boehm-gc/gc_priv.h

   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) 1996-1999 by Silicon Graphics.  All rights reserved.
   5  * Copyright (c) 1999 by Hewlett-Packard Company. All rights reserved.
   6  *
   7  *
   8  * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
   9  * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
  10  *
  11  * Permission is hereby granted to use or copy this program
  12  * for any purpose,  provided the above notices are retained on all copies.
  13  * Permission to modify the code and to distribute modified code is granted,
  14  * provided the above notices are retained, and a notice that the code was
  15  * modified is included with the above copyright notice.
  16  */
  17 /* Boehm, February 16, 1996 2:30 pm PST */
  18
  19
  20 # ifndef GC_PRIVATE_H
  21 # define GC_PRIVATE_H
  22
  23 #if defined(mips) && defined(SYSTYPE_BSD) && defined(sony_news)
  24     /* sony RISC NEWS, NEWSOS 4 */
  25 #   define BSD_TIME
  26 /*    typedef long ptrdiff_t;   -- necessary on some really old systems */
  27 #endif
  28
  29 #if defined(mips) && defined(SYSTYPE_BSD43)
  30     /* MIPS RISCOS 4 */
  31 #   define BSD_TIME
  32 #endif
  33
  34 #ifdef BSD_TIME
  35 #   include <sys/types.h>
  36 #   include <sys/time.h>
  37 #   include <sys/resource.h>
  38 #endif /* BSD_TIME */
  39
  40 # ifndef GC_H
  41 #   include "gc.h"
  42 # endif
  43
  44 typedef GC_word word;
  45 typedef GC_signed_word signed_word;
  46
  47 # ifndef GCCONFIG_H
  48 #   include "gcconfig.h"
  49 # endif
  50
  51 # ifndef HEADERS_H
  52 #   include "gc_hdrs.h"
  53 # endif
  54
  55 typedef int GC_bool;
  56 # define TRUE 1
  57 # define FALSE 0
  58
  59 typedef char * ptr_t;   /* A generic pointer to which we can add        */
  60                         /* byte displacements.                          */
  61                         /* Preferably identical to caddr_t, if it       */
  62                         /* exists.                                      */
  63
  64 #if defined(__STDC__)
  65 #   include <stdlib.h>
  66 #   if !(defined( sony_news ) )
  67 #       include <stddef.h>
  68 #   endif
  69 #   define VOLATILE volatile
  70 #else
  71 #   ifdef MSWIN32
  72 #       include <stdlib.h>
  73 #   endif
  74 #   define VOLATILE
  75 #endif
  76
  77 #define CONST GC_CONST
  78
  79 #if 0 /* was once defined for AMIGA */
  80 #   define GC_FAR __far
  81 #else
  82 #   define GC_FAR
  83 #endif
  84
  85 /*********************************/
  86 /*                               */
  87 /* Definitions for conservative  */
  88 /* collector                     */
  89 /*                               */
  90 /*********************************/
  91
  92 /*********************************/
  93 /*                               */
  94 /* Easily changeable parameters  */
  95 /*                               */
  96 /*********************************/
  97
  98 #define STUBBORN_ALLOC  /* Define stubborn allocation primitives        */
  99 #if defined(SRC_M3) || defined(SMALL_CONFIG)
 100 # undef STUBBORN_ALLOC
 101 #endif
 102
 103
 104 /* #define ALL_INTERIOR_POINTERS */
 105                     /* Forces all pointers into the interior of an      */
 106                     /* object to be considered valid.  Also causes the  */
 107                     /* sizes of all objects to be inflated by at least  */
 108                     /* one byte.  This should suffice to guarantee      */
 109                     /* that in the presence of a compiler that does     */
 110                     /* not perform garbage-collector-unsafe             */
 111                     /* optimizations, all portable, strictly ANSI       */
 112                     /* conforming C programs should be safely usable    */
 113                     /* with malloc replaced by GC_malloc and free       */
 114                     /* calls removed.  There are several disadvantages: */
 115                     /* 1. There are probably no interesting, portable,  */
 116                     /*    strictly ANSI conforming C programs.          */
 117                     /* 2. This option makes it hard for the collector   */
 118                     /*    to allocate space that is not ``pointed to''  */
 119                     /*    by integers, etc.  Under SunOS 4.X with a     */
 120                     /*    statically linked libc, we empiricaly         */
 121                     /*    observed that it would be difficult to        */
 122                     /*    allocate individual objects larger than 100K. */
 123                     /*    Even if only smaller objects are allocated,   */
 124                     /*    more swap space is likely to be needed.       */
 125                     /*    Fortunately, much of this will never be       */
 126                     /*    touched.                                      */
 127                     /* If you can easily avoid using this option, do.   */
 128                     /* If not, try to keep individual objects small.    */
 129
 130 #define PRINTSTATS  /* Print garbage collection statistics              */
 131                     /* For less verbose output, undefine in reclaim.c   */
 132
 133 #define PRINTTIMES  /* Print the amount of time consumed by each garbage   */
 134                     /* collection.                                         */
 135
 136 #define PRINTBLOCKS /* Print object sizes associated with heap blocks,     */
 137                     /* whether the objects are atomic or composite, and    */
 138                     /* whether or not the block was found to be empty      */
 139                     /* during the reclaim phase.  Typically generates       */
 140                     /* about one screenful per garbage collection.         */
 141 #undef PRINTBLOCKS
 142
 143 #ifdef SILENT
 144 #  ifdef PRINTSTATS
 145 #    undef PRINTSTATS
 146 #  endif
 147 #  ifdef PRINTTIMES
 148 #    undef PRINTTIMES
 149 #  endif
 150 #  ifdef PRINTNBLOCKS
 151 #    undef PRINTNBLOCKS
 152 #  endif
 153 #endif
 154
 155 #if defined(PRINTSTATS) && !defined(GATHERSTATS)
 156 #   define GATHERSTATS
 157 #endif
 158
 159 #ifdef FINALIZE_ON_DEMAND
 160 #   define GC_INVOKE_FINALIZERS()
 161 #else
 162 #   define GC_INVOKE_FINALIZERS() (void)GC_invoke_finalizers()
 163 #endif
 164
 165 #define MERGE_SIZES /* Round up some object sizes, so that fewer distinct */
 166                     /* free lists are actually maintained.  This applies  */
 167                     /* only to the top level routines in misc.c, not to   */
 168                     /* user generated code that calls GC_allocobj and     */
 169                     /* GC_allocaobj directly.                             */
 170                     /* Slows down average programs slightly.  May however */
 171                     /* substantially reduce fragmentation if allocation   */
 172                     /* request sizes are widely scattered.                */
 173                     /* May save significant amounts of space for obj_map  */
 174                     /* entries.                                           */
 175
 176 #ifndef OLD_BLOCK_ALLOC
 177    /* Macros controlling large block allocation strategy.       */
 178 #  define EXACT_FIRST   /* Make a complete pass through the large object */
 179                         /* free list before splitting a block            */
 180 #  define PRESERVE_LAST /* Do not divide last allocated heap segment     */
 181                         /* unless we would otherwise need to expand the  */
 182                         /* heap.                                         */
 183 #endif
 184
 185 /* ALIGN_DOUBLE requires MERGE_SIZES at present. */
 186 # if defined(ALIGN_DOUBLE) && !defined(MERGE_SIZES)
 187 #   define MERGE_SIZES
 188 # endif
 189
 190 #if defined(ALL_INTERIOR_POINTERS) && !defined(DONT_ADD_BYTE_AT_END)
 191 # define ADD_BYTE_AT_END
 192 #endif
 193
 194
 195 # ifndef LARGE_CONFIG
 196 #   define MINHINCR 16  /* Minimum heap increment, in blocks of HBLKSIZE  */
 197                         /* Must be multiple of largest page size.         */
 198 #   define MAXHINCR 512 /* Maximum heap increment, in blocks              */
 199 # else
 200 #   define MINHINCR 64
 201 #   define MAXHINCR 4096
 202 # endif
 203
 204 # define TIME_LIMIT 50     /* We try to keep pause times from exceeding  */
 205                            /* this by much. In milliseconds.             */
 206
 207 # define BL_LIMIT GC_black_list_spacing
 208                            /* If we need a block of N bytes, and we have */
 209                            /* a block of N + BL_LIMIT bytes available,   */
 210                            /* and N > BL_LIMIT,                          */
 211                            /* but all possible positions in it are       */
 212                            /* blacklisted, we just use it anyway (and    */
 213                            /* print a warning, if warnings are enabled). */
 214                            /* This risks subsequently leaking the block  */
 215                            /* due to a false reference.  But not using   */
 216                            /* the block risks unreasonable immediate     */
 217                            /* heap growth.                               */
 218
 219 /*********************************/
 220 /*                               */
 221 /* Stack saving for debugging    */
 222 /*                               */
 223 /*********************************/
 224
 225 #ifdef SAVE_CALL_CHAIN
 226
 227 /*
 228  * Number of frames and arguments to save in objects allocated by
 229  * debugging allocator.
