boehm-gc/misc.c

   1 /*
   2  * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
   3  * Copyright (c) 1991-1994 by Xerox Corporation.  All rights reserved.
   4  * Copyright (c) 1999-2001 by Hewlett-Packard Company. All rights reserved.
   5  *
   6  * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
   7  * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
   8  *
   9  * Permission is hereby granted to use or copy this program
  10  * for any purpose,  provided the above notices are retained on all copies.
  11  * Permission to modify the code and to distribute modified code is granted,
  12  * provided the above notices are retained, and a notice that the code was
  13  * modified is included with the above copyright notice.
  14  */
  15 /* Boehm, July 31, 1995 5:02 pm PDT */
  16
  17
  18 #include <stdio.h>
  19 #include <limits.h>
  20 #ifndef _WIN32_WCE
  21 #include <signal.h>
  22 #endif
  23
  24 #define I_HIDE_POINTERS /* To make GC_call_with_alloc_lock visible */
  25 #include "private/gc_pmark.h"
  26
  27 #ifdef GC_SOLARIS_THREADS
  28 # include <sys/syscall.h>
  29 #endif
  30 #if defined(MSWIN32) || defined(MSWINCE)
  31 # define WIN32_LEAN_AND_MEAN
  32 # define NOSERVICE
  33 # include <windows.h>
  34 # include <tchar.h>
  35 #endif
  36
  37 # ifdef THREADS
  38 #   ifdef PCR
  39 #     include "il/PCR_IL.h"
  40       PCR_Th_ML GC_allocate_ml;
  41 #   else
  42 #     ifdef SRC_M3
  43         /* Critical section counter is defined in the M3 runtime        */
  44         /* That's all we use.                                           */
  45 #     else
  46 #       ifdef GC_SOLARIS_THREADS
  47           mutex_t GC_allocate_ml;       /* Implicitly initialized.      */
  48 #       else
  49 #          if defined(GC_WIN32_THREADS)
  50 #             if defined(GC_PTHREADS)
  51                   pthread_mutex_t GC_allocate_ml = PTHREAD_MUTEX_INITIALIZER;
  52 #             elif defined(GC_DLL)
  53                  __declspec(dllexport) CRITICAL_SECTION GC_allocate_ml;
  54 #             else
  55                  CRITICAL_SECTION GC_allocate_ml;
  56 #             endif
  57 #          else
  58 #             if defined(GC_PTHREADS) && !defined(GC_SOLARIS_THREADS)
  59 #               if defined(USE_SPIN_LOCK)
  60                   pthread_t GC_lock_holder = NO_THREAD;
  61 #               else
  62                   pthread_mutex_t GC_allocate_ml = PTHREAD_MUTEX_INITIALIZER;
  63                   pthread_t GC_lock_holder = NO_THREAD;
  64                         /* Used only for assertions, and to prevent      */
  65                         /* recursive reentry in the system call wrapper. */
  66 #               endif
  67 #             else
  68                   --> declare allocator lock here
  69 #             endif
  70 #          endif
  71 #       endif
  72 #     endif
  73 #   endif
  74 # endif
  75
  76 #if defined(NOSYS) || defined(ECOS)
  77 #undef STACKBASE
  78 #endif
  79
  80 /* Dont unnecessarily call GC_register_main_static_data() in case       */
  81 /* dyn_load.c isn't linked in.                                          */
  82 #ifdef DYNAMIC_LOADING
  83 # define GC_REGISTER_MAIN_STATIC_DATA() GC_register_main_static_data()
  84 #else
  85 # define GC_REGISTER_MAIN_STATIC_DATA() TRUE
  86 #endif
  87
  88 GC_FAR struct _GC_arrays GC_arrays /* = { 0 } */;
  89
  90
  91 GC_bool GC_debugging_started = FALSE;
  92         /* defined here so we don't have to load debug_malloc.o */
  93
  94 void (*GC_check_heap) GC_PROTO((void)) = (void (*) GC_PROTO((void)))0;
  95 void (*GC_print_all_smashed) GC_PROTO((void)) = (void (*) GC_PROTO((void)))0;
  96
  97 void (*GC_start_call_back) GC_PROTO((void)) = (void (*) GC_PROTO((void)))0;
  98
  99 ptr_t GC_stackbottom = 0;
 100
 101 #ifdef IA64
 102   ptr_t GC_register_stackbottom = 0;
 103 #endif
 104
 105 GC_bool GC_dont_gc = 0;
 106
 107 GC_bool GC_dont_precollect = 0;
 108
 109 GC_bool GC_quiet = 0;
 110
 111 GC_bool GC_print_stats = 0;
 112
 113 GC_bool GC_print_back_height = 0;
 114
 115 #ifndef NO_DEBUGGING
 116   GC_bool GC_dump_regularly = 0;  /* Generate regular debugging dumps. */
 117 #endif
 118
 119 #ifdef FIND_LEAK
 120   int GC_find_leak = 1;
 121 #else
 122   int GC_find_leak = 0;
 123 #endif
 124
 125 #ifdef ALL_INTERIOR_POINTERS
 126   int GC_all_interior_pointers = 1;
 127 #else
 128   int GC_all_interior_pointers = 0;
 129 #endif
 130
 131 long GC_large_alloc_warn_interval = 5;
 132         /* Interval between unsuppressed warnings.      */
 133
 134 long GC_large_alloc_warn_suppressed = 0;
 135         /* Number of warnings suppressed so far.        */
 136
 137 /*ARGSUSED*/
 138 GC_PTR GC_default_oom_fn GC_PROTO((size_t bytes_requested))
 139 {
 140     return(0);
 141 }
 142
 143 GC_PTR (*GC_oom_fn) GC_PROTO((size_t bytes_requested)) = GC_default_oom_fn;
 144
 145 extern signed_word GC_mem_found;
 146
 147 void * GC_project2(arg1, arg2)
 148 void *arg1;
 149 void *arg2;
 150 {
 151   return arg2;
 152 }
