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