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 #             elif defined(SN_TARGET_PS3)
  68                   #include <pthread.h>
  69                   pthread_mutex_t GC_allocate_ml;
  70 #             else
  71                   --> declare allocator lock here
  72 #             endif
  73 #          endif
  74 #       endif
  75 #     endif
  76 #   endif
  77 # endif
  78
  79 #if defined(NOSYS) || defined(ECOS)
  80 #undef STACKBASE
  81 #endif
  82
  83 /* Dont unnecessarily call GC_register_main_static_data() in case       */
  84 /* dyn_load.c isn't linked in.                                          */
  85 #ifdef DYNAMIC_LOADING
  86 # define GC_REGISTER_MAIN_STATIC_DATA() GC_register_main_static_data()
  87 #elif defined(GC_DONT_REGISTER_MAIN_STATIC_DATA)
  88 # define GC_REGISTER_MAIN_STATIC_DATA() FALSE
  89 #else
  90 # define GC_REGISTER_MAIN_STATIC_DATA() TRUE
  91 #endif
  92
  93 GC_FAR struct _GC_arrays GC_arrays /* = { 0 } */;
  94
  95
  96 GC_bool GC_debugging_started = FALSE;
  97         /* defined here so we don't have to load debug_malloc.o */
  98
  99 void (*GC_check_heap) GC_PROTO((void)) = (void (*) GC_PROTO((void)))0;
 100 void (*GC_print_all_smashed) GC_PROTO((void)) = (void (*) GC_PROTO((void)))0;
 101
 102 void (*GC_start_call_back) GC_PROTO((void)) = (void (*) GC_PROTO((void)))0;
 103
 104 ptr_t GC_stackbottom = 0;
 105
 106 #ifdef IA64
 107   ptr_t GC_register_stackbottom = 0;
 108 #endif
 109
 110 GC_bool GC_dont_gc = 0;
 111
 112 GC_bool GC_dont_precollect = 0;
 113
 114 GC_bool GC_quiet = 0;
 115
 116 GC_bool GC_print_stats = 0;
 117
 118 GC_bool GC_print_back_height = 0;
 119
 120 #ifndef NO_DEBUGGING
 121   GC_bool GC_dump_regularly = 0;  /* Generate regular debugging dumps. */
 122 #endif
 123
 124 #ifdef KEEP_BACK_PTRS
 125   long GC_backtraces = 0;       /* Number of random backtraces to       */
 126                                 /* generate for each GC.                */
 127 #endif
 128
 129 #ifdef FIND_LEAK
 130   int GC_find_leak = 1;
 131 #else
 132   int GC_find_leak = 0;
 133 #endif
 134
 135 #ifdef ALL_INTERIOR_POINTERS
 136   int GC_all_interior_pointers = 1;
 137 #else
 138   int GC_all_interior_pointers = 0;
 139 #endif
 140
 141 long GC_large_alloc_warn_interval = 5;
 142         /* Interval between unsuppressed warnings.      */
 143
 144 long GC_large_alloc_warn_suppressed = 0;
 145         /* Number of warnings suppressed so far.        */
 146
 147 /*ARGSUSED*/
 148 GC_PTR GC_default_oom_fn GC_PROTO((size_t bytes_requested))
 149 {
 150     return(0);
 151 }
 152
 153 GC_PTR (*GC_oom_fn) GC_PROTO((size_t bytes_requested)) = GC_default_oom_fn;
 154
 155 extern signed_word GC_mem_found;
 156
 157 void * GC_project2(arg1, arg2)
 158 void *arg1;
 159 void *arg2;
 160 {
 161   return arg2;
 162 }
 163
 164 # ifdef MERGE_SIZES
 165     /* Set things up so that GC_size_map[i] >= words(i),                */
 166     /* but not too much bigger                                          */
 167     /* and so that size_map contains relatively few distinct entries    */
 168     /* This is stolen from Russ Atkinson's Cedar quantization           */
 169     /* alogrithm (but we precompute it).                                */
 170
 171
 172     void GC_init_size_map()
 173     {
 174         register unsigned i;
 175
 176         /* Map size 0 to something bigger.                      */
 177         /* This avoids problems at lower levels.                */
 178         /* One word objects don't have to be 2 word aligned,    */
 179         /* unless we're using mark bytes.                       */
 180           for (i = 0; i < sizeof(word); i++) {
 181               GC_size_map[i] = MIN_WORDS;
 182           }
 183 #         if MIN_WORDS > 1
 184             GC_size_map[sizeof(word)] = MIN_WORDS;
 185 #         else
 186             GC_size_map[sizeof(word)] = ROUNDED_UP_WORDS(sizeof(word));
 187 #         endif
 188         for (i = sizeof(word) + 1; i <= 8 * sizeof(word); i++) {
 189             GC_size_map[i] = ALIGNED_WORDS(i);
 190         }
 191         for (i = 8*sizeof(word) + 1; i <= 16 * sizeof(word); i++) {
 192               GC_size_map[i] = (ROUNDED_UP_WORDS(i) + 1) & (~1);
 193         }
 194 #       ifdef GC_GCJ_SUPPORT
 195            /* Make all sizes up to 32 words predictable, so that a      */
 196            /* compiler can statically perform the same computation,     */
 197            /* or at least a computation that results in similar size    */
 198            /* classes.                                                  */
 199            for (i = 16*sizeof(word) + 1; i <= 32 * sizeof(word); i++) {
 200               GC_size_map[i] = (ROUNDED_UP_WORDS(i) + 3) & (~3);
 201            }
 202 #       endif
 203         /* We leave the rest of the array to be filled in on demand. */
 204     }
 205
 206     /* Fill in additional entries in GC_size_map, including the ith one */
 207     /* We assume the ith entry is currently 0.                          */