 230  */
 231 #   define NFRAMES 6    /* Number of frames to save. Even for           */
 232                         /* alignment reasons.                           */
 233 #   define NARGS 2      /* Mumber of arguments to save for each call.   */
 234
 235 #   define NEED_CALLINFO
 236
 237 /* Fill in the pc and argument information for up to NFRAMES of my      */
 238 /* callers.  Ignore my frame and my callers frame.                      */
 239 void GC_save_callers (/* struct callinfo info[NFRAMES] */);
 240
 241 void GC_print_callers (/* struct callinfo info[NFRAMES] */);
 242
 243 #else
 244
 245 # ifdef GC_ADD_CALLER
 246 #   define NFRAMES 1
 247 #   define NARGS 0
 248 #   define NEED_CALLINFO
 249 # endif
 250
 251 #endif
 252
 253 #ifdef NEED_CALLINFO
 254     struct callinfo {
 255         word ci_pc;
 256 #       if NARGS > 0
 257             word ci_arg[NARGS]; /* bit-wise complement to avoid retention */
 258 #       endif
 259 #       if defined(ALIGN_DOUBLE) && (NFRAMES * (NARGS + 1)) % 2 == 1
 260             /* Likely alignment problem. */
 261             word ci_dummy;
 262 #       endif
 263     };
 264 #endif
 265
 266
 267 /*********************************/
 268 /*                               */
 269 /* OS interface routines         */
 270 /*                               */
 271 /*********************************/
 272
 273 #ifdef BSD_TIME
 274 #   undef CLOCK_TYPE
 275 #   undef GET_TIME
 276 #   undef MS_TIME_DIFF
 277 #   define CLOCK_TYPE struct timeval
 278 #   define GET_TIME(x) { struct rusage rusage; \
 279                          getrusage (RUSAGE_SELF,  &rusage); \
 280                          x = rusage.ru_utime; }
 281 #   define MS_TIME_DIFF(a,b) ((double) (a.tv_sec - b.tv_sec) * 1000.0 \
 282                                + (double) (a.tv_usec - b.tv_usec) / 1000.0)
 283 #else /* !BSD_TIME */
 284 #   include <time.h>
 285 #   if !defined(__STDC__) && defined(SPARC) && defined(SUNOS4)
 286       clock_t clock();  /* Not in time.h, where it belongs      */
 287 #   endif
 288 #   if defined(FREEBSD) && !defined(CLOCKS_PER_SEC)
 289 #     include <machine/limits.h>
 290 #     define CLOCKS_PER_SEC CLK_TCK
 291 #   endif
 292 #   if !defined(CLOCKS_PER_SEC)
 293 #     define CLOCKS_PER_SEC 1000000
 294 /*
 295  * This is technically a bug in the implementation.  ANSI requires that
 296  * CLOCKS_PER_SEC be defined.  But at least under SunOS4.1.1, it isn't.
 297  * Also note that the combination of ANSI C and POSIX is incredibly gross
 298  * here. The type clock_t is used by both clock() and times().  But on
 299  * some machines these use different notions of a clock tick,  CLOCKS_PER_SEC
 300  * seems to apply only to clock.  Hence we use it here.  On many machines,
 301  * including SunOS, clock actually uses units of microseconds (which are
 302  * not really clock ticks).
 303  */
 304 #   endif
 305 #   define CLOCK_TYPE clock_t
 306 #   define GET_TIME(x) x = clock()
 307 #   define MS_TIME_DIFF(a,b) ((unsigned long) \
 308                 (1000.0*(double)((a)-(b))/(double)CLOCKS_PER_SEC))
 309 #endif /* !BSD_TIME */
 310
 311 /* We use bzero and bcopy internally.  They may not be available.       */
 312 # if defined(SPARC) && defined(SUNOS4)
 313 #   define BCOPY_EXISTS
 314 # endif
 315 # if defined(M68K) && defined(AMIGA)
 316 #   define BCOPY_EXISTS
 317 # endif
 318 # if defined(M68K) && defined(NEXT)
 319 #   define BCOPY_EXISTS
 320 # endif
 321 # if defined(VAX)
 322 #   define BCOPY_EXISTS
 323 # endif
 324 # if defined(AMIGA)
 325 #   include <string.h>
 326 #   define BCOPY_EXISTS
 327 # endif
 328
 329 # ifndef BCOPY_EXISTS
 330 #   include <string.h>
 331 #   define BCOPY(x,y,n) memcpy(y, x, (size_t)(n))
 332 #   define BZERO(x,n)  memset(x, 0, (size_t)(n))
 333 # else
 334 #   define BCOPY(x,y,n) bcopy((char *)(x),(char *)(y),(int)(n))
 335 #   define BZERO(x,n) bzero((char *)(x),(int)(n))
 336 # endif
 337
 338 /* HBLKSIZE aligned allocation.  0 is taken to mean failure     */
 339 /* space is assumed to be cleared.                              */
 340 /* In the case os USE_MMAP, the argument must also be a         */
 341 /* physical page size.                                          */
 342 /* GET_MEM is currently not assumed to retrieve 0 filled space, */
 343 /* though we should perhaps take advantage of the case in which */
 344 /* does.                                                        */
 345 # ifdef PCR
 346     char * real_malloc();
 347 #   define GET_MEM(bytes) HBLKPTR(real_malloc((size_t)bytes + GC_page_size) \
 348                                   + GC_page_size-1)
 349 # else
 350 #   ifdef OS2
 351       void * os2_alloc(size_t bytes);
 352 #     define GET_MEM(bytes) HBLKPTR((ptr_t)os2_alloc((size_t)bytes \
 353                                     + GC_page_size) \
 354                                     + GC_page_size-1)
 355 #   else
 356 #     if defined(AMIGA) || defined(NEXT) || defined(MACOSX) || defined(DOS4GW)
 357 #       define GET_MEM(bytes) HBLKPTR((size_t) \
 358                                       calloc(1, (size_t)bytes + GC_page_size) \
 359                                       + GC_page_size-1)
 360 #     else
 361 #       ifdef MSWIN32
 362           extern ptr_t GC_win32_get_mem();
 363 #         define GET_MEM(bytes) (struct hblk *)GC_win32_get_mem(bytes)
 364 #       else
 365 #         ifdef MACOS
 366 #           if defined(USE_TEMPORARY_MEMORY)
 367                 extern Ptr GC_MacTemporaryNewPtr(size_t size,
 368                                                  Boolean clearMemory);
 369 #               define GET_MEM(bytes) HBLKPTR( \
 370                     GC_MacTemporaryNewPtr(bytes + GC_page_size, true) \
 371                     + GC_page_size-1)
 372 #           else
 373 #                   define GET_MEM(bytes) HBLKPTR( \
 374                         NewPtrClear(bytes + GC_page_size) + GC_page_size-1)
 375 #           endif
 376 #         else
 377               extern ptr_t GC_unix_get_mem();
 378 #             define GET_MEM(bytes) (struct hblk *)GC_unix_get_mem(bytes)
 379 #         endif
 380 #       endif
 381 #     endif
 382 #   endif
 383 # endif
 384
 385 /*
 386  * Mutual exclusion between allocator/collector routines.
