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 /* Dont unnecessarily call GC_register_main_static_data() in case      */
  79 /* dyn_load.c isn't linked in.                                         */
  80 #ifdef DYNAMIC_LOADING
  81 # define GC_REGISTER_MAIN_STATIC_DATA() GC_register_main_static_data()
  82 #else
  83 # define GC_REGISTER_MAIN_STATIC_DATA() TRUE
  84 #endif
  85
  86 GC_FAR struct _GC_arrays GC_arrays /* = { 0 } */;
  87
  88
  89 GC_bool GC_debugging_started = FALSE;
  90         /* defined here so we don't have to load debug_malloc.o */
  91
  92 void (*GC_check_heap) GC_PROTO((void)) = (void (*) GC_PROTO((void)))0;
  93
  94 void (*GC_start_call_back) GC_PROTO((void)) = (void (*) GC_PROTO((void)))0;
  95
  96 ptr_t GC_stackbottom = 0;
  97
  98 #ifdef IA64
  99   ptr_t GC_register_stackbottom = 0;
 100 #endif
 101
 102 GC_bool GC_dont_gc = 0;
 103
 104 GC_bool GC_dont_precollect = 0;
 105
 106 GC_bool GC_quiet = 0;
 107
 108 GC_bool GC_print_stats = 0;
 109
 110 GC_bool GC_print_back_height = 0;
 111
 112 #ifdef FIND_LEAK
 113   int GC_find_leak = 1;
 114 #else
 115   int GC_find_leak = 0;
 116 #endif
 117
 118 #ifdef ALL_INTERIOR_POINTERS
 119   int GC_all_interior_pointers = 1;
 120 #else
 121   int GC_all_interior_pointers = 0;
 122 #endif
 123
 124 long GC_large_alloc_warn_interval = 5;
 125         /* Interval between unsuppressed warnings.      */
 126
 127 long GC_large_alloc_warn_suppressed = 0;
 128         /* Number of warnings suppressed so far.        */
 129
 130 /*ARGSUSED*/
 131 GC_PTR GC_default_oom_fn GC_PROTO((size_t bytes_requested))
 132 {
 133     return(0);
 134 }
 135
 136 GC_PTR (*GC_oom_fn) GC_PROTO((size_t bytes_requested)) = GC_default_oom_fn;
 137
 138 extern signed_word GC_mem_found;
 139
 140 # ifdef MERGE_SIZES
 141     /* Set things up so that GC_size_map[i] >= words(i),                */
 142     /* but not too much bigger                                          */
 143     /* and so that size_map contains relatively few distinct entries    */
 144     /* This is stolen from Russ Atkinson's Cedar quantization           */
 145     /* alogrithm (but we precompute it).                                */
 146
 147
 148     void GC_init_size_map()
 149     {
 150         register unsigned i;
 151
 152         /* Map size 0 to something bigger.                      */
 153         /* This avoids problems at lower levels.                */
 154         /* One word objects don't have to be 2 word aligned,    */
 155         /* unless we're using mark bytes.                       */
 156           for (i = 0; i < sizeof(word); i++) {
 157               GC_size_map[i] = MIN_WORDS;
 158           }
 159 #         if MIN_WORDS > 1
 160             GC_size_map[sizeof(word)] = MIN_WORDS;
 161 #         else
 162             GC_size_map[sizeof(word)] = ROUNDED_UP_WORDS(sizeof(word));
 163 #         endif
 164         for (i = sizeof(word) + 1; i <= 8 * sizeof(word); i++) {
 165             GC_size_map[i] = ALIGNED_WORDS(i);
 166         }
 167         for (i = 8*sizeof(word) + 1; i <= 16 * sizeof(word); i++) {
 168               GC_size_map[i] = (ROUNDED_UP_WORDS(i) + 1) & (~1);
 169         }
 170 #       ifdef GC_GCJ_SUPPORT
 171            /* Make all sizes up to 32 words predictable, so that a      */
 172            /* compiler can statically perform the same computation,     */
 173            /* or at least a computation that results in similar size    */
 174            /* classes.                                                  */
 175            for (i = 16*sizeof(word) + 1; i <= 32 * sizeof(word); i++) {
 176               GC_size_map[i] = (ROUNDED_UP_WORDS(i) + 3) & (~3);
 177            }
 178 #       endif
 179         /* We leave the rest of the array to be filled in on demand. */
 180     }
 181
 182     /* Fill in additional entries in GC_size_map, including the ith one */
 183     /* We assume the ith entry is currently 0.                          */
 184     /* Note that a filled in section of the array ending at n always    */
 185     /* has length at least n/4.                                         */
 186     void GC_extend_size_map(i)
 187     word i;
 188     {
 189         word orig_word_sz = ROUNDED_UP_WORDS(i);
 190         word word_sz = orig_word_sz;
 191         register word byte_sz = WORDS_TO_BYTES(word_sz);
 192                                 /* The size we try to preserve.         */
 193                                 /* Close to to i, unless this would     */
 194                                 /* introduce too many distinct sizes.   */