 208     /* Note that a filled in section of the array ending at n always    */
 209     /* has length at least n/4.                                         */
 210     void GC_extend_size_map(i)
 211     word i;
 212     {
 213         word orig_word_sz = ROUNDED_UP_WORDS(i);
 214         word word_sz = orig_word_sz;
 215         register word byte_sz = WORDS_TO_BYTES(word_sz);
 216                                 /* The size we try to preserve.         */
 217                                 /* Close to to i, unless this would     */
 218                                 /* introduce too many distinct sizes.   */
 219         word smaller_than_i = byte_sz - (byte_sz >> 3);
 220         word much_smaller_than_i = byte_sz - (byte_sz >> 2);
 221         register word low_limit;        /* The lowest indexed entry we  */
 222                                         /* initialize.                  */
 223         register word j;
 224
 225         if (GC_size_map[smaller_than_i] == 0) {
 226             low_limit = much_smaller_than_i;
 227             while (GC_size_map[low_limit] != 0) low_limit++;
 228         } else {
 229             low_limit = smaller_than_i + 1;
 230             while (GC_size_map[low_limit] != 0) low_limit++;
 231             word_sz = ROUNDED_UP_WORDS(low_limit);
 232             word_sz += word_sz >> 3;
 233             if (word_sz < orig_word_sz) word_sz = orig_word_sz;
 234         }
 235 #       ifdef ALIGN_DOUBLE
 236             word_sz += 1;
 237             word_sz &= ~1;
 238 #       endif
 239         if (word_sz > MAXOBJSZ) {
 240             word_sz = MAXOBJSZ;
 241         }
 242         /* If we can fit the same number of larger objects in a block,  */
 243         /* do so.                                                       */
 244         {
 245             size_t number_of_objs = BODY_SZ/word_sz;
 246             word_sz = BODY_SZ/number_of_objs;
 247 #           ifdef ALIGN_DOUBLE
 248                 word_sz &= ~1;
 249 #           endif
 250         }
 251         byte_sz = WORDS_TO_BYTES(word_sz);
 252         if (GC_all_interior_pointers) {
 253             /* We need one extra byte; don't fill in GC_size_map[byte_sz] */
 254             byte_sz -= EXTRA_BYTES;
 255         }
 256
 257         for (j = low_limit; j <= byte_sz; j++) GC_size_map[j] = word_sz;
 258     }
 259 # endif
 260
 261
 262 /*
 263  * The following is a gross hack to deal with a problem that can occur
 264  * on machines that are sloppy about stack frame sizes, notably SPARC.
 265  * Bogus pointers may be written to the stack and not cleared for
 266  * a LONG time, because they always fall into holes in stack frames
 267  * that are not written.  We partially address this by clearing
 268  * sections of the stack whenever we get control.
 269  */
 270 word GC_stack_last_cleared = 0; /* GC_no when we last did this */
 271 # ifdef THREADS
 272 #   define BIG_CLEAR_SIZE 2048  /* Clear this much now and then.        */
 273 #   define SMALL_CLEAR_SIZE 256 /* Clear this much every time.          */
 274 # endif
 275 # define CLEAR_SIZE 213  /* Granularity for GC_clear_stack_inner */
 276 # define DEGRADE_RATE 50
 277
 278 word GC_min_sp;         /* Coolest stack pointer value from which we've */
 279                         /* already cleared the stack.                   */
 280
 281 word GC_high_water;
 282                         /* "hottest" stack pointer value we have seen   */
 283                         /* recently.  Degrades over time.               */
 284
 285 word GC_words_allocd_at_reset;
 286
 287 #if defined(ASM_CLEAR_CODE)
 288   extern ptr_t GC_clear_stack_inner();
 289 #else
 290 /* Clear the stack up to about limit.  Return arg. */
 291 /*ARGSUSED*/
 292 ptr_t GC_clear_stack_inner(arg, limit)
 293 ptr_t arg;
 294 word limit;
 295 {
 296     word dummy[CLEAR_SIZE];
 297
 298     BZERO(dummy, CLEAR_SIZE*sizeof(word));
 299     if ((word)(dummy) COOLER_THAN limit) {
 300         (void) GC_clear_stack_inner(arg, limit);
 301     }
 302     /* Make sure the recursive call is not a tail call, and the bzero   */
 303     /* call is not recognized as dead code.                             */
 304     GC_noop1((word)dummy);
 305     return(arg);
 306 }
 307 #endif
 308
 309 /* Clear some of the inaccessible part of the stack.  Returns its       */
 310 /* argument, so it can be used in a tail call position, hence clearing  */
 311 /* another frame.                                                       */
 312 ptr_t GC_clear_stack(arg)
 313 ptr_t arg;
 314 {
 315     register word sp = (word)GC_approx_sp();  /* Hotter than actual sp */
 316 #   ifdef THREADS
 317         word dummy[SMALL_CLEAR_SIZE];
 318         static unsigned random_no = 0;
 319                                  /* Should be more random than it is ... */
 320                                  /* Used to occasionally clear a bigger  */
 321                                  /* chunk.                               */
 322 #   endif
 323     register word limit;
