 693 #   endif
 694     GC_STATIC_ASSERT(sizeof (ptr_t) == sizeof(word));
 695     GC_STATIC_ASSERT(sizeof (signed_word) == sizeof(word));
 696     GC_STATIC_ASSERT(sizeof (struct hblk) == HBLKSIZE);
 697 #   ifndef THREADS
 698 #     if defined(STACK_GROWS_UP) && defined(STACK_GROWS_DOWN)
 699         ABORT(
 700           "Only one of STACK_GROWS_UP and STACK_GROWS_DOWN should be defd\n");
 701 #     endif
 702 #     if !defined(STACK_GROWS_UP) && !defined(STACK_GROWS_DOWN)
 703         ABORT(
 704           "One of STACK_GROWS_UP and STACK_GROWS_DOWN should be defd\n");
 705 #     endif
 706 #     ifdef STACK_GROWS_DOWN
 707         GC_ASSERT((word)(&dummy) <= (word)GC_stackbottom);
 708 #     else
 709         GC_ASSERT((word)(&dummy) >= (word)GC_stackbottom);
 710 #     endif
 711 #   endif
 712 #   if !defined(_AUX_SOURCE) || defined(__GNUC__)
 713       GC_ASSERT((word)(-1) > (word)0);
 714       /* word should be unsigned */
 715 #   endif
 716     GC_ASSERT((signed_word)(-1) < (signed_word)0);
 717
 718     /* Add initial guess of root sets.  Do this first, since sbrk(0)    */
 719     /* might be used.                                                   */
 720       if (GC_REGISTER_MAIN_STATIC_DATA()) GC_register_data_segments();
 721     GC_init_headers();
 722     GC_bl_init();
 723     GC_mark_init();
 724     {
 725         char * sz_str = GETENV("GC_INITIAL_HEAP_SIZE");
 726         if (sz_str != NULL) {
 727           initial_heap_sz = atoi(sz_str);
 728           if (initial_heap_sz <= MINHINCR * HBLKSIZE) {
 729             WARN("Bad initial heap size %s - ignoring it.\n",
 730                  sz_str);
 731           }
 732           initial_heap_sz = divHBLKSZ(initial_heap_sz);
 733         }
 734     }
 735     {
 736         char * sz_str = GETENV("GC_MAXIMUM_HEAP_SIZE");
 737         if (sz_str != NULL) {
 738           word max_heap_sz = (word)atol(sz_str);
 739           if (max_heap_sz < initial_heap_sz * HBLKSIZE) {
 740             WARN("Bad maximum heap size %s - ignoring it.\n",
 741                  sz_str);
 742           }
 743           if (0 == GC_max_retries) GC_max_retries = 2;
 744           GC_set_max_heap_size(max_heap_sz);
 745         }
 746     }
 747     if (!GC_expand_hp_inner(initial_heap_sz)) {
 748         GC_err_printf0("Can't start up: not enough memory\n");
 749         EXIT();
 750     }
 751     /* Preallocate large object map.  It's otherwise inconvenient to    */
 752     /* deal with failure.                                               */
 753       if (!GC_add_map_entry((word)0)) {
 754         GC_err_printf0("Can't start up: not enough memory\n");
 755         EXIT();
 756       }
 757     GC_register_displacement_inner(0L);
 758 #   ifdef MERGE_SIZES
 759       GC_init_size_map();
 760 #   endif
 761 #   ifdef PCR
 762       if (PCR_IL_Lock(PCR_Bool_false, PCR_allSigsBlocked, PCR_waitForever)
 763           != PCR_ERes_okay) {
 764           ABORT("Can't lock load state\n");
 765       } else if (PCR_IL_Unlock() != PCR_ERes_okay) {
 766           ABORT("Can't unlock load state\n");
 767       }
 768       PCR_IL_Unlock();
 769       GC_pcr_install();
 770 #   endif
 771 #   if !defined(SMALL_CONFIG)
 772       if (!GC_no_win32_dlls && 0 != GETENV("GC_ENABLE_INCREMENTAL")) {
 773         GC_ASSERT(!GC_incremental);
 774         GC_setpagesize();
 775 #       ifndef GC_SOLARIS_THREADS
 776           GC_dirty_init();
 777 #       endif
 778         GC_ASSERT(GC_words_allocd == 0)
 779         GC_incremental = TRUE;
 780       }
 781 #   endif /* !SMALL_CONFIG */
 782     COND_DUMP;
 783     /* Get black list set up and/or incremental GC started */
 784       if (!GC_dont_precollect || GC_incremental) GC_gcollect_inner();
 785     GC_is_initialized = TRUE;
 786 #   ifdef STUBBORN_ALLOC
 787         GC_stubborn_init();
 788 #   endif
 789     /* Convince lint that some things are used */