 195         word smaller_than_i = byte_sz - (byte_sz >> 3);
 196         word much_smaller_than_i = byte_sz - (byte_sz >> 2);
 197         register word low_limit;        /* The lowest indexed entry we  */
 198                                         /* initialize.                  */
 199         register word j;
 200
 201         if (GC_size_map[smaller_than_i] == 0) {
 202             low_limit = much_smaller_than_i;
 203             while (GC_size_map[low_limit] != 0) low_limit++;
 204         } else {
 205             low_limit = smaller_than_i + 1;
 206             while (GC_size_map[low_limit] != 0) low_limit++;
 207             word_sz = ROUNDED_UP_WORDS(low_limit);
 208             word_sz += word_sz >> 3;
 209             if (word_sz < orig_word_sz) word_sz = orig_word_sz;
 210         }
 211 #       ifdef ALIGN_DOUBLE
 212             word_sz += 1;
 213             word_sz &= ~1;
 214 #       endif
 215         if (word_sz > MAXOBJSZ) {
 216             word_sz = MAXOBJSZ;
 217         }
 218         /* If we can fit the same number of larger objects in a block,  */
 219         /* do so.                                                       */
 220         {
 221             size_t number_of_objs = BODY_SZ/word_sz;
 222             word_sz = BODY_SZ/number_of_objs;
 223 #           ifdef ALIGN_DOUBLE
 224                 word_sz &= ~1;
 225 #           endif
 226         }
 227         byte_sz = WORDS_TO_BYTES(word_sz);
 228         if (GC_all_interior_pointers) {
 229             /* We need one extra byte; don't fill in GC_size_map[byte_sz] */
 230             byte_sz--;
 231         }
 232
 233         for (j = low_limit; j <= byte_sz; j++) GC_size_map[j] = word_sz;
 234     }
 235 # endif
 236
 237
 238 /*
 239  * The following is a gross hack to deal with a problem that can occur
 240  * on machines that are sloppy about stack frame sizes, notably SPARC.
 241  * Bogus pointers may be written to the stack and not cleared for
 242  * a LONG time, because they always fall into holes in stack frames
 243  * that are not written.  We partially address this by clearing
 244  * sections of the stack whenever we get control.
 245  */
 246 word GC_stack_last_cleared = 0; /* GC_no when we last did this */
 247 # ifdef THREADS
 248 #   define BIG_CLEAR_SIZE 2048  /* Clear this much now and then.        */
 249 #   define SMALL_CLEAR_SIZE 256 /* Clear this much every time.          */
 250 # endif
 251 # define CLEAR_SIZE 213  /* Granularity for GC_clear_stack_inner */
 252 # define DEGRADE_RATE 50
 253
 254 word GC_min_sp;         /* Coolest stack pointer value from which we've */
 255                         /* already cleared the stack.                   */
 256
 257 word GC_high_water;
 258                         /* "hottest" stack pointer value we have seen   */
 259                         /* recently.  Degrades over time.               */
 260
 261 word GC_words_allocd_at_reset;
 262
 263 #if defined(ASM_CLEAR_CODE)
 264   extern ptr_t GC_clear_stack_inner();
 265 #else
 266 /* Clear the stack up to about limit.  Return arg. */
 267 /*ARGSUSED*/
 268 ptr_t GC_clear_stack_inner(arg, limit)
 269 ptr_t arg;
 270 word limit;
 271 {
 272     word dummy[CLEAR_SIZE];
 273
 274     BZERO(dummy, CLEAR_SIZE*sizeof(word));
 275     if ((word)(dummy) COOLER_THAN limit) {
 276         (void) GC_clear_stack_inner(arg, limit);
 277     }
 278     /* Make sure the recursive call is not a tail call, and the bzero   */
 279     /* call is not recognized as dead code.                             */
 280     GC_noop1((word)dummy);
 281     return(arg);
 282 }
 283 #endif
 284
 285 /* Clear some of the inaccessible part of the stack.  Returns its       */
 286 /* argument, so it can be used in a tail call position, hence clearing  */
 287 /* another frame.                                                       */
 288 ptr_t GC_clear_stack(arg)
 289 ptr_t arg;
 290 {
 291     register word sp = (word)GC_approx_sp();  /* Hotter than actual sp */
 292 #   ifdef THREADS
 293         word dummy[SMALL_CLEAR_SIZE];
 294         static unsigned random_no = 0;
 295                                  /* Should be more random than it is ... */
 296                                  /* Used to occasionally clear a bigger  */
 297                                  /* chunk.                               */
 298 #   endif
 299     register word limit;
 300
 301 #   define SLOP 400
 302         /* Extra bytes we clear every time.  This clears our own        */
 303         /* activation record, and should cause more frequent            */