 324
 325 #   define SLOP 400
 326         /* Extra bytes we clear every time.  This clears our own        */
 327         /* activation record, and should cause more frequent            */
 328         /* clearing near the cold end of the stack, a good thing.       */
 329 #   define GC_SLOP 4000
 330         /* We make GC_high_water this much hotter than we really saw    */
 331         /* saw it, to cover for GC noise etc. above our current frame.  */
 332 #   define CLEAR_THRESHOLD 100000
 333         /* We restart the clearing process after this many bytes of     */
 334         /* allocation.  Otherwise very heavily recursive programs       */
 335         /* with sparse stacks may result in heaps that grow almost      */
 336         /* without bounds.  As the heap gets larger, collection         */
 337         /* frequency decreases, thus clearing frequency would decrease, */
 338         /* thus more junk remains accessible, thus the heap gets        */
 339         /* larger ...                                                   */
 340 # ifdef THREADS
 341     if (++random_no % 13 == 0) {
 342         limit = sp;
 343         MAKE_HOTTER(limit, BIG_CLEAR_SIZE*sizeof(word));
 344         limit &= ~0xf;  /* Make it sufficiently aligned for assembly    */
 345                         /* implementations of GC_clear_stack_inner.     */
 346         return GC_clear_stack_inner(arg, limit);
 347     } else {
 348         BZERO(dummy, SMALL_CLEAR_SIZE*sizeof(word));
 349         return arg;
 350     }
 351 # else
 352     if (GC_gc_no > GC_stack_last_cleared) {
 353         /* Start things over, so we clear the entire stack again */
 354         if (GC_stack_last_cleared == 0) GC_high_water = (word) GC_stackbottom;
 355         GC_min_sp = GC_high_water;
 356         GC_stack_last_cleared = GC_gc_no;
 357         GC_words_allocd_at_reset = GC_words_allocd;
 358     }
 359     /* Adjust GC_high_water */
 360         MAKE_COOLER(GC_high_water, WORDS_TO_BYTES(DEGRADE_RATE) + GC_SLOP);
 361         if (sp HOTTER_THAN GC_high_water) {
 362             GC_high_water = sp;
 363         }
 364         MAKE_HOTTER(GC_high_water, GC_SLOP);
 365     limit = GC_min_sp;
 366     MAKE_HOTTER(limit, SLOP);
 367     if (sp COOLER_THAN limit) {
 368         limit &= ~0xf;  /* Make it sufficiently aligned for assembly    */
 369                         /* implementations of GC_clear_stack_inner.     */
 370         GC_min_sp = sp;
 371         return(GC_clear_stack_inner(arg, limit));
 372     } else if (WORDS_TO_BYTES(GC_words_allocd - GC_words_allocd_at_reset)
 373                > CLEAR_THRESHOLD) {
 374         /* Restart clearing process, but limit how much clearing we do. */
 375         GC_min_sp = sp;
 376         MAKE_HOTTER(GC_min_sp, CLEAR_THRESHOLD/4);
 377         if (GC_min_sp HOTTER_THAN GC_high_water) GC_min_sp = GC_high_water;
 378         GC_words_allocd_at_reset = GC_words_allocd;
 379     }
 380     return(arg);
 381 # endif
 382 }
 383
 384
 385 /* Return a pointer to the base address of p, given a pointer to a      */
 386 /* an address within an object.  Return 0 o.w.                          */
 387 # ifdef __STDC__
 388     GC_PTR GC_base(GC_PTR p)
 389 # else
 390     GC_PTR GC_base(p)
 391     GC_PTR p;
 392 # endif
 393 {
 394     register word r;
 395     register struct hblk *h;
 396     register bottom_index *bi;
 397     register hdr *candidate_hdr;
 398     register word limit;
 399
 400     r = (word)p;
 401     if (!GC_is_initialized) return 0;
 402     h = HBLKPTR(r);
 403     GET_BI(r, bi);
 404     candidate_hdr = HDR_FROM_BI(bi, r);
 405     if (candidate_hdr == 0) return(0);
 406     /* If it's a pointer to the middle of a large object, move it       */
 407     /* to the beginning.                                                */
 408         while (IS_FORWARDING_ADDR_OR_NIL(candidate_hdr)) {
 409            h = FORWARDED_ADDR(h,candidate_hdr);
 410            r = (word)h;
 411            candidate_hdr = HDR(h);
 412         }
 413     if (candidate_hdr -> hb_map == GC_invalid_map) return(0);
 414     /* Make sure r points to the beginning of the object */
 415         r &= ~(WORDS_TO_BYTES(1) - 1);
 416         {
 417             register int offset = HBLKDISPL(r);
 418             register signed_word sz = candidate_hdr -> hb_sz;
 419             register signed_word map_entry;
 420
 421             map_entry = MAP_ENTRY((candidate_hdr -> hb_map), offset);
 422             if (map_entry > CPP_MAX_OFFSET) {
 423                 map_entry = (signed_word)(BYTES_TO_WORDS(offset)) % sz;
 424             }
 425             r -= WORDS_TO_BYTES(map_entry);
 426             limit = r + WORDS_TO_BYTES(sz);
 427             if (limit > (word)(h + 1)
 428                 && sz <= BYTES_TO_WORDS(HBLKSIZE)) {
 429                 return(0);
 430             }
 431             if ((word)p >= limit) return(0);
 432         }
 433     return((GC_PTR)r);
 434 }
 435
 436
 437 /* Return the size of an object, given a pointer to its base.           */