 387  * Needed if there is more than one allocator thread.
 388  * FASTLOCK() is assumed to try to acquire the lock in a cheap and
 389  * dirty way that is acceptable for a few instructions, e.g. by
 390  * inhibiting preemption.  This is assumed to have succeeded only
 391  * if a subsequent call to FASTLOCK_SUCCEEDED() returns TRUE.
 392  * FASTUNLOCK() is called whether or not FASTLOCK_SUCCEEDED().
 393  * If signals cannot be tolerated with the FASTLOCK held, then
 394  * FASTLOCK should disable signals.  The code executed under
 395  * FASTLOCK is otherwise immune to interruption, provided it is
 396  * not restarted.
 397  * DCL_LOCK_STATE declares any local variables needed by LOCK and UNLOCK
 398  * and/or DISABLE_SIGNALS and ENABLE_SIGNALS and/or FASTLOCK.
 399  * (There is currently no equivalent for FASTLOCK.)
 400  */
 401 # ifdef THREADS
 402 #  ifdef PCR_OBSOLETE   /* Faster, but broken with multiple lwp's       */
 403 #    include  "th/PCR_Th.h"
 404 #    include  "th/PCR_ThCrSec.h"
 405      extern struct PCR_Th_MLRep GC_allocate_ml;
 406 #    define DCL_LOCK_STATE  PCR_sigset_t GC_old_sig_mask
 407 #    define LOCK() PCR_Th_ML_Acquire(&GC_allocate_ml)
 408 #    define UNLOCK() PCR_Th_ML_Release(&GC_allocate_ml)
 409 #    define FASTLOCK() PCR_ThCrSec_EnterSys()
 410      /* Here we cheat (a lot): */
 411 #        define FASTLOCK_SUCCEEDED() (*(int *)(&GC_allocate_ml) == 0)
 412                 /* TRUE if nobody currently holds the lock */
 413 #    define FASTUNLOCK() PCR_ThCrSec_ExitSys()
 414 #  endif
 415 #  ifdef PCR
 416 #    include <base/PCR_Base.h>
 417 #    include <th/PCR_Th.h>
 418      extern PCR_Th_ML GC_allocate_ml;
 419 #    define DCL_LOCK_STATE \
 420          PCR_ERes GC_fastLockRes; PCR_sigset_t GC_old_sig_mask
 421 #    define LOCK() PCR_Th_ML_Acquire(&GC_allocate_ml)
 422 #    define UNLOCK() PCR_Th_ML_Release(&GC_allocate_ml)
 423 #    define FASTLOCK() (GC_fastLockRes = PCR_Th_ML_Try(&GC_allocate_ml))
 424 #    define FASTLOCK_SUCCEEDED() (GC_fastLockRes == PCR_ERes_okay)
 425 #    define FASTUNLOCK()  {\
 426         if( FASTLOCK_SUCCEEDED() ) PCR_Th_ML_Release(&GC_allocate_ml); }
 427 #  endif
 428 #  ifdef SRC_M3
 429      extern word RT0u__inCritical;
 430 #    define LOCK() RT0u__inCritical++
 431 #    define UNLOCK() RT0u__inCritical--
 432 #  endif
 433 #  ifdef SOLARIS_THREADS
 434 #    include <thread.h>
 435 #    include <signal.h>
 436      extern mutex_t GC_allocate_ml;
 437 #    define LOCK() mutex_lock(&GC_allocate_ml);
 438 #    define UNLOCK() mutex_unlock(&GC_allocate_ml);
 439 #  endif
 440 #  ifdef LINUX_THREADS
 441 #    include <pthread.h>
 442 #    if defined(I386)
 443        inline static int GC_test_and_set(volatile unsigned int *addr) {
 444           int oldval;
 445           /* Note: the "xchg" instruction does not need a "lock" prefix */
 446           __asm__ __volatile__("xchgl %0, %1"
 447                 : "=r"(oldval), "=m"(*(addr))
 448                 : "0"(1), "m"(*(addr)));
 449           return oldval;
 450        }
 451 #    else
 452 #     if defined(POWERPC)
 453        inline static int GC_test_and_set(volatile unsigned int *addr) {
 454         int oldval;
 455         int temp = 1; // locked value
 456
 457         __asm__ __volatile__(
 458                "1:\tlwarx %0,0,%3\n"   // load and reserve
 459                "\tcmpwi %0, 0\n"       // if load is
 460                "\tbne 2f\n"            //   non-zero, return already set
 461                "\tstwcx. %2,0,%1\n"    // else store conditional
 462                "\tbne- 1b\n"           // retry if lost reservation
 463                "2:\t\n"                // oldval is zero if we set
 464               : "=&r"(oldval), "=p"(addr)
 465               : "r"(temp), "1"(addr)
 466               : "memory");
 467         return (int)oldval;
 468        }
 469 #     else
 470 #      ifdef ALPHA
 471          inline static int GC_test_and_set(volatile unsigned int *
 472 addr)
 473          {
 474            unsigned long oldvalue;
 475            unsigned long temp;
 476
 477            __asm__ __volatile__(
 478                                 "1:     ldl_l %0,%1\n"
 479                                 "       and %0,%3,%2\n"
 480                                 "       bne %2,2f\n"
 481                                 "       xor %0,%3,%0\n"
 482                                 "       stl_c %0,%1\n"
 483                                 "       beq %0,3f\n"
 484                                 "       mb\n"
 485                                 "2:\n"
 486                                 ".section .text2,\"ax\"\n"
 487                                 "3:     br 1b\n"
 488                                 ".previous"
 489                                 :"=&r" (temp), "=m" (*addr), "=&r"
 490 (oldvalue)
 491                                 :"Ir" (1), "m" (*addr));
 492
 493            return oldvalue;
 494          }
 495 #      else
 496          -- > Need implementation of GC_test_and_set()
 497 #      endif
 498 #     endif
 499 #    endif
 500      inline static void GC_clear(volatile unsigned int *addr) {
 501           *(addr) = 0;
 502      }
 503
 504      extern volatile unsigned int GC_allocate_lock;
 505         /* This is not a mutex because mutexes that obey the (optional)     */
 506         /* POSIX scheduling rules are subject to convoys in high contention */
 507         /* applications.  This is basically a spin lock.                    */
 508      extern pthread_t GC_lock_holder;
 509      extern void GC_lock(void);
 510         /* Allocation lock holder.  Only set if acquired by client through */
 511         /* GC_call_with_alloc_lock.                                        */
 512 #    define SET_LOCK_HOLDER() GC_lock_holder = pthread_self()
 513 #    define NO_THREAD (pthread_t)(-1)
 514 #    define UNSET_LOCK_HOLDER() GC_lock_holder = NO_THREAD
 515 #    define I_HOLD_LOCK() (pthread_equal(GC_lock_holder, pthread_self()))
 516 #    define LOCK() \
 517                 { if (GC_test_and_set(&GC_allocate_lock)) GC_lock(); }
 518 #    define UNLOCK() \
 519                 GC_clear(&GC_allocate_lock)
 520      extern GC_bool GC_collecting;
 521 #    define ENTER_GC() \
 522                 { \
 523                     GC_collecting = 1; \