 304         /* clearing near the cold end of the stack, a good thing.       */
 305 #   define GC_SLOP 4000
 306         /* We make GC_high_water this much hotter than we really saw    */
 307         /* saw it, to cover for GC noise etc. above our current frame.  */
 308 #   define CLEAR_THRESHOLD 100000
 309         /* We restart the clearing process after this many bytes of     */
 310         /* allocation.  Otherwise very heavily recursive programs       */
 311         /* with sparse stacks may result in heaps that grow almost      */
 312         /* without bounds.  As the heap gets larger, collection         */
 313         /* frequency decreases, thus clearing frequency would decrease, */
 314         /* thus more junk remains accessible, thus the heap gets        */
 315         /* larger ...                                                   */
 316 # ifdef THREADS
 317     if (++random_no % 13 == 0) {
 318         limit = sp;
 319         MAKE_HOTTER(limit, BIG_CLEAR_SIZE*sizeof(word));
 320         limit &= ~0xf;  /* Make it sufficiently aligned for assembly    */
 321                         /* implementations of GC_clear_stack_inner.     */
 322         return GC_clear_stack_inner(arg, limit);
 323     } else {
 324         BZERO(dummy, SMALL_CLEAR_SIZE*sizeof(word));
 325         return arg;
 326     }
 327 # else
 328     if (GC_gc_no > GC_stack_last_cleared) {
 329         /* Start things over, so we clear the entire stack again */
 330         if (GC_stack_last_cleared == 0) GC_high_water = (word) GC_stackbottom;
 331         GC_min_sp = GC_high_water;
 332         GC_stack_last_cleared = GC_gc_no;
 333         GC_words_allocd_at_reset = GC_words_allocd;
 334     }
 335     /* Adjust GC_high_water */
 336         MAKE_COOLER(GC_high_water, WORDS_TO_BYTES(DEGRADE_RATE) + GC_SLOP);
 337         if (sp HOTTER_THAN GC_high_water) {
 338             GC_high_water = sp;
 339         }
 340         MAKE_HOTTER(GC_high_water, GC_SLOP);
 341     limit = GC_min_sp;
 342     MAKE_HOTTER(limit, SLOP);
 343     if (sp COOLER_THAN limit) {
 344         limit &= ~0xf;  /* Make it sufficiently aligned for assembly    */
 345                         /* implementations of GC_clear_stack_inner.     */
 346         GC_min_sp = sp;
 347         return(GC_clear_stack_inner(arg, limit));
 348     } else if (WORDS_TO_BYTES(GC_words_allocd - GC_words_allocd_at_reset)
 349                > CLEAR_THRESHOLD) {
 350         /* Restart clearing process, but limit how much clearing we do. */
 351         GC_min_sp = sp;
 352         MAKE_HOTTER(GC_min_sp, CLEAR_THRESHOLD/4);
 353         if (GC_min_sp HOTTER_THAN GC_high_water) GC_min_sp = GC_high_water;
 354         GC_words_allocd_at_reset = GC_words_allocd;
 355     }
 356     return(arg);
 357 # endif
 358 }
 359
 360
 361 /* Return a pointer to the base address of p, given a pointer to a      */
 362 /* an address within an object.  Return 0 o.w.                          */
 363 # ifdef __STDC__
 364     GC_PTR GC_base(GC_PTR p)
 365 # else
 366     GC_PTR GC_base(p)
 367     GC_PTR p;
 368 # endif
 369 {
 370     register word r;
 371     register struct hblk *h;
 372     register bottom_index *bi;
 373     register hdr *candidate_hdr;
 374     register word limit;
 375
 376     r = (word)p;
 377     if (!GC_is_initialized) return 0;
 378     h = HBLKPTR(r);
 379     GET_BI(r, bi);
 380     candidate_hdr = HDR_FROM_BI(bi, r);
 381     if (candidate_hdr == 0) return(0);
 382     /* If it's a pointer to the middle of a large object, move it       */
 383     /* to the beginning.                                                */
 384         while (IS_FORWARDING_ADDR_OR_NIL(candidate_hdr)) {
 385            h = FORWARDED_ADDR(h,candidate_hdr);
 386            r = (word)h;
 387            candidate_hdr = HDR(h);
 388         }
 389     if (candidate_hdr -> hb_map == GC_invalid_map) return(0);
 390     /* Make sure r points to the beginning of the object */
 391         r &= ~(WORDS_TO_BYTES(1) - 1);
 392         {
 393             register int offset = HBLKDISPL(r);
 394             register signed_word sz = candidate_hdr -> hb_sz;
 395             register signed_word map_entry;
 396
 397             map_entry = MAP_ENTRY((candidate_hdr -> hb_map), offset);
 398             if (map_entry > CPP_MAX_OFFSET) {
 399                 map_entry = (signed_word)(BYTES_TO_WORDS(offset)) % sz;
 400             }
 401             r -= WORDS_TO_BYTES(map_entry);
 402             limit = r + WORDS_TO_BYTES(sz);
 403             if (limit > (word)(h + 1)
 404                 && sz <= BYTES_TO_WORDS(HBLKSIZE)) {