 438 /* (For small obects this also happens to work from interior pointers,  */
 439 /* but that shouldn't be relied upon.)                                  */
 440 # ifdef __STDC__
 441     size_t GC_size(GC_PTR p)
 442 # else
 443     size_t GC_size(p)
 444     GC_PTR p;
 445 # endif
 446 {
 447     register int sz;
 448     register hdr * hhdr = HDR(p);
 449
 450     sz = WORDS_TO_BYTES(hhdr -> hb_sz);
 451     return(sz);
 452 }
 453
 454 size_t GC_get_heap_size GC_PROTO(())
 455 {
 456     return ((size_t) GC_heapsize);
 457 }
 458
 459 size_t GC_get_free_bytes GC_PROTO(())
 460 {
 461     return ((size_t) GC_large_free_bytes);
 462 }
 463
 464 size_t GC_get_bytes_since_gc GC_PROTO(())
 465 {
 466     return ((size_t) WORDS_TO_BYTES(GC_words_allocd));
 467 }
 468
 469 size_t GC_get_total_bytes GC_PROTO(())
 470 {
 471     return ((size_t) WORDS_TO_BYTES(GC_words_allocd+GC_words_allocd_before_gc));
 472 }
 473
 474 int GC_get_suspend_signal GC_PROTO(())
 475 {
 476 #if defined(SIG_SUSPEND) && defined(GC_PTHREADS) && !defined(GC_MACOSX_THREADS) && !defined(GC_OPENBSD_THREADS)
 477         return SIG_SUSPEND;
 478 #else
 479         return -1;
 480 #endif
 481 }
 482
 483 int GC_get_thr_restart_signal GC_PROTO(())
 484 {
 485 #if defined(SIG_THR_RESTART) && defined(GC_PTHREADS) && !defined(GC_MACOSX_THREADS) && !defined(GC_OPENBSD_THREADS)
 486         return SIG_THR_RESTART;
 487 #else
 488         return -1;
 489 #endif
 490 }
 491
 492
 493
 494 GC_bool GC_is_initialized = FALSE;
 495
 496 void GC_init()
 497 {
 498 #if defined(SN_TARGET_PS3)
 499         pthread_mutexattr_t mattr;
 500 #endif
 501
 502     DCL_LOCK_STATE;
 503
 504     DISABLE_SIGNALS();
 505
 506 #if defined(GC_WIN32_THREADS) && !defined(GC_PTHREADS)
 507     if (!GC_is_initialized) {
 508       BOOL (WINAPI *pfn) (LPCRITICAL_SECTION, DWORD) = NULL;
 509       HMODULE hK32 = GetModuleHandle(_T("kernel32.dll"));
 510       if (hK32)
 511           pfn = GetProcAddress(hK32,
 512                           "InitializeCriticalSectionAndSpinCount");
 513       if (pfn)
 514           pfn(&GC_allocate_ml, 4000);
 515       else
 516           InitializeCriticalSection (&GC_allocate_ml);
 517     }
 518 #endif /* MSWIN32 */
 519 #if defined(SN_TARGET_PS3)
 520         pthread_mutexattr_init (&mattr);
 521
 522         pthread_mutex_init (&GC_allocate_ml, &mattr);
 523         pthread_mutexattr_destroy (&mattr);
 524
 525 #endif
 526
 527     LOCK();
 528     GC_init_inner();
 529     UNLOCK();
 530     ENABLE_SIGNALS();
 531
 532 #   if defined(PARALLEL_MARK) || defined(THREAD_LOCAL_ALLOC)
 533         /* Make sure marker threads and started and thread local */
 534         /* allocation is initialized, in case we didn't get      */
 535         /* called from GC_init_parallel();                       */
 536         {
 537           extern void GC_init_parallel(void);
 538           GC_init_parallel();
 539         }
 540 #   endif /* PARALLEL_MARK || THREAD_LOCAL_ALLOC */
 541
 542 #   if defined(DYNAMIC_LOADING) && defined(DARWIN)
 543     {
 544         /* This must be called WITHOUT the allocation lock held
 545         and before any threads are created */
 546         extern void GC_init_dyld();
 547         GC_init_dyld();
 548     }
 549 #   endif
 550 }
 551
 552 #if defined(MSWIN32) || defined(MSWINCE)
 553     CRITICAL_SECTION GC_write_cs;
 554 #endif
 555
 556 #ifdef MSWIN32
 557     extern void GC_init_win32 GC_PROTO((void));
 558 #endif
 559
 560 extern void GC_setpagesize();
 561
 562
 563 #ifdef MSWIN32
 564 extern GC_bool GC_no_win32_dlls;
 565 #else
 566 # define GC_no_win32_dlls FALSE
 567 #endif
 568
 569 void GC_exit_check GC_PROTO((void))
 570 {
 571    GC_gcollect();
 572 }
 573
 574 #ifdef SEARCH_FOR_DATA_START
 575   extern void GC_init_linux_data_start GC_PROTO((void));
 576 #endif
 577
 578 #ifdef UNIX_LIKE
 579
 580 extern void GC_set_and_save_fault_handler GC_PROTO((void (*handler)(int)));
 581
 582 static void looping_handler(sig)
 583 int sig;
 584 {
 585     GC_err_printf1("Caught signal %d: looping in handler\n", sig);
 586     for(;;);
 587 }
 588
 589 static GC_bool installed_looping_handler = FALSE;
 590
 591 static void maybe_install_looping_handler()
 592 {
 593     /* Install looping handler before the write fault handler, so we    */
 594     /* handle write faults correctly.                                   */
 595       if (!installed_looping_handler && 0 != GETENV("GC_LOOP_ON_ABORT")) {
 596         GC_set_and_save_fault_handler(looping_handler);
 597         installed_looping_handler = TRUE;
 598       }
 599 }
 600
 601 #else /* !UNIX_LIKE */
 602
 603 # define maybe_install_looping_handler()
 604
 605 #endif
 606
 607 void GC_init_inner()
 608 {
 609 #   if !defined(THREADS) && defined(GC_ASSERTIONS)
 610         word dummy;
 611 #   endif
 612     word initial_heap_sz = (word)MINHINCR;
 613
 614     if (GC_is_initialized) return;
 615 #   ifdef PRINTSTATS
 616       GC_print_stats = 1;
