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  *
   5  * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
   6  * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
   7  *
   8  * Permission is hereby granted to use or copy this program
   9  * for any purpose,  provided the above notices are retained on all copies.
  10  * Permission to modify the code and to distribute modified code is granted,
  11  * provided the above notices are retained, and a notice that the code was
  12  * modified is included with the above copyright notice.
  13  */
  14 /* Boehm, July 31, 1995 5:02 pm PDT */
  15
  16
  17 #include <stdio.h>
  18 #ifndef _WIN32_WCE
  19 #include <signal.h>
  20 #endif
  21
  22 #define I_HIDE_POINTERS /* To make GC_call_with_alloc_lock visible */
  23 #include "private/gc_pmark.h"
  24
  25 #ifdef GC_SOLARIS_THREADS
  26 # include <sys/syscall.h>
  27 #endif
  28 #if defined(MSWIN32) || defined(MSWINCE)
  29 # define WIN32_LEAN_AND_MEAN
  30 # define NOSERVICE
  31 # include <windows.h>
  32 # include <tchar.h>
  33 #endif
  34
  35 # ifdef THREADS
  36 #   ifdef PCR
  37 #     include "il/PCR_IL.h"
  38       PCR_Th_ML GC_allocate_ml;
  39 #   else
  40 #     ifdef SRC_M3
  41         /* Critical section counter is defined in the M3 runtime        */
  42         /* That's all we use.                                           */
  43 #     else
  44 #       ifdef GC_SOLARIS_THREADS
  45           mutex_t GC_allocate_ml;       /* Implicitly initialized.      */
  46 #       else
  47 #          ifdef GC_WIN32_THREADS
  48 #             if !defined(GC_NOT_DLL) && (defined(_DLL) || defined(GC_DLL))
  49                  __declspec(dllexport) CRITICAL_SECTION GC_allocate_ml;
  50 #             else
  51                  CRITICAL_SECTION GC_allocate_ml;
  52 #             endif
  53 #          else
  54 #             if defined(GC_PTHREADS) && !defined(GC_SOLARIS_THREADS)
  55 #               if defined(USE_SPIN_LOCK)
  56                   pthread_t GC_lock_holder = NO_THREAD;
  57 #               else
  58                   pthread_mutex_t GC_allocate_ml = PTHREAD_MUTEX_INITIALIZER;
  59                   pthread_t GC_lock_holder = NO_THREAD;
  60                         /* Used only for assertions, and to prevent      */
  61                         /* recursive reentry in the system call wrapper. */
  62 #               endif
  63 #             else
  64                   --> declare allocator lock here
  65 #             endif
  66 #          endif
  67 #       endif
  68 #     endif
  69 #   endif
  70 # endif
  71
  72 #ifdef ECOS
  73 #undef STACKBASE
  74 #endif
  75
  76 GC_FAR struct _GC_arrays GC_arrays /* = { 0 } */;
  77
  78
  79 GC_bool GC_debugging_started = FALSE;
  80         /* defined here so we don't have to load debug_malloc.o */
  81
  82 void (*GC_check_heap) GC_PROTO((void)) = (void (*) GC_PROTO((void)))0;
  83
  84 void (*GC_start_call_back) GC_PROTO((void)) = (void (*) GC_PROTO((void)))0;
  85
  86 ptr_t GC_stackbottom = 0;
  87
  88 #ifdef IA64
  89   ptr_t GC_register_stackbottom = 0;
  90 #endif
  91
  92 GC_bool GC_dont_gc = 0;
  93
  94 GC_bool GC_dont_precollect = 0;
  95
  96 GC_bool GC_quiet = 0;
  97
  98 GC_bool GC_print_stats = 0;
  99
 100 #ifdef FIND_LEAK
 101   int GC_find_leak = 1;
 102 #else
 103   int GC_find_leak = 0;
 104 #endif
 105
 106 #ifdef ALL_INTERIOR_POINTERS
 107   int GC_all_interior_pointers = 1;
 108 #else
 109   int GC_all_interior_pointers = 0;
 110 #endif
 111
 112 /*ARGSUSED*/
 113 GC_PTR GC_default_oom_fn GC_PROTO((size_t bytes_requested))
 114 {
 115     return(0);
 116 }
 117
 118 GC_PTR (*GC_oom_fn) GC_PROTO((size_t bytes_requested)) = GC_default_oom_fn;
 119
 120 extern signed_word GC_mem_found;
 121
 122 # ifdef MERGE_SIZES
 123     /* Set things up so that GC_size_map[i] >= words(i),                */
 124     /* but not too much bigger                                          */
 125     /* and so that size_map contains relatively few distinct entries    */
 126     /* This is stolen from Russ Atkinson's Cedar quantization           */
 127     /* alogrithm (but we precompute it).                                */
 128
 129
 130     void GC_init_size_map()
 131     {
 132         register unsigned i;
 133
 134         /* Map size 0 to something bigger.                      */
