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)
 477         return SIG_SUSPEND;
 478 #else
 479         return -1;
 480 #endif
 481 }
 482
 483 GC_bool GC_is_initialized = FALSE;
 484
 485 void GC_init()
 486 {
 487 #if defined(SN_TARGET_PS3)
 488         pthread_mutexattr_t mattr;
 489 #endif
 490
 491     DCL_LOCK_STATE;
 492
 493     DISABLE_SIGNALS();
 494
 495 #if defined(GC_WIN32_THREADS) && !defined(GC_PTHREADS)
 496     if (!GC_is_initialized) {
 497       BOOL (WINAPI *pfn) (LPCRITICAL_SECTION, DWORD) = NULL;
 498       HMODULE hK32 = GetModuleHandle(_T("kernel32.dll"));
 499       if (hK32)
 500           pfn = GetProcAddress(hK32,
 501                           "InitializeCriticalSectionAndSpinCount");
 502       if (pfn)
 503           pfn(&GC_allocate_ml, 4000);
 504       else
 505           InitializeCriticalSection (&GC_allocate_ml);
 506     }
 507 #endif /* MSWIN32 */
 508 #if defined(SN_TARGET_PS3)
 509         pthread_mutexattr_init (&mattr);
 510
 511         pthread_mutex_init (&GC_allocate_ml, &mattr);
 512         pthread_mutexattr_destroy (&mattr);
 513
 514 #endif
 515
 516     LOCK();
 517     GC_init_inner();
 518     UNLOCK();
 519     ENABLE_SIGNALS();
 520
 521 #   if defined(PARALLEL_MARK) || defined(THREAD_LOCAL_ALLOC)
 522         /* Make sure marker threads and started and thread local */
 523         /* allocation is initialized, in case we didn't get      */
 524         /* called from GC_init_parallel();                       */
 525         {
 526           extern void GC_init_parallel(void);
 527           GC_init_parallel();
 528         }
 529 #   endif /* PARALLEL_MARK || THREAD_LOCAL_ALLOC */
 530
 531 #   if defined(DYNAMIC_LOADING) && defined(DARWIN)
 532     {
 533         /* This must be called WITHOUT the allocation lock held
 534         and before any threads are created */
 535         extern void GC_init_dyld();
 536         GC_init_dyld();
 537     }
 538 #   endif
 539 }
 540
 541 #if defined(MSWIN32) || defined(MSWINCE)
 542     CRITICAL_SECTION GC_write_cs;
 543 #endif
 544
 545 #ifdef MSWIN32
 546     extern void GC_init_win32 GC_PROTO((void));
 547 #endif
 548
 549 extern void GC_setpagesize();
 550
 551
 552 #ifdef MSWIN32
 553 extern GC_bool GC_no_win32_dlls;
 554 #else
 555 # define GC_no_win32_dlls FALSE
 556 #endif
 557
 558 void GC_exit_check GC_PROTO((void))
 559 {
 560    GC_gcollect();
 561 }
 562
 563 #ifdef SEARCH_FOR_DATA_START
 564   extern void GC_init_linux_data_start GC_PROTO((void));
 565 #endif
 566
 567 #ifdef UNIX_LIKE
 568
 569 extern void GC_set_and_save_fault_handler GC_PROTO((void (*handler)(int)));
 570
 571 static void looping_handler(sig)
 572 int sig;
 573 {
 574     GC_err_printf1("Caught signal %d: looping in handler\n", sig);
 575     for(;;);
 576 }
 577
 578 static GC_bool installed_looping_handler = FALSE;
 579
 580 static void maybe_install_looping_handler()
 581 {
 582     /* Install looping handler before the write fault handler, so we    */
 583     /* handle write faults correctly.                                   */
 584       if (!installed_looping_handler && 0 != GETENV("GC_LOOP_ON_ABORT")) {
 585         GC_set_and_save_fault_handler(looping_handler);
 586         installed_looping_handler = TRUE;
 587       }
 588 }
 589
 590 #else /* !UNIX_LIKE */
 591
 592 # define maybe_install_looping_handler()