 405                 return(0);
 406             }
 407             if ((word)p >= limit) return(0);
 408         }
 409     return((GC_PTR)r);
 410 }
 411
 412
 413 /* Return the size of an object, given a pointer to its base.           */
 414 /* (For small obects this also happens to work from interior pointers,  */
 415 /* but that shouldn't be relied upon.)                                  */
 416 # ifdef __STDC__
 417     size_t GC_size(GC_PTR p)
 418 # else
 419     size_t GC_size(p)
 420     GC_PTR p;
 421 # endif
 422 {
 423     register int sz;
 424     register hdr * hhdr = HDR(p);
 425
 426     sz = WORDS_TO_BYTES(hhdr -> hb_sz);
 427     return(sz);
 428 }
 429
 430 size_t GC_get_heap_size GC_PROTO(())
 431 {
 432     return ((size_t) GC_heapsize);
 433 }
 434
 435 size_t GC_get_free_bytes GC_PROTO(())
 436 {
 437     return ((size_t) GC_large_free_bytes);
 438 }
 439
 440 size_t GC_get_bytes_since_gc GC_PROTO(())
 441 {
 442     return ((size_t) WORDS_TO_BYTES(GC_words_allocd));
 443 }
 444
 445 size_t GC_get_total_bytes GC_PROTO(())
 446 {
 447     return ((size_t) WORDS_TO_BYTES(GC_words_allocd+GC_words_allocd_before_gc));
 448 }
 449
 450 GC_bool GC_is_initialized = FALSE;
 451
 452 void GC_init()
 453 {
 454     DCL_LOCK_STATE;
 455
 456     DISABLE_SIGNALS();
 457
 458 #ifdef MSWIN32
 459     if (!GC_is_initialized) InitializeCriticalSection(&GC_allocate_ml);
 460 #endif /* MSWIN32 */
 461
 462     LOCK();
 463     GC_init_inner();
 464     UNLOCK();
 465     ENABLE_SIGNALS();
 466
 467 #   if defined(PARALLEL_MARK) || defined(THREAD_LOCAL_ALLOC)
 468         /* Make sure marker threads and started and thread local */
 469         /* allocation is initialized, in case we didn't get      */
 470         /* called from GC_init_parallel();                       */
 471         {
 472           extern void GC_init_parallel(void);
 473           GC_init_parallel();
 474         }
 475 #   endif /* PARALLEL_MARK || THREAD_LOCAL_ALLOC */
 476 }
 477
 478 #if defined(MSWIN32) || defined(MSWINCE)
 479     CRITICAL_SECTION GC_write_cs;
 480 #endif
 481
 482 #ifdef MSWIN32
 483     extern void GC_init_win32 GC_PROTO((void));
 484 #endif
 485
 486 extern void GC_setpagesize();
 487
 488 #ifdef UNIX_LIKE
 489
 490 extern void GC_set_and_save_fault_handler GC_PROTO((void (*handler)(int)));
 491
 492 static void looping_handler(sig)
 493 int sig;
 494 {
 495     GC_err_printf1("Caught signal %d: looping in handler\n", sig);
 496     for(;;);
 497 }
 498 #endif
 499
 500 #ifdef MSWIN32
 501 extern GC_bool GC_no_win32_dlls;
 502 #else
 503 # define GC_no_win32_dlls FALSE
 504 #endif
 505
 506 void GC_init_inner()
 507 {
 508 #   if !defined(THREADS) && defined(GC_ASSERTIONS)
 509         word dummy;
 510 #   endif
 511     word initial_heap_sz = (word)MINHINCR;
 512
 513     if (GC_is_initialized) return;
 514 #   ifdef PRINTSTATS
 515       GC_print_stats = 1;
 516 #   endif
 517 #   if defined(MSWIN32) || defined(MSWINCE)
 518         InitializeCriticalSection(&GC_write_cs);
 519 #   endif
 520
 521     if (0 != GETENV("GC_PRINT_STATS")) {
 522       GC_print_stats = 1;
 523     }
 524     if (0 != GETENV("GC_FIND_LEAK")) {
 525       GC_find_leak = 1;
 526     }
 527     if (0 != GETENV("GC_ALL_INTERIOR_POINTERS")) {
 528       GC_all_interior_pointers = 1;
 529     }
 530     if (0 != GETENV("GC_DONT_GC")) {
 531       GC_dont_gc = 1;
 532     }
 533     if (0 != GETENV("GC_PRINT_BACK_HEIGHT")) {
 534       GC_print_back_height = 1;
 535     }
 536     if (0 != GETENV("GC_NO_BLACKLIST_WARNING")) {
 537       GC_large_alloc_warn_interval = LONG_MAX;
 538     }
 539     {
 540       char * time_limit_string = GETENV("GC_PAUSE_TIME_TARGET");
 541       if (0 != time_limit_string) {
 542         long time_limit = atol(time_limit_string);
 543         if (time_limit < 5) {
 544           WARN("GC_PAUSE_TIME_TARGET environment variable value too small "
 545                "or bad syntax: Ignoring\n", 0);
 546         } else {
 547           GC_time_limit = time_limit;
 548         }
 549       }
 550     }
 551     {
 552       char * interval_string = GETENV("GC_LARGE_ALLOC_WARN_INTERVAL");
 553       if (0 != interval_string) {
 554         long interval = atol(interval_string);
 555         if (interval <= 0) {
 556           WARN("GC_LARGE_ALLOC_WARN_INTERVAL environment variable has "
 557                "bad value: Ignoring\n", 0);
 558         } else {
 559           GC_large_alloc_warn_interval = interval;
 560         }
 561       }
 562     }
 563 #   ifdef UNIX_LIKE
 564       if (0 != GETENV("GC_LOOP_ON_ABORT")) {