 153
 154 # ifdef MERGE_SIZES
 155     /* Set things up so that GC_size_map[i] >= words(i),                */
 156     /* but not too much bigger                                          */
 157     /* and so that size_map contains relatively few distinct entries    */
 158     /* This is stolen from Russ Atkinson's Cedar quantization           */
 159     /* alogrithm (but we precompute it).                                */
 160
 161
 162     void GC_init_size_map()
 163     {
 164         register unsigned i;
 165
 166         /* Map size 0 to something bigger.                      */
 167         /* This avoids problems at lower levels.                */
 168         /* One word objects don't have to be 2 word aligned,    */
 169         /* unless we're using mark bytes.                       */
 170           for (i = 0; i < sizeof(word); i++) {
 171               GC_size_map[i] = MIN_WORDS;
 172           }
 173 #         if MIN_WORDS > 1
 174             GC_size_map[sizeof(word)] = MIN_WORDS;
 175 #         else
 176             GC_size_map[sizeof(word)] = ROUNDED_UP_WORDS(sizeof(word));
 177 #         endif
 178         for (i = sizeof(word) + 1; i <= 8 * sizeof(word); i++) {
 179             GC_size_map[i] = ALIGNED_WORDS(i);
 180         }
 181         for (i = 8*sizeof(word) + 1; i <= 16 * sizeof(word); i++) {
 182               GC_size_map[i] = (ROUNDED_UP_WORDS(i) + 1) & (~1);
 183         }
 184 #       ifdef GC_GCJ_SUPPORT
 185            /* Make all sizes up to 32 words predictable, so that a      */
 186            /* compiler can statically perform the same computation,     */
 187            /* or at least a computation that results in similar size    */
 188            /* classes.                                                  */
 189            for (i = 16*sizeof(word) + 1; i <= 32 * sizeof(word); i++) {
 190               GC_size_map[i] = (ROUNDED_UP_WORDS(i) + 3) & (~3);
 191            }
 192 #       endif
 193         /* We leave the rest of the array to be filled in on demand. */
 194     }
 195
 196     /* Fill in additional entries in GC_size_map, including the ith one */
 197     /* We assume the ith entry is currently 0.                          */
 198     /* Note that a filled in section of the array ending at n always    */
 199     /* has length at least n/4.                                         */
 200     void GC_extend_size_map(i)
 201     word i;
 202     {
 203         word orig_word_sz = ROUNDED_UP_WORDS(i);
 204         word word_sz = orig_word_sz;
 205         register word byte_sz = WORDS_TO_BYTES(word_sz);
 206                                 /* The size we try to preserve.         */
 207                                 /* Close to to i, unless this would     */
 208                                 /* introduce too many distinct sizes.   */
 209         word smaller_than_i = byte_sz - (byte_sz >> 3);
 210         word much_smaller_than_i = byte_sz - (byte_sz >> 2);
 211         register word low_limit;        /* The lowest indexed entry we  */
 212                                         /* initialize.                  */
 213         register word j;
 214
 215         if (GC_size_map[smaller_than_i] == 0) {
 216             low_limit = much_smaller_than_i;
 217             while (GC_size_map[low_limit] != 0) low_limit++;
 218         } else {
 219             low_limit = smaller_than_i + 1;
 220             while (GC_size_map[low_limit] != 0) low_limit++;
 221             word_sz = ROUNDED_UP_WORDS(low_limit);
 222             word_sz += word_sz >> 3;
 223             if (word_sz < orig_word_sz) word_sz = orig_word_sz;
 224         }
 225 #       ifdef ALIGN_DOUBLE
 226             word_sz += 1;
 227             word_sz &= ~1;
 228 #       endif
 229         if (word_sz > MAXOBJSZ) {
 230             word_sz = MAXOBJSZ;
 231         }
 232         /* If we can fit the same number of larger objects in a block,  */
 233         /* do so.                                                       */
 234         {
 235             size_t number_of_objs = BODY_SZ/word_sz;
 236             word_sz = BODY_SZ/number_of_objs;
 237 #           ifdef ALIGN_DOUBLE
 238                 word_sz &= ~1;
 239 #           endif
 240         }
 241         byte_sz = WORDS_TO_BYTES(word_sz);
 242         if (GC_all_interior_pointers) {
 243             /* We need one extra byte; don't fill in GC_size_map[byte_sz] */
 244             byte_sz--;
 245         }
 246
 247         for (j = low_limit; j <= byte_sz; j++) GC_size_map[j] = word_sz;
 248     }
 249 # endif
 250
 251
 252 /*
 253  * The following is a gross hack to deal with a problem that can occur
 254  * on machines that are sloppy about stack frame sizes, notably SPARC.
 255  * Bogus pointers may be written to the stack and not cleared for
 256  * a LONG time, because they always fall into holes in stack frames
 257  * that are not written.  We partially address this by clearing
 258  * sections of the stack whenever we get control.