 524                 }
 525 #    define EXIT_GC() GC_collecting = 0;
 526 #  endif /* LINUX_THREADS */
 527 #  if defined(HPUX_THREADS)
 528 #    include <pthread.h>
 529      extern pthread_mutex_t GC_allocate_ml;
 530 #    define LOCK() pthread_mutex_lock(&GC_allocate_ml)
 531 #    define UNLOCK() pthread_mutex_unlock(&GC_allocate_ml)
 532 #  endif
 533 #  if defined(IRIX_THREADS) || defined(IRIX_JDK_THREADS)
 534      /* This may also eventually be appropriate for HPUX_THREADS */
 535 #    include <pthread.h>
 536 #    ifndef HPUX_THREADS
 537         /* This probably should never be included, but I can't test     */
 538         /* on Irix anymore.                                             */
 539 #       include <mutex.h>
 540 #    endif
 541
 542 #    ifndef HPUX_THREADS
 543 #      if __mips < 3 || !(defined (_ABIN32) || defined(_ABI64)) \
 544         || !defined(_COMPILER_VERSION) || _COMPILER_VERSION < 700
 545 #        define GC_test_and_set(addr, v) test_and_set(addr,v)
 546 #      else
 547 #        define GC_test_and_set(addr, v) __test_and_set(addr,v)
 548 #      endif
 549 #    else
 550        /* I couldn't find a way to do this inline on HP/UX      */
 551 #    endif
 552      extern unsigned long GC_allocate_lock;
 553         /* This is not a mutex because mutexes that obey the (optional)         */
 554         /* POSIX scheduling rules are subject to convoys in high contention     */
 555         /* applications.  This is basically a spin lock.                        */
 556      extern pthread_t GC_lock_holder;
 557      extern void GC_lock(void);
 558         /* Allocation lock holder.  Only set if acquired by client through */
 559         /* GC_call_with_alloc_lock.                                        */
 560 #    define SET_LOCK_HOLDER() GC_lock_holder = pthread_self()
 561 #    define NO_THREAD (pthread_t)(-1)
 562 #    define UNSET_LOCK_HOLDER() GC_lock_holder = NO_THREAD
 563 #    define I_HOLD_LOCK() (pthread_equal(GC_lock_holder, pthread_self()))
 564 #    ifdef HPUX_THREADS
 565 #      define LOCK() { if (!GC_test_and_clear(&GC_allocate_lock)) GC_lock(); }
 566        /* The following is INCORRECT, since the memory model is too weak. */
 567 #      define UNLOCK() { GC_noop1(&GC_allocate_lock); \
 568                         *(volatile unsigned long *)(&GC_allocate_lock) = 1; }
 569 #    else
 570 #      define LOCK() { if (GC_test_and_set(&GC_allocate_lock, 1)) GC_lock(); }
 571 #      if __mips >= 3 && (defined (_ABIN32) || defined(_ABI64)) \
 572            && defined(_COMPILER_VERSION) && _COMPILER_VERSION >= 700
 573 #           define UNLOCK() __lock_release(&GC_allocate_lock)
 574 #      else
 575             /* The function call in the following should prevent the    */
 576             /* compiler from moving assignments to below the UNLOCK.    */
 577             /* This is probably not necessary for ucode or gcc 2.8.     */
 578             /* It may be necessary for Ragnarok and future gcc          */
 579             /* versions.                                                */
 580 #           define UNLOCK() { GC_noop1(&GC_allocate_lock); \
 581                         *(volatile unsigned long *)(&GC_allocate_lock) = 0; }
 582 #      endif
 583 #    endif
 584      extern GC_bool GC_collecting;
 585 #    define ENTER_GC() \
 586                 { \
 587                     GC_collecting = 1; \
 588                 }
 589 #    define EXIT_GC() GC_collecting = 0;
 590 #  endif /* IRIX_THREADS || IRIX_JDK_THREADS */
 591 #  ifdef WIN32_THREADS
 592 #    include <windows.h>
 593      GC_API CRITICAL_SECTION GC_allocate_ml;
 594 #    define LOCK() EnterCriticalSection(&GC_allocate_ml);
 595 #    define UNLOCK() LeaveCriticalSection(&GC_allocate_ml);
 596 #  endif
 597 #  ifndef SET_LOCK_HOLDER
 598 #      define SET_LOCK_HOLDER()
 599 #      define UNSET_LOCK_HOLDER()
 600 #      define I_HOLD_LOCK() FALSE
 601                 /* Used on platforms were locks can be reacquired,      */
 602                 /* so it doesn't matter if we lie.                      */
 603 #  endif
 604 # else
 605 #    define LOCK()
 606 #    define UNLOCK()
 607 # endif
 608 # ifndef SET_LOCK_HOLDER
 609 #   define SET_LOCK_HOLDER()
 610 #   define UNSET_LOCK_HOLDER()
 611 #   define I_HOLD_LOCK() FALSE
 612                 /* Used on platforms were locks can be reacquired,      */
 613                 /* so it doesn't matter if we lie.                      */
 614 # endif
 615 # ifndef ENTER_GC
 616 #   define ENTER_GC()
 617 #   define EXIT_GC()
 618 # endif
 619
 620 # ifndef DCL_LOCK_STATE
 621 #   define DCL_LOCK_STATE
 622 # endif
 623 # ifndef FASTLOCK
 624 #   define FASTLOCK() LOCK()
 625 #   define FASTLOCK_SUCCEEDED() TRUE
 626 #   define FASTUNLOCK() UNLOCK()
 627 # endif
 628
 629 /* Delay any interrupts or signals that may abort this thread.  Data    */
 630 /* structures are in a consistent state outside this pair of calls.     */
 631 /* ANSI C allows both to be empty (though the standard isn't very       */
 632 /* clear on that point).  Standard malloc implementations are usually   */
 633 /* neither interruptable nor thread-safe, and thus correspond to        */
 634 /* empty definitions.                                                   */
 635 # ifdef PCR
 636 #   define DISABLE_SIGNALS() \
 637                  PCR_Th_SetSigMask(PCR_allSigsBlocked,&GC_old_sig_mask)
 638 #   define ENABLE_SIGNALS() \
 639                 PCR_Th_SetSigMask(&GC_old_sig_mask, NIL)
 640 # else
 641 #   if defined(SRC_M3) || defined(AMIGA) || defined(SOLARIS_THREADS) \
 642         || defined(MSWIN32) || defined(MACOS) || defined(DJGPP) \
 643         || defined(NO_SIGNALS) || defined(IRIX_THREADS) \
 644         || defined(IRIX_JDK_THREADS) || defined(LINUX_THREADS)
 645                         /* Also useful for debugging.           */
 646         /* Should probably use thr_sigsetmask for SOLARIS_THREADS. */
 647 #     define DISABLE_SIGNALS()
 648 #     define ENABLE_SIGNALS()
 649 #   else
 650 #     define DISABLE_SIGNALS() GC_disable_signals()
 651         void GC_disable_signals();
 652 #     define ENABLE_SIGNALS() GC_enable_signals()
 653         void GC_enable_signals();
 654 #   endif
 655 # endif
 656
 657 /*
 658  * Stop and restart mutator threads.
