boehm-gc/include/gc.h

   1 /*
   2  * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
   3  * Copyright (c) 1991-1995 by Xerox Corporation.  All rights reserved.
   4  * Copyright 1996-1999 by Silicon Graphics.  All rights reserved.
   5  * Copyright 1999 by Hewlett-Packard Company.  All rights reserved.
   6  *
   7  * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
   8  * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
   9  *
  10  * Permission is hereby granted to use or copy this program
  11  * for any purpose,  provided the above notices are retained on all copies.
  12  * Permission to modify the code and to distribute modified code is granted,
  13  * provided the above notices are retained, and a notice that the code was
  14  * modified is included with the above copyright notice.
  15  */
  16
  17 /*
  18  * Note that this defines a large number of tuning hooks, which can
  19  * safely be ignored in nearly all cases.  For normal use it suffices
  20  * to call only GC_MALLOC and perhaps GC_REALLOC.
  21  * For better performance, also look at GC_MALLOC_ATOMIC, and
  22  * GC_enable_incremental.  If you need an action to be performed
  23  * immediately before an object is collected, look at GC_register_finalizer.
  24  * If you are using Solaris threads, look at the end of this file.
  25  * Everything else is best ignored unless you encounter performance
  26  * problems.
  27  */
  28
  29 #ifndef _GC_H
  30
  31 # define _GC_H
  32
  33 /*
  34  * Some tests for old macros.  These violate our namespace rules and will
  35  * disappear shortly.  Use the GC_ names.
  36  */
  37 #if defined(SOLARIS_THREADS) || defined(_SOLARIS_THREADS)
  38 # define GC_SOLARIS_THREADS
  39 #endif
  40 #if defined(_SOLARIS_PTHREADS)
  41 # define GC_SOLARIS_PTHREADS
  42 #endif
  43 #if defined(IRIX_THREADS)
  44 # define GC_IRIX_THREADS
  45 #endif
  46 #if defined(HPUX_THREADS)
  47 # define GC_HPUX_THREADS
  48 #endif
  49 #if defined(OSF1_THREADS)
  50 # define GC_OSF1_THREADS
  51 #endif
  52 #if defined(LINUX_THREADS)
  53 # define GC_LINUX_THREADS
  54 #endif
  55 #if defined(WIN32_THREADS)
  56 # define GC_WIN32_THREADS
  57 #endif
  58 #if defined(USE_LD_WRAP)
  59 # define GC_USE_LD_WRAP
  60 #endif
  61
  62 #if !defined(_REENTRANT) && (defined(GC_SOLARIS_THREADS) \
  63                              || defined(GC_SOLARIS_PTHREADS) \
  64                              || defined(GC_HPUX_THREADS) \
  65                              || defined(GC_LINUX_THREADS))
  66 # define _REENTRANT
  67         /* Better late than never.  This fails if system headers that   */
  68         /* depend on this were previously included.                     */
  69 #endif
  70
  71 #if defined(GC_SOLARIS_PTHREADS) && !defined(GC_SOLARIS_THREADS)
  72 #   define GC_SOLARIS_THREADS
  73 #endif
  74
  75 # if defined(GC_SOLARIS_PTHREADS) || defined(GC_FREEBSD_THREADS) || \
  76         defined(GC_IRIX_THREADS) || defined(GC_LINUX_THREADS) || \
  77         defined(GC_HPUX_THREADS) || defined(GC_OSF1_THREADS)
  78 #   define GC_PTHREADS
  79 # endif
  80
  81 # define __GC
  82 # include <stddef.h>
  83 # ifdef _WIN32_WCE
  84 /* Yet more kluges for WinCE */
  85 #   include <stdlib.h>          /* size_t is defined here */
  86     typedef long ptrdiff_t;     /* ptrdiff_t is not defined */
  87 # endif
  88
  89 #if defined(__MINGW32__) &&defined(_DLL) && !defined(GC_NOT_DLL)
  90 # ifdef GC_BUILD
  91 #   define GC_API __declspec(dllexport)
  92 # else
  93 #   define GC_API __declspec(dllimport)
  94 # endif
  95 #endif
  96
  97 #if (defined(__DMC__) || defined(_MSC_VER)) \
  98                 && (defined(_DLL) && !defined(GC_NOT_DLL) \
  99                     || defined(GC_DLL))
 100 # ifdef GC_BUILD
 101 #   define GC_API extern __declspec(dllexport)
 102 # else
 103 #   define GC_API __declspec(dllimport)
 104 # endif
 105 #endif
 106
 107 #if defined(__WATCOMC__) && defined(GC_DLL)
 108 # ifdef GC_BUILD
 109 #   define GC_API extern __declspec(dllexport)
 110 # else
 111 #   define GC_API extern __declspec(dllimport)
 112 # endif
 113 #endif
 114
 115 #ifndef GC_API
 116 #define GC_API extern
 117 #endif
 118
 119 # if defined(__STDC__) || defined(__cplusplus)
 120 #   define GC_PROTO(args) args
 121     typedef void * GC_PTR;
 122 #   define GC_CONST const
 123 # else
 124 #   define GC_PROTO(args) ()
 125     typedef char * GC_PTR;
 126 #   define GC_CONST
 127 #  endif
 128
 129 # ifdef __cplusplus
 130     extern "C" {
 131 # endif
 132
 133
 134 /* Define word and signed_word to be unsigned and signed types of the   */
 135 /* size as char * or void *.  There seems to be no way to do this       */
 136 /* even semi-portably.  The following is probably no better/worse       */
 137 /* than almost anything else.                                           */
 138 /* The ANSI standard suggests that size_t and ptr_diff_t might be       */
 139 /* better choices.  But those appear to have incorrect definitions      */
 140 /* on may systems.  Notably "typedef int size_t" seems to be both       */
 141 /* frequent and WRONG.                                                  */
 142 typedef unsigned long GC_word;
 143 typedef long GC_signed_word;
 144
 145 /* Public read-only variables */
 146
 147 GC_API GC_word GC_gc_no;/* Counter incremented per collection.          */
 148                         /* Includes empty GCs at startup.               */
 149
 150 GC_API int GC_parallel; /* GC is parallelized for performance on        */
 151                         /* multiprocessors.  Currently set only         */
 152                         /* implicitly if collector is built with        */
 153                         /* -DPARALLEL_MARK and if either:               */
 154                         /*  Env variable GC_NPROC is set to > 1, or     */
 155                         /*  GC_NPROC is not set and this is an MP.      */
 156                         /* If GC_parallel is set, incremental           */
 157                         /* collection is aonly partially functional,    */
 158                         /* and may not be desirable.                    */
 159
 160
 161 /* Public R/W variables */
 162
 163 GC_API GC_PTR (*GC_oom_fn) GC_PROTO((size_t bytes_requested));
 164                         /* When there is insufficient memory to satisfy */
 165                         /* an allocation request, we return             */
 166                         /* (*GC_oom_fn)().  By default this just        */
 167                         /* returns 0.                                   */
 168                         /* If it returns, it must return 0 or a valid   */
 169                         /* pointer to a previously allocated heap       */
 170                         /* object.                                      */
 171
 172 GC_API int GC_find_leak;
 173                         /* Do not actually garbage collect, but simply  */
 174                         /* report inaccessible memory that was not      */
 175                         /* deallocated with GC_free.  Initial value     */
 176                         /* is determined by FIND_LEAK macro.            */
 177
 178 GC_API int GC_all_interior_pointers;
 179                         /* Arrange for pointers to object interiors to  */
 180                         /* be recognized as valid.  May not be changed  */
 181                         /* after GC initialization.                     */
 182                         /* Initial value is determined by               */
 183                         /* -DALL_INTERIOR_POINTERS.                     */
 184                         /* Unless DONT_ADD_BYTE_AT_END is defined, this */
 185                         /* also affects whether sizes are increased by  */