 565         GC_set_and_save_fault_handler(looping_handler);
 566       }
 567 #   endif
 568     /* Adjust normal object descriptor for extra allocation.    */
 569     if (ALIGNMENT > GC_DS_TAGS && EXTRA_BYTES != 0) {
 570       GC_obj_kinds[NORMAL].ok_descriptor = ((word)(-ALIGNMENT) | GC_DS_LENGTH);
 571     }
 572     GC_setpagesize();
 573     GC_exclude_static_roots(beginGC_arrays, endGC_arrays);
 574     GC_exclude_static_roots(beginGC_obj_kinds, endGC_obj_kinds);
 575 #   ifdef SEPARATE_GLOBALS
 576       GC_exclude_static_roots(beginGC_objfreelist, endGC_objfreelist);
 577       GC_exclude_static_roots(beginGC_aobjfreelist, endGC_aobjfreelist);
 578 #   endif
 579 #   ifdef MSWIN32
 580         GC_init_win32();
 581 #   endif
 582 #   if defined(SEARCH_FOR_DATA_START)
 583         GC_init_linux_data_start();
 584 #   endif
 585 #   if (defined(NETBSD) || defined(OPENBSD)) && defined(__ELF__)
 586         GC_init_netbsd_elf();
 587 #   endif
 588 #   if defined(GC_PTHREADS) || defined(GC_SOLARIS_THREADS)
 589         GC_thr_init();
 590 #   endif
 591 #   ifdef GC_SOLARIS_THREADS
 592         /* We need dirty bits in order to find live stack sections.     */
 593         GC_dirty_init();
 594 #   endif
 595 #   if !defined(THREADS) || defined(GC_PTHREADS) || defined(GC_WIN32_THREADS) \
 596         || defined(GC_SOLARIS_THREADS)
 597       if (GC_stackbottom == 0) {
 598         GC_stackbottom = GC_get_stack_base();
 599 #       if defined(LINUX) && defined(IA64)
 600           GC_register_stackbottom = GC_get_register_stack_base();
 601 #       endif
 602       }
 603 #   endif
 604     GC_ASSERT(sizeof (ptr_t) == sizeof(word));
 605     GC_ASSERT(sizeof (signed_word) == sizeof(word));
 606     GC_ASSERT(sizeof (struct hblk) == HBLKSIZE);
 607 #   ifndef THREADS
 608 #     if defined(STACK_GROWS_UP) && defined(STACK_GROWS_DOWN)
 609         ABORT(
 610           "Only one of STACK_GROWS_UP and STACK_GROWS_DOWN should be defd\n");
 611 #     endif
 612 #     if !defined(STACK_GROWS_UP) && !defined(STACK_GROWS_DOWN)
 613         ABORT(
 614           "One of STACK_GROWS_UP and STACK_GROWS_DOWN should be defd\n");
 615 #     endif
 616 #     ifdef STACK_GROWS_DOWN
 617         GC_ASSERT((word)(&dummy) <= (word)GC_stackbottom);
 618 #     else
 619         GC_ASSERT((word)(&dummy) >= (word)GC_stackbottom);
 620 #     endif
 621 #   endif
 622 #   if !defined(_AUX_SOURCE) || defined(__GNUC__)
 623       GC_ASSERT((word)(-1) > (word)0);
 624       /* word should be unsigned */
 625 #   endif
 626     GC_ASSERT((signed_word)(-1) < (signed_word)0);
 627
 628     /* Add initial guess of root sets.  Do this first, since sbrk(0)    */
 629     /* might be used.                                                   */
 630       if (GC_REGISTER_MAIN_STATIC_DATA()) GC_register_data_segments();
 631     GC_init_headers();
 632     GC_bl_init();
 633     GC_mark_init();
 634     {
 635         char * sz_str = GETENV("GC_INITIAL_HEAP_SIZE");
 636         if (sz_str != NULL) {
 637           initial_heap_sz = atoi(sz_str);
 638           if (initial_heap_sz <= MINHINCR * HBLKSIZE) {
 639             WARN("Bad initial heap size %s - ignoring it.\n",
 640                  sz_str);
 641           }
 642           initial_heap_sz = divHBLKSZ(initial_heap_sz);
 643         }
 644     }
 645     if (!GC_expand_hp_inner(initial_heap_sz)) {
 646         GC_err_printf0("Can't start up: not enough memory\n");
 647         EXIT();
 648     }
 649     /* Preallocate large object map.  It's otherwise inconvenient to    */
 650     /* deal with failure.                                               */
 651       if (!GC_add_map_entry((word)0)) {
 652         GC_err_printf0("Can't start up: not enough memory\n");
 653         EXIT();
 654       }
 655     GC_register_displacement_inner(0L);
 656 #   ifdef MERGE_SIZES
 657       GC_init_size_map();
 658 #   endif
 659 #   ifdef PCR
 660       if (PCR_IL_Lock(PCR_Bool_false, PCR_allSigsBlocked, PCR_waitForever)
 661           != PCR_ERes_okay) {
 662           ABORT("Can't lock load state\n");
 663       } else if (PCR_IL_Unlock() != PCR_ERes_okay) {
 664           ABORT("Can't unlock load state\n");
 665       }
 666       PCR_IL_Unlock();
 667       GC_pcr_install();
 668 #   endif
 669 #   if !defined(SMALL_CONFIG)
 670       if (!GC_no_win32_dlls && 0 != GETENV("GC_ENABLE_INCREMENTAL")) {
 671         GC_ASSERT(!GC_incremental);
 672         GC_setpagesize();
 673 #       ifndef GC_SOLARIS_THREADS
 674           GC_dirty_init();
 675 #       endif
 676         GC_ASSERT(GC_words_allocd == 0)