 135         /* This avoids problems at lower levels.                */
 136         /* One word objects don't have to be 2 word aligned,    */
 137         /* unless we're using mark bytes.                       */
 138           for (i = 0; i < sizeof(word); i++) {
 139               GC_size_map[i] = MIN_WORDS;
 140           }
 141 #         if MIN_WORDS > 1
 142             GC_size_map[sizeof(word)] = MIN_WORDS;
 143 #         else
 144             GC_size_map[sizeof(word)] = ROUNDED_UP_WORDS(sizeof(word));
 145 #         endif
 146         for (i = sizeof(word) + 1; i <= 8 * sizeof(word); i++) {
 147             GC_size_map[i] = ALIGNED_WORDS(i);
 148         }
 149         for (i = 8*sizeof(word) + 1; i <= 16 * sizeof(word); i++) {
 150               GC_size_map[i] = (ROUNDED_UP_WORDS(i) + 1) & (~1);
 151         }
 152 #       ifdef GC_GCJ_SUPPORT
 153            /* Make all sizes up to 32 words predictable, so that a      */
 154            /* compiler can statically perform the same computation,     */
 155            /* or at least a computation that results in similar size    */
 156            /* classes.                                                  */
 157            for (i = 16*sizeof(word) + 1; i <= 32 * sizeof(word); i++) {
 158               GC_size_map[i] = (ROUNDED_UP_WORDS(i) + 3) & (~3);
 159            }
 160 #       endif
 161         /* We leave the rest of the array to be filled in on demand. */
 162     }
 163
 164     /* Fill in additional entries in GC_size_map, including the ith one */
 165     /* We assume the ith entry is currently 0.                          */
 166     /* Note that a filled in section of the array ending at n always    */
 167     /* has length at least n/4.                                         */
 168     void GC_extend_size_map(i)
 169     word i;
 170     {
 171         word orig_word_sz = ROUNDED_UP_WORDS(i);
 172         word word_sz = orig_word_sz;
 173         register word byte_sz = WORDS_TO_BYTES(word_sz);
 174                                 /* The size we try to preserve.         */
 175                                 /* Close to to i, unless this would     */
 176                                 /* introduce too many distinct sizes.   */
 177         word smaller_than_i = byte_sz - (byte_sz >> 3);
 178         word much_smaller_than_i = byte_sz - (byte_sz >> 2);
 179         register word low_limit;        /* The lowest indexed entry we  */
 180                                         /* initialize.                  */
 181         register word j;
 182
 183         if (GC_size_map[smaller_than_i] == 0) {
 184             low_limit = much_smaller_than_i;
 185             while (GC_size_map[low_limit] != 0) low_limit++;
 186         } else {
 187             low_limit = smaller_than_i + 1;
 188             while (GC_size_map[low_limit] != 0) low_limit++;
 189             word_sz = ROUNDED_UP_WORDS(low_limit);
 190             word_sz += word_sz >> 3;
 191             if (word_sz < orig_word_sz) word_sz = orig_word_sz;
 192         }
 193 #       ifdef ALIGN_DOUBLE
 194             word_sz += 1;
 195             word_sz &= ~1;
 196 #       endif
 197         if (word_sz > MAXOBJSZ) {
 198             word_sz = MAXOBJSZ;
 199         }
 200         /* If we can fit the same number of larger objects in a block,  */
 201         /* do so.                                                       */
 202         {
 203             size_t number_of_objs = BODY_SZ/word_sz;
 204             word_sz = BODY_SZ/number_of_objs;
 205 #           ifdef ALIGN_DOUBLE
 206                 word_sz &= ~1;
 207 #           endif
 208         }
 209         byte_sz = WORDS_TO_BYTES(word_sz);
 210         if (GC_all_interior_pointers) {
 211             /* We need one extra byte; don't fill in GC_size_map[byte_sz] */
 212             byte_sz--;
 213         }
 214
 215         for (j = low_limit; j <= byte_sz; j++) GC_size_map[j] = word_sz;
 216     }
 217 # endif
 218
 219
 220 /*
 221  * The following is a gross hack to deal with a problem that can occur
 222  * on machines that are sloppy about stack frame sizes, notably SPARC.
 223  * Bogus pointers may be written to the stack and not cleared for
 224  * a LONG time, because they always fall into holes in stack frames
 225  * that are not written.  We partially address this by clearing
 226  * sections of the stack whenever we get control.