 186                         /* at least a byte to allow "off the end"       */
 187                         /* pointer recognition.                         */
 188                         /* MUST BE 0 or 1.                              */
 189
 190 GC_API int GC_quiet;    /* Disable statistics output.  Only matters if  */
 191                         /* collector has been compiled with statistics  */
 192                         /* enabled.  This involves a performance cost,  */
 193                         /* and is thus not the default.                 */
 194
 195 GC_API int GC_finalize_on_demand;
 196                         /* If nonzero, finalizers will only be run in   */
 197                         /* response to an explicit GC_invoke_finalizers */
 198                         /* call.  The default is determined by whether  */
 199                         /* the FINALIZE_ON_DEMAND macro is defined      */
 200                         /* when the collector is built.                 */
 201
 202 GC_API int GC_java_finalization;
 203                         /* Mark objects reachable from finalizable      */
 204                         /* objects in a separate postpass.  This makes  */
 205                         /* it a bit safer to use non-topologically-     */
 206                         /* ordered finalization.  Default value is      */
 207                         /* determined by JAVA_FINALIZATION macro.       */
 208
 209 GC_API void (* GC_finalizer_notifier)();
 210                         /* Invoked by the collector when there are      */
 211                         /* objects to be finalized.  Invoked at most    */
 212                         /* once per GC cycle.  Never invoked unless     */
 213                         /* GC_finalize_on_demand is set.                */
 214                         /* Typically this will notify a finalization    */
 215                         /* thread, which will call GC_invoke_finalizers */
 216                         /* in response.                                 */
 217
 218 GC_API int GC_dont_gc;  /* Dont collect unless explicitly requested, e.g. */
 219                         /* because it's not safe.                         */
 220
 221 GC_API int GC_dont_expand;
 222                         /* Dont expand heap unless explicitly requested */
 223                         /* or forced to.                                */
 224
 225 GC_API int GC_use_entire_heap;
 226                 /* Causes the nonincremental collector to use the       */
 227                 /* entire heap before collecting.  This was the only    */
 228                 /* option for GC versions < 5.0.  This sometimes        */
 229                 /* results in more large block fragmentation, since     */
 230                 /* very larg blocks will tend to get broken up          */
 231                 /* during each GC cycle.  It is likely to result in a   */
 232                 /* larger working set, but lower collection             */
 233                 /* frequencies, and hence fewer instructions executed   */
 234                 /* in the collector.                                    */
 235
 236 GC_API int GC_full_freq;    /* Number of partial collections between    */
 237                             /* full collections.  Matters only if       */
 238                             /* GC_incremental is set.                   */
 239                             /* Full collections are also triggered if   */
 240                             /* the collector detects a substantial      */
 241                             /* increase in the number of in-use heap    */
 242                             /* blocks.  Values in the tens are now      */
 243                             /* perfectly reasonable, unlike for         */
 244                             /* earlier GC versions.                     */
 245
 246 GC_API GC_word GC_non_gc_bytes;
 247                         /* Bytes not considered candidates for collection. */
 248                         /* Used only to control scheduling of collections. */
 249                         /* Updated by GC_malloc_uncollectable and GC_free. */
 250                         /* Wizards only.                                   */
 251
 252 GC_API int GC_no_dls;
 253                         /* Don't register dynamic library data segments. */
 254                         /* Wizards only.  Should be used only if the     */
 255                         /* application explicitly registers all roots.   */
 256                         /* In Microsoft Windows environments, this will  */
 257                         /* usually also prevent registration of the      */
 258                         /* main data segment as part of the root set.    */
 259
 260 GC_API GC_word GC_free_space_divisor;
 261                         /* We try to make sure that we allocate at      */
 262                         /* least N/GC_free_space_divisor bytes between  */
 263                         /* collections, where N is the heap size plus   */
 264                         /* a rough estimate of the root set size.       */
 265                         /* Initially, GC_free_space_divisor = 4.        */
 266                         /* Increasing its value will use less space     */
 267                         /* but more collection time.  Decreasing it     */
 268                         /* will appreciably decrease collection time    */
 269                         /* at the expense of space.                     */
 270                         /* GC_free_space_divisor = 1 will effectively   */
 271                         /* disable collections.                         */
 272
 273 GC_API GC_word GC_max_retries;
 274                         /* The maximum number of GCs attempted before   */
 275                         /* reporting out of memory after heap           */
 276                         /* expansion fails.  Initially 0.               */
 277
 278
 279 GC_API char *GC_stackbottom;    /* Cool end of user stack.              */
 280                                 /* May be set in the client prior to    */
 281                                 /* calling any GC_ routines.  This      */
 282                                 /* avoids some overhead, and            */
 283                                 /* potentially some signals that can    */
 284                                 /* confuse debuggers.  Otherwise the    */
 285                                 /* collector attempts to set it         */
 286                                 /* automatically.                       */
 287                                 /* For multithreaded code, this is the  */
 288                                 /* cold end of the stack for the        */
 289                                 /* primordial thread.                   */
 290
 291 GC_API int GC_dont_precollect;  /* Don't collect as part of             */
 292                                 /* initialization.  Should be set only  */
 293                                 /* if the client wants a chance to      */
 294                                 /* manually initialize the root set     */
 295                                 /* before the first collection.         */
 296                                 /* Interferes with blacklisting.        */
 297                                 /* Wizards only.                        */
 298
 299 /* Public procedures */
 300
 301 /* Initialize the collector.  This is only required when using thread-local
 302  * allocation, since unlike the regular allocation routines, GC_local_malloc
 303  * is not self-initializing.  If you use GC_local_malloc you should arrange
 304  * to call this somehow (e.g. from a constructor) before doing any allocation.
