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