 659  */
 660 # ifdef PCR
 661 #     include "th/PCR_ThCtl.h"
 662 #     define STOP_WORLD() \
 663         PCR_ThCtl_SetExclusiveMode(PCR_ThCtl_ExclusiveMode_stopNormal, \
 664                                    PCR_allSigsBlocked, \
 665                                    PCR_waitForever)
 666 #     define START_WORLD() \
 667         PCR_ThCtl_SetExclusiveMode(PCR_ThCtl_ExclusiveMode_null, \
 668                                    PCR_allSigsBlocked, \
 669                                    PCR_waitForever);
 670 # else
 671 #   if defined(SOLARIS_THREADS) || defined(WIN32_THREADS) \
 672         || defined(IRIX_THREADS) || defined(LINUX_THREADS) \
 673         || defined(IRIX_JDK_THREADS) || defined(HPUX_THREADS)
 674       void GC_stop_world();
 675       void GC_start_world();
 676 #     define STOP_WORLD() GC_stop_world()
 677 #     define START_WORLD() GC_start_world()
 678 #   else
 679 #     define STOP_WORLD()
 680 #     define START_WORLD()
 681 #   endif
 682 # endif
 683
 684 /* Abandon ship */
 685 # ifdef PCR
 686 #   define ABORT(s) PCR_Base_Panic(s)
 687 # else
 688 #   ifdef SMALL_CONFIG
 689 #       define ABORT(msg) abort();
 690 #   else
 691         GC_API void GC_abort();
 692 #       define ABORT(msg) GC_abort(msg);
 693 #   endif
 694 # endif
 695
 696 /* Exit abnormally, but without making a mess (e.g. out of memory) */
 697 # ifdef PCR
 698 #   define EXIT() PCR_Base_Exit(1,PCR_waitForever)
 699 # else
 700 #   define EXIT() (void)exit(1)
 701 # endif
 702
 703 /* Print warning message, e.g. almost out of memory.    */
 704 # define WARN(msg,arg) (*GC_current_warn_proc)(msg, (GC_word)(arg))
 705 extern GC_warn_proc GC_current_warn_proc;
 706
 707 /*********************************/
 708 /*                               */
 709 /* Word-size-dependent defines   */
 710 /*                               */
 711 /*********************************/
 712
 713 #if CPP_WORDSZ == 32
 714 #  define WORDS_TO_BYTES(x)   ((x)<<2)
 715 #  define BYTES_TO_WORDS(x)   ((x)>>2)
 716 #  define LOGWL               ((word)5)    /* log[2] of CPP_WORDSZ */
 717 #  define modWORDSZ(n) ((n) & 0x1f)        /* n mod size of word            */
 718 #  if ALIGNMENT != 4
 719 #       define UNALIGNED
 720 #  endif
 721 #endif
 722
 723 #if CPP_WORDSZ == 64
 724 #  define WORDS_TO_BYTES(x)   ((x)<<3)
 725 #  define BYTES_TO_WORDS(x)   ((x)>>3)
 726 #  define LOGWL               ((word)6)    /* log[2] of CPP_WORDSZ */
 727 #  define modWORDSZ(n) ((n) & 0x3f)        /* n mod size of word            */
 728 #  if ALIGNMENT != 8
 729 #       define UNALIGNED
 730 #  endif
 731 #endif
 732
 733 #define WORDSZ ((word)CPP_WORDSZ)
 734 #define SIGNB  ((word)1 << (WORDSZ-1))
 735 #define BYTES_PER_WORD      ((word)(sizeof (word)))
 736 #define ONES                ((word)(-1))
 737 #define divWORDSZ(n) ((n) >> LOGWL)        /* divide n by size of word      */
 738
 739 /*********************/
 740 /*                   */
 741 /*  Size Parameters  */
 742 /*                   */
 743 /*********************/
 744
 745 /*  heap block size, bytes. Should be power of 2 */
 746
 747 #ifndef HBLKSIZE
 748 # ifdef SMALL_CONFIG
 749 #   define CPP_LOG_HBLKSIZE 10
 750 # else
 751 #   if CPP_WORDSZ == 32
 752 #     define CPP_LOG_HBLKSIZE 12
 753 #   else
 754 #     define CPP_LOG_HBLKSIZE 13
 755 #   endif
 756 # endif
 757 #else
 758 # if HBLKSIZE == 512
 759 #   define CPP_LOG_HBLKSIZE 9
 760 # endif
 761 # if HBLKSIZE == 1024
 762 #   define CPP_LOG_HBLKSIZE 10
 763 # endif
 764 # if HBLKSIZE == 2048
 765 #   define CPP_LOG_HBLKSIZE 11
 766 # endif
 767 # if HBLKSIZE == 4096
 768 #   define CPP_LOG_HBLKSIZE 12
 769 # endif
 770 # if HBLKSIZE == 8192
 771 #   define CPP_LOG_HBLKSIZE 13
 772 # endif
 773 # if HBLKSIZE == 16384
 774 #   define CPP_LOG_HBLKSIZE 14
 775 # endif
 776 # ifndef CPP_LOG_HBLKSIZE
 777     --> fix HBLKSIZE
 778 # endif
 779 # undef HBLKSIZE
 780 #endif
 781 # define CPP_HBLKSIZE (1 << CPP_LOG_HBLKSIZE)
 782 # define LOG_HBLKSIZE   ((word)CPP_LOG_HBLKSIZE)
 783 # define HBLKSIZE ((word)CPP_HBLKSIZE)
 784
 785
 786 /*  max size objects supported by freelist (larger objects may be   */
 787 /*  allocated, but less efficiently)                                */
 788
 789 #define CPP_MAXOBJSZ    BYTES_TO_WORDS(CPP_HBLKSIZE/2)
 790 #define MAXOBJSZ ((word)CPP_MAXOBJSZ)
 791
 792 # define divHBLKSZ(n) ((n) >> LOG_HBLKSIZE)
 793
 794 # define HBLK_PTR_DIFF(p,q) divHBLKSZ((ptr_t)p - (ptr_t)q)
 795         /* Equivalent to subtracting 2 hblk pointers.   */
 796         /* We do it this way because a compiler should  */
 797         /* find it hard to use an integer division      */
 798         /* instead of a shift.  The bundled SunOS 4.1   */
 799         /* o.w. sometimes pessimizes the subtraction to */
 800         /* involve a call to .div.                      */
 801
 802 # define modHBLKSZ(n) ((n) & (HBLKSIZE-1))
 803
 804 # define HBLKPTR(objptr) ((struct hblk *)(((word) (objptr)) & ~(HBLKSIZE-1)))
 805
 806 # define HBLKDISPL(objptr) (((word) (objptr)) & (HBLKSIZE-1))
 807
 808 /* Round up byte allocation requests to integral number of words, etc. */
 809 # ifdef ADD_BYTE_AT_END
 810 #   define ROUNDED_UP_WORDS(n) BYTES_TO_WORDS((n) + WORDS_TO_BYTES(1))
 811 #   ifdef ALIGN_DOUBLE
 812 #       define ALIGNED_WORDS(n) (BYTES_TO_WORDS((n) + WORDS_TO_BYTES(2)) & ~1)
 813 #   else
 814 #       define ALIGNED_WORDS(n) ROUNDED_UP_WORDS(n)
 815 #   endif
 816 #   define SMALL_OBJ(bytes) ((bytes) < WORDS_TO_BYTES(MAXOBJSZ))
 817 #   define ADD_SLOP(bytes) ((bytes)+1)
 818 # else
 819 #   define ROUNDED_UP_WORDS(n) BYTES_TO_WORDS((n) + (WORDS_TO_BYTES(1) - 1))
 820 #   ifdef ALIGN_DOUBLE
 821 #       define ALIGNED_WORDS(n) \
 822                         (BYTES_TO_WORDS((n) + WORDS_TO_BYTES(2) - 1) & ~1)
 823 #   else
 824 #       define ALIGNED_WORDS(n) ROUNDED_UP_WORDS(n)
 825 #   endif
 826 #   define SMALL_OBJ(bytes) ((bytes) <= WORDS_TO_BYTES(MAXOBJSZ))
 827 #   define ADD_SLOP(bytes) (bytes)
 828 # endif
 829
 830
 831 /*
 832  * Hash table representation of sets of pages.  This assumes it is
 833  * OK to add spurious entries to sets.
 834  * Used by black-listing code, and perhaps by dirty bit maintenance code.