 305  */
 306 GC_API void GC_init GC_PROTO((void));
 307
 308 GC_API unsigned long GC_time_limit;
 309                                 /* If incremental collection is enabled, */
 310                                 /* We try to terminate collections       */
 311                                 /* after this many milliseconds.  Not a  */
 312                                 /* hard time bound.  Setting this to     */
 313                                 /* GC_TIME_UNLIMITED will essentially    */
 314                                 /* disable incremental collection while  */
 315                                 /* leaving generational collection       */
 316                                 /* enabled.                              */
 317 #       define GC_TIME_UNLIMITED 999999
 318                                 /* Setting GC_time_limit to this value   */
 319                                 /* will disable the "pause time exceeded */
 320                                 /* tests.                                */
 321
 322 /*
 323  * general purpose allocation routines, with roughly malloc calling conv.
 324  * The atomic versions promise that no relevant pointers are contained
 325  * in the object.  The nonatomic versions guarantee that the new object
 326  * is cleared.  GC_malloc_stubborn promises that no changes to the object
 327  * will occur after GC_end_stubborn_change has been called on the
 328  * result of GC_malloc_stubborn. GC_malloc_uncollectable allocates an object
 329  * that is scanned for pointers to collectable objects, but is not itself
 330  * collectable.  The object is scanned even if it does not appear to
 331  * be reachable.  GC_malloc_uncollectable and GC_free called on the resulting
 332  * object implicitly update GC_non_gc_bytes appropriately.
 333  *
 334  * Note that the GC_malloc_stubborn support is stubbed out by default
 335  * starting in 6.0.  GC_malloc_stubborn is an alias for GC_malloc unless
 336  * the collector is built with STUBBORN_ALLOC defined.
 337  */
 338 GC_API GC_PTR GC_malloc GC_PROTO((size_t size_in_bytes));
 339 GC_API GC_PTR GC_malloc_atomic GC_PROTO((size_t size_in_bytes));
 340 GC_API GC_PTR GC_malloc_uncollectable GC_PROTO((size_t size_in_bytes));
 341 GC_API GC_PTR GC_malloc_stubborn GC_PROTO((size_t size_in_bytes));
 342
 343 /* The following is only defined if the library has been suitably       */
 344 /* compiled:                                                            */
 345 GC_API GC_PTR GC_malloc_atomic_uncollectable GC_PROTO((size_t size_in_bytes));
 346
 347 /* Explicitly deallocate an object.  Dangerous if used incorrectly.     */
 348 /* Requires a pointer to the base of an object.                         */
 349 /* If the argument is stubborn, it should not be changeable when freed. */
 350 /* An object should not be enable for finalization when it is           */
 351 /* explicitly deallocated.                                              */
 352 /* GC_free(0) is a no-op, as required by ANSI C for free.               */
 353 GC_API void GC_free GC_PROTO((GC_PTR object_addr));
 354
 355 /*
 356  * Stubborn objects may be changed only if the collector is explicitly informed.
 357  * The collector is implicitly informed of coming change when such
 358  * an object is first allocated.  The following routines inform the
 359  * collector that an object will no longer be changed, or that it will
 360  * once again be changed.  Only nonNIL pointer stores into the object
 361  * are considered to be changes.  The argument to GC_end_stubborn_change
 362  * must be exacly the value returned by GC_malloc_stubborn or passed to
 363  * GC_change_stubborn.  (In the second case it may be an interior pointer
 364  * within 512 bytes of the beginning of the objects.)
 365  * There is a performance penalty for allowing more than
 366  * one stubborn object to be changed at once, but it is acceptable to
 367  * do so.  The same applies to dropping stubborn objects that are still
 368  * changeable.
 369  */
 370 GC_API void GC_change_stubborn GC_PROTO((GC_PTR));
 371 GC_API void GC_end_stubborn_change GC_PROTO((GC_PTR));
 372
 373 /* Return a pointer to the base (lowest address) of an object given     */
 374 /* a pointer to a location within the object.                           */
 375 /* I.e. map an interior pointer to the corresponding bas pointer.       */
 376 /* Note that with debugging allocation, this returns a pointer to the   */
 377 /* actual base of the object, i.e. the debug information, not to        */
 378 /* the base of the user object.                                         */
 379 /* Return 0 if displaced_pointer doesn't point to within a valid        */
 380 /* object.                                                              */
 381 GC_API GC_PTR GC_base GC_PROTO((GC_PTR displaced_pointer));
 382
 383 /* Given a pointer to the base of an object, return its size in bytes.  */
 384 /* The returned size may be slightly larger than what was originally    */
 385 /* requested.                                                           */
 386 GC_API size_t GC_size GC_PROTO((GC_PTR object_addr));
 387
 388 /* For compatibility with C library.  This is occasionally faster than  */
 389 /* a malloc followed by a bcopy.  But if you rely on that, either here  */
 390 /* or with the standard C library, your code is broken.  In my          */
 391 /* opinion, it shouldn't have been invented, but now we're stuck. -HB   */
 392 /* The resulting object has the same kind as the original.              */
 393 /* If the argument is stubborn, the result will have changes enabled.   */
 394 /* It is an error to have changes enabled for the original object.      */
 395 /* Follows ANSI comventions for NULL old_object.                        */
 396 GC_API GC_PTR GC_realloc
 397         GC_PROTO((GC_PTR old_object, size_t new_size_in_bytes));
 398
 399 /* Explicitly increase the heap size.   */
 400 /* Returns 0 on failure, 1 on success.  */
 401 GC_API int GC_expand_hp GC_PROTO((size_t number_of_bytes));
 402
 403 /* Limit the heap size to n bytes.  Useful when you're debugging,       */