 593
 594 #endif
 595
 596 void GC_init_inner()
 597 {
 598 #   if !defined(THREADS) && defined(GC_ASSERTIONS)
 599         word dummy;
 600 #   endif
 601     word initial_heap_sz = (word)MINHINCR;
 602
 603     if (GC_is_initialized) return;
 604 #   ifdef PRINTSTATS
 605       GC_print_stats = 1;
 606 #   endif
 607 #   if defined(MSWIN32) || defined(MSWINCE)
 608       InitializeCriticalSection(&GC_write_cs);
 609 #   endif
 610     if (0 != GETENV("GC_PRINT_STATS")) {
 611       GC_print_stats = 1;
 612     }
 613 #   ifndef NO_DEBUGGING
 614       if (0 != GETENV("GC_DUMP_REGULARLY")) {
 615         GC_dump_regularly = 1;
 616       }
 617 #   endif
 618 #   ifdef KEEP_BACK_PTRS
 619       {
 620         char * backtraces_string = GETENV("GC_BACKTRACES");
 621         if (0 != backtraces_string) {
 622           GC_backtraces = atol(backtraces_string);
 623           if (backtraces_string[0] == '\0') GC_backtraces = 1;
 624         }
 625       }
 626 #   endif
 627     if (0 != GETENV("GC_FIND_LEAK")) {
 628       GC_find_leak = 1;
 629 #     ifdef __STDC__
 630         atexit(GC_exit_check);
 631 #     endif
 632     }
 633     if (0 != GETENV("GC_ALL_INTERIOR_POINTERS")) {
 634       GC_all_interior_pointers = 1;
 635     }
 636     if (0 != GETENV("GC_DONT_GC")) {
 637       GC_dont_gc = 1;
 638     }
 639     if (0 != GETENV("GC_PRINT_BACK_HEIGHT")) {
 640       GC_print_back_height = 1;
 641     }
 642     if (0 != GETENV("GC_NO_BLACKLIST_WARNING")) {
 643       GC_large_alloc_warn_interval = LONG_MAX;
 644     }
 645     {
 646       char * time_limit_string = GETENV("GC_PAUSE_TIME_TARGET");
 647       if (0 != time_limit_string) {
 648         long time_limit = atol(time_limit_string);
 649         if (time_limit < 5) {
 650           WARN("GC_PAUSE_TIME_TARGET environment variable value too small "
 651                "or bad syntax: Ignoring\n", 0);
 652         } else {
 653           GC_time_limit = time_limit;
 654         }
 655       }
 656     }
 657     {
 658       char * interval_string = GETENV("GC_LARGE_ALLOC_WARN_INTERVAL");
 659       if (0 != interval_string) {
 660         long interval = atol(interval_string);
 661         if (interval <= 0) {
 662           WARN("GC_LARGE_ALLOC_WARN_INTERVAL environment variable has "
 663                "bad value: Ignoring\n", 0);
 664         } else {
 665           GC_large_alloc_warn_interval = interval;
 666         }
 667       }
 668     }
 669     maybe_install_looping_handler();
 670     /* Adjust normal object descriptor for extra allocation.    */
 671     if (ALIGNMENT > GC_DS_TAGS && EXTRA_BYTES != 0) {
 672       GC_obj_kinds[NORMAL].ok_descriptor = ((word)(-ALIGNMENT) | GC_DS_LENGTH);
 673     }
 674     GC_setpagesize();
 675     GC_exclude_static_roots(beginGC_arrays, endGC_arrays);
 676     GC_exclude_static_roots(beginGC_obj_kinds, endGC_obj_kinds);
 677 #   ifdef SEPARATE_GLOBALS
 678       GC_exclude_static_roots(beginGC_objfreelist, endGC_objfreelist);
 679       GC_exclude_static_roots(beginGC_aobjfreelist, endGC_aobjfreelist);
 680 #   endif
 681 #   ifdef MSWIN32
 682         GC_init_win32();
 683 #   endif
 684 #   if defined(SEARCH_FOR_DATA_START)
 685         GC_init_linux_data_start();
 686 #   endif
 687 #   if (defined(NETBSD) || defined(OPENBSD)) && defined(__ELF__)
 688         GC_init_netbsd_elf();