 227  */
 228 word GC_stack_last_cleared = 0; /* GC_no when we last did this */
 229 # ifdef THREADS
 230 #   define BIG_CLEAR_SIZE 2048  /* Clear this much now and then.        */
 231 #   define SMALL_CLEAR_SIZE 256 /* Clear this much every time.          */
 232 # endif
 233 # define CLEAR_SIZE 213  /* Granularity for GC_clear_stack_inner */
 234 # define DEGRADE_RATE 50
 235
 236 word GC_min_sp;         /* Coolest stack pointer value from which we've */
 237                         /* already cleared the stack.                   */
 238
 239 word GC_high_water;
 240                         /* "hottest" stack pointer value we have seen   */
 241                         /* recently.  Degrades over time.               */
 242
 243 word GC_words_allocd_at_reset;
 244
 245 #if defined(ASM_CLEAR_CODE)
 246   extern ptr_t GC_clear_stack_inner();
 247 #else
 248 /* Clear the stack up to about limit.  Return arg. */
 249 /*ARGSUSED*/
 250 ptr_t GC_clear_stack_inner(arg, limit)
 251 ptr_t arg;
 252 word limit;
 253 {
 254     word dummy[CLEAR_SIZE];
 255
 256     BZERO(dummy, CLEAR_SIZE*sizeof(word));
 257     if ((word)(dummy) COOLER_THAN limit) {
 258         (void) GC_clear_stack_inner(arg, limit);
 259     }
 260     /* Make sure the recursive call is not a tail call, and the bzero   */
 261     /* call is not recognized as dead code.                             */
 262     GC_noop1((word)dummy);
 263     return(arg);
 264 }
 265 #endif
 266
 267 /* Clear some of the inaccessible part of the stack.  Returns its       */
 268 /* argument, so it can be used in a tail call position, hence clearing  */
 269 /* another frame.                                                       */
 270 ptr_t GC_clear_stack(arg)
 271 ptr_t arg;
 272 {
 273     register word sp = (word)GC_approx_sp();  /* Hotter than actual sp */
 274 #   ifdef THREADS
 275         word dummy[SMALL_CLEAR_SIZE];
 276         static unsigned random_no = 0;
 277                                  /* Should be more random than it is ... */
 278                                  /* Used to occasionally clear a bigger  */
 279                                  /* chunk.                               */
 280 #   endif
 281     register word limit;
 282
 283 #   define SLOP 400
 284         /* Extra bytes we clear every time.  This clears our own        */
 285         /* activation record, and should cause more frequent            */
 286         /* clearing near the cold end of the stack, a good thing.       */
 287 #   define GC_SLOP 4000
 288         /* We make GC_high_water this much hotter than we really saw    */
 289         /* saw it, to cover for GC noise etc. above our current frame.  */
 290 #   define CLEAR_THRESHOLD 100000
 291         /* We restart the clearing process after this many bytes of     */
 292         /* allocation.  Otherwise very heavily recursive programs       */
 293         /* with sparse stacks may result in heaps that grow almost      */
 294         /* without bounds.  As the heap gets larger, collection         */
 295         /* frequency decreases, thus clearing frequency would decrease, */
 296         /* thus more junk remains accessible, thus the heap gets        */
 297         /* larger ...                                                   */
 298 # ifdef THREADS
 299     if (++random_no % 13 == 0) {
 300         limit = sp;
 301         MAKE_HOTTER(limit, BIG_CLEAR_SIZE*sizeof(word));
 302         limit &= ~0xf;  /* Make it sufficiently aligned for assembly    */
 303                         /* implementations of GC_clear_stack_inner.     */
 304         return GC_clear_stack_inner(arg, limit);
 305     } else {
 306         BZERO(dummy, SMALL_CLEAR_SIZE*sizeof(word));
 307         return arg;
 308     }
 309 # else
 310     if (GC_gc_no > GC_stack_last_cleared) {
 311         /* Start things over, so we clear the entire stack again */
 312         if (GC_stack_last_cleared == 0) GC_high_water = (word) GC_stackbottom;
 313         GC_min_sp = GC_high_water;
 314         GC_stack_last_cleared = GC_gc_no;
 315         GC_words_allocd_at_reset = GC_words_allocd;