 790 #   ifdef LINT
 791       {
 792           extern char * GC_copyright[];
 793           extern int GC_read();
 794           extern void GC_register_finalizer_no_order();
 795
 796           GC_noop(GC_copyright, GC_find_header,
 797                   GC_push_one, GC_call_with_alloc_lock, GC_read,
 798                   GC_dont_expand,
 799 #                 ifndef NO_DEBUGGING
 800                     GC_dump,
 801 #                 endif
 802                   GC_register_finalizer_no_order);
 803       }
 804 #   endif
 805 }
 806
 807 void GC_enable_incremental GC_PROTO(())
 808 {
 809 # if !defined(SMALL_CONFIG) && !defined(KEEP_BACK_PTRS)
 810   /* If we are keeping back pointers, the GC itself dirties all */
 811   /* pages on which objects have been marked, making            */
 812   /* incremental GC pointless.                                  */
 813   if (!GC_find_leak) {
 814     DCL_LOCK_STATE;
 815
 816     DISABLE_SIGNALS();
 817     LOCK();
 818     if (GC_incremental) goto out;
 819     GC_setpagesize();
 820     if (GC_no_win32_dlls) goto out;
 821 #   ifndef GC_SOLARIS_THREADS
 822       maybe_install_looping_handler();  /* Before write fault handler! */
 823       GC_dirty_init();
 824 #   endif
 825     if (!GC_is_initialized) {
 826         GC_init_inner();
 827     }
 828     if (GC_incremental) goto out;
 829     if (GC_dont_gc) {
 830         /* Can't easily do it. */
 831         UNLOCK();
 832         ENABLE_SIGNALS();
 833         return;
 834     }
 835     if (GC_words_allocd > 0) {
 836         /* There may be unmarked reachable objects      */
 837         GC_gcollect_inner();
 838     }   /* else we're OK in assuming everything's       */
 839         /* clean since nothing can point to an          */
 840         /* unmarked object.                             */
 841     GC_read_dirty();
 842     GC_incremental = TRUE;
 843 out:
 844     UNLOCK();
 845     ENABLE_SIGNALS();
 846   }
 847 # endif
 848 }
 849
 850
 851 #if defined(MSWIN32) || defined(MSWINCE)
 852 # define LOG_FILE _T("gc.log")
 853
 854   HANDLE GC_stdout = 0;
 855
 856   void GC_deinit()
 857   {
 858       if (GC_is_initialized) {
 859         DeleteCriticalSection(&GC_write_cs);
 860       }
 861   }
 862
 863   int GC_write(buf, len)
 864   GC_CONST char * buf;
 865   size_t len;
 866   {
 867       BOOL tmp;
 868       DWORD written;
 869       if (len == 0)
 870           return 0;
 871       EnterCriticalSection(&GC_write_cs);
 872       if (GC_stdout == INVALID_HANDLE_VALUE) {
 873           return -1;
 874       } else if (GC_stdout == 0) {
 875           GC_stdout = CreateFile(LOG_FILE, GENERIC_WRITE,
 876                                  FILE_SHARE_READ | FILE_SHARE_WRITE,
 877                                  NULL, CREATE_ALWAYS, FILE_FLAG_WRITE_THROUGH,
 878                                  NULL);
 879           if (GC_stdout == INVALID_HANDLE_VALUE) ABORT("Open of log file failed");
 880       }
 881       tmp = WriteFile(GC_stdout, buf, len, &written, NULL);
 882       if (!tmp)
 883           DebugBreak();
 884       LeaveCriticalSection(&GC_write_cs);
 885       return tmp ? (int)written : -1;
 886   }
 887
 888 #endif
 889
 890 #if defined(OS2) || defined(MACOS)
 891 FILE * GC_stdout = NULL;
 892 FILE * GC_stderr = NULL;
 893 int GC_tmp;  /* Should really be local ... */
 894
 895   void GC_set_files()
 896   {
 897       if (GC_stdout == NULL) {
 898         GC_stdout = stdout;
 899     }
 900     if (GC_stderr == NULL) {
 901         GC_stderr = stderr;
 902     }
 903   }
 904 #endif
 905
 906 #if !defined(OS2) && !defined(MACOS) && !defined(MSWIN32) && !defined(MSWINCE)
 907   int GC_stdout = 1;
 908   int GC_stderr = 2;
 909 # if !defined(AMIGA)
 910 #   include <unistd.h>
 911 # endif
 912 #endif
 913
 914 #if !defined(MSWIN32) && !defined(MSWINCE) && !defined(OS2) \