 677         GC_incremental = TRUE;
 678       }
 679 #   endif /* !SMALL_CONFIG */
 680     /* Get black list set up and/or incrmental GC started */
 681       if (!GC_dont_precollect || GC_incremental) GC_gcollect_inner();
 682     GC_is_initialized = TRUE;
 683 #   ifdef STUBBORN_ALLOC
 684         GC_stubborn_init();
 685 #   endif
 686     /* Convince lint that some things are used */
 687 #   ifdef LINT
 688       {
 689           extern char * GC_copyright[];
 690           extern int GC_read();
 691           extern void GC_register_finalizer_no_order();
 692
 693           GC_noop(GC_copyright, GC_find_header,
 694                   GC_push_one, GC_call_with_alloc_lock, GC_read,
 695                   GC_dont_expand,
 696 #                 ifndef NO_DEBUGGING
 697                     GC_dump,
 698 #                 endif
 699                   GC_register_finalizer_no_order);
 700       }
 701 #   endif
 702 }
 703
 704 void GC_enable_incremental GC_PROTO(())
 705 {
 706 # if !defined(SMALL_CONFIG)
 707   if (!GC_find_leak) {
 708     DCL_LOCK_STATE;
 709
 710     DISABLE_SIGNALS();
 711     LOCK();
 712     if (GC_incremental) goto out;
 713     GC_setpagesize();
 714     if (GC_no_win32_dlls) goto out;
 715 #   ifndef GC_SOLARIS_THREADS
 716         GC_dirty_init();
 717 #   endif
 718     if (!GC_is_initialized) {
 719         GC_init_inner();
 720     }
 721     if (GC_incremental) goto out;
 722     if (GC_dont_gc) {
 723         /* Can't easily do it. */
 724         UNLOCK();
 725         ENABLE_SIGNALS();
 726         return;
 727     }
 728     if (GC_words_allocd > 0) {
 729         /* There may be unmarked reachable objects      */
 730         GC_gcollect_inner();
 731     }   /* else we're OK in assuming everything's       */
 732         /* clean since nothing can point to an          */
 733         /* unmarked object.                             */
 734     GC_read_dirty();
 735     GC_incremental = TRUE;
 736 out:
 737     UNLOCK();
 738     ENABLE_SIGNALS();
 739   }
 740 # endif
 741 }
 742
 743
 744 #if defined(MSWIN32) || defined(MSWINCE)
 745 # define LOG_FILE _T("gc.log")
 746
 747   HANDLE GC_stdout = 0;
 748
 749   void GC_deinit()
 750   {
 751       if (GC_is_initialized) {
 752         DeleteCriticalSection(&GC_write_cs);
 753       }
 754   }
 755
 756   int GC_write(buf, len)
 757   GC_CONST char * buf;
 758   size_t len;
 759   {
 760       BOOL tmp;
 761       DWORD written;
 762       if (len == 0)
 763           return 0;
 764       EnterCriticalSection(&GC_write_cs);
 765       if (GC_stdout == INVALID_HANDLE_VALUE) {
 766           return -1;
 767       } else if (GC_stdout == 0) {
 768           GC_stdout = CreateFile(LOG_FILE, GENERIC_WRITE,
 769                                  FILE_SHARE_READ | FILE_SHARE_WRITE,
 770                                  NULL, CREATE_ALWAYS, FILE_FLAG_WRITE_THROUGH,
 771                                  NULL);
 772           if (GC_stdout == INVALID_HANDLE_VALUE) ABORT("Open of log file failed");
 773       }
 774       tmp = WriteFile(GC_stdout, buf, len, &written, NULL);
 775       if (!tmp)
 776           DebugBreak();
 777       LeaveCriticalSection(&GC_write_cs);
 778       return tmp ? (int)written : -1;
 779   }
 780
 781 #endif
 782
 783 #if defined(OS2) || defined(MACOS)
 784 FILE * GC_stdout = NULL;
 785 FILE * GC_stderr = NULL;
 786 int GC_tmp;  /* Should really be local ... */
 787
 788   void GC_set_files()
 789   {
 790       if (GC_stdout == NULL) {
 791         GC_stdout = stdout;
 792     }
 793     if (GC_stderr == NULL) {
 794         GC_stderr = stderr;
 795     }
 796   }
 797 #endif
 798
 799 #if !defined(OS2) && !defined(MACOS) && !defined(MSWIN32) && !defined(MSWINCE)
 800   int GC_stdout = 1;
 801   int GC_stderr = 2;
 802 # if !defined(AMIGA)
 803 #   include <unistd.h>
 804 # endif
 805 #endif
 806
 807 #if !defined(MSWIN32) && !defined(MSWINCE) && !defined(OS2) \
 808     && !defined(MACOS)  && !defined(ECOS) && !defined(NOSYS)
 809 int GC_write(fd, buf, len)
 810 int fd;
 811 GC_CONST char *buf;
 812 size_t len;
 813 {
 814      register int bytes_written = 0;
 815      register int result;
 816
 817      while (bytes_written < len) {
 818 #       ifdef GC_SOLARIS_THREADS
 819             result = syscall(SYS_write, fd, buf + bytes_written,
 820                                             len - bytes_written);
 821 #       else
 822             result = write(fd, buf + bytes_written, len - bytes_written);
 823 #       endif
 824         if (-1 == result) return(result);
 825         bytes_written += result;