 316     }
 317     /* Adjust GC_high_water */
 318         MAKE_COOLER(GC_high_water, WORDS_TO_BYTES(DEGRADE_RATE) + GC_SLOP);
 319         if (sp HOTTER_THAN GC_high_water) {
 320             GC_high_water = sp;
 321         }
 322         MAKE_HOTTER(GC_high_water, GC_SLOP);
 323     limit = GC_min_sp;
 324     MAKE_HOTTER(limit, SLOP);
 325     if (sp COOLER_THAN limit) {
 326         limit &= ~0xf;  /* Make it sufficiently aligned for assembly    */
 327                         /* implementations of GC_clear_stack_inner.     */
 328         GC_min_sp = sp;
 329         return(GC_clear_stack_inner(arg, limit));
 330     } else if (WORDS_TO_BYTES(GC_words_allocd - GC_words_allocd_at_reset)
 331                > CLEAR_THRESHOLD) {
 332         /* Restart clearing process, but limit how much clearing we do. */
 333         GC_min_sp = sp;
 334         MAKE_HOTTER(GC_min_sp, CLEAR_THRESHOLD/4);
 335         if (GC_min_sp HOTTER_THAN GC_high_water) GC_min_sp = GC_high_water;
 336         GC_words_allocd_at_reset = GC_words_allocd;
 337     }
 338     return(arg);
 339 # endif
 340 }
 341
 342
 343 /* Return a pointer to the base address of p, given a pointer to a      */
 344 /* an address within an object.  Return 0 o.w.                          */
 345 # ifdef __STDC__
 346     GC_PTR GC_base(GC_PTR p)
 347 # else
 348     GC_PTR GC_base(p)
 349     GC_PTR p;
 350 # endif
 351 {
 352     register word r;
 353     register struct hblk *h;
 354     register bottom_index *bi;
 355     register hdr *candidate_hdr;
 356     register word limit;
 357
 358     r = (word)p;
 359     if (!GC_is_initialized) return 0;
 360     h = HBLKPTR(r);
 361     GET_BI(r, bi);
 362     candidate_hdr = HDR_FROM_BI(bi, r);
 363     if (candidate_hdr == 0) return(0);
 364     /* If it's a pointer to the middle of a large object, move it       */
 365     /* to the beginning.                                                */
 366         while (IS_FORWARDING_ADDR_OR_NIL(candidate_hdr)) {
 367            h = FORWARDED_ADDR(h,candidate_hdr);
 368            r = (word)h;
 369            candidate_hdr = HDR(h);
 370         }
 371     if (candidate_hdr -> hb_map == GC_invalid_map) return(0);
 372     /* Make sure r points to the beginning of the object */
 373         r &= ~(WORDS_TO_BYTES(1) - 1);
 374         {
 375             register int offset = HBLKDISPL(r);
 376             register signed_word sz = candidate_hdr -> hb_sz;
 377             register signed_word map_entry;
 378
 379             map_entry = MAP_ENTRY((candidate_hdr -> hb_map), offset);
 380             if (map_entry > CPP_MAX_OFFSET) {
 381                 map_entry = (signed_word)(BYTES_TO_WORDS(offset)) % sz;
 382             }
 383             r -= WORDS_TO_BYTES(map_entry);
 384             limit = r + WORDS_TO_BYTES(sz);
 385             if (limit > (word)(h + 1)
 386                 && sz <= BYTES_TO_WORDS(HBLKSIZE)) {
 387                 return(0);
 388             }
 389             if ((word)p >= limit) return(0);
 390         }
 391     return((GC_PTR)r);
 392 }
 393
 394
 395 /* Return the size of an object, given a pointer to its base.           */
 396 /* (For small obects this also happens to work from interior pointers,  */
 397 /* but that shouldn't be relied upon.)                                  */
 398 # ifdef __STDC__
 399     size_t GC_size(GC_PTR p)
 400 # else
 401     size_t GC_size(p)
 402     GC_PTR p;
 403 # endif
 404 {
 405     register int sz;
 406     register hdr * hhdr = HDR(p);
 407
 408     sz = WORDS_TO_BYTES(hhdr -> hb_sz);
 409     return(sz);
 410 }
 411
 412 size_t GC_get_heap_size GC_PROTO(())
 413 {
 414     return ((size_t) GC_heapsize);
 415 }
 416
 417 size_t GC_get_free_bytes GC_PROTO(())
 418 {
 419     return ((size_t) GC_large_free_bytes);
 420 }
 421
 422 size_t GC_get_bytes_since_gc GC_PROTO(())
 423 {
 424     return ((size_t) WORDS_TO_BYTES(GC_words_allocd));
 425 }
 426
 427 size_t GC_get_total_bytes GC_PROTO(())
 428 {
 429     return ((size_t) WORDS_TO_BYTES(GC_words_allocd+GC_words_allocd_before_gc));
 430 }
 431