 915     && !defined(MACOS)  && !defined(ECOS) && !defined(NOSYS)
 916 int GC_write(fd, buf, len)
 917 int fd;
 918 GC_CONST char *buf;
 919 size_t len;
 920 {
 921      register int bytes_written = 0;
 922      register int result;
 923
 924      while (bytes_written < len) {
 925 #       ifdef GC_SOLARIS_THREADS
 926             result = syscall(SYS_write, fd, buf + bytes_written,
 927                                             len - bytes_written);
 928 #       else
 929             result = write(fd, buf + bytes_written, len - bytes_written);
 930 #       endif
 931         if (-1 == result) return(result);
 932         bytes_written += result;
 933     }
 934     return(bytes_written);
 935 }
 936 #endif /* UN*X */
 937
 938 #ifdef ECOS
 939 int GC_write(fd, buf, len)
 940 {
 941   _Jv_diag_write (buf, len);
 942   return len;
 943 }
 944 #endif
 945
 946 #ifdef NOSYS
 947 int GC_write(fd, buf, len)
 948 {
 949   /* No writing.  */
 950   return len;
 951 }
 952 #endif
 953
 954
 955 #if defined(MSWIN32) || defined(MSWINCE)
 956 #   define WRITE(f, buf, len) GC_write(buf, len)
 957 #else
 958 #   if defined(OS2) || defined(MACOS)
 959 #   define WRITE(f, buf, len) (GC_set_files(), \
 960                                GC_tmp = fwrite((buf), 1, (len), (f)), \
 961                                fflush(f), GC_tmp)
 962 #   else
 963 #     define WRITE(f, buf, len) GC_write((f), (buf), (len))
 964 #   endif
 965 #endif
 966
 967 /* A version of printf that is unlikely to call malloc, and is thus safer */
 968 /* to call from the collector in case malloc has been bound to GC_malloc. */
 969 /* Assumes that no more than 1023 characters are written at once.         */
 970 /* Assumes that all arguments have been converted to something of the     */
 971 /* same size as long, and that the format conversions expect something    */
 972 /* of that size.                                                          */
 973 void GC_printf(format, a, b, c, d, e, f)
 974 GC_CONST char * format;
 975 long a, b, c, d, e, f;
 976 {
 977     char buf[1025];
 978
 979     if (GC_quiet) return;
 980     buf[1024] = 0x15;
 981     (void) sprintf(buf, format, a, b, c, d, e, f);
 982     if (buf[1024] != 0x15) ABORT("GC_printf clobbered stack");
 983     if (WRITE(GC_stdout, buf, strlen(buf)) < 0) ABORT("write to stdout failed");
 984 }
 985
 986 void GC_err_printf(format, a, b, c, d, e, f)
 987 GC_CONST char * format;
 988 long a, b, c, d, e, f;
 989 {
 990     char buf[1025];
 991
 992     buf[1024] = 0x15;
 993     (void) sprintf(buf, format, a, b, c, d, e, f);
 994     if (buf[1024] != 0x15) ABORT("GC_err_printf clobbered stack");
 995     if (WRITE(GC_stderr, buf, strlen(buf)) < 0) ABORT("write to stderr failed");
 996 }
 997
 998 void GC_err_puts(s)
 999 GC_CONST char *s;
1000 {
1001     if (WRITE(GC_stderr, s, strlen(s)) < 0) ABORT("write to stderr failed");
1002 }
1003
1004 #if defined(LINUX) && !defined(SMALL_CONFIG)
1005 void GC_err_write(buf, len)
1006 GC_CONST char *buf;
1007 size_t len;
1008 {
1009     if (WRITE(GC_stderr, buf, len) < 0) ABORT("write to stderr failed");
1010 }
1011 #endif
1012
1013 # if defined(__STDC__) || defined(__cplusplus)
1014     void GC_default_warn_proc(char *msg, GC_word arg)
1015 # else
1016     void GC_default_warn_proc(msg, arg)
1017     char *msg;
1018     GC_word arg;
1019 # endif
1020 {
1021     GC_err_printf1(msg, (unsigned long)arg);
1022 }
1023
1024 GC_warn_proc GC_current_warn_proc = GC_default_warn_proc;
1025
1026 # if defined(__STDC__) || defined(__cplusplus)
1027     GC_warn_proc GC_set_warn_proc(GC_warn_proc p)
1028 # else
1029     GC_warn_proc GC_set_warn_proc(p)
1030     GC_warn_proc p;
1031 # endif
1032 {
1033     GC_warn_proc result;
1034
1035 #   ifdef GC_WIN32_THREADS
1036       GC_ASSERT(GC_is_initialized);
1037 #   endif
1038     LOCK();
1039     result = GC_current_warn_proc;