 826     }
 827     return(bytes_written);
 828 }
 829 #endif /* UN*X */
 830
 831 #ifdef ECOS
 832 int GC_write(fd, buf, len)
 833 {
 834   _Jv_diag_write (buf, len);
 835   return len;
 836 }
 837 #endif
 838
 839 #ifdef NOSYS
 840 int GC_write(fd, buf, len)
 841 {
 842   /* No writing.  */
 843   return len;
 844 }
 845 #endif
 846
 847
 848 #if defined(MSWIN32) || defined(MSWINCE)
 849 #   define WRITE(f, buf, len) GC_write(buf, len)
 850 #else
 851 #   if defined(OS2) || defined(MACOS)
 852 #   define WRITE(f, buf, len) (GC_set_files(), \
 853                                GC_tmp = fwrite((buf), 1, (len), (f)), \
 854                                fflush(f), GC_tmp)
 855 #   else
 856 #     define WRITE(f, buf, len) GC_write((f), (buf), (len))
 857 #   endif
 858 #endif
 859
 860 /* A version of printf that is unlikely to call malloc, and is thus safer */
 861 /* to call from the collector in case malloc has been bound to GC_malloc. */
 862 /* Assumes that no more than 1023 characters are written at once.         */
 863 /* Assumes that all arguments have been converted to something of the     */
 864 /* same size as long, and that the format conversions expect something    */
 865 /* of that size.                                                          */
 866 void GC_printf(format, a, b, c, d, e, f)
 867 GC_CONST char * format;
 868 long a, b, c, d, e, f;
 869 {
 870     char buf[1025];
 871
 872     if (GC_quiet) return;
 873     buf[1024] = 0x15;
 874     (void) sprintf(buf, format, a, b, c, d, e, f);
 875     if (buf[1024] != 0x15) ABORT("GC_printf clobbered stack");
 876     if (WRITE(GC_stdout, buf, strlen(buf)) < 0) ABORT("write to stdout failed");
 877 }
 878
 879 void GC_err_printf(format, a, b, c, d, e, f)
 880 GC_CONST char * format;
 881 long a, b, c, d, e, f;
 882 {
 883     char buf[1025];
 884
 885     buf[1024] = 0x15;
 886     (void) sprintf(buf, format, a, b, c, d, e, f);
 887     if (buf[1024] != 0x15) ABORT("GC_err_printf clobbered stack");
 888     if (WRITE(GC_stderr, buf, strlen(buf)) < 0) ABORT("write to stderr failed");
 889 }
 890
 891 void GC_err_puts(s)
 892 GC_CONST char *s;
 893 {
 894     if (WRITE(GC_stderr, s, strlen(s)) < 0) ABORT("write to stderr failed");
 895 }
 896
 897 #if defined(LINUX) && !defined(SMALL_CONFIG)
 898 void GC_err_write(buf, len)
 899 GC_CONST char *buf;
 900 size_t len;
 901 {
 902     if (WRITE(GC_stderr, buf, len) < 0) ABORT("write to stderr failed");
 903 }
 904 #endif
 905
 906 # if defined(__STDC__) || defined(__cplusplus)
 907     void GC_default_warn_proc(char *msg, GC_word arg)
 908 # else
 909     void GC_default_warn_proc(msg, arg)
 910     char *msg;
 911     GC_word arg;
 912 # endif
 913 {
 914     GC_err_printf1(msg, (unsigned long)arg);
 915 }
 916
 917 GC_warn_proc GC_current_warn_proc = GC_default_warn_proc;
 918
 919 # if defined(__STDC__) || defined(__cplusplus)
 920     GC_warn_proc GC_set_warn_proc(GC_warn_proc p)
 921 # else
 922     GC_warn_proc GC_set_warn_proc(p)
 923     GC_warn_proc p;
 924 # endif
 925 {
 926     GC_warn_proc result;
 927
 928     LOCK();
 929     result = GC_current_warn_proc;
 930     GC_current_warn_proc = p;
 931     UNLOCK();
 932     return(result);
 933 }
 934
 935
 936 #ifndef PCR
 937 void GC_abort(msg)
 938 GC_CONST char * msg;
 939 {
 940 #   if defined(MSWIN32)
 941       (void) MessageBoxA(NULL, msg, "Fatal error in gc", MB_ICONERROR|MB_OK);
 942       DebugBreak();
 943 #   else
 944       GC_err_printf1("%s\n", msg);
 945 #   endif
 946     if (GETENV("GC_LOOP_ON_ABORT") != NULL) {
 947             /* In many cases it's easier to debug a running process.    */
 948             /* It's arguably nicer to sleep, but that makes it harder   */
 949             /* to look at the thread if the debugger doesn't know much  */
 950             /* about threads.                                           */
 951             for(;;) {}
 952     }
 953 #   ifdef MSWIN32
 954         DebugBreak();
 955 #   else
 956         (void) abort();
 957 #   endif
 958 }
 959 #endif
 960
 961 #ifdef NEED_CALLINFO
 962
 963 #ifdef HAVE_BUILTIN_BACKTRACE
 964 # include <execinfo.h>
 965 # ifdef LINUX
 966 #   include <unistd.h>
 967 # endif
 968 #endif
 969
 970 void GC_print_callers (info)
 971 struct callinfo info[NFRAMES];
 972 {
 973     register int i;
 974
 975 #   if NFRAMES == 1
 976       GC_err_printf0("\tCaller at allocation:\n");
 977 #   else
 978       GC_err_printf0("\tCall chain at allocation:\n");
 979 #   endif
 980     for (i = 0; i < NFRAMES; i++) {
 981         if (info[i].ci_pc == 0) break;