 432 GC_bool GC_is_initialized = FALSE;
 433
 434 void GC_init()
 435 {
 436     DCL_LOCK_STATE;
 437
 438     DISABLE_SIGNALS();
 439     LOCK();
 440     GC_init_inner();
 441     UNLOCK();
 442     ENABLE_SIGNALS();
 443
 444 #   if defined(PARALLEL_MARK) || defined(THREAD_LOCAL_ALLOC)
 445         /* Make sure marker threads and started and thread local */
 446         /* allocation is initialized, in case we didn't get      */
 447         /* called from GC_init_parallel();                       */
 448         {
 449           extern void GC_init_parallel(void);
 450           GC_init_parallel();
 451         }
 452 #   endif /* PARALLEL_MARK || THREAD_LOCAL_ALLOC */
 453 }
 454
 455 #if defined(MSWIN32) || defined(MSWINCE)
 456     CRITICAL_SECTION GC_write_cs;
 457 #endif
 458
 459 #ifdef MSWIN32
 460     extern void GC_init_win32 GC_PROTO((void));
 461 #endif
 462
 463 extern void GC_setpagesize();
 464
 465 #ifdef UNIX_LIKE
 466
 467 extern void GC_set_and_save_fault_handler GC_PROTO((void (*handler)(int)));
 468
 469 static void looping_handler(sig)
 470 int sig;
 471 {
 472     GC_err_printf1("Caught signal %d: looping in handler\n", sig);
 473     for(;;);
 474 }
 475 #endif
 476
 477 void GC_init_inner()
 478 {
 479 #   if !defined(THREADS) && defined(GC_ASSERTIONS)
 480         word dummy;
 481 #   endif
 482     word initial_heap_sz = (word)MINHINCR;
 483
 484     if (GC_is_initialized) return;
 485 #   ifdef PRINTSTATS
 486       GC_print_stats = 1;
 487 #   endif
 488     if (0 != GETENV("GC_PRINT_STATS")) {
 489       GC_print_stats = 1;
 490     }
 491     if (0 != GETENV("GC_FIND_LEAK")) {
 492       GC_find_leak = 1;
 493     }
 494     if (0 != GETENV("GC_ALL_INTERIOR_POINTERS")) {
 495       GC_all_interior_pointers = 1;
 496     }
 497     if (0 != GETENV("GC_DONT_GC")) {
 498       GC_dont_gc = 1;
 499     }
 500 #   ifdef UNIX_LIKE
 501       if (0 != GETENV("GC_LOOP_ON_ABORT")) {
 502         GC_set_and_save_fault_handler(looping_handler);
 503       }
 504 #   endif
 505     /* Adjust normal object descriptor for extra allocation.    */
 506     if (ALIGNMENT > GC_DS_TAGS && EXTRA_BYTES != 0) {
 507       GC_obj_kinds[NORMAL].ok_descriptor = ((word)(-ALIGNMENT) | GC_DS_LENGTH);
 508     }
 509 #   if defined(MSWIN32) || defined(MSWINCE)
 510         InitializeCriticalSection(&GC_write_cs);
 511 #   endif
 512     GC_setpagesize();
 513     GC_exclude_static_roots(beginGC_arrays, endGC_arrays);
 514     GC_exclude_static_roots(beginGC_obj_kinds, endGC_obj_kinds);
 515 #   ifdef SEPARATE_GLOBALS
 516       GC_exclude_static_roots(beginGC_objfreelist, endGC_objfreelist);
 517       GC_exclude_static_roots(beginGC_aobjfreelist, endGC_aobjfreelist);
 518 #   endif
 519 #   ifdef MSWIN32
 520         GC_init_win32();
 521 #   endif
 522 #   if defined(SEARCH_FOR_DATA_START)
 523         GC_init_linux_data_start();
 524 #   endif
 525 #   if (defined(NETBSD) || defined(OPENBSD)) && defined(__ELF__)
 526         GC_init_netbsd_elf();
 527 #   endif
 528 #   if defined(GC_PTHREADS) || defined(GC_SOLARIS_THREADS)
 529         GC_thr_init();
 530 #   endif
 531 #   ifdef GC_SOLARIS_THREADS
 532         /* We need dirty bits in order to find live stack sections.     */
 533         GC_dirty_init();
 534 #   endif
 535 #   if !defined(THREADS) || defined(GC_PTHREADS) || defined(GC_WIN32_THREADS) \
 536         || defined(GC_SOLARIS_THREADS)
 537       if (GC_stackbottom == 0) {
 538         GC_stackbottom = GC_get_stack_base();
 539 #       if defined(LINUX) && defined(IA64)
 540           GC_register_stackbottom = GC_get_register_stack_base();
 541 #       endif
 542       }
 543 #   endif
 544     GC_ASSERT(sizeof (ptr_t) == sizeof(word));
 545     GC_ASSERT(sizeof (signed_word) == sizeof(word));
 546     GC_ASSERT(sizeof (struct hblk) == HBLKSIZE);
 547 #   ifndef THREADS
 548 #     if defined(STACK_GROWS_UP) && defined(STACK_GROWS_DOWN)
 549         ABORT(
 550           "Only one of STACK_GROWS_UP and STACK_GROWS_DOWN should be defd\n");
 551 #     endif
 552 #     if !defined(STACK_GROWS_UP) && !defined(STACK_GROWS_DOWN)
 553         ABORT(