 689 #   endif
 690 #   if defined(GC_PTHREADS) || defined(GC_SOLARIS_THREADS) \
 691        || defined(GC_WIN32_THREADS)
 692         GC_thr_init();
 693 #   endif
 694 #   ifdef GC_SOLARIS_THREADS
 695         /* We need dirty bits in order to find live stack sections.     */
 696         GC_dirty_init();
 697 #   endif
 698 #   if !defined(THREADS) || defined(GC_PTHREADS) || defined(GC_WIN32_THREADS) \
 699         || defined(GC_SOLARIS_THREADS)
 700       if (GC_stackbottom == 0) {
 701         GC_stackbottom = GC_get_stack_base();
 702 #       if (defined(LINUX) || defined(HPUX)) && defined(IA64)
 703           GC_register_stackbottom = GC_get_register_stack_base();
 704 #       endif
 705       } else {
 706 #       if (defined(LINUX) || defined(HPUX)) && defined(IA64)
 707           if (GC_register_stackbottom == 0) {
 708             WARN("GC_register_stackbottom should be set with GC_stackbottom", 0);
 709             /* The following may fail, since we may rely on             */
 710             /* alignment properties that may not hold with a user set   */
 711             /* GC_stackbottom.                                          */
 712             GC_register_stackbottom = GC_get_register_stack_base();
 713           }
 714 #       endif
 715       }
 716 #   endif
 717     GC_STATIC_ASSERT(sizeof (ptr_t) == sizeof(word));
 718     GC_STATIC_ASSERT(sizeof (signed_word) == sizeof(word));
 719     GC_STATIC_ASSERT(sizeof (struct hblk) == HBLKSIZE);
 720 #   ifndef THREADS
 721 #     if defined(STACK_GROWS_UP) && defined(STACK_GROWS_DOWN)
 722         ABORT(
 723           "Only one of STACK_GROWS_UP and STACK_GROWS_DOWN should be defd\n");
 724 #     endif
 725 #     if !defined(STACK_GROWS_UP) && !defined(STACK_GROWS_DOWN)
 726         ABORT(
 727           "One of STACK_GROWS_UP and STACK_GROWS_DOWN should be defd\n");
 728 #     endif
 729 #     ifdef STACK_GROWS_DOWN
 730         GC_ASSERT((word)(&dummy) <= (word)GC_stackbottom);
 731 #     else
 732         GC_ASSERT((word)(&dummy) >= (word)GC_stackbottom);
 733 #     endif
 734 #   endif
 735 #   if !defined(_AUX_SOURCE) || defined(__GNUC__)
 736       GC_ASSERT((word)(-1) > (word)0);
 737       /* word should be unsigned */
 738 #   endif
 739     GC_ASSERT((signed_word)(-1) < (signed_word)0);
 740
 741     /* Add initial guess of root sets.  Do this first, since sbrk(0)    */
 742     /* might be used.                                                   */
 743       if (GC_REGISTER_MAIN_STATIC_DATA()) GC_register_data_segments();
 744     GC_init_headers();
 745     GC_bl_init();
 746     GC_mark_init();
 747     {
 748         char * sz_str = GETENV("GC_INITIAL_HEAP_SIZE");
 749         if (sz_str != NULL) {
 750           initial_heap_sz = atoi(sz_str);
 751           if (initial_heap_sz <= MINHINCR * HBLKSIZE) {
 752             WARN("Bad initial heap size %s - ignoring it.\n",
 753                  sz_str);
 754           }
 755           initial_heap_sz = divHBLKSZ(initial_heap_sz);
 756         }
 757     }
 758     {
 759         char * sz_str = GETENV("GC_MAXIMUM_HEAP_SIZE");
 760         if (sz_str != NULL) {
 761           word max_heap_sz = (word)atol(sz_str);
 762           if (max_heap_sz < initial_heap_sz * HBLKSIZE) {
 763             WARN("Bad maximum heap size %s - ignoring it.\n",
 764                  sz_str);
 765           }