 404 /* especially on systems that don't handle running out of memory well.  */
 405 /* n == 0 ==> unbounded.  This is the default.                          */
 406 GC_API void GC_set_max_heap_size GC_PROTO((GC_word n));
 407
 408 /* Inform the collector that a certain section of statically allocated  */
 409 /* memory contains no pointers to garbage collected memory.  Thus it    */
 410 /* need not be scanned.  This is sometimes important if the application */
 411 /* maps large read/write files into the address space, which could be   */
 412 /* mistaken for dynamic library data segments on some systems.          */
 413 GC_API void GC_exclude_static_roots GC_PROTO((GC_PTR start, GC_PTR finish));
 414
 415 /* Clear the set of root segments.  Wizards only. */
 416 GC_API void GC_clear_roots GC_PROTO((void));
 417
 418 /* Add a root segment.  Wizards only. */
 419 GC_API void GC_add_roots GC_PROTO((char * low_address,
 420                                    char * high_address_plus_1));
 421
 422 /* Add a displacement to the set of those considered valid by the       */
 423 /* collector.  GC_register_displacement(n) means that if p was returned */
 424 /* by GC_malloc, then (char *)p + n will be considered to be a valid    */
 425 /* pointer to n.  N must be small and less than the size of p.          */
 426 /* (All pointers to the interior of objects from the stack are          */
 427 /* considered valid in any case.  This applies to heap objects and      */
 428 /* static data.)                                                        */
 429 /* Preferably, this should be called before any other GC procedures.    */
 430 /* Calling it later adds to the probability of excess memory            */
 431 /* retention.                                                           */
 432 /* This is a no-op if the collector was compiled with recognition of    */
 433 /* arbitrary interior pointers enabled, which is now the default.       */
 434 GC_API void GC_register_displacement GC_PROTO((GC_word n));
 435
 436 /* The following version should be used if any debugging allocation is  */
 437 /* being done.                                                          */
 438 GC_API void GC_debug_register_displacement GC_PROTO((GC_word n));
 439
 440 /* Explicitly trigger a full, world-stop collection.    */
 441 GC_API void GC_gcollect GC_PROTO((void));
 442
 443 /* Trigger a full world-stopped collection.  Abort the collection if    */
 444 /* and when stop_func returns a nonzero value.  Stop_func will be       */
 445 /* called frequently, and should be reasonably fast.  This works even   */
 446 /* if virtual dirty bits, and hence incremental collection is not       */
 447 /* available for this architecture.  Collections can be aborted faster  */
 448 /* than normal pause times for incremental collection.  However,        */
 449 /* aborted collections do no useful work; the next collection needs     */
 450 /* to start from the beginning.                                         */
 451 /* Return 0 if the collection was aborted, 1 if it succeeded.           */
 452 typedef int (* GC_stop_func) GC_PROTO((void));
 453 GC_API int GC_try_to_collect GC_PROTO((GC_stop_func stop_func));
 454
 455 /* Return the number of bytes in the heap.  Excludes collector private  */
 456 /* data structures.  Includes empty blocks and fragmentation loss.      */
 457 /* Includes some pages that were allocated but never written.           */
 458 GC_API size_t GC_get_heap_size GC_PROTO((void));
 459
 460 /* Return a lower bound on the number of free bytes in the heap.        */
 461 GC_API size_t GC_get_free_bytes GC_PROTO((void));
 462
 463 /* Return the number of bytes allocated since the last collection.      */
 464 GC_API size_t GC_get_bytes_since_gc GC_PROTO((void));
 465
 466 /* Return the total number of bytes allocated in this process.          */
 467 /* Never decreases.                                                     */
 468 GC_API size_t GC_get_total_bytes GC_PROTO((void));
 469
 470 /* Enable incremental/generational collection.  */
 471 /* Not advisable unless dirty bits are          */
 472 /* available or most heap objects are           */
 473 /* pointerfree(atomic) or immutable.            */
 474 /* Don't use in leak finding mode.              */
 475 /* Ignored if GC_dont_gc is true.               */
 476 /* Only the generational piece of this is       */
 477 /* functional if GC_parallel is TRUE.           */
 478 GC_API void GC_enable_incremental GC_PROTO((void));
 479
 480 /* Does incremental mode write-protect pages?  Returns zero or  */
 481 /* more of the following, or'ed together:                       */
 482 #define GC_PROTECTS_POINTER_HEAP  1 /* May protect non-atomic objs.     */
 483 #define GC_PROTECTS_PTRFREE_HEAP  2
 484 #define GC_PROTECTS_STATIC_DATA   4 /* Curently never.                  */
 485 #define GC_PROTECTS_STACK         8 /* Probably impractical.            */
 486
 487 #define GC_PROTECTS_NONE 0
 488 GC_API int GC_incremental_protection_needs GC_PROTO((void));
 489
 490 /* Perform some garbage collection work, if appropriate.        */
 491 /* Return 0 if there is no more work to be done.                */
 492 /* Typically performs an amount of work corresponding roughly   */
 493 /* to marking from one page.  May do more work if further       */
 494 /* progress requires it, e.g. if incremental collection is      */
 495 /* disabled.  It is reasonable to call this in a wait loop      */
 496 /* until it returns 0.                                          */
 497 GC_API int GC_collect_a_little GC_PROTO((void));
 498
 499 /* Allocate an object of size lb bytes.  The client guarantees that     */
 500 /* as long as the object is live, it will be referenced by a pointer    */
 501 /* that points to somewhere within the first 256 bytes of the object.   */
 502 /* (This should normally be declared volatile to prevent the compiler   */
 503 /* from invalidating this assertion.)  This routine is only useful      */
 504 /* if a large array is being allocated.  It reduces the chance of       */