 554           "One of STACK_GROWS_UP and STACK_GROWS_DOWN should be defd\n");
 555 #     endif
 556 #     ifdef STACK_GROWS_DOWN
 557         GC_ASSERT((word)(&dummy) <= (word)GC_stackbottom);
 558 #     else
 559         GC_ASSERT((word)(&dummy) >= (word)GC_stackbottom);
 560 #     endif
 561 #   endif
 562 #   if !defined(_AUX_SOURCE) || defined(__GNUC__)
 563       GC_ASSERT((word)(-1) > (word)0);
 564       /* word should be unsigned */
 565 #   endif
 566     GC_ASSERT((signed_word)(-1) < (signed_word)0);
 567
 568     /* Add initial guess of root sets.  Do this first, since sbrk(0)    */
 569     /* might be used.                                                   */
 570       GC_register_data_segments();
 571     GC_init_headers();
 572     GC_bl_init();
 573     GC_mark_init();
 574     {
 575         char * sz_str = GETENV("GC_INITIAL_HEAP_SIZE");
 576         if (sz_str != NULL) {
 577           initial_heap_sz = atoi(sz_str);
 578           if (initial_heap_sz <= MINHINCR * HBLKSIZE) {
 579             WARN("Bad initial heap size %s - ignoring it.\n",
 580                  sz_str);
 581           }
 582           initial_heap_sz = divHBLKSZ(initial_heap_sz);
 583         }
 584     }
 585     if (!GC_expand_hp_inner(initial_heap_sz)) {
 586         GC_err_printf0("Can't start up: not enough memory\n");
 587         EXIT();
 588     }
 589     /* Preallocate large object map.  It's otherwise inconvenient to    */
 590     /* deal with failure.                                               */
 591       if (!GC_add_map_entry((word)0)) {
 592         GC_err_printf0("Can't start up: not enough memory\n");
 593         EXIT();
 594       }
 595     GC_register_displacement_inner(0L);
 596 #   ifdef MERGE_SIZES
 597       GC_init_size_map();
 598 #   endif
 599 #   ifdef PCR
 600       if (PCR_IL_Lock(PCR_Bool_false, PCR_allSigsBlocked, PCR_waitForever)
 601           != PCR_ERes_okay) {
 602           ABORT("Can't lock load state\n");
 603       } else if (PCR_IL_Unlock() != PCR_ERes_okay) {
 604           ABORT("Can't unlock load state\n");
 605       }
 606       PCR_IL_Unlock();
 607       GC_pcr_install();
 608 #   endif
 609     /* Get black list set up */
 610       if (!GC_dont_precollect) GC_gcollect_inner();
 611     GC_is_initialized = TRUE;
 612 #   ifdef STUBBORN_ALLOC
 613         GC_stubborn_init();
 614 #   endif
 615     /* Convince lint that some things are used */
 616 #   ifdef LINT
 617       {
 618           extern char * GC_copyright[];
 619           extern int GC_read();
 620           extern void GC_register_finalizer_no_order();
 621
 622           GC_noop(GC_copyright, GC_find_header,
 623                   GC_push_one, GC_call_with_alloc_lock, GC_read,
 624                   GC_dont_expand,
 625 #                 ifndef NO_DEBUGGING
 626                     GC_dump,
 627 #                 endif
 628                   GC_register_finalizer_no_order);
 629       }
 630 #   endif
 631 }
 632
 633 void GC_enable_incremental GC_PROTO(())
 634 {
 635 # if !defined(SMALL_CONFIG)
 636   if (!GC_find_leak) {
 637     DCL_LOCK_STATE;
 638
 639     DISABLE_SIGNALS();
 640     LOCK();
 641     if (GC_incremental) goto out;
 642     GC_setpagesize();
 643 #   ifdef MSWIN32
 644       {
 645         extern GC_bool GC_is_win32s();
 646
 647         /* VirtualProtect is not functional under win32s.       */
 648         if (GC_is_win32s()) goto out;
 649       }
 650 #   endif /* MSWIN32 */
 651 #   ifndef GC_SOLARIS_THREADS
 652         GC_dirty_init();
 653 #   endif
 654     if (!GC_is_initialized) {
 655         GC_init_inner();
 656     }
 657     if (GC_dont_gc) {
 658         /* Can't easily do it. */
 659         UNLOCK();
 660         ENABLE_SIGNALS();
 661         return;
 662     }
 663     if (GC_words_allocd > 0) {
 664         /* There may be unmarked reachable objects      */
 665         GC_gcollect_inner();
 666     }   /* else we're OK in assuming everything's       */
 667         /* clean since nothing can point to an          */
 668         /* unmarked object.                             */