 766           if (0 == GC_max_retries) GC_max_retries = 2;
 767           GC_set_max_heap_size(max_heap_sz);
 768         }
 769     }
 770     if (!GC_expand_hp_inner(initial_heap_sz)) {
 771         GC_err_printf0("Can't start up: not enough memory\n");
 772         EXIT();
 773     }
 774     /* Preallocate large object map.  It's otherwise inconvenient to    */
 775     /* deal with failure.                                               */
 776       if (!GC_add_map_entry((word)0)) {
 777         GC_err_printf0("Can't start up: not enough memory\n");
 778         EXIT();
 779       }
 780     GC_register_displacement_inner(0L);
 781 #   ifdef MERGE_SIZES
 782       GC_init_size_map();
 783 #   endif
 784 #   ifdef PCR
 785       if (PCR_IL_Lock(PCR_Bool_false, PCR_allSigsBlocked, PCR_waitForever)
 786           != PCR_ERes_okay) {
 787           ABORT("Can't lock load state\n");
 788       } else if (PCR_IL_Unlock() != PCR_ERes_okay) {
 789           ABORT("Can't unlock load state\n");
 790       }
 791       PCR_IL_Unlock();
 792       GC_pcr_install();
 793 #   endif
 794 #   if !defined(SMALL_CONFIG)
 795       if (!GC_no_win32_dlls && 0 != GETENV("GC_ENABLE_INCREMENTAL")) {
 796         GC_ASSERT(!GC_incremental);
 797         GC_setpagesize();
 798 #       ifndef GC_SOLARIS_THREADS
 799           GC_dirty_init();
 800 #       endif
 801         GC_ASSERT(GC_words_allocd == 0)
 802         GC_incremental = TRUE;
 803       }
 804 #   endif /* !SMALL_CONFIG */
 805     COND_DUMP;
 806     /* Get black list set up and/or incremental GC started */
 807       if (!GC_dont_precollect || GC_incremental) GC_gcollect_inner();
 808     GC_is_initialized = TRUE;
 809 #   ifdef STUBBORN_ALLOC
 810         GC_stubborn_init();
 811 #   endif
 812     /* Convince lint that some things are used */
 813 #   ifdef LINT
 814       {
 815           extern char * GC_copyright[];
 816           extern int GC_read();
 817           extern void GC_register_finalizer_no_order();
 818
 819           GC_noop(GC_copyright, GC_find_header,
 820                   GC_push_one, GC_call_with_alloc_lock, GC_read,
 821                   GC_dont_expand,
 822 #                 ifndef NO_DEBUGGING
 823                     GC_dump,
 824 #                 endif
 825                   GC_register_finalizer_no_order);
 826       }
 827 #   endif
 828 }
 829
 830 void GC_enable_incremental GC_PROTO(())
 831 {
 832 # if !defined(SMALL_CONFIG) && !defined(KEEP_BACK_PTRS)
 833   /* If we are keeping back pointers, the GC itself dirties all */
 834   /* pages on which objects have been marked, making            */
 835   /* incremental GC pointless.                                  */
 836   if (!GC_find_leak) {
 837     DCL_LOCK_STATE;
 838
 839     DISABLE_SIGNALS();
 840     LOCK();
 841     if (GC_incremental) goto out;
 842     GC_setpagesize();
 843     if (GC_no_win32_dlls) goto out;
 844 #   ifndef GC_SOLARIS_THREADS
 845       maybe_install_looping_handler();  /* Before write fault handler! */
 846       GC_dirty_init();
 847 #   endif
 848     if (!GC_is_initialized) {
 849         GC_init_inner();
 850     }
 851     if (GC_incremental) goto out;
 852     if (GC_dont_gc) {
 853         /* Can't easily do it. */
 854         UNLOCK();
 855         ENABLE_SIGNALS();
 856         return;
 857     }
 858     if (GC_words_allocd > 0) {