 259  */
 260 word GC_stack_last_cleared = 0; /* GC_no when we last did this */
 261 # ifdef THREADS
 262 #   define BIG_CLEAR_SIZE 2048  /* Clear this much now and then.        */
 263 #   define SMALL_CLEAR_SIZE 256 /* Clear this much every time.          */
 264 # endif
 265 # define CLEAR_SIZE 213  /* Granularity for GC_clear_stack_inner */
 266 # define DEGRADE_RATE 50
 267
 268 word GC_min_sp;         /* Coolest stack pointer value from which we've */
 269                         /* already cleared the stack.                   */
 270
 271 word GC_high_water;
 272                         /* "hottest" stack pointer value we have seen   */
 273                         /* recently.  Degrades over time.               */
 274
 275 word GC_words_allocd_at_reset;
 276
 277 #if defined(ASM_CLEAR_CODE)
 278   extern ptr_t GC_clear_stack_inner();
 279 #else
 280 /* Clear the stack up to about limit.  Return arg. */
 281 /*ARGSUSED*/
 282 ptr_t GC_clear_stack_inner(arg, limit)
 283 ptr_t arg;
 284 word limit;
 285 {
 286     word dummy[CLEAR_SIZE];
 287
 288     BZERO(dummy, CLEAR_SIZE*sizeof(word));
 289     if ((word)(dummy) COOLER_THAN limit) {
 290         (void) GC_clear_stack_inner(arg, limit);
 291     }
 292     /* Make sure the recursive call is not a tail call, and the bzero   */
 293     /* call is not recognized as dead code.                             */
 294     GC_noop1((word)dummy);
 295     return(arg);
 296 }
 297 #endif
 298
 299 /* Clear some of the inaccessible part of the stack.  Returns its       */
 300 /* argument, so it can be used in a tail call position, hence clearing  */
 301 /* another frame.                                                       */
 302 ptr_t GC_clear_stack(arg)
 303 ptr_t arg;
 304 {
 305     register word sp = (word)GC_approx_sp();  /* Hotter than actual sp */
 306 #   ifdef THREADS
 307         word dummy[SMALL_CLEAR_SIZE];
 308         static unsigned random_no = 0;
 309                                  /* Should be more random than it is ... */
 310                                  /* Used to occasionally clear a bigger  */
 311                                  /* chunk.                               */
 312 #   endif
 313     register word limit;
 314
 315 #   define SLOP 400
 316         /* Extra bytes we clear every time.  This clears our own        */
 317         /* activation record, and should cause more frequent            */
 318         /* clearing near the cold end of the stack, a good thing.       */
 319 #   define GC_SLOP 4000
 320         /* We make GC_high_water this much hotter than we really saw    */
 321         /* saw it, to cover for GC noise etc. above our current frame.  */
 322 #   define CLEAR_THRESHOLD 100000
 323         /* We restart the clearing process after this many bytes of     */
 324         /* allocation.  Otherwise very heavily recursive programs       */
 325         /* with sparse stacks may result in heaps that grow almost      */
 326         /* without bounds.  As the heap gets larger, collection         */
 327         /* frequency decreases, thus clearing frequency would decrease, */
 328         /* thus more junk remains accessible, thus the heap gets        */
 329         /* larger ...                                                   */
 330 # ifdef THREADS
 331     if (++random_no % 13 == 0) {
 332         limit = sp;
 333         MAKE_HOTTER(limit, BIG_CLEAR_SIZE*sizeof(word));
 334         limit &= ~0xf;  /* Make it sufficiently aligned for assembly    */
 335                         /* implementations of GC_clear_stack_inner.     */
 336         return GC_clear_stack_inner(arg, limit);
 337     } else {
 338         BZERO(dummy, SMALL_CLEAR_SIZE*sizeof(word));
 339         return arg;
 340     }
 341 # else
 342     if (GC_gc_no > GC_stack_last_cleared) {
 343         /* Start things over, so we clear the entire stack again */
 344         if (GC_stack_last_cleared == 0) GC_high_water = (word) GC_stackbottom;
 345         GC_min_sp = GC_high_water;
 346         GC_stack_last_cleared = GC_gc_no;
 347         GC_words_allocd_at_reset = GC_words_allocd;
 348     }
 349     /* Adjust GC_high_water */
 350         MAKE_COOLER(GC_high_water, WORDS_TO_BYTES(DEGRADE_RATE) + GC_SLOP);
 351         if (sp HOTTER_THAN GC_high_water) {
 352             GC_high_water = sp;
 353         }
 354         MAKE_HOTTER(GC_high_water, GC_SLOP);
 355     limit = GC_min_sp;
 356     MAKE_HOTTER(limit, SLOP);
 357     if (sp COOLER_THAN limit) {
 358         limit &= ~0xf;  /* Make it sufficiently aligned for assembly    */
 359                         /* implementations of GC_clear_stack_inner.     */
 360         GC_min_sp = sp;