 835  */
 836
 837 # ifdef LARGE_CONFIG
 838 #   define LOG_PHT_ENTRIES  17
 839 # else
 840 #   define LOG_PHT_ENTRIES  14  /* Collisions are likely if heap grows  */
 841                                 /* to more than 16K hblks = 64MB.       */
 842                                 /* Each hash table occupies 2K bytes.   */
 843 # endif
 844 # define PHT_ENTRIES ((word)1 << LOG_PHT_ENTRIES)
 845 # define PHT_SIZE (PHT_ENTRIES >> LOGWL)
 846 typedef word page_hash_table[PHT_SIZE];
 847
 848 # define PHT_HASH(addr) ((((word)(addr)) >> LOG_HBLKSIZE) & (PHT_ENTRIES - 1))
 849
 850 # define get_pht_entry_from_index(bl, index) \
 851                 (((bl)[divWORDSZ(index)] >> modWORDSZ(index)) & 1)
 852 # define set_pht_entry_from_index(bl, index) \
 853                 (bl)[divWORDSZ(index)] |= (word)1 << modWORDSZ(index)
 854 # define clear_pht_entry_from_index(bl, index) \
 855                 (bl)[divWORDSZ(index)] &= ~((word)1 << modWORDSZ(index))
 856
 857
 858
 859 /********************************************/
 860 /*                                          */
 861 /*    H e a p   B l o c k s                 */
 862 /*                                          */
 863 /********************************************/
 864
 865 /*  heap block header */
 866 #define HBLKMASK   (HBLKSIZE-1)
 867
 868 #define BITS_PER_HBLK (HBLKSIZE * 8)
 869
 870 #define MARK_BITS_PER_HBLK (BITS_PER_HBLK/CPP_WORDSZ)
 871            /* upper bound                                    */
 872            /* We allocate 1 bit/word.  Only the first word   */
 873            /* in each object is actually marked.             */
 874
 875 # ifdef ALIGN_DOUBLE
 876 #   define MARK_BITS_SZ (((MARK_BITS_PER_HBLK + 2*CPP_WORDSZ - 1) \
 877                           / (2*CPP_WORDSZ))*2)
 878 # else
 879 #   define MARK_BITS_SZ ((MARK_BITS_PER_HBLK + CPP_WORDSZ - 1)/CPP_WORDSZ)
 880 # endif
 881            /* Upper bound on number of mark words per heap block  */
 882
 883 struct hblkhdr {
 884     word hb_sz;  /* If in use, size in words, of objects in the block. */
 885                  /* if free, the size in bytes of the whole block      */
 886     struct hblk * hb_next;      /* Link field for hblk free list         */
 887                                 /* and for lists of chunks waiting to be */
 888                                 /* reclaimed.                            */
 889     struct hblk * hb_prev;      /* Backwards link for free list.        */
 890     word hb_descr;              /* object descriptor for marking.  See  */
 891                                 /* mark.h.                              */
 892     char* hb_map;       /* A pointer to a pointer validity map of the block. */
 893                         /* See GC_obj_map.                                   */
 894                         /* Valid for all blocks with headers.                */
 895                         /* Free blocks point to GC_invalid_map.              */
 896     unsigned char hb_obj_kind;
 897                          /* Kind of objects in the block.  Each kind    */
 898                          /* identifies a mark procedure and a set of    */
 899                          /* list headers.  Sometimes called regions.    */
 900     unsigned char hb_flags;
 901 #       define IGNORE_OFF_PAGE  1       /* Ignore pointers that do not  */
 902                                         /* point to the first page of   */
 903                                         /* this object.                 */
 904 #       define WAS_UNMAPPED 2   /* This is a free block, which has      */
 905                                 /* been unmapped from the address       */
 906                                 /* space.                               */
 907                                 /* GC_remap must be invoked on it       */
 908                                 /* before it can be reallocated.        */
 909                                 /* Only set with USE_MUNMAP.            */
 910     unsigned short hb_last_reclaimed;
 911                                 /* Value of GC_gc_no when block was     */
 912                                 /* last allocated or swept. May wrap.   */
 913                                 /* For a free block, this is maintained */
 914                                 /* unly for USE_MUNMAP, and indicates   */
 915                                 /* when the header was allocated, or    */
 916                                 /* when the size of the block last      */
 917                                 /* changed.                             */
 918     word hb_marks[MARK_BITS_SZ];
 919                             /* Bit i in the array refers to the             */
 920                             /* object starting at the ith word (header      */
 921                             /* INCLUDED) in the heap block.                 */
 922                             /* The lsb of word 0 is numbered 0.             */
 923                             /* Unused bits are invalid, and are             */
 924                             /* occasionally set, e.g for uncollectable      */
 925                             /* objects.                                     */
 926 };
 927
 928 /*  heap block body */
 929
 930 # define DISCARD_WORDS 0
 931         /* Number of words to be dropped at the beginning of each block */
 932         /* Must be a multiple of WORDSZ.  May reasonably be nonzero     */
 933         /* on machines that don't guarantee longword alignment of       */
 934         /* pointers, so that the number of false hits is minimized.     */
 935         /* 0 and WORDSZ are probably the only reasonable values.        */
 936
 937 # define BODY_SZ ((HBLKSIZE-WORDS_TO_BYTES(DISCARD_WORDS))/sizeof(word))
 938
 939 struct hblk {
 940 #   if (DISCARD_WORDS != 0)
 941         word garbage[DISCARD_WORDS];
 942 #   endif
 943     word hb_body[BODY_SZ];
 944 };
 945
 946 # define HDR_WORDS ((word)DISCARD_WORDS)
 947 # define HDR_BYTES ((word)WORDS_TO_BYTES(DISCARD_WORDS))
 948
 949 # define OBJ_SZ_TO_BLOCKS(sz) \
 950     divHBLKSZ(HDR_BYTES + WORDS_TO_BYTES(sz) + HBLKSIZE-1)
 951     /* Size of block (in units of HBLKSIZE) needed to hold objects of   */