 859         /* There may be unmarked reachable objects      */
 860         GC_gcollect_inner();
 861     }   /* else we're OK in assuming everything's       */
 862         /* clean since nothing can point to an          */
 863         /* unmarked object.                             */
 864     GC_read_dirty();
 865     GC_incremental = TRUE;
 866 out:
 867     UNLOCK();
 868     ENABLE_SIGNALS();
 869   }
 870 # endif
 871 }
 872
 873
 874 #if defined(MSWIN32) || defined(MSWINCE)
 875 # define LOG_FILE _T("gc.log")
 876
 877   HANDLE GC_stdout = 0;
 878
 879   void GC_deinit()
 880   {
 881       if (GC_is_initialized) {
 882         DeleteCriticalSection(&GC_write_cs);
 883       }
 884   }
 885
 886   int GC_write(buf, len)
 887   GC_CONST char * buf;
 888   size_t len;
 889   {
 890       BOOL tmp;
 891       DWORD written;
 892       if (len == 0)
 893           return 0;
 894       EnterCriticalSection(&GC_write_cs);
 895       if (GC_stdout == INVALID_HANDLE_VALUE) {
 896           return -1;
 897       } else if (GC_stdout == 0) {
 898           GC_stdout = CreateFile(LOG_FILE, GENERIC_WRITE,
 899                                  FILE_SHARE_READ | FILE_SHARE_WRITE,
 900                                  NULL, CREATE_ALWAYS, FILE_FLAG_WRITE_THROUGH,
 901                                  NULL);
 902           if (GC_stdout == INVALID_HANDLE_VALUE) ABORT("Open of log file failed");
 903       }
 904       tmp = WriteFile(GC_stdout, buf, len, &written, NULL);
 905       if (!tmp)
 906           DebugBreak();
 907       LeaveCriticalSection(&GC_write_cs);
 908       return tmp ? (int)written : -1;
 909   }
 910
 911 #endif
 912
 913 #if defined(OS2) || defined(MACOS)
 914 FILE * GC_stdout = NULL;
 915 FILE * GC_stderr = NULL;
 916 int GC_tmp;  /* Should really be local ... */
 917
 918   void GC_set_files()
 919   {
 920       if (GC_stdout == NULL) {
 921         GC_stdout = stdout;
 922     }
 923     if (GC_stderr == NULL) {
 924         GC_stderr = stderr;
 925     }
 926   }
 927 #endif
 928
 929 #if !defined(OS2) && !defined(MACOS) && !defined(MSWIN32) && !defined(MSWINCE)
 930   int GC_stdout = 1;
 931   int GC_stderr = 2;
 932 # if !defined(AMIGA)
 933 #   include <unistd.h>
 934 # endif
 935 #endif
 936
 937 #if !defined(MSWIN32) && !defined(MSWINCE) && !defined(OS2) \
 938     && !defined(MACOS)  && !defined(ECOS) && !defined(NOSYS)
 939 int GC_write(fd, buf, len)
 940 int fd;
 941 GC_CONST char *buf;
 942 size_t len;
 943 {
 944      register int bytes_written = 0;
 945      register int result;
 946
 947      while (bytes_written < len) {
 948 #       ifdef GC_SOLARIS_THREADS
 949             result = syscall(SYS_write, fd, buf + bytes_written,
 950                                             len - bytes_written);
 951 #       else
 952             result = write(fd, buf + bytes_written, len - bytes_written);
 953 #       endif
 954         if (-1 == result) return(result);
 955         bytes_written += result;
 956     }
 957     return(bytes_written);
 958 }
 959 #endif /* UN*X */
 960
 961 #ifdef ECOS
 962 int GC_write(fd, buf, len)
 963 {
 964   _Jv_diag_write (buf, len);
 965   return len;
 966 }
 967 #endif
 968
 969 #ifdef NOSYS
 970 int GC_write(fd, buf, len)
 971 {
 972   /* No writing.  */
 973   return len;
 974 }
 975 #endif
 976
 977
 978 #if defined(MSWIN32) || defined(MSWINCE)