 361         return(GC_clear_stack_inner(arg, limit));
 362     } else if (WORDS_TO_BYTES(GC_words_allocd - GC_words_allocd_at_reset)
 363                > CLEAR_THRESHOLD) {
 364         /* Restart clearing process, but limit how much clearing we do. */
 365         GC_min_sp = sp;
 366         MAKE_HOTTER(GC_min_sp, CLEAR_THRESHOLD/4);
 367         if (GC_min_sp HOTTER_THAN GC_high_water) GC_min_sp = GC_high_water;
 368         GC_words_allocd_at_reset = GC_words_allocd;
 369     }
 370     return(arg);
 371 # endif
 372 }
 373
 374
 375 /* Return a pointer to the base address of p, given a pointer to a      */
 376 /* an address within an object.  Return 0 o.w.                          */
 377 # ifdef __STDC__
 378     GC_PTR GC_base(GC_PTR p)
 379 # else
 380     GC_PTR GC_base(p)
 381     GC_PTR p;
 382 # endif
 383 {
 384     register word r;
 385     register struct hblk *h;
 386     register bottom_index *bi;
 387     register hdr *candidate_hdr;
 388     register word limit;
 389
 390     r = (word)p;
 391     if (!GC_is_initialized) return 0;
 392     h = HBLKPTR(r);
 393     GET_BI(r, bi);
 394     candidate_hdr = HDR_FROM_BI(bi, r);
 395     if (candidate_hdr == 0) return(0);
 396     /* If it's a pointer to the middle of a large object, move it       */
 397     /* to the beginning.                                                */
 398         while (IS_FORWARDING_ADDR_OR_NIL(candidate_hdr)) {
 399            h = FORWARDED_ADDR(h,candidate_hdr);
 400            r = (word)h;
 401            candidate_hdr = HDR(h);
 402         }
 403     if (candidate_hdr -> hb_map == GC_invalid_map) return(0);
 404     /* Make sure r points to the beginning of the object */
 405         r &= ~(WORDS_TO_BYTES(1) - 1);
 406         {
 407             register int offset = HBLKDISPL(r);
 408             register signed_word sz = candidate_hdr -> hb_sz;
 409             register signed_word map_entry;
 410
 411             map_entry = MAP_ENTRY((candidate_hdr -> hb_map), offset);
 412             if (map_entry > CPP_MAX_OFFSET) {
 413                 map_entry = (signed_word)(BYTES_TO_WORDS(offset)) % sz;
 414             }
 415             r -= WORDS_TO_BYTES(map_entry);
 416             limit = r + WORDS_TO_BYTES(sz);
 417             if (limit > (word)(h + 1)
 418                 && sz <= BYTES_TO_WORDS(HBLKSIZE)) {
 419                 return(0);
 420             }
 421             if ((word)p >= limit) return(0);
 422         }
 423     return((GC_PTR)r);
 424 }
 425
 426
 427 /* Return the size of an object, given a pointer to its base.           */
 428 /* (For small obects this also happens to work from interior pointers,  */
 429 /* but that shouldn't be relied upon.)                                  */
 430 # ifdef __STDC__
 431     size_t GC_size(GC_PTR p)
 432 # else
 433     size_t GC_size(p)
 434     GC_PTR p;
 435 # endif
 436 {
 437     register int sz;
 438     register hdr * hhdr = HDR(p);
 439
 440     sz = WORDS_TO_BYTES(hhdr -> hb_sz);
 441     return(sz);
 442 }
 443
 444 size_t GC_get_heap_size GC_PROTO(())
 445 {
 446     return ((size_t) GC_heapsize);
 447 }
 448
 449 size_t GC_get_free_bytes GC_PROTO(())
 450 {
 451     return ((size_t) GC_large_free_bytes);
 452 }
 453
 454 size_t GC_get_bytes_since_gc GC_PROTO(())
 455 {
 456     return ((size_t) WORDS_TO_BYTES(GC_words_allocd));
 457 }
 458
 459 size_t GC_get_total_bytes GC_PROTO(())
 460 {
 461     return ((size_t) WORDS_TO_BYTES(GC_words_allocd+GC_words_allocd_before_gc));
 462 }
 463
 464 GC_bool GC_is_initialized = FALSE;
 465
 466 void GC_init()
 467 {
 468     DCL_LOCK_STATE;
 469
 470     DISABLE_SIGNALS();
 471
 472 #if defined(GC_WIN32_THREADS) && !defined(GC_PTHREADS)
 473     if (!GC_is_initialized) InitializeCriticalSection(&GC_allocate_ml);
 474 #endif /* MSWIN32 */
 475
 476     LOCK();
 477     GC_init_inner();
 478     UNLOCK();
 479     ENABLE_SIGNALS();
 480
 481 #   if defined(PARALLEL_MARK) || defined(THREAD_LOCAL_ALLOC)
 482         /* Make sure marker threads and started and thread local */
 483         /* allocation is initialized, in case we didn't get      */
 484         /* called from GC_init_parallel();                       */
 485         {
 486           extern void GC_init_parallel(void);
 487           GC_init_parallel();
 488         }
 489 #   endif /* PARALLEL_MARK || THREAD_LOCAL_ALLOC */
 490
 491 #   if defined(DYNAMIC_LOADING) && defined(DARWIN)
 492     {
 493         /* This must be called WITHOUT the allocation lock held
 494         and before any threads are created */
 495         extern void GC_init_dyld();
 496         GC_init_dyld();
 497     }
 498 #   endif
 499 }
 500
 501 #if defined(MSWIN32) || defined(MSWINCE)