 617 #   endif
 618 #   if defined(MSWIN32) || defined(MSWINCE)
 619       InitializeCriticalSection(&GC_write_cs);
 620 #   endif
 621     if (0 != GETENV("GC_PRINT_STATS")) {
 622       GC_print_stats = 1;
 623     }
 624 #   ifndef NO_DEBUGGING
 625       if (0 != GETENV("GC_DUMP_REGULARLY")) {
 626         GC_dump_regularly = 1;
 627       }
 628 #   endif
 629 #   ifdef KEEP_BACK_PTRS
 630       {
 631         char * backtraces_string = GETENV("GC_BACKTRACES");
 632         if (0 != backtraces_string) {
 633           GC_backtraces = atol(backtraces_string);
 634           if (backtraces_string[0] == '\0') GC_backtraces = 1;
 635         }
 636       }
 637 #   endif
 638     if (0 != GETENV("GC_FIND_LEAK")) {
 639       GC_find_leak = 1;
 640 #     ifdef __STDC__
 641         atexit(GC_exit_check);
 642 #     endif
 643     }
 644     if (0 != GETENV("GC_ALL_INTERIOR_POINTERS")) {
 645       GC_all_interior_pointers = 1;
 646     }
 647     if (0 != GETENV("GC_DONT_GC")) {
 648       GC_dont_gc = 1;
 649     }
 650     if (0 != GETENV("GC_PRINT_BACK_HEIGHT")) {
 651       GC_print_back_height = 1;
 652     }
 653     if (0 != GETENV("GC_NO_BLACKLIST_WARNING")) {
 654       GC_large_alloc_warn_interval = LONG_MAX;
 655     }
 656     {
 657       char * time_limit_string = GETENV("GC_PAUSE_TIME_TARGET");
 658       if (0 != time_limit_string) {
 659         long time_limit = atol(time_limit_string);
 660         if (time_limit < 5) {
 661           WARN("GC_PAUSE_TIME_TARGET environment variable value too small "
 662                "or bad syntax: Ignoring\n", 0);
 663         } else {
 664           GC_time_limit = time_limit;
 665         }
 666       }
 667     }
 668     {
 669       char * interval_string = GETENV("GC_LARGE_ALLOC_WARN_INTERVAL");
 670       if (0 != interval_string) {
 671         long interval = atol(interval_string);
 672         if (interval <= 0) {
 673           WARN("GC_LARGE_ALLOC_WARN_INTERVAL environment variable has "
 674                "bad value: Ignoring\n", 0);
 675         } else {
 676           GC_large_alloc_warn_interval = interval;
 677         }
 678       }
 679     }
 680     maybe_install_looping_handler();
 681     /* Adjust normal object descriptor for extra allocation.    */
 682     if (ALIGNMENT > GC_DS_TAGS && EXTRA_BYTES != 0) {
 683       GC_obj_kinds[NORMAL].ok_descriptor = ((word)(-ALIGNMENT) | GC_DS_LENGTH);
 684     }
 685     GC_setpagesize();
 686     GC_exclude_static_roots(beginGC_arrays, endGC_arrays);
 687     GC_exclude_static_roots(beginGC_obj_kinds, endGC_obj_kinds);
 688 #   ifdef SEPARATE_GLOBALS
 689       GC_exclude_static_roots(beginGC_objfreelist, endGC_objfreelist);
 690       GC_exclude_static_roots(beginGC_aobjfreelist, endGC_aobjfreelist);
 691 #   endif
 692 #   ifdef MSWIN32
 693         GC_init_win32();
 694 #   endif
 695 #   if defined(SEARCH_FOR_DATA_START)
 696         GC_init_linux_data_start();
 697 #   endif
 698 #   if defined(NETBSD) && defined(__ELF__)
 699         GC_init_netbsd_elf();
 700 #   endif
 701 #   if defined(GC_PTHREADS) || defined(GC_SOLARIS_THREADS) \
 702        || defined(GC_WIN32_THREADS)
 703         GC_thr_init();
 704 #   endif
 705 #   ifdef GC_SOLARIS_THREADS
 706         /* We need dirty bits in order to find live stack sections.     */
 707         GC_dirty_init();
 708 #   endif
 709 #   if !defined(THREADS) || defined(GC_PTHREADS) || defined(GC_WIN32_THREADS) \
 710         || defined(GC_SOLARIS_THREADS)
 711       if (GC_stackbottom == 0) {
 712         GC_stackbottom = GC_get_stack_base();
 713 #       if (defined(LINUX) || defined(HPUX)) && defined(IA64)
 714           GC_register_stackbottom = GC_get_register_stack_base();
 715 #       endif
 716       } else {
 717 #       if (defined(LINUX) || defined(HPUX)) && defined(IA64)
 718           if (GC_register_stackbottom == 0) {
 719             WARN("GC_register_stackbottom should be set with GC_stackbottom", 0);
 720             /* The following may fail, since we may rely on             */
 721             /* alignment properties that may not hold with a user set   */
 722             /* GC_stackbottom.                                          */
 723             GC_register_stackbottom = GC_get_register_stack_base();
 724           }
 725 #       endif
 726       }
 727 #   endif
 728     GC_STATIC_ASSERT(sizeof (ptr_t) == sizeof(word));
 729     GC_STATIC_ASSERT(sizeof (signed_word) == sizeof(word));
 730     GC_STATIC_ASSERT(sizeof (struct hblk) == HBLKSIZE);
 731 #   ifndef THREADS
 732 #     if defined(STACK_GROWS_UP) && defined(STACK_GROWS_DOWN)
 733         ABORT(
 734           "Only one of STACK_GROWS_UP and STACK_GROWS_DOWN should be defd\n");
 735 #     endif
 736 #     if !defined(STACK_GROWS_UP) && !defined(STACK_GROWS_DOWN)
 737         ABORT(
 738           "One of STACK_GROWS_UP and STACK_GROWS_DOWN should be defd\n");
 739 #     endif
 740 #     ifdef STACK_GROWS_DOWN
 741         GC_ASSERT((word)(&dummy) <= (word)GC_stackbottom);
 742 #     else