 982 #       if NARGS > 0
 983         {
 984           int j;
 985
 986           GC_err_printf0("\t\targs: ");
 987           for (j = 0; j < NARGS; j++) {
 988             if (j != 0) GC_err_printf0(", ");
 989             GC_err_printf2("%d (0x%X)", ~(info[i].ci_arg[j]),
 990                                         ~(info[i].ci_arg[j]));
 991           }
 992           GC_err_printf0("\n");
 993         }
 994 #       endif
 995 #       if defined(HAVE_BUILTIN_BACKTRACE) && !defined(REDIRECT_MALLOC)
 996           /* Unfortunately backtrace_symbols calls malloc, which makes  */
 997           /* it dangersous if that has been redirected.                 */
 998           {
 999             char **sym_name =
1000               backtrace_symbols((void **)(&(info[i].ci_pc)), 1);
1001             char *name = sym_name[0];
1002             GC_bool found_it = (strchr(name, '(') != 0);
1003             FILE *pipe;
1004 #           ifdef LINUX
1005               if (!found_it) {
1006 #               define EXE_SZ 100
1007                 static char exe_name[EXE_SZ];
1008 #               define CMD_SZ 200
1009                 char cmd_buf[CMD_SZ];
1010 #               define RESULT_SZ 200
1011                 static char result_buf[RESULT_SZ];
1012                 size_t result_len;
1013                 static GC_bool found_exe_name = FALSE;
1014                 static GC_bool will_fail = FALSE;
1015                 int ret_code;
1016                 /* Unfortunately, this is the common case for the       */
1017                 /* main executable.                                     */
1018                 /* Try to get it via a hairy and expensive scheme.      */
1019                 /* First we get the name of the executable:             */
1020                 if (will_fail) goto out;
1021                 if (!found_exe_name) {
1022                   ret_code = readlink("/proc/self/exe", exe_name, EXE_SZ);
1023                   if (ret_code < 0 || ret_code >= EXE_SZ || exe_name[0] != '/') {
1024                     will_fail = TRUE;   /* Dont try again. */
1025                     goto out;
1026                   }
1027                   exe_name[ret_code] = '\0';
1028                   found_exe_name = TRUE;
1029                 }
1030                 /* Then we use popen to start addr2line -e <exe> <addr> */
1031                 /* There are faster ways to do this, but hopefully this */
1032                 /* isn't time critical.                                 */
1033                 sprintf(cmd_buf, "/usr/bin/addr2line -e %s 0x%lx", exe_name,
1034                                  (unsigned long)info[i].ci_pc);
1035                 pipe = popen(cmd_buf, "r");
1036                 if (pipe < 0 || fgets(result_buf, RESULT_SZ, pipe) == 0) {
1037                   will_fail = TRUE;
1038                   goto out;
1039                 }
1040                 result_len = strlen(result_buf);
1041                 if (result_buf[result_len - 1] == '\n') --result_len;
1042                 if (result_buf[0] == '?'
1043                     || result_buf[result_len-2] == ':'
1044                        && result_buf[result_len-1] == '0')
1045                     goto out;
1046                 if (result_len < RESULT_SZ - 25) {
1047                   /* Add in hex address */
1048                     sprintf(result_buf + result_len, " [0x%lx]",
1049                           (unsigned long)info[i].ci_pc);
1050                 }
1051                 name = result_buf;
1052                 pclose(pipe);
1053                 out:
1054               }
1055 #           endif
1056             GC_err_printf1("\t\t%s\n", name);
1057             free(sym_name);
1058           }
1059 #       else
1060           GC_err_printf1("\t\t##PC##= 0x%lx\n", info[i].ci_pc);
1061 #       endif
1062     }
1063 }
1064
1065 #endif /* SAVE_CALL_CHAIN */
1066
1067 /* Needed by SRC_M3, gcj, and should perhaps be the official interface  */
1068 /* to GC_dont_gc.                                                       */
1069 void GC_enable()
1070 {
1071     GC_dont_gc--;
1072 }
1073
1074 void GC_disable()
1075 {
1076     GC_dont_gc++;
1077 }
1078
1079 #if !defined(NO_DEBUGGING)
1080
1081 void GC_dump()
1082 {
1083     GC_printf0("***Static roots:\n");
1084     GC_print_static_roots();
1085     GC_printf0("\n***Heap sections:\n");
1086     GC_print_heap_sects();
1087     GC_printf0("\n***Free blocks:\n");
1088     GC_print_hblkfreelist();
1089     GC_printf0("\n***Blocks in use:\n");
1090     GC_print_block_list();
1091 }
1092
1093 #endif /* NO_DEBUGGING */