 502     CRITICAL_SECTION GC_write_cs;
 503 #endif
 504
 505 #ifdef MSWIN32
 506     extern void GC_init_win32 GC_PROTO((void));
 507 #endif
 508
 509 extern void GC_setpagesize();
 510
 511
 512 #ifdef MSWIN32
 513 extern GC_bool GC_no_win32_dlls;
 514 #else
 515 # define GC_no_win32_dlls FALSE
 516 #endif
 517
 518 void GC_exit_check GC_PROTO((void))
 519 {
 520    GC_gcollect();
 521 }
 522
 523 #ifdef SEARCH_FOR_DATA_START
 524   extern void GC_init_linux_data_start GC_PROTO((void));
 525 #endif
 526
 527 #ifdef UNIX_LIKE
 528
 529 extern void GC_set_and_save_fault_handler GC_PROTO((void (*handler)(int)));
 530
 531 static void looping_handler(sig)
 532 int sig;
 533 {
 534     GC_err_printf1("Caught signal %d: looping in handler\n", sig);
 535     for(;;);
 536 }
 537
 538 static GC_bool installed_looping_handler = FALSE;
 539
 540 void maybe_install_looping_handler()
 541 {
 542     /* Install looping handler before the write fault handler, so we    */
 543     /* handle write faults correctly.                                   */
 544       if (!installed_looping_handler && 0 != GETENV("GC_LOOP_ON_ABORT")) {
 545         GC_set_and_save_fault_handler(looping_handler);
 546         installed_looping_handler = TRUE;
 547       }
 548 }
 549
 550 #else /* !UNIX_LIKE */
 551
 552 # define maybe_install_looping_handler()
 553
 554 #endif
 555
 556 void GC_init_inner()
 557 {
 558 #   if !defined(THREADS) && defined(GC_ASSERTIONS)
 559         word dummy;
 560 #   endif
 561     word initial_heap_sz = (word)MINHINCR;
 562
 563     if (GC_is_initialized) return;
 564 #   ifdef PRINTSTATS
 565       GC_print_stats = 1;
 566 #   endif
 567 #   if defined(MSWIN32) || defined(MSWINCE)
 568       InitializeCriticalSection(&GC_write_cs);
 569 #   endif
 570     if (0 != GETENV("GC_PRINT_STATS")) {
 571       GC_print_stats = 1;
 572     }
 573 #   ifndef NO_DEBUGGING
 574       if (0 != GETENV("GC_DUMP_REGULARLY")) {
 575         GC_dump_regularly = 1;
 576       }
 577 #   endif
 578     if (0 != GETENV("GC_FIND_LEAK")) {
 579       GC_find_leak = 1;
 580 #     ifdef __STDC__
 581         atexit(GC_exit_check);
 582 #     endif
 583     }
 584     if (0 != GETENV("GC_ALL_INTERIOR_POINTERS")) {
 585       GC_all_interior_pointers = 1;
 586     }
 587     if (0 != GETENV("GC_DONT_GC")) {
 588       GC_dont_gc = 1;
 589     }
 590     if (0 != GETENV("GC_PRINT_BACK_HEIGHT")) {
 591       GC_print_back_height = 1;
 592     }
 593     if (0 != GETENV("GC_NO_BLACKLIST_WARNING")) {
 594       GC_large_alloc_warn_interval = LONG_MAX;
 595     }
 596     {
 597       char * time_limit_string = GETENV("GC_PAUSE_TIME_TARGET");
 598       if (0 != time_limit_string) {
 599         long time_limit = atol(time_limit_string);
 600         if (time_limit < 5) {
 601           WARN("GC_PAUSE_TIME_TARGET environment variable value too small "
 602                "or bad syntax: Ignoring\n", 0);
 603         } else {
 604           GC_time_limit = time_limit;
 605         }
 606       }
 607     }
 608     {
 609       char * interval_string = GETENV("GC_LARGE_ALLOC_WARN_INTERVAL");
 610       if (0 != interval_string) {
 611         long interval = atol(interval_string);
 612         if (interval <= 0) {
 613           WARN("GC_LARGE_ALLOC_WARN_INTERVAL environment variable has "
 614                "bad value: Ignoring\n", 0);
 615         } else {
 616           GC_large_alloc_warn_interval = interval;
 617         }
 618       }
 619     }
 620     maybe_install_looping_handler();
 621     /* Adjust normal object descriptor for extra allocation.    */
 622     if (ALIGNMENT > GC_DS_TAGS && EXTRA_BYTES != 0) {
 623       GC_obj_kinds[NORMAL].ok_descriptor = ((word)(-ALIGNMENT) | GC_DS_LENGTH);
 624     }
 625     GC_setpagesize();
 626     GC_exclude_static_roots(beginGC_arrays, endGC_arrays);
 627     GC_exclude_static_roots(beginGC_obj_kinds, endGC_obj_kinds);
 628 #   ifdef SEPARATE_GLOBALS
 629       GC_exclude_static_roots(beginGC_objfreelist, endGC_objfreelist);
 630       GC_exclude_static_roots(beginGC_aobjfreelist, endGC_aobjfreelist);
 631 #   endif
 632 #   ifdef MSWIN32
 633         GC_init_win32();
 634 #   endif
 635 #   if defined(SEARCH_FOR_DATA_START)
 636         GC_init_linux_data_start();
 637 #   endif
 638 #   if (defined(NETBSD) || defined(OPENBSD)) && defined(__ELF__)
 639         GC_init_netbsd_elf();
 640 #   endif
 641 #   if defined(GC_PTHREADS) || defined(GC_SOLARIS_THREADS)
 642         GC_thr_init();
 643 #   endif
 644 #   ifdef GC_SOLARIS_THREADS
 645         /* We need dirty bits in order to find live stack sections.     */
 646         GC_dirty_init();
 647 #   endif
 648 #   if !defined(THREADS) || defined(GC_PTHREADS) || defined(GC_WIN32_THREADS) \