 743         GC_ASSERT((word)(&dummy) >= (word)GC_stackbottom);
 744 #     endif
 745 #   endif
 746 #   if !defined(_AUX_SOURCE) || defined(__GNUC__)
 747       GC_ASSERT((word)(-1) > (word)0);
 748       /* word should be unsigned */
 749 #   endif
 750     GC_ASSERT((signed_word)(-1) < (signed_word)0);
 751
 752     /* Add initial guess of root sets.  Do this first, since sbrk(0)    */
 753     /* might be used.                                                   */
 754       if (GC_REGISTER_MAIN_STATIC_DATA()) GC_register_data_segments();
 755     GC_init_headers();
 756     GC_bl_init();
 757     GC_mark_init();
 758     {
 759         char * sz_str = GETENV("GC_INITIAL_HEAP_SIZE");
 760         if (sz_str != NULL) {
 761           initial_heap_sz = atoi(sz_str);
 762           if (initial_heap_sz <= MINHINCR * HBLKSIZE) {
 763             WARN("Bad initial heap size %s - ignoring it.\n",
 764                  sz_str);
 765           }
 766           initial_heap_sz = divHBLKSZ(initial_heap_sz);
 767         }
 768     }
 769     {
 770         char * sz_str = GETENV("GC_MAXIMUM_HEAP_SIZE");
 771         if (sz_str != NULL) {
 772           word max_heap_sz = (word)atol(sz_str);
 773           if (max_heap_sz < initial_heap_sz * HBLKSIZE) {
 774             WARN("Bad maximum heap size %s - ignoring it.\n",
 775                  sz_str);
 776           }
 777           if (0 == GC_max_retries) GC_max_retries = 2;
 778           GC_set_max_heap_size(max_heap_sz);
 779         }
 780     }
 781     if (!GC_expand_hp_inner(initial_heap_sz)) {
 782         GC_err_printf0("Can't start up: not enough memory\n");
 783         EXIT();
 784     }
 785     /* Preallocate large object map.  It's otherwise inconvenient to    */
 786     /* deal with failure.                                               */
 787       if (!GC_add_map_entry((word)0)) {
 788         GC_err_printf0("Can't start up: not enough memory\n");
 789         EXIT();
 790       }
 791     GC_register_displacement_inner(0L);
 792 #   ifdef MERGE_SIZES
 793       GC_init_size_map();
 794 #   endif
 795 #   ifdef PCR
 796       if (PCR_IL_Lock(PCR_Bool_false, PCR_allSigsBlocked, PCR_waitForever)
 797           != PCR_ERes_okay) {
 798           ABORT("Can't lock load state\n");
 799       } else if (PCR_IL_Unlock() != PCR_ERes_okay) {
 800           ABORT("Can't unlock load state\n");
 801       }
 802       PCR_IL_Unlock();
 803       GC_pcr_install();
 804 #   endif
 805 #   if !defined(SMALL_CONFIG)
 806       if (!GC_no_win32_dlls && 0 != GETENV("GC_ENABLE_INCREMENTAL")) {
 807         GC_ASSERT(!GC_incremental);
 808         GC_setpagesize();
 809 #       ifndef GC_SOLARIS_THREADS
 810           GC_dirty_init();
 811 #       endif
 812         GC_ASSERT(GC_words_allocd == 0)
 813         GC_incremental = TRUE;
 814       }
 815 #   endif /* !SMALL_CONFIG */
 816     COND_DUMP;
 817     /* Get black list set up and/or incremental GC started */
 818       if (!GC_dont_precollect || GC_incremental) GC_gcollect_inner();
 819     GC_is_initialized = TRUE;
 820 #   ifdef STUBBORN_ALLOC
 821         GC_stubborn_init();
 822 #   endif
 823     /* Convince lint that some things are used */
 824 #   ifdef LINT
 825       {
 826           extern char * GC_copyright[];
 827           extern int GC_read();
 828           extern void GC_register_finalizer_no_order();
 829
 830           GC_noop(GC_copyright, GC_find_header,
 831                   GC_push_one, GC_call_with_alloc_lock, GC_read,
 832                   GC_dont_expand,
 833 #                 ifndef NO_DEBUGGING
 834                     GC_dump,
 835 #                 endif
 836                   GC_register_finalizer_no_order);
 837       }
 838 #   endif
 839 }
 840
 841 void GC_enable_incremental GC_PROTO(())
 842 {
 843 # if !defined(SMALL_CONFIG) && !defined(KEEP_BACK_PTRS)
 844   /* If we are keeping back pointers, the GC itself dirties all */
 845   /* pages on which objects have been marked, making            */
 846   /* incremental GC pointless.                                  */
 847   if (!GC_find_leak) {
 848     DCL_LOCK_STATE;
 849
 850     DISABLE_SIGNALS();
 851     LOCK();
 852     if (GC_incremental) goto out;
 853     GC_setpagesize();
 854     if (GC_no_win32_dlls) goto out;
 855 #   ifndef GC_SOLARIS_THREADS
 856       maybe_install_looping_handler();  /* Before write fault handler! */
 857       GC_dirty_init();
 858 #   endif
 859     if (!GC_is_initialized) {
 860         GC_init_inner();
 861     }
 862     if (GC_incremental) goto out;
 863     if (GC_dont_gc) {
 864         /* Can't easily do it. */
 865         UNLOCK();
 866         ENABLE_SIGNALS();
 867         return;
 868     }
 869     if (GC_words_allocd > 0) {
 870         /* There may be unmarked reachable objects      */
 871         GC_gcollect_inner();
 872     }   /* else we're OK in assuming everything's       */
 873         /* clean since nothing can point to an          */
 874         /* unmarked object.                             */