 979 #   define WRITE(f, buf, len) GC_write(buf, len)
 980 #else
 981 #   if defined(OS2) || defined(MACOS)
 982 #   define WRITE(f, buf, len) (GC_set_files(), \
 983                                GC_tmp = fwrite((buf), 1, (len), (f)), \
 984                                fflush(f), GC_tmp)
 985 #   else
 986 #     define WRITE(f, buf, len) GC_write((f), (buf), (len))
 987 #   endif
 988 #endif
 989
 990 /* A version of printf that is unlikely to call malloc, and is thus safer */
 991 /* to call from the collector in case malloc has been bound to GC_malloc. */
 992 /* Assumes that no more than 1023 characters are written at once.         */
 993 /* Assumes that all arguments have been converted to something of the     */
 994 /* same size as long, and that the format conversions expect something    */
 995 /* of that size.                                                          */
 996 void GC_printf(format, a, b, c, d, e, f)
 997 GC_CONST char * format;
 998 long a, b, c, d, e, f;
 999 {
1000     char buf[1025];
1001
1002     if (GC_quiet) return;
1003     buf[1024] = 0x15;
1004     (void) sprintf(buf, format, a, b, c, d, e, f);
1005     if (buf[1024] != 0x15) ABORT("GC_printf clobbered stack");
1006     if (WRITE(GC_stdout, buf, strlen(buf)) < 0) ABORT("write to stdout failed");
1007 }
1008
1009 void GC_err_printf(format, a, b, c, d, e, f)
1010 GC_CONST char * format;
1011 long a, b, c, d, e, f;
1012 {
1013     char buf[1025];
1014
1015     buf[1024] = 0x15;
1016     (void) sprintf(buf, format, a, b, c, d, e, f);
1017     if (buf[1024] != 0x15) ABORT("GC_err_printf clobbered stack");
1018     if (WRITE(GC_stderr, buf, strlen(buf)) < 0) ABORT("write to stderr failed");
1019 }
1020
1021 void GC_err_puts(s)
1022 GC_CONST char *s;
1023 {
1024     if (WRITE(GC_stderr, s, strlen(s)) < 0) ABORT("write to stderr failed");
1025 }
1026
1027 #if defined(LINUX) && !defined(SMALL_CONFIG)
1028 void GC_err_write(buf, len)
1029 GC_CONST char *buf;
1030 size_t len;
1031 {
1032     if (WRITE(GC_stderr, buf, len) < 0) ABORT("write to stderr failed");
1033 }
1034 #endif
1035
1036 # if defined(__STDC__) || defined(__cplusplus)
1037     void GC_default_warn_proc(char *msg, GC_word arg)
1038 # else
1039     void GC_default_warn_proc(msg, arg)
1040     char *msg;
1041     GC_word arg;
1042 # endif
1043 {
1044     GC_err_printf1(msg, (unsigned long)arg);
1045 }
1046
1047 GC_warn_proc GC_current_warn_proc = GC_default_warn_proc;
1048
1049 # if defined(__STDC__) || defined(__cplusplus)
1050     GC_warn_proc GC_set_warn_proc(GC_warn_proc p)
1051 # else
1052     GC_warn_proc GC_set_warn_proc(p)
1053     GC_warn_proc p;
1054 # endif
1055 {
1056     GC_warn_proc result;
1057
1058 #   ifdef GC_WIN32_THREADS
1059       GC_ASSERT(GC_is_initialized);
1060 #   endif
1061     LOCK();
1062     result = GC_current_warn_proc;
1063     GC_current_warn_proc = p;
1064     UNLOCK();
1065     return(result);
1066 }
1067
1068 # if defined(__STDC__) || defined(__cplusplus)
1069     GC_word GC_set_free_space_divisor (GC_word value)
1070 # else
1071     GC_word GC_set_free_space_divisor (value)
1072     GC_word value;
1073 # endif
1074 {
1075     GC_word old = GC_free_space_divisor;
1076     GC_free_space_divisor = value;
1077     return old;
1078 }
1079
1080 #ifndef PCR
1081 void GC_abort(msg)
1082 GC_CONST char * msg;
1083 {