 505 /* accidentally retaining such an array as a result of scanning an      */
 506 /* integer that happens to be an address inside the array.  (Actually,  */
 507 /* it reduces the chance of the allocator not finding space for such    */
 508 /* an array, since it will try hard to avoid introducing such a false   */
 509 /* reference.)  On a SunOS 4.X or MS Windows system this is recommended */
 510 /* for arrays likely to be larger than 100K or so.  For other systems,  */
 511 /* or if the collector is not configured to recognize all interior      */
 512 /* pointers, the threshold is normally much higher.                     */
 513 GC_API GC_PTR GC_malloc_ignore_off_page GC_PROTO((size_t lb));
 514 GC_API GC_PTR GC_malloc_atomic_ignore_off_page GC_PROTO((size_t lb));
 515
 516 #if defined(__sgi) && !defined(__GNUC__) && _COMPILER_VERSION >= 720
 517 #   define GC_ADD_CALLER
 518 #   define GC_RETURN_ADDR (GC_word)__return_address
 519 #endif
 520
 521 #ifdef GC_ADD_CALLER
 522 #  define GC_EXTRAS GC_RETURN_ADDR, __FILE__, __LINE__
 523 #  define GC_EXTRA_PARAMS GC_word ra, GC_CONST char * s, int i
 524 #else
 525 #  define GC_EXTRAS __FILE__, __LINE__
 526 #  define GC_EXTRA_PARAMS GC_CONST char * s, int i
 527 #endif
 528
 529 /* Debugging (annotated) allocation.  GC_gcollect will check            */
 530 /* objects allocated in this way for overwrites, etc.                   */
 531 GC_API GC_PTR GC_debug_malloc
 532         GC_PROTO((size_t size_in_bytes, GC_EXTRA_PARAMS));
 533 GC_API GC_PTR GC_debug_malloc_atomic
 534         GC_PROTO((size_t size_in_bytes, GC_EXTRA_PARAMS));
 535 GC_API GC_PTR GC_debug_malloc_uncollectable
 536         GC_PROTO((size_t size_in_bytes, GC_EXTRA_PARAMS));
 537 GC_API GC_PTR GC_debug_malloc_stubborn
 538         GC_PROTO((size_t size_in_bytes, GC_EXTRA_PARAMS));
 539 GC_API void GC_debug_free GC_PROTO((GC_PTR object_addr));
 540 GC_API GC_PTR GC_debug_realloc
 541         GC_PROTO((GC_PTR old_object, size_t new_size_in_bytes,
 542                   GC_EXTRA_PARAMS));
 543
 544 GC_API void GC_debug_change_stubborn GC_PROTO((GC_PTR));
 545 GC_API void GC_debug_end_stubborn_change GC_PROTO((GC_PTR));
 546 # ifdef GC_DEBUG
 547 #   define GC_MALLOC(sz) GC_debug_malloc(sz, GC_EXTRAS)
 548 #   define GC_MALLOC_ATOMIC(sz) GC_debug_malloc_atomic(sz, GC_EXTRAS)
 549 #   define GC_MALLOC_UNCOLLECTABLE(sz) GC_debug_malloc_uncollectable(sz, \
 550                                                         GC_EXTRAS)
 551 #   define GC_REALLOC(old, sz) GC_debug_realloc(old, sz, GC_EXTRAS)
 552 #   define GC_FREE(p) GC_debug_free(p)
 553 #   define GC_REGISTER_FINALIZER(p, f, d, of, od) \
 554         GC_debug_register_finalizer(p, f, d, of, od)
 555 #   define GC_REGISTER_FINALIZER_IGNORE_SELF(p, f, d, of, od) \
 556         GC_debug_register_finalizer_ignore_self(p, f, d, of, od)
 557 #   define GC_REGISTER_FINALIZER_NO_ORDER(p, f, d, of, od) \
 558         GC_debug_register_finalizer_no_order(p, f, d, of, od)
 559 #   define GC_MALLOC_STUBBORN(sz) GC_debug_malloc_stubborn(sz, GC_EXTRAS);
 560 #   define GC_CHANGE_STUBBORN(p) GC_debug_change_stubborn(p)
 561 #   define GC_END_STUBBORN_CHANGE(p) GC_debug_end_stubborn_change(p)
 562 #   define GC_GENERAL_REGISTER_DISAPPEARING_LINK(link, obj) \
 563         GC_general_register_disappearing_link(link, GC_base(obj))
 564 #   define GC_REGISTER_DISPLACEMENT(n) GC_debug_register_displacement(n)
 565 # else
 566 #   define GC_MALLOC(sz) GC_malloc(sz)
 567 #   define GC_MALLOC_ATOMIC(sz) GC_malloc_atomic(sz)
 568 #   define GC_MALLOC_UNCOLLECTABLE(sz) GC_malloc_uncollectable(sz)
 569 #   define GC_REALLOC(old, sz) GC_realloc(old, sz)
 570 #   define GC_FREE(p) GC_free(p)
 571 #   define GC_REGISTER_FINALIZER(p, f, d, of, od) \
 572         GC_register_finalizer(p, f, d, of, od)
 573 #   define GC_REGISTER_FINALIZER_IGNORE_SELF(p, f, d, of, od) \
 574         GC_register_finalizer_ignore_self(p, f, d, of, od)
 575 #   define GC_REGISTER_FINALIZER_NO_ORDER(p, f, d, of, od) \
 576         GC_register_finalizer_no_order(p, f, d, of, od)
 577 #   define GC_MALLOC_STUBBORN(sz) GC_malloc_stubborn(sz)
 578 #   define GC_CHANGE_STUBBORN(p) GC_change_stubborn(p)
 579 #   define GC_END_STUBBORN_CHANGE(p) GC_end_stubborn_change(p)
 580 #   define GC_GENERAL_REGISTER_DISAPPEARING_LINK(link, obj) \
 581         GC_general_register_disappearing_link(link, obj)
 582 #   define GC_REGISTER_DISPLACEMENT(n) GC_register_displacement(n)
 583 # endif
 584 /* The following are included because they are often convenient, and    */
 585 /* reduce the chance for a misspecifed size argument.  But calls may    */
 586 /* expand to something syntactically incorrect if t is a complicated    */
 587 /* type expression.                                                     */
 588 # define GC_NEW(t) (t *)GC_MALLOC(sizeof (t))
 589 # define GC_NEW_ATOMIC(t) (t *)GC_MALLOC_ATOMIC(sizeof (t))
 590 # define GC_NEW_STUBBORN(t) (t *)GC_MALLOC_STUBBORN(sizeof (t))
 591 # define GC_NEW_UNCOLLECTABLE(t) (t *)GC_MALLOC_UNCOLLECTABLE(sizeof (t))
 592
 593 /* Finalization.  Some of these primitives are grossly unsafe.          */
 594 /* The idea is to make them both cheap, and sufficient to build         */
 595 /* a safer layer, closer to PCedar finalization.                        */
 596 /* The interface represents my conclusions from a long discussion       */
 597 /* with Alan Demers, Dan Greene, Carl Hauser, Barry Hayes,              */
 598 /* Christian Jacobi, and Russ Atkinson.  It's not perfect, and          */
 599 /* probably nobody else agrees with it.     Hans-J. Boehm  3/13/92      */
 600 typedef void (*GC_finalization_proc)
 601         GC_PROTO((GC_PTR obj, GC_PTR client_data));
 602
 603 GC_API void GC_register_finalizer
 604         GC_PROTO((GC_PTR obj, GC_finalization_proc fn, GC_PTR cd,
 605                   GC_finalization_proc *ofn, GC_PTR *ocd));
 606 GC_API void GC_debug_register_finalizer
 607         GC_PROTO((GC_PTR obj, GC_finalization_proc fn, GC_PTR cd,
 608                   GC_finalization_proc *ofn, GC_PTR *ocd));