 649         || defined(GC_SOLARIS_THREADS)
 650       if (GC_stackbottom == 0) {
 651         GC_stackbottom = GC_get_stack_base();
 652 #       if defined(LINUX) && defined(IA64)
 653           GC_register_stackbottom = GC_get_register_stack_base();
 654 #       endif
 655       } else {
 656 #       if defined(LINUX) && defined(IA64)
 657           if (GC_register_stackbottom == 0) {
 658             WARN("GC_register_stackbottom should be set with GC_stackbottom", 0);
 659             /* The following is likely to fail, since we rely on        */
 660             /* alignment properties that may not hold with a user set   */
 661             /* GC_stackbottom.                                          */
 662             GC_register_stackbottom = GC_get_register_stack_base();
 663           }
 664 #       endif
 665       }
 666 #   endif
 667     GC_STATIC_ASSERT(sizeof (ptr_t) == sizeof(word));
 668     GC_STATIC_ASSERT(sizeof (signed_word) == sizeof(word));
 669     GC_STATIC_ASSERT(sizeof (struct hblk) == HBLKSIZE);
 670 #   ifndef THREADS
 671 #     if defined(STACK_GROWS_UP) && defined(STACK_GROWS_DOWN)
 672         ABORT(
 673           "Only one of STACK_GROWS_UP and STACK_GROWS_DOWN should be defd\n");
 674 #     endif
 675 #     if !defined(STACK_GROWS_UP) && !defined(STACK_GROWS_DOWN)
 676         ABORT(
 677           "One of STACK_GROWS_UP and STACK_GROWS_DOWN should be defd\n");
 678 #     endif
 679 #     ifdef STACK_GROWS_DOWN
 680         GC_ASSERT((word)(&dummy) <= (word)GC_stackbottom);
 681 #     else
 682         GC_ASSERT((word)(&dummy) >= (word)GC_stackbottom);
 683 #     endif
 684 #   endif
 685 #   if !defined(_AUX_SOURCE) || defined(__GNUC__)
 686       GC_ASSERT((word)(-1) > (word)0);
 687       /* word should be unsigned */
 688 #   endif
 689     GC_ASSERT((signed_word)(-1) < (signed_word)0);
 690
 691     /* Add initial guess of root sets.  Do this first, since sbrk(0)    */
 692     /* might be used.                                                   */
 693       if (GC_REGISTER_MAIN_STATIC_DATA()) GC_register_data_segments();
 694     GC_init_headers();
 695     GC_bl_init();
 696     GC_mark_init();
 697     {
 698         char * sz_str = GETENV("GC_INITIAL_HEAP_SIZE");
 699         if (sz_str != NULL) {
 700           initial_heap_sz = atoi(sz_str);
 701           if (initial_heap_sz <= MINHINCR * HBLKSIZE) {
 702             WARN("Bad initial heap size %s - ignoring it.\n",
 703                  sz_str);
 704           }
 705           initial_heap_sz = divHBLKSZ(initial_heap_sz);
 706         }
 707     }
 708     {
 709         char * sz_str = GETENV("GC_MAXIMUM_HEAP_SIZE");
 710         if (sz_str != NULL) {
 711           word max_heap_sz = (word)atol(sz_str);
 712           if (max_heap_sz < initial_heap_sz * HBLKSIZE) {
 713             WARN("Bad maximum heap size %s - ignoring it.\n",
 714                  sz_str);
 715           }
 716           if (0 == GC_max_retries) GC_max_retries = 2;
 717           GC_set_max_heap_size(max_heap_sz);
 718         }
 719     }
 720     if (!GC_expand_hp_inner(initial_heap_sz)) {
 721         GC_err_printf0("Can't start up: not enough memory\n");
 722         EXIT();
 723     }
 724     /* Preallocate large object map.  It's otherwise inconvenient to    */
 725     /* deal with failure.                                               */
 726       if (!GC_add_map_entry((word)0)) {
 727         GC_err_printf0("Can't start up: not enough memory\n");
 728         EXIT();
 729       }
 730     GC_register_displacement_inner(0L);
 731 #   ifdef MERGE_SIZES
 732       GC_init_size_map();
 733 #   endif
 734 #   ifdef PCR
 735       if (PCR_IL_Lock(PCR_Bool_false, PCR_allSigsBlocked, PCR_waitForever)
 736           != PCR_ERes_okay) {
 737           ABORT("Can't lock load state\n");
 738       } else if (PCR_IL_Unlock() != PCR_ERes_okay) {
 739           ABORT("Can't unlock load state\n");
 740       }
 741       PCR_IL_Unlock();
 742       GC_pcr_install();
 743 #   endif
 744 #   if !defined(SMALL_CONFIG)
 745       if (!GC_no_win32_dlls && 0 != GETENV("GC_ENABLE_INCREMENTAL")) {
 746         GC_ASSERT(!GC_incremental);
 747         GC_setpagesize();
 748 #       ifndef GC_SOLARIS_THREADS
 749           GC_dirty_init();
 750 #       endif
 751         GC_ASSERT(GC_words_allocd == 0)
 752         GC_incremental = TRUE;
 753       }
 754 #   endif /* !SMALL_CONFIG */
 755     COND_DUMP;
 756     /* Get black list set up and/or incrmental GC started */
 757       if (!GC_dont_precollect || GC_incremental) GC_gcollect_inner();
 758     GC_is_initialized = TRUE;
 759 #   ifdef STUBBORN_ALLOC
 760         GC_stubborn_init();
 761 #   endif