 669     GC_read_dirty();
 670     GC_incremental = TRUE;
 671 out:
 672     UNLOCK();
 673     ENABLE_SIGNALS();
 674   }
 675 # endif
 676 }
 677
 678
 679 #if defined(MSWIN32) || defined(MSWINCE)
 680 # define LOG_FILE _T("gc.log")
 681
 682   HANDLE GC_stdout = 0;
 683
 684   void GC_deinit()
 685   {
 686       if (GC_is_initialized) {
 687         DeleteCriticalSection(&GC_write_cs);
 688       }
 689   }
 690
 691   int GC_write(buf, len)
 692   GC_CONST char * buf;
 693   size_t len;
 694   {
 695       BOOL tmp;
 696       DWORD written;
 697       if (len == 0)
 698           return 0;
 699       EnterCriticalSection(&GC_write_cs);
 700       if (GC_stdout == INVALID_HANDLE_VALUE) {
 701           return -1;
 702       } else if (GC_stdout == 0) {
 703           GC_stdout = CreateFile(LOG_FILE, GENERIC_WRITE,
 704                                  FILE_SHARE_READ | FILE_SHARE_WRITE,
 705                                  NULL, CREATE_ALWAYS, FILE_FLAG_WRITE_THROUGH,
 706                                  NULL);
 707           if (GC_stdout == INVALID_HANDLE_VALUE) ABORT("Open of log file failed");
 708       }
 709       tmp = WriteFile(GC_stdout, buf, len, &written, NULL);
 710       if (!tmp)
 711           DebugBreak();
 712       LeaveCriticalSection(&GC_write_cs);
 713       return tmp ? (int)written : -1;
 714   }
 715
 716 #endif
 717
 718 #if defined(OS2) || defined(MACOS)
 719 FILE * GC_stdout = NULL;
 720 FILE * GC_stderr = NULL;
 721 int GC_tmp;  /* Should really be local ... */
 722
 723   void GC_set_files()
 724   {
 725       if (GC_stdout == NULL) {
 726         GC_stdout = stdout;
 727     }
 728     if (GC_stderr == NULL) {
 729         GC_stderr = stderr;
 730     }
 731   }
 732 #endif
 733
 734 #if !defined(OS2) && !defined(MACOS) && !defined(MSWIN32) && !defined(MSWINCE)
 735   int GC_stdout = 1;
 736   int GC_stderr = 2;
 737 # if !defined(__AMIGAOS__)
 738 #   include <unistd.h>
 739 # endif
 740 #endif
 741
 742 #if !defined(MSWIN32) && !defined(MSWINCE) && !defined(OS2) && !defined(MACOS)
 743 int GC_write(fd, buf, len)
 744 int fd;
 745 GC_CONST char *buf;
 746 size_t len;
 747 {
 748      register int bytes_written = 0;
 749      register int result;
 750
 751      while (bytes_written < len) {
 752 #       ifdef GC_SOLARIS_THREADS
 753             result = syscall(SYS_write, fd, buf + bytes_written,
 754                                             len - bytes_written);
 755 #       else
 756             result = write(fd, buf + bytes_written, len - bytes_written);
 757 #       endif
 758         if (-1 == result) return(result);
 759         bytes_written += result;
 760     }
 761     return(bytes_written);
 762 }
 763 #endif /* UN*X */
 764
 765 #if defined(ECOS)
 766 int GC_write(fd, buf, len)
 767 {
 768   _Jv_diag_write (buf, len);
 769   return len;
 770 }
 771 #endif
 772
 773
 774 #if defined(MSWIN32) || defined(MSWINCE)
 775 #   define WRITE(f, buf, len) GC_write(buf, len)
 776 #else
 777 #   if defined(OS2) || defined(MACOS)
 778 #   define WRITE(f, buf, len) (GC_set_files(), \
 779                                GC_tmp = fwrite((buf), 1, (len), (f)), \
 780                                fflush(f), GC_tmp)
 781 #   else
 782 #     define WRITE(f, buf, len) GC_write((f), (buf), (len))
 783 #   endif
 784 #endif
 785
 786 /* A version of printf that is unlikely to call malloc, and is thus safer */
 787 /* to call from the collector in case malloc has been bound to GC_malloc. */
 788 /* Assumes that no more than 1023 characters are written at once.         */
 789 /* Assumes that all arguments have been converted to something of the     */
 790 /* same size as long, and that the format conversions expect something    */
 791 /* of that size.                                                          */
 792 void GC_printf(format, a, b, c, d, e, f)
 793 GC_CONST char * format;
 794 long a, b, c, d, e, f;
 795 {
 796     char buf[1025];
 797
 798     if (GC_quiet) return;
 799     buf[1024] = 0x15;
 800     (void) sprintf(buf, format, a, b, c, d, e, f);
 801     if (buf[1024] != 0x15) ABORT("GC_printf clobbered stack");