 609         /* When obj is no longer accessible, invoke             */
 610         /* (*fn)(obj, cd).  If a and b are inaccessible, and    */
 611         /* a points to b (after disappearing links have been    */
 612         /* made to disappear), then only a will be              */
 613         /* finalized.  (If this does not create any new         */
 614         /* pointers to b, then b will be finalized after the    */
 615         /* next collection.)  Any finalizable object that       */
 616         /* is reachable from itself by following one or more    */
 617         /* pointers will not be finalized (or collected).       */
 618         /* Thus cycles involving finalizable objects should     */
 619         /* be avoided, or broken by disappearing links.         */
 620         /* All but the last finalizer registered for an object  */
 621         /* is ignored.                                          */
 622         /* Finalization may be removed by passing 0 as fn.      */
 623         /* Finalizers are implicitly unregistered just before   */
 624         /* they are invoked.                                    */
 625         /* The old finalizer and client data are stored in      */
 626         /* *ofn and *ocd.                                       */
 627         /* Fn is never invoked on an accessible object,         */
 628         /* provided hidden pointers are converted to real       */
 629         /* pointers only if the allocation lock is held, and    */
 630         /* such conversions are not performed by finalization   */
 631         /* routines.                                            */
 632         /* If GC_register_finalizer is aborted as a result of   */
 633         /* a signal, the object may be left with no             */
 634         /* finalization, even if neither the old nor new        */
 635         /* finalizer were NULL.                                 */
 636         /* Obj should be the nonNULL starting address of an     */
 637         /* object allocated by GC_malloc or friends.            */
 638         /* Note that any garbage collectable object referenced  */
 639         /* by cd will be considered accessible until the        */
 640         /* finalizer is invoked.                                */
 641
 642 /* Another versions of the above follow.  It ignores            */
 643 /* self-cycles, i.e. pointers from a finalizable object to      */
 644 /* itself.  There is a stylistic argument that this is wrong,   */
 645 /* but it's unavoidable for C++, since the compiler may         */
 646 /* silently introduce these.  It's also benign in that specific */
 647 /* case.                                                        */
 648 /* Note that cd will still be viewed as accessible, even if it  */
 649 /* refers to the object itself.                                 */
 650 GC_API void GC_register_finalizer_ignore_self
 651         GC_PROTO((GC_PTR obj, GC_finalization_proc fn, GC_PTR cd,
 652                   GC_finalization_proc *ofn, GC_PTR *ocd));
 653 GC_API void GC_debug_register_finalizer_ignore_self
 654         GC_PROTO((GC_PTR obj, GC_finalization_proc fn, GC_PTR cd,
 655                   GC_finalization_proc *ofn, GC_PTR *ocd));
 656
 657 /* Another version of the above.  It ignores all cycles.        */
 658 /* It should probably only be used by Java implementations.     */
 659 /* Note that cd will still be viewed as accessible, even if it  */
 660 /* refers to the object itself.                                 */
 661 GC_API void GC_register_finalizer_no_order
 662         GC_PROTO((GC_PTR obj, GC_finalization_proc fn, GC_PTR cd,
 663                   GC_finalization_proc *ofn, GC_PTR *ocd));
 664 GC_API void GC_debug_register_finalizer_no_order
 665         GC_PROTO((GC_PTR obj, GC_finalization_proc fn, GC_PTR cd,
 666                   GC_finalization_proc *ofn, GC_PTR *ocd));
 667
 668
 669 /* The following routine may be used to break cycles between    */
 670 /* finalizable objects, thus causing cyclic finalizable         */
 671 /* objects to be finalized in the correct order.  Standard      */
 672 /* use involves calling GC_register_disappearing_link(&p),      */
 673 /* where p is a pointer that is not followed by finalization    */
 674 /* code, and should not be considered in determining            */
 675 /* finalization order.                                          */
 676 GC_API int GC_register_disappearing_link GC_PROTO((GC_PTR * /* link */));
 677         /* Link should point to a field of a heap allocated     */
 678         /* object obj.  *link will be cleared when obj is       */
 679         /* found to be inaccessible.  This happens BEFORE any   */
 680         /* finalization code is invoked, and BEFORE any         */
 681         /* decisions about finalization order are made.         */
 682         /* This is useful in telling the finalizer that         */
 683         /* some pointers are not essential for proper           */
 684         /* finalization.  This may avoid finalization cycles.   */
 685         /* Note that obj may be resurrected by another          */
 686         /* finalizer, and thus the clearing of *link may        */
 687         /* be visible to non-finalization code.                 */
 688         /* There's an argument that an arbitrary action should  */
 689         /* be allowed here, instead of just clearing a pointer. */
 690         /* But this causes problems if that action alters, or   */
 691         /* examines connectivity.                               */
 692         /* Returns 1 if link was already registered, 0          */
 693         /* otherwise.                                           */
 694         /* Only exists for backward compatibility.  See below:  */
 695
 696 GC_API int GC_general_register_disappearing_link
 697         GC_PROTO((GC_PTR * /* link */, GC_PTR obj));
 698         /* A slight generalization of the above. *link is       */
 699         /* cleared when obj first becomes inaccessible.  This   */
 700         /* can be used to implement weak pointers easily and    */