 952     /* given sz (in words).                                             */
 953
 954 /* Object free list link */
 955 # define obj_link(p) (*(ptr_t *)(p))
 956
 957 /* The type of mark procedures.  This really belongs in gc_mark.h.      */
 958 /* But we put it here, so that we can avoid scanning the mark proc      */
 959 /* table.                                                               */
 960 typedef struct ms_entry * (*mark_proc)(/* word * addr, mark_stack_ptr,
 961                                           mark_stack_limit, env */);
 962 # define LOG_MAX_MARK_PROCS 6
 963 # define MAX_MARK_PROCS (1 << LOG_MAX_MARK_PROCS)
 964
 965 /* Root sets.  Logically private to mark_rts.c.  But we don't want the  */
 966 /* tables scanned, so we put them here.                                 */
 967 /* MAX_ROOT_SETS is the maximum number of ranges that can be    */
 968 /* registered as static roots.                                  */
 969 # ifdef LARGE_CONFIG
 970 #   define MAX_ROOT_SETS 4096
 971 # else
 972 #   ifdef PCR
 973 #     define MAX_ROOT_SETS 1024
 974 #   else
 975 #     ifdef MSWIN32
 976 #       define MAX_ROOT_SETS 512
 977             /* Under NT, we add only written pages, which can result    */
 978             /* in many small root sets.                                 */
 979 #     else
 980 #       define MAX_ROOT_SETS 64
 981 #     endif
 982 #   endif
 983 # endif
 984
 985 # define MAX_EXCLUSIONS (MAX_ROOT_SETS/4)
 986 /* Maximum number of segments that can be excluded from root sets.      */
 987
 988 /*
 989  * Data structure for excluded static roots.
 990  */
 991 struct exclusion {
 992     ptr_t e_start;
 993     ptr_t e_end;
 994 };
 995
 996 /* Data structure for list of root sets.                                */
 997 /* We keep a hash table, so that we can filter out duplicate additions. */
 998 /* Under Win32, we need to do a better job of filtering overlaps, so    */
 999 /* we resort to sequential search, and pay the price.                   */
1000 struct roots {
1001         ptr_t r_start;
1002         ptr_t r_end;
1003 #       ifndef MSWIN32
1004           struct roots * r_next;
1005 #       endif
1006         GC_bool r_tmp;
1007                 /* Delete before registering new dynamic libraries */
1008 };
1009
1010 #ifndef MSWIN32
1011     /* Size of hash table index to roots.       */
1012 #   define LOG_RT_SIZE 6
1013 #   define RT_SIZE (1 << LOG_RT_SIZE) /* Power of 2, may be != MAX_ROOT_SETS */
1014 #endif
1015
1016 /* Lists of all heap blocks and free lists      */
1017 /* as well as other random data structures      */
1018 /* that should not be scanned by the            */
1019 /* collector.                                   */
1020 /* These are grouped together in a struct       */
1021 /* so that they can be easily skipped by the    */
1022 /* GC_mark routine.                             */
1023 /* The ordering is weird to make GC_malloc      */
1024 /* faster by keeping the important fields       */
1025 /* sufficiently close together that a           */
1026 /* single load of a base register will do.      */
1027 /* Scalars that could easily appear to          */
1028 /* be pointers are also put here.               */
1029 /* The main fields should precede any           */
1030 /* conditionally included fields, so that       */
1031 /* gc_inl.h will work even if a different set   */
1032 /* of macros is defined when the client is      */
1033 /* compiled.                                    */
1034
1035 struct _GC_arrays {
1036   word _heapsize;
1037   word _max_heapsize;
1038   ptr_t _last_heap_addr;
1039   ptr_t _prev_heap_addr;
1040   word _large_free_bytes;
1041         /* Total bytes contained in blocks on large object free */
1042         /* list.                                                */
1043   word _words_allocd_before_gc;
1044                 /* Number of words allocated before this        */
1045                 /* collection cycle.                            */
1046   word _words_allocd;
1047         /* Number of words allocated during this collection cycle */
1048   word _words_wasted;
1049         /* Number of words wasted due to internal fragmentation */
1050         /* in large objects, or due to dropping blacklisted     */
1051         /* blocks, since last gc.  Approximate.                 */
1052   word _words_finalized;
1053         /* Approximate number of words in objects (and headers) */
1054         /* That became ready for finalization in the last       */
1055         /* collection.                                          */
1056   word _non_gc_bytes_at_gc;
1057         /* Number of explicitly managed bytes of storage        */
1058         /* at last collection.                                  */
1059   word _mem_freed;
1060         /* Number of explicitly deallocated words of memory     */
1061         /* since last collection.                               */
1062   mark_proc _mark_procs[MAX_MARK_PROCS];
1063         /* Table of user-defined mark procedures.  There is     */
1064         /* a small number of these, which can be referenced     */
1065         /* by DS_PROC mark descriptors.  See gc_mark.h.         */
1066   ptr_t _objfreelist[MAXOBJSZ+1];
1067                           /* free list for objects */
1068   ptr_t _aobjfreelist[MAXOBJSZ+1];
1069                           /* free list for atomic objs  */
1070
1071   ptr_t _uobjfreelist[MAXOBJSZ+1];
1072                           /* uncollectable but traced objs      */
1073                           /* objects on this and auobjfreelist  */
1074                           /* are always marked, except during   */
1075                           /* garbage collections.               */
1076 # ifdef ATOMIC_UNCOLLECTABLE
1077     ptr_t _auobjfreelist[MAXOBJSZ+1];
1078 # endif
1079                           /* uncollectable but traced objs      */
1080
1081 # ifdef GATHERSTATS
1082     word _composite_in_use;
1083                 /* Number of words in accessible composite      */
1084                 /* objects.                                     */
1085     word _atomic_in_use;
1086                 /* Number of words in accessible atomic         */