 762     /* Convince lint that some things are used */
 763 #   ifdef LINT
 764       {
 765           extern char * GC_copyright[];
 766           extern int GC_read();
 767           extern void GC_register_finalizer_no_order();
 768
 769           GC_noop(GC_copyright, GC_find_header,
 770                   GC_push_one, GC_call_with_alloc_lock, GC_read,
 771                   GC_dont_expand,
 772 #                 ifndef NO_DEBUGGING
 773                     GC_dump,
 774 #                 endif
 775                   GC_register_finalizer_no_order);
 776       }
 777 #   endif
 778 }
 779
 780 void GC_enable_incremental GC_PROTO(())
 781 {
 782 # if !defined(SMALL_CONFIG)
 783   if (!GC_find_leak) {
 784     DCL_LOCK_STATE;
 785
 786     DISABLE_SIGNALS();
 787     LOCK();
 788     if (GC_incremental) goto out;
 789     GC_setpagesize();
 790     if (GC_no_win32_dlls) goto out;
 791 #   ifndef GC_SOLARIS_THREADS
 792       maybe_install_looping_handler();  /* Before write fault handler! */
 793       GC_dirty_init();
 794 #   endif
 795     if (!GC_is_initialized) {
 796         GC_init_inner();
 797     }
 798     if (GC_incremental) goto out;
 799     if (GC_dont_gc) {
 800         /* Can't easily do it. */
 801         UNLOCK();
 802         ENABLE_SIGNALS();
 803         return;
 804     }
 805     if (GC_words_allocd > 0) {
 806         /* There may be unmarked reachable objects      */
 807         GC_gcollect_inner();
 808     }   /* else we're OK in assuming everything's       */
 809         /* clean since nothing can point to an          */
 810         /* unmarked object.                             */
 811     GC_read_dirty();
 812     GC_incremental = TRUE;
 813 out:
 814     UNLOCK();
 815     ENABLE_SIGNALS();
 816   }
 817 # endif
 818 }
 819
 820
 821 #if defined(MSWIN32) || defined(MSWINCE)
 822 # define LOG_FILE _T("gc.log")
 823
 824   HANDLE GC_stdout = 0;
 825
 826   void GC_deinit()
 827   {
 828       if (GC_is_initialized) {
 829         DeleteCriticalSection(&GC_write_cs);
 830       }
 831   }
 832
 833   int GC_write(buf, len)
 834   GC_CONST char * buf;
 835   size_t len;
 836   {
 837       BOOL tmp;
 838       DWORD written;
 839       if (len == 0)
 840           return 0;
 841       EnterCriticalSection(&GC_write_cs);
 842       if (GC_stdout == INVALID_HANDLE_VALUE) {
 843           return -1;
 844       } else if (GC_stdout == 0) {
 845           GC_stdout = CreateFile(LOG_FILE, GENERIC_WRITE,
 846                                  FILE_SHARE_READ | FILE_SHARE_WRITE,
 847                                  NULL, CREATE_ALWAYS, FILE_FLAG_WRITE_THROUGH,
 848                                  NULL);
 849           if (GC_stdout == INVALID_HANDLE_VALUE) ABORT("Open of log file failed");
 850       }
 851       tmp = WriteFile(GC_stdout, buf, len, &written, NULL);
 852       if (!tmp)
 853           DebugBreak();
 854       LeaveCriticalSection(&GC_write_cs);
 855       return tmp ? (int)written : -1;
 856   }
 857
 858 #endif
 859
 860 #if defined(OS2) || defined(MACOS)
 861 FILE * GC_stdout = NULL;
 862 FILE * GC_stderr = NULL;
 863 int GC_tmp;  /* Should really be local ... */
 864
 865   void GC_set_files()
 866   {
 867       if (GC_stdout == NULL) {
 868         GC_stdout = stdout;
 869     }
 870     if (GC_stderr == NULL) {
 871         GC_stderr = stderr;
 872     }
 873   }
 874 #endif
 875
 876 #if !defined(OS2) && !defined(MACOS) && !defined(MSWIN32) && !defined(MSWINCE)
 877   int GC_stdout = 1;
 878   int GC_stderr = 2;
 879 # if !defined(AMIGA)
 880 #   include <unistd.h>
 881 # endif
 882 #endif
 883
 884 #if !defined(MSWIN32) && !defined(MSWINCE) && !defined(OS2) \
 885     && !defined(MACOS)  && !defined(ECOS) && !defined(NOSYS)
 886 int GC_write(fd, buf, len)
 887 int fd;
 888 GC_CONST char *buf;
 889 size_t len;
 890 {
 891      register int bytes_written = 0;
 892      register int result;
 893
 894      while (bytes_written < len) {
 895 #       ifdef GC_SOLARIS_THREADS
 896             result = syscall(SYS_write, fd, buf + bytes_written,
 897                                             len - bytes_written);
 898 #       else
 899             result = write(fd, buf + bytes_written, len - bytes_written);
 900 #       endif
 901         if (-1 == result) return(result);
 902         bytes_written += result;
 903     }
 904     return(bytes_written);
 905 }
 906 #endif /* UN*X */
 907
 908 #ifdef ECOS
 909 int GC_write(fd, buf, len)
 910 {
 911   _Jv_diag_write (buf, len);
 912   return len;
 913 }
 914 #endif
 915
 916 #ifdef NOSYS
 917 int GC_write(fd, buf, len)
 918 {
 919   /* No writing.  */
 920   return len;
 921 }
 922 #endif
 923
 924
 925 #if defined(MSWIN32) || defined(MSWINCE)