 701         /* safely. Typically link will point to a location      */
 702         /* holding a disguised pointer to obj.  (A pointer      */
 703         /* inside an "atomic" object is effectively             */
 704         /* disguised.)   In this way soft                       */
 705         /* pointers are broken before any object                */
 706         /* reachable from them are finalized.  Each link        */
 707         /* May be registered only once, i.e. with one obj       */
 708         /* value.  This was added after a long email discussion */
 709         /* with John Ellis.                                     */
 710         /* Obj must be a pointer to the first word of an object */
 711         /* we allocated.  It is unsafe to explicitly deallocate */
 712         /* the object containing link.  Explicitly deallocating */
 713         /* obj may or may not cause link to eventually be       */
 714         /* cleared.                                             */
 715 GC_API int GC_unregister_disappearing_link GC_PROTO((GC_PTR * /* link */));
 716         /* Returns 0 if link was not actually registered.       */
 717         /* Undoes a registration by either of the above two     */
 718         /* routines.                                            */
 719
 720 /* Auxiliary fns to make finalization work correctly with displaced     */
 721 /* pointers introduced by the debugging allocators.                     */
 722 GC_API GC_PTR GC_make_closure GC_PROTO((GC_finalization_proc fn, GC_PTR data));
 723 GC_API void GC_debug_invoke_finalizer GC_PROTO((GC_PTR obj, GC_PTR data));
 724
 725 /* Returns !=0  if GC_invoke_finalizers has something to do.            */
 726 GC_API int GC_should_invoke_finalizers GC_PROTO((void));
 727
 728 GC_API int GC_invoke_finalizers GC_PROTO((void));
 729         /* Run finalizers for all objects that are ready to     */
 730         /* be finalized.  Return the number of finalizers       */
 731         /* that were run.  Normally this is also called         */
 732         /* implicitly during some allocations.  If              */
 733         /* GC-finalize_on_demand is nonzero, it must be called  */
 734         /* explicitly.                                          */
 735
 736 /* GC_set_warn_proc can be used to redirect or filter warning messages. */
 737 /* p may not be a NULL pointer.                                         */
 738 typedef void (*GC_warn_proc) GC_PROTO((char *msg, GC_word arg));
 739 GC_API GC_warn_proc GC_set_warn_proc GC_PROTO((GC_warn_proc p));
 740     /* Returns old warning procedure.   */
 741
 742 /* The following is intended to be used by a higher level       */
 743 /* (e.g. Java-like) finalization facility.  It is expected      */
 744 /* that finalization code will arrange for hidden pointers to   */
 745 /* disappear.  Otherwise objects can be accessed after they     */
 746 /* have been collected.                                         */
 747 /* Note that putting pointers in atomic objects or in           */
 748 /* nonpointer slots of "typed" objects is equivalent to         */
 749 /* disguising them in this way, and may have other advantages.  */
 750 # if defined(I_HIDE_POINTERS) || defined(GC_I_HIDE_POINTERS)
 751     typedef GC_word GC_hidden_pointer;
 752 #   define HIDE_POINTER(p) (~(GC_hidden_pointer)(p))
 753 #   define REVEAL_POINTER(p) ((GC_PTR)(HIDE_POINTER(p)))
 754     /* Converting a hidden pointer to a real pointer requires verifying */
 755     /* that the object still exists.  This involves acquiring the       */
 756     /* allocator lock to avoid a race with the collector.               */
 757 # endif /* I_HIDE_POINTERS */
 758
 759 typedef GC_PTR (*GC_fn_type) GC_PROTO((GC_PTR client_data));
 760 GC_API GC_PTR GC_call_with_alloc_lock
 761                 GC_PROTO((GC_fn_type fn, GC_PTR client_data));
 762
 763 /* The following routines are primarily intended for use with a         */
 764 /* preprocessor which inserts calls to check C pointer arithmetic.      */
 765
 766 /* Check that p and q point to the same object.                 */
 767 /* Fail conspicuously if they don't.                            */
 768 /* Returns the first argument.                                  */
 769 /* Succeeds if neither p nor q points to the heap.              */
 770 /* May succeed if both p and q point to between heap objects.   */
 771 GC_API GC_PTR GC_same_obj GC_PROTO((GC_PTR p, GC_PTR q));
 772
 773 /* Checked pointer pre- and post- increment operations.  Note that      */
 774 /* the second argument is in units of bytes, not multiples of the       */
 775 /* object size.  This should either be invoked from a macro, or the     */
 776 /* call should be automatically generated.                              */
 777 GC_API GC_PTR GC_pre_incr GC_PROTO((GC_PTR *p, size_t how_much));
 778 GC_API GC_PTR GC_post_incr GC_PROTO((GC_PTR *p, size_t how_much));
 779
 780 /* Check that p is visible                                              */
 781 /* to the collector as a possibly pointer containing location.          */
 782 /* If it isn't fail conspicuously.                                      */
 783 /* Returns the argument in all cases.  May erroneously succeed          */
 784 /* in hard cases.  (This is intended for debugging use with             */
 785 /* untyped allocations.  The idea is that it should be possible, though */
 786 /* slow, to add such a call to all indirect pointer stores.)            */
 787 /* Currently useless for multithreaded worlds.                          */
 788 GC_API GC_PTR GC_is_visible GC_PROTO((GC_PTR p));
 789
 790 /* Check that if p is a pointer to a heap page, then it points to       */
 791 /* a valid displacement within a heap object.                           */
 792 /* Fail conspicuously if this property does not hold.                   */
 793 /* Uninteresting with GC_all_interior_pointers.                         */
 794 /* Always returns its argument.                                         */
 795 GC_API GC_PTR GC_is_valid_displacement GC_PROTO((GC_PTR p));