 875     GC_read_dirty();
 876     GC_incremental = TRUE;
 877 out:
 878     UNLOCK();
 879     ENABLE_SIGNALS();
 880   }
 881 # endif
 882 }
 883
 884
 885 #if defined(MSWIN32) || defined(MSWINCE)
 886 # define LOG_FILE _T("gc.log")
 887
 888   HANDLE GC_stdout = 0;
 889
 890   void GC_deinit()
 891   {
 892       if (GC_is_initialized) {
 893         DeleteCriticalSection(&GC_write_cs);
 894       }
 895   }
 896
 897   int GC_write(buf, len)
 898   GC_CONST char * buf;
 899   size_t len;
 900   {
 901       BOOL tmp;
 902       DWORD written;
 903       if (len == 0)
 904           return 0;
 905       EnterCriticalSection(&GC_write_cs);
 906       if (GC_stdout == INVALID_HANDLE_VALUE) {
 907           return -1;
 908       } else if (GC_stdout == 0) {
 909           GC_stdout = CreateFile(LOG_FILE, GENERIC_WRITE,
 910                                  FILE_SHARE_READ | FILE_SHARE_WRITE,
 911                                  NULL, CREATE_ALWAYS, FILE_FLAG_WRITE_THROUGH,
 912                                  NULL);
 913           if (GC_stdout == INVALID_HANDLE_VALUE) ABORT("Open of log file failed");
 914       }
 915       tmp = WriteFile(GC_stdout, buf, len, &written, NULL);
 916       if (!tmp)
 917           DebugBreak();
 918       LeaveCriticalSection(&GC_write_cs);
 919       return tmp ? (int)written : -1;
 920   }
 921
 922 #endif
 923
 924 #if defined(OS2) || defined(MACOS)
 925 FILE * GC_stdout = NULL;
 926 FILE * GC_stderr = NULL;
 927 int GC_tmp;  /* Should really be local ... */
 928
 929   void GC_set_files()
 930   {
 931       if (GC_stdout == NULL) {
 932         GC_stdout = stdout;
 933     }
 934     if (GC_stderr == NULL) {
 935         GC_stderr = stderr;
 936     }
 937   }
 938 #endif
 939
 940 #if !defined(OS2) && !defined(MACOS) && !defined(MSWIN32) && !defined(MSWINCE)
 941   int GC_stdout = 1;
 942   int GC_stderr = 2;
 943 # if !defined(AMIGA)
 944 #   include <unistd.h>
 945 # endif
 946 #endif
 947
 948 #if !defined(MSWIN32) && !defined(MSWINCE) && !defined(OS2) \
 949     && !defined(MACOS)  && !defined(ECOS) && !defined(NOSYS)
 950 int GC_write(fd, buf, len)
 951 int fd;
 952 GC_CONST char *buf;
 953 size_t len;
 954 {
 955      register int bytes_written = 0;
 956      register int result;
 957
 958      while (bytes_written < len) {
 959 #       ifdef GC_SOLARIS_THREADS
 960             result = syscall(SYS_write, fd, buf + bytes_written,
 961                                             len - bytes_written);
 962 #       else
 963             result = write(fd, buf + bytes_written, len - bytes_written);
 964 #       endif
 965         if (-1 == result) return(result);
 966         bytes_written += result;
 967     }
 968     return(bytes_written);
 969 }
 970 #endif /* UN*X */
 971
 972 #ifdef ECOS
 973 int GC_write(fd, buf, len)
 974 {
 975   _Jv_diag_write (buf, len);
 976   return len;
 977 }
 978 #endif
 979
 980 #ifdef NOSYS
 981 int GC_write(fd, buf, len)
 982 {
 983   /* No writing.  */
 984   return len;
 985 }
 986 #endif
 987
 988
 989 #if defined(MSWIN32) || defined(MSWINCE)
 990 #   define WRITE(f, buf, len) GC_write(buf, len)
 991 #else
 992 #   if defined(OS2) || defined(MACOS)
 993 #   define WRITE(f, buf, len) (GC_set_files(), \
 994                                GC_tmp = fwrite((buf), 1, (len), (f)), \
 995                                fflush(f), GC_tmp)
 996 #   else
 997 #     define WRITE(f, buf, len) GC_write((f), (buf), (len))
 998 #   endif
 999 #endif
1000
1001 /* A version of printf that is unlikely to call malloc, and is thus safer */
1002 /* to call from the collector in case malloc has been bound to GC_malloc. */
1003 /* Assumes that no more than 1023 characters are written at once.         */
1004 /* Assumes that all arguments have been converted to something of the     */
1005 /* same size as long, and that the format conversions expect something    */
1006 /* of that size.                                                          */
1007 void GC_printf(format, a, b, c, d, e, f)
1008 GC_CONST char * format;
1009 long a, b, c, d, e, f;
1010 {
1011     char buf[1025];
1012
1013     if (GC_quiet) return;
1014     buf[1024] = 0x15;
1015     (void) sprintf(buf, format, a, b, c, d, e, f);
1016     if (buf[1024] != 0x15) ABORT("GC_printf clobbered stack");
1017 #ifdef NACL
1018     WRITE(GC_stdout, buf, strlen(buf));
1019 #else
1020     if (WRITE(GC_stdout, buf, strlen(buf)) < 0) ABORT("write to stdout failed");
1021 #endif
1022 }
1023
1024 void GC_err_printf(format, a, b, c, d, e, f)
1025 GC_CONST char * format;
1026 long a, b, c, d, e, f;
1027 {
1028     char buf[1025];
1029
1030     buf[1024] = 0x15;
1031     (void) sprintf(buf, format, a, b, c, d, e, f);
1032     if (buf[1024] != 0x15) ABORT("GC_err_printf clobbered stack");
1033 #ifdef NACL
1034     WRITE(GC_stderr, buf, strlen(buf));
1035 #else
1036     if (WRITE(GC_stderr, buf, strlen(buf)) < 0) ABORT("write to stderr failed");
1037 #endif
1038 }
1039
1040 void GC_err_puts(s)
1041 GC_CONST char *s;
1042 {