 926 #   define WRITE(f, buf, len) GC_write(buf, len)
 927 #else
 928 #   if defined(OS2) || defined(MACOS)
 929 #   define WRITE(f, buf, len) (GC_set_files(), \
 930                                GC_tmp = fwrite((buf), 1, (len), (f)), \
 931                                fflush(f), GC_tmp)
 932 #   else
 933 #     define WRITE(f, buf, len) GC_write((f), (buf), (len))
 934 #   endif
 935 #endif
 936
 937 /* A version of printf that is unlikely to call malloc, and is thus safer */
 938 /* to call from the collector in case malloc has been bound to GC_malloc. */
 939 /* Assumes that no more than 1023 characters are written at once.         */
 940 /* Assumes that all arguments have been converted to something of the     */
 941 /* same size as long, and that the format conversions expect something    */
 942 /* of that size.                                                          */
 943 void GC_printf(format, a, b, c, d, e, f)
 944 GC_CONST char * format;
 945 long a, b, c, d, e, f;
 946 {
 947     char buf[1025];
 948
 949     if (GC_quiet) return;
 950     buf[1024] = 0x15;
 951     (void) sprintf(buf, format, a, b, c, d, e, f);
 952     if (buf[1024] != 0x15) ABORT("GC_printf clobbered stack");
 953     if (WRITE(GC_stdout, buf, strlen(buf)) < 0) ABORT("write to stdout failed");
 954 }
 955
 956 void GC_err_printf(format, a, b, c, d, e, f)
 957 GC_CONST char * format;
 958 long a, b, c, d, e, f;
 959 {
 960     char buf[1025];
 961
 962     buf[1024] = 0x15;
 963     (void) sprintf(buf, format, a, b, c, d, e, f);
 964     if (buf[1024] != 0x15) ABORT("GC_err_printf clobbered stack");
 965     if (WRITE(GC_stderr, buf, strlen(buf)) < 0) ABORT("write to stderr failed");
 966 }
 967
 968 void GC_err_puts(s)
 969 GC_CONST char *s;
 970 {
 971     if (WRITE(GC_stderr, s, strlen(s)) < 0) ABORT("write to stderr failed");
 972 }
 973
 974 #if defined(LINUX) && !defined(SMALL_CONFIG)
 975 void GC_err_write(buf, len)
 976 GC_CONST char *buf;
 977 size_t len;
 978 {
 979     if (WRITE(GC_stderr, buf, len) < 0) ABORT("write to stderr failed");
 980 }
 981 #endif
 982
 983 # if defined(__STDC__) || defined(__cplusplus)
 984     void GC_default_warn_proc(char *msg, GC_word arg)
 985 # else
 986     void GC_default_warn_proc(msg, arg)
 987     char *msg;
 988     GC_word arg;
 989 # endif
 990 {
 991     GC_err_printf1(msg, (unsigned long)arg);
 992 }
 993
 994 GC_warn_proc GC_current_warn_proc = GC_default_warn_proc;
 995
 996 # if defined(__STDC__) || defined(__cplusplus)
 997     GC_warn_proc GC_set_warn_proc(GC_warn_proc p)
 998 # else
 999     GC_warn_proc GC_set_warn_proc(p)
1000     GC_warn_proc p;
1001 # endif
1002 {
1003     GC_warn_proc result;
1004
1005     LOCK();
1006     result = GC_current_warn_proc;
1007     GC_current_warn_proc = p;
1008     UNLOCK();
1009     return(result);
1010 }
1011
1012 # if defined(__STDC__) || defined(__cplusplus)
1013     GC_word GC_set_free_space_divisor (GC_word value)
1014 # else
1015     GC_word GC_set_free_space_divisor (value)
1016     GC_word value;
1017 # endif
1018 {
1019     GC_word old = GC_free_space_divisor;
1020     GC_free_space_divisor = value;
1021     return old;
1022 }
1023
1024 #ifndef PCR
1025 void GC_abort(msg)
1026 GC_CONST char * msg;
1027 {
1028 #   if defined(MSWIN32)
1029       (void) MessageBoxA(NULL, msg, "Fatal error in gc", MB_ICONERROR|MB_OK);
1030       DebugBreak();
1031 #   else
1032       GC_err_printf1("%s\n", msg);
1033 #   endif
1034     if (GETENV("GC_LOOP_ON_ABORT") != NULL) {
1035             /* In many cases it's easier to debug a running process.    */
1036             /* It's arguably nicer to sleep, but that makes it harder   */
1037             /* to look at the thread if the debugger doesn't know much  */
1038             /* about threads.                                           */
1039             for(;;) {}
1040     }
1041 #   ifdef MSWIN32
1042         DebugBreak();
1043 #   else
1044         (void) abort();
1045 #   endif
1046 }
1047 #endif
1048
1049 void GC_enable()
1050 {
1051     LOCK();
1052     GC_dont_gc--;
1053     UNLOCK();
1054 }
1055
1056 void GC_disable()
1057 {
1058     LOCK();
1059     GC_dont_gc++;
1060     UNLOCK();
1061 }
1062
1063 #if !defined(NO_DEBUGGING)
1064
1065 void GC_dump()
1066 {
1067     GC_printf0("***Static roots:\n");
1068     GC_print_static_roots();
1069     GC_printf0("\n***Heap sections:\n");
1070     GC_print_heap_sects();
1071     GC_printf0("\n***Free blocks:\n");
1072     GC_print_hblkfreelist();
1073     GC_printf0("\n***Blocks in use:\n");
1074     GC_print_block_list();
1075     GC_printf0("\n***Finalization statistics:\n");
1076     GC_print_finalization_stats();
1077 }
1078
1079 #endif /* NO_DEBUGGING */