1087                 /* objects.                                     */
1088 # endif
1089 # ifdef USE_MUNMAP
1090     word _unmapped_bytes;
1091 # endif
1092 # ifdef MERGE_SIZES
1093     unsigned _size_map[WORDS_TO_BYTES(MAXOBJSZ+1)];
1094         /* Number of words to allocate for a given allocation request in */
1095         /* bytes.                                                        */
1096 # endif
1097
1098 # ifdef STUBBORN_ALLOC
1099     ptr_t _sobjfreelist[MAXOBJSZ+1];
1100 # endif
1101                           /* free list for immutable objects    */
1102   ptr_t _obj_map[MAXOBJSZ+1];
1103                        /* If not NIL, then a pointer to a map of valid  */
1104                        /* object addresses. _obj_map[sz][i] is j if the */
1105                        /* address block_start+i is a valid pointer      */
1106                        /* to an object at                               */
1107                        /* block_start+i&~3 - WORDS_TO_BYTES(j).         */
1108                        /* (If ALL_INTERIOR_POINTERS is defined, then    */
1109                        /* instead ((short *)(hb_map[sz])[i] is j if     */
1110                        /* block_start+WORDS_TO_BYTES(i) is in the       */
1111                        /* interior of an object starting at             */
1112                        /* block_start+WORDS_TO_BYTES(i-j)).             */
1113                        /* It is OBJ_INVALID if                          */
1114                        /* block_start+WORDS_TO_BYTES(i) is not          */
1115                        /* valid as a pointer to an object.              */
1116                        /* We assume all values of j <= OBJ_INVALID.     */
1117                        /* The zeroth entry corresponds to large objects.*/
1118 #   ifdef ALL_INTERIOR_POINTERS
1119 #       define map_entry_type short
1120 #       define OBJ_INVALID 0x7fff
1121 #       define MAP_ENTRY(map, bytes) \
1122                 (((map_entry_type *)(map))[BYTES_TO_WORDS(bytes)])
1123 #       define MAP_ENTRIES BYTES_TO_WORDS(HBLKSIZE)
1124 #       define MAP_SIZE (MAP_ENTRIES * sizeof(map_entry_type))
1125 #       define OFFSET_VALID(displ) TRUE
1126 #       define CPP_MAX_OFFSET (HBLKSIZE - HDR_BYTES - 1)
1127 #       define MAX_OFFSET ((word)CPP_MAX_OFFSET)
1128 #   else
1129 #       define map_entry_type char
1130 #       define OBJ_INVALID 0x7f
1131 #       define MAP_ENTRY(map, bytes) \
1132                 (map)[bytes]
1133 #       define MAP_ENTRIES HBLKSIZE
1134 #       define MAP_SIZE MAP_ENTRIES
1135 #       define CPP_MAX_OFFSET (WORDS_TO_BYTES(OBJ_INVALID) - 1)
1136 #       define MAX_OFFSET ((word)CPP_MAX_OFFSET)
1137 #       define VALID_OFFSET_SZ \
1138           (CPP_MAX_OFFSET > WORDS_TO_BYTES(CPP_MAXOBJSZ)? \
1139            CPP_MAX_OFFSET+1 \
1140            : WORDS_TO_BYTES(CPP_MAXOBJSZ)+1)
1141         char _valid_offsets[VALID_OFFSET_SZ];
1142                                 /* GC_valid_offsets[i] == TRUE ==> i    */
1143                                 /* is registered as a displacement.     */
1144 #       define OFFSET_VALID(displ) GC_valid_offsets[displ]
1145         char _modws_valid_offsets[sizeof(word)];
1146                                 /* GC_valid_offsets[i] ==>                */
1147                                 /* GC_modws_valid_offsets[i%sizeof(word)] */
1148 #   endif
1149 # ifdef STUBBORN_ALLOC
1150     page_hash_table _changed_pages;
1151         /* Stubborn object pages that were changes since last call to   */
1152         /* GC_read_changed.                                             */
1153     page_hash_table _prev_changed_pages;
1154         /* Stubborn object pages that were changes before last call to  */
1155         /* GC_read_changed.                                             */
1156 # endif
1157 # if defined(PROC_VDB) || defined(MPROTECT_VDB)
1158     page_hash_table _grungy_pages; /* Pages that were dirty at last        */
1159                                      /* GC_read_dirty.                     */
1160 # endif
1161 # ifdef MPROTECT_VDB
1162     VOLATILE page_hash_table _dirty_pages;
1163                         /* Pages dirtied since last GC_read_dirty. */
1164 # endif
1165 # ifdef PROC_VDB
1166     page_hash_table _written_pages;     /* Pages ever dirtied   */
1167 # endif
1168 # ifdef LARGE_CONFIG
1169 #   if CPP_WORDSZ > 32
1170 #     define MAX_HEAP_SECTS 4096        /* overflows at roughly 64 GB      */
1171 #   else
1172 #     define MAX_HEAP_SECTS 768         /* Separately added heap sections. */
1173 #   endif
1174 # else
1175 #   define MAX_HEAP_SECTS 256
1176 # endif
1177   struct HeapSect {
1178       ptr_t hs_start; word hs_bytes;
1179   } _heap_sects[MAX_HEAP_SECTS];
1180 # ifdef MSWIN32
1181     ptr_t _heap_bases[MAX_HEAP_SECTS];
1182                 /* Start address of memory regions obtained from kernel. */
1183 # endif
1184   struct roots _static_roots[MAX_ROOT_SETS];
1185 # ifndef MSWIN32
1186     struct roots * _root_index[RT_SIZE];
1187 # endif
1188   struct exclusion _excl_table[MAX_EXCLUSIONS];
1189   /* Block header index; see gc_headers.h */
1190   bottom_index * _all_nils;
1191   bottom_index * _top_index [TOP_SZ];
1192 #ifdef SAVE_CALL_CHAIN
1193   struct callinfo _last_stack[NFRAMES]; /* Stack at last garbage collection.*/
1194                                         /* Useful for debugging mysterious  */
1195                                         /* object disappearances.           */
1196                                         /* In the multithreaded case, we    */
1197                                         /* currently only save the calling  */
1198                                         /* stack.                           */
1199 #endif
1200 };
1201
1202 GC_API GC_FAR struct _GC_arrays GC_arrays;
1203
1204 # define GC_objfreelist GC_arrays._objfreelist
1205 # define GC_aobjfreelist GC_arrays._aobjfreelist
1206 # define GC_uobjfreelist GC_arrays._uobjfreelist
1207 # ifdef ATOMIC_UNCOLLECTABLE
1208 #   define GC_auobjfreelist GC_arrays._auobjfreelist
1209 # endif
1210 # define GC_sobjfreelist GC_arrays._sobjfreelist
1211 # define GC_valid_offsets GC_arrays._valid_offsets
1212 # define GC_modws_valid_