1040     GC_current_warn_proc = p;
1041     UNLOCK();
1042     return(result);
1043 }
1044
1045 # if defined(__STDC__) || defined(__cplusplus)
1046     GC_word GC_set_free_space_divisor (GC_word value)
1047 # else
1048     GC_word GC_set_free_space_divisor (value)
1049     GC_word value;
1050 # endif
1051 {
1052     GC_word old = GC_free_space_divisor;
1053     GC_free_space_divisor = value;
1054     return old;
1055 }
1056
1057 #ifndef PCR
1058 void GC_abort(msg)
1059 GC_CONST char * msg;
1060 {
1061 #   if defined(MSWIN32)
1062       (void) MessageBoxA(NULL, msg, "Fatal error in gc", MB_ICONERROR|MB_OK);
1063 #   else
1064       GC_err_printf1("%s\n", msg);
1065 #   endif
1066     if (GETENV("GC_LOOP_ON_ABORT") != NULL) {
1067             /* In many cases it's easier to debug a running process.    */
1068             /* It's arguably nicer to sleep, but that makes it harder   */
1069             /* to look at the thread if the debugger doesn't know much  */
1070             /* about threads.                                           */
1071             for(;;) {}
1072     }
1073 #   if defined(MSWIN32) || defined(MSWINCE)
1074         DebugBreak();
1075 #   else
1076         (void) abort();
1077 #   endif
1078 }
1079 #endif
1080
1081 void GC_enable()
1082 {
1083     LOCK();
1084     GC_dont_gc--;
1085     UNLOCK();
1086 }
1087
1088 void GC_disable()
1089 {
1090     LOCK();
1091     GC_dont_gc++;
1092     UNLOCK();
1093 }
1094
1095 /* Helper procedures for new kind creation.     */
1096 void ** GC_new_free_list_inner()
1097 {
1098     void *result = GC_INTERNAL_MALLOC((MAXOBJSZ+1)*sizeof(ptr_t), PTRFREE);
1099     if (result == 0) ABORT("Failed to allocate freelist for new kind");
1100     BZERO(result, (MAXOBJSZ+1)*sizeof(ptr_t));
1101     return result;
1102 }
1103
1104 void ** GC_new_free_list()
1105 {
1106     void *result;
1107     LOCK(); DISABLE_SIGNALS();
1108     result = GC_new_free_list_inner();
1109     UNLOCK(); ENABLE_SIGNALS();
1110     return result;
1111 }
1112
1113 int GC_new_kind_inner(fl, descr, adjust, clear)
1114 void **fl;
1115 GC_word descr;
1116 int adjust;
1117 int clear;
1118 {
1119     int result = GC_n_kinds++;
1120
1121     if (GC_n_kinds > MAXOBJKINDS) ABORT("Too many kinds");
1122     GC_obj_kinds[result].ok_freelist = (ptr_t *)fl;
1123     GC_obj_kinds[result].ok_reclaim_list = 0;
1124     GC_obj_kinds[result].ok_descriptor = descr;
1125     GC_obj_kinds[result].ok_relocate_descr = adjust;
1126     GC_obj_kinds[result].ok_init = clear;
1127     return result;
1128 }
1129
1130 int GC_new_kind(fl, descr, adjust, clear)
1131 void **fl;
1132 GC_word descr;
1133 int adjust;
1134 int clear;
1135 {
1136     int result;
1137     LOCK(); DISABLE_SIGNALS();
1138     result = GC_new_kind_inner(fl, descr, adjust, clear);
1139     UNLOCK(); ENABLE_SIGNALS();
1140     return result;
1141 }
1142
1143 int GC_new_proc_inner(proc)
1144 GC_mark_proc proc;
1145 {
1146     int result = GC_n_mark_procs++;
1147
1148     if (GC_n_mark_procs > MAX_MARK_PROCS) ABORT("Too many mark procedures");
1149     GC_mark_procs[result] = proc;
1150     return result;
1151 }
1152
1153 int GC_new_proc(proc)
1154 GC_mark_proc proc;
1155 {
1156     int result;
1157     LOCK(); DISABLE_SIGNALS();
1158     result = GC_new_proc_inner(proc);
1159     UNLOCK(); ENABLE_SIGNALS();
1160     return result;
1161 }
1162
1163
1164 #if !defined(NO_DEBUGGING)
1165
1166 void GC_dump()
1167 {
1168     GC_printf0("***Static roots:\n");
1169     GC_print_static_roots();
1170     GC_printf0("\n***Heap sections:\n");
1171     GC_print_heap_sects();
1172     GC_printf0("\n***Free blocks:\n");
1173     GC_print_hblkfreelist();
1174     GC_printf0("\n***Blocks in use:\n");
1175     GC_print_block_list();
1176     GC_printf0("\n***Finalization statistics:\n");
1177     GC_print_finalization_stats();
1178 }
1179
1180 #endif /* NO_DEBUGGING */