 796
 797 /* Safer, but slow, pointer addition.  Probably useful mainly with      */
 798 /* a preprocessor.  Useful only for heap pointers.                      */
 799 #ifdef GC_DEBUG
 800 #   define GC_PTR_ADD3(x, n, type_of_result) \
 801         ((type_of_result)GC_same_obj((x)+(n), (x)))
 802 #   define GC_PRE_INCR3(x, n, type_of_result) \
 803         ((type_of_result)GC_pre_incr(&(x), (n)*sizeof(*x))
 804 #   define GC_POST_INCR2(x, type_of_result) \
 805         ((type_of_result)GC_post_incr(&(x), sizeof(*x))
 806 #   ifdef __GNUC__
 807 #       define GC_PTR_ADD(x, n) \
 808             GC_PTR_ADD3(x, n, typeof(x))
 809 #       define GC_PRE_INCR(x, n) \
 810             GC_PRE_INCR3(x, n, typeof(x))
 811 #       define GC_POST_INCR(x, n) \
 812             GC_POST_INCR3(x, typeof(x))
 813 #   else
 814         /* We can't do this right without typeof, which ANSI    */
 815         /* decided was not sufficiently useful.  Repeatedly     */
 816         /* mentioning the arguments seems too dangerous to be   */
 817         /* useful.  So does not casting the result.             */
 818 #       define GC_PTR_ADD(x, n) ((x)+(n))
 819 #   endif
 820 #else   /* !GC_DEBUG */
 821 #   define GC_PTR_ADD3(x, n, type_of_result) ((x)+(n))
 822 #   define GC_PTR_ADD(x, n) ((x)+(n))
 823 #   define GC_PRE_INCR3(x, n, type_of_result) ((x) += (n))
 824 #   define GC_PRE_INCR(x, n) ((x) += (n))
 825 #   define GC_POST_INCR2(x, n, type_of_result) ((x)++)
 826 #   define GC_POST_INCR(x, n) ((x)++)
 827 #endif
 828
 829 /* Safer assignment of a pointer to a nonstack location.        */
 830 #ifdef GC_DEBUG
 831 # ifdef __STDC__
 832 #   define GC_PTR_STORE(p, q) \
 833         (*(void **)GC_is_visible(p) = GC_is_valid_displacement(q))
 834 # else
 835 #   define GC_PTR_STORE(p, q) \
 836         (*(char **)GC_is_visible(p) = GC_is_valid_displacement(q))
 837 # endif
 838 #else /* !GC_DEBUG */
 839 #   define GC_PTR_STORE(p, q) *((p) = (q))
 840 #endif
 841
 842 /* Fynctions called to report pointer checking errors */
 843 GC_API void (*GC_same_obj_print_proc) GC_PROTO((GC_PTR p, GC_PTR q));
 844
 845 GC_API void (*GC_is_valid_displacement_print_proc)
 846         GC_PROTO((GC_PTR p));
 847
 848 GC_API void (*GC_is_visible_print_proc)
 849         GC_PROTO((GC_PTR p));
 850
 851
 852 /* For pthread support, we generally need to intercept a number of      */
 853 /* thread library calls.  We do that here by macro defining them.       */
 854
 855 #if !defined(GC_USE_LD_WRAP) && \
 856     (defined(GC_PTHREADS) || defined(GC_SOLARIS_THREADS))
 857 # include "gc_pthread_redirects.h"
 858 #endif
 859
 860 # if defined(PCR) || defined(GC_SOLARIS_THREADS) || \
 861      defined(GC_PTHREADS) || defined(GC_WIN32_THREADS)
 862         /* Any flavor of threads except SRC_M3. */
 863 /* This returns a list of objects, linked through their first           */
 864 /* word.  Its use can greatly reduce lock contention problems, since    */
 865 /* the allocation lock can be acquired and released many fewer times.   */
 866 /* lb must be large enough to hold the pointer field.                   */
 867 /* It is used internally by gc_local_alloc.h, which provides a simpler  */
 868 /* programming interface on Linux.                                      */
 869 GC_PTR GC_malloc_many(size_t lb);
 870 #define GC_NEXT(p) (*(GC_PTR *)(p))     /* Retrieve the next element    */
 871                                         /* in returned list.            */
 872 extern void GC_thr_init();      /* Needed for Solaris/X86       */
 873
 874 #endif /* THREADS && !SRC_M3 */
 875
 876 #if defined(GC_WIN32_THREADS)
 877 # include <windows.h>
 878
 879   /*
 880    * All threads must be created using GC_CreateThread, so that they will be
 881    * recorded in the thread table.
 882    */
 883   HANDLE WINAPI GC_CreateThread(
 884       LPSECURITY_ATTRIBUTES lpThreadAttributes,
 885       DWORD dwStackSize, LPTHREAD_START_ROUTINE lpStartAddress,
 886       LPVOID lpParameter, DWORD dwCreationFlags, LPDWORD lpThreadId );
 887
 888 # if defined(_WIN32_WCE)
 889   /*
 890    * win32_threads.c implements the real WinMain, which will start a new thread
 891    * to call GC_WinMain after initializing the garbage collector.
 892    */
 893   int WINAPI GC_WinMain(
 894       HINSTANCE hInstance,
 895       HINSTANCE hPrevInstance,
 896       LPWSTR lpCmdLine,
 897       int nCmdShow );
 898
 899 #  ifndef GC_BUILD
 900 #    define WinMain GC_WinMain
 901 #    define CreateThread GC_CreateThread
 902 #  endif
 903 # endif /* defined(_WIN32_WCE) */
 904
 905 #endif /* defined(GC_WIN32_THREADS) */
 906
 907 /*
 908  * If you are planning on putting
 909  * the collector in a SunOS 5 dynamic library, you need to call GC_INIT()
 910  * from the statically loaded program section.
 911  * This circumvents a Solaris 2.X (X<=4) linker bug.
 912  */
 913 #if defined(sparc) || defined(__sparc)
 914 #   define GC_INIT() { extern end, etext; \
 915                        GC_noop(&end, &etext); }
 916 #else
 917 # if (defined(__CYGWIN32__) && defined(GC_USE_DLL)) || defined (_AIX)
 918     /*
 919      * Similarly gnu-win32 DLLs need explicit initialization
 920      */
 921 #   define GC_INIT() { GC_add_roots(DATASTART, DATAEND); }
 922 # else
 923 #   define GC_INIT()
 924 # endif
 925 #endif
 926
 927 #if !defined(_WIN32_WCE) \
 928     && ((defined(_MSDOS) || defined(_MSC_VER)) && (_M_IX86 >= 300) \
 929         || defined(_WIN32) && !defined(__CYGWIN32__) && !defined(__CYGWIN__))
 930   /* win32S may not free all resources on process exit.  */
 931   /* This explicitly deallocates the heap.               */
 932     GC_API void GC_win32_free_heap ();
 933 #endif
 934
 935 #if ( defined(_AMIGA) && !defined(GC_AMIGA_MAKINGLIB) )
 936   /* Allocation really goes through GC_amiga_allocwrapper_do */
 937 # include "gc_amiga_redirects.h"
 938 #endif
 939
 940 #if defined(GC_REDIRECT_TO_LOCAL) && !defined(GC_LOCAL_ALLOC_H)
 941 #  include  "gc_local_alloc.h"
 942 #endif
 943
 944 #ifdef __cplusplus
 945     }  /* end of extern "C" */
 946 #endif
 947
 948 #endif /* _GC_H */