1084 #   if defined(MSWIN32)
1085       (void) MessageBoxA(NULL, msg, "Fatal error in gc", MB_ICONERROR|MB_OK);
1086 #   else
1087       GC_err_printf1("%s\n", msg);
1088 #   endif
1089     if (GETENV("GC_LOOP_ON_ABORT") != NULL) {
1090             /* In many cases it's easier to debug a running process.    */
1091             /* It's arguably nicer to sleep, but that makes it harder   */
1092             /* to look at the thread if the debugger doesn't know much  */
1093             /* about threads.                                           */
1094             for(;;) {}
1095     }
1096 #   if defined(MSWIN32) || defined(MSWINCE)
1097         DebugBreak();
1098 #   else
1099         (void) abort();
1100 #   endif
1101 }
1102 #endif
1103
1104 void GC_enable()
1105 {
1106     LOCK();
1107     GC_dont_gc--;
1108     UNLOCK();
1109 }
1110
1111 void GC_disable()
1112 {
1113     LOCK();
1114     GC_dont_gc++;
1115     UNLOCK();
1116 }
1117
1118 /* Helper procedures for new kind creation.     */
1119 void ** GC_new_free_list_inner()
1120 {
1121     void *result = GC_INTERNAL_MALLOC((MAXOBJSZ+1)*sizeof(ptr_t), PTRFREE);
1122     if (result == 0) ABORT("Failed to allocate freelist for new kind");
1123     BZERO(result, (MAXOBJSZ+1)*sizeof(ptr_t));
1124     return result;
1125 }
1126
1127 void ** GC_new_free_list()
1128 {
1129     void *result;
1130     LOCK(); DISABLE_SIGNALS();
1131     result = GC_new_free_list_inner();
1132     UNLOCK(); ENABLE_SIGNALS();
1133     return result;
1134 }
1135
1136 int GC_new_kind_inner(fl, descr, adjust, clear)
1137 void **fl;
1138 GC_word descr;
1139 int adjust;
1140 int clear;
1141 {
1142     int result = GC_n_kinds++;
1143
1144     if (GC_n_kinds > MAXOBJKINDS) ABORT("Too many kinds");
1145     GC_obj_kinds[result].ok_freelist = (ptr_t *)fl;
1146     GC_obj_kinds[result].ok_reclaim_list = 0;
1147     GC_obj_kinds[result].ok_descriptor = descr;
1148     GC_obj_kinds[result].ok_relocate_descr = adjust;
1149     GC_obj_kinds[result].ok_init = clear;
1150     return result;
1151 }
1152
1153 int GC_new_kind(fl, descr, adjust, clear)
1154 void **fl;
1155 GC_word descr;
1156 int adjust;
1157 int clear;
1158 {
1159     int result;
1160     LOCK(); DISABLE_SIGNALS();
1161     result = GC_new_kind_inner(fl, descr, adjust, clear);
1162     UNLOCK(); ENABLE_SIGNALS();
1163     return result;
1164 }
1165
1166 int GC_new_proc_inner(proc)
1167 GC_mark_proc proc;
1168 {
1169     int result = GC_n_mark_procs++;
1170
1171     if (GC_n_mark_procs > MAX_MARK_PROCS) ABORT("Too many mark procedures");
1172     GC_mark_procs[result] = proc;
1173     return result;
1174 }
1175
1176 int GC_new_proc(proc)
1177 GC_mark_proc proc;
1178 {
1179     int result;
1180     LOCK(); DISABLE_SIGNALS();
1181     result = GC_new_proc_inner(proc);
1182     UNLOCK(); ENABLE_SIGNALS();
1183     return result;
1184 }
1185
1186
1187 #if !defined(NO_DEBUGGING)
1188
1189 void GC_dump()
1190 {
1191     GC_printf0("***Static roots:\n");
1192     GC_print_static_roots();
1193     GC_printf0("\n***Heap sections:\n");
1194     GC_print_heap_sects();
1195     GC_printf0("\n***Free blocks:\n");
1196     GC_print_hblkfreelist();
1197     GC_printf0("\n***Blocks in use:\n");
1198     GC_print_block_list();
1199     GC_printf0("\n***Finalization statistics:\n");
1200     GC_print_finalization_stats();
1201 }
1202
1203 #endif /* NO_DEBUGGING */