 802     if (WRITE(GC_stdout, buf, strlen(buf)) < 0) ABORT("write to stdout failed");
 803 }
 804
 805 void GC_err_printf(format, a, b, c, d, e, f)
 806 GC_CONST char * format;
 807 long a, b, c, d, e, f;
 808 {
 809     char buf[1025];
 810
 811     buf[1024] = 0x15;
 812     (void) sprintf(buf, format, a, b, c, d, e, f);
 813     if (buf[1024] != 0x15) ABORT("GC_err_printf clobbered stack");
 814     if (WRITE(GC_stderr, buf, strlen(buf)) < 0) ABORT("write to stderr failed");
 815 }
 816
 817 void GC_err_puts(s)
 818 GC_CONST char *s;
 819 {
 820     if (WRITE(GC_stderr, s, strlen(s)) < 0) ABORT("write to stderr failed");
 821 }
 822
 823 #if defined(LINUX) && !defined(SMALL_CONFIG)
 824 void GC_err_write(buf, len)
 825 GC_CONST char *buf;
 826 size_t len;
 827 {
 828     if (WRITE(GC_stderr, buf, len) < 0) ABORT("write to stderr failed");
 829 }
 830 #endif
 831
 832 # if defined(__STDC__) || defined(__cplusplus)
 833     void GC_default_warn_proc(char *msg, GC_word arg)
 834 # else
 835     void GC_default_warn_proc(msg, arg)
 836     char *msg;
 837     GC_word arg;
 838 # endif
 839 {
 840     GC_err_printf1(msg, (unsigned long)arg);
 841 }
 842
 843 GC_warn_proc GC_current_warn_proc = GC_default_warn_proc;
 844
 845 # if defined(__STDC__) || defined(__cplusplus)
 846     GC_warn_proc GC_set_warn_proc(GC_warn_proc p)
 847 # else
 848     GC_warn_proc GC_set_warn_proc(p)
 849     GC_warn_proc p;
 850 # endif
 851 {
 852     GC_warn_proc result;
 853
 854     LOCK();
 855     result = GC_current_warn_proc;
 856     GC_current_warn_proc = p;
 857     UNLOCK();
 858     return(result);
 859 }
 860
 861
 862 #ifndef PCR
 863 void GC_abort(msg)
 864 GC_CONST char * msg;
 865 {
 866 #   if defined(MSWIN32)
 867       (void) MessageBoxA(NULL, msg, "Fatal error in gc", MB_ICONERROR|MB_OK);
 868       DebugBreak();
 869 #   else
 870       GC_err_printf1("%s\n", msg);
 871 #   endif
 872     if (GETENV("GC_LOOP_ON_ABORT") != NULL) {
 873             /* In many cases it's easier to debug a running process.    */
 874             /* It's arguably nicer to sleep, but that makes it harder   */
 875             /* to look at the thread if the debugger doesn't know much  */
 876             /* about threads.                                           */
 877             for(;;) {}
 878     }
 879 #   ifdef MSWIN32
 880         DebugBreak();
 881 #   else
 882         (void) abort();
 883 #   endif
 884 }
 885 #endif
 886
 887 #ifdef NEED_CALLINFO
 888
 889 void GC_print_callers (info)
 890 struct callinfo info[NFRAMES];
 891 {
 892     register int i;
 893
 894 #   if NFRAMES == 1
 895       GC_err_printf0("\tCaller at allocation:\n");
 896 #   else
 897       GC_err_printf0("\tCall chain at allocation:\n");
 898 #   endif
 899     for (i = 0; i < NFRAMES; i++) {
 900         if (info[i].ci_pc == 0) break;
 901 #       if NARGS > 0
 902         {
 903           int j;
 904
 905           GC_err_printf0("\t\targs: ");
 906           for (j = 0; j < NARGS; j++) {
 907             if (j != 0) GC_err_printf0(", ");
 908             GC_err_printf2("%d (0x%X)", ~(info[i].ci_arg[j]),
 909                                         ~(info[i].ci_arg[j]));
 910           }
 911           GC_err_printf0("\n");
 912         }
 913 #       endif
 914         GC_err_printf1("\t\t##PC##= 0x%X\n", info[i].ci_pc);
 915     }
 916 }
 917
 918 #endif /* SAVE_CALL_CHAIN */
 919
 920 /* Needed by SRC_M3, gcj, and should perhaps be the official interface  */
 921 /* to GC_dont_gc.                                                       */
 922 void GC_enable()
 923 {
 924     GC_dont_gc--;
 925 }
 926
 927 void GC_disable()
 928 {
 929     GC_dont_gc++;
 930 }
 931
 932 #if !defined(NO_DEBUGGING)
 933
 934 void GC_dump()
 935 {
 936     GC_printf0("***Static roots:\n");
 937     GC_print_static_roots();
 938     GC_printf0("\n***Heap sections:\n");
 939     GC_print_heap_sects();
 940     GC_printf0("\n***Free blocks:\n");
 941     GC_print_hblkfreelist();
 942     GC_printf0("\n***Blocks in use:\n");
 943     GC_print_block_list();
 944 }
 945
 946 #endif /* NO_DEBUGGING */