1043 #ifdef NACL
1044     WRITE(GC_stderr, s, strlen(s));
1045 #else
1046     if (WRITE(GC_stderr, s, strlen(s)) < 0) ABORT("write to stderr failed");
1047 #endif
1048 }
1049
1050 #if defined(LINUX) && !defined(SMALL_CONFIG)
1051 void GC_err_write(buf, len)
1052 GC_CONST char *buf;
1053 size_t len;
1054 {
1055     if (WRITE(GC_stderr, buf, len) < 0) ABORT("write to stderr failed");
1056 }
1057 #endif
1058
1059 # if defined(__STDC__) || defined(__cplusplus)
1060     void GC_default_warn_proc(char *msg, GC_word arg)
1061 # else
1062     void GC_default_warn_proc(msg, arg)
1063     char *msg;
1064     GC_word arg;
1065 # endif
1066 {
1067     GC_err_printf1(msg, (unsigned long)arg);
1068 }
1069
1070 GC_warn_proc GC_current_warn_proc = GC_default_warn_proc;
1071
1072 # if defined(__STDC__) || defined(__cplusplus)
1073     GC_warn_proc GC_set_warn_proc(GC_warn_proc p)
1074 # else
1075     GC_warn_proc GC_set_warn_proc(p)
1076     GC_warn_proc p;
1077 # endif
1078 {
1079     GC_warn_proc result;
1080
1081 #   ifdef GC_WIN32_THREADS
1082       GC_ASSERT(GC_is_initialized);
1083 #   endif
1084     LOCK();
1085     result = GC_current_warn_proc;
1086     GC_current_warn_proc = p;
1087     UNLOCK();
1088     return(result);
1089 }
1090
1091 # if defined(__STDC__) || defined(__cplusplus)
1092     GC_word GC_set_free_space_divisor (GC_word value)
1093 # else
1094     GC_word GC_set_free_space_divisor (value)
1095     GC_word value;
1096 # endif
1097 {
1098     GC_word old = GC_free_space_divisor;
1099     GC_free_space_divisor = value;
1100     return old;
1101 }
1102
1103 #ifndef PCR
1104 void GC_abort(msg)
1105 GC_CONST char * msg;
1106 {
1107 #   if defined(MSWIN32)
1108       (void) MessageBoxA(NULL, msg, "Fatal error in gc", MB_ICONERROR|MB_OK);
1109 #   else
1110       GC_err_printf1("%s\n", msg);
1111 #   endif
1112     if (GETENV("GC_LOOP_ON_ABORT") != NULL) {
1113             /* In many cases it's easier to debug a running process.    */
1114             /* It's arguably nicer to sleep, but that makes it harder   */
1115             /* to look at the thread if the debugger doesn't know much  */
1116             /* about threads.                                           */
1117             for(;;) {}
1118     }
1119 #   if defined(MSWIN32) || defined(MSWINCE)
1120         DebugBreak();
1121 #   else
1122         (void) abort();
1123 #   endif
1124 }
1125 #endif
1126
1127 void GC_enable()
1128 {
1129     LOCK();
1130     GC_dont_gc--;
1131     UNLOCK();
1132 }
1133
1134 void GC_disable()
1135 {
1136     LOCK();
1137     GC_dont_gc++;
1138     UNLOCK();
1139 }
1140
1141 /* Helper procedures for new kind creation.     */
1142 void ** GC_new_free_list_inner()
1143 {
1144     void *result = GC_INTERNAL_MALLOC((MAXOBJSZ+1)*sizeof(ptr_t), PTRFREE);
1145     if (result == 0) ABORT("Failed to allocate freelist for new kind");
1146     BZERO(result, (MAXOBJSZ+1)*sizeof(ptr_t));
1147     return result;
1148 }
1149
1150 void ** GC_new_free_list()
1151 {
1152     void *result;
1153     LOCK(); DISABLE_SIGNALS();
1154     result = GC_new_free_list_inner();
1155     UNLOCK(); ENABLE_SIGNALS();
1156     return result;
1157 }
1158
1159 int GC_new_kind_inner(fl, descr, adjust, clear)
1160 void **fl;
1161 GC_word descr;
1162 int adjust;
1163 int clear;
1164 {
1165     int result = GC_n_kinds++;
1166
1167     if (GC_n_kinds > MAXOBJKINDS) ABORT("Too many kinds");
1168     GC_obj_kinds[result].ok_freelist = (ptr_t *)fl;
1169     GC_obj_kinds[result].ok_reclaim_list = 0;
1170     GC_obj_kinds[result].ok_descriptor = descr;
1171     GC_obj_kinds[result].ok_relocate_descr = adjust;
1172     GC_obj_kinds[result].ok_init = clear;
1173     return result;
1174 }
1175
1176 int GC_new_kind(fl, descr, adjust, clear)
1177 void **fl;
1178 GC_word descr;
1179 int adjust;
1180 int clear;
1181 {
1182     int result;
1183     LOCK(); DISABLE_SIGNALS();
1184     result = GC_new_kind_inner(fl, descr, adjust, clear);
1185     UNLOCK(); ENABLE_SIGNALS();
1186     return result;
1187 }
1188
1189 int GC_new_proc_inner(proc)
1190 GC_mark_proc proc;
1191 {
1192     int result = GC_n_mark_procs++;
1193
1194     if (GC_n_mark_procs > MAX_MARK_PROCS) ABORT("Too many mark procedures");
1195     GC_mark_procs[result] = proc;
1196     return result;
1197 }
1198
1199 int GC_new_proc(proc)
1200 GC_mark_proc proc;
1201 {
1202     int result;
1203     LOCK(); DISABLE_SIGNALS();
1204     result = GC_new_proc_inner(proc);
1205     UNLOCK(); ENABLE_SIGNALS();
1206     return result;
1207 }
1208
1209
1210 #if !defined(NO_DEBUGGING)
1211
1212 void GC_dump()
1213 {
1214     GC_printf0("***Static roots:\n");
1215     GC_print_static_roots();
1216     GC_printf0("\n***Heap sections:\n");
1217     GC_print_heap_sects();
1218     GC_printf0("\n***Free blocks:\n");
1219     GC_print_hblkfreelist();
1220     GC_printf0("\n***Blocks in use:\n");
1221     GC_print_block_list();
1222     GC_printf0("\n***Finalization statistics:\n");
1223     GC_print_finalization_stats();
1224 }
1225
1226 #endif /* NO_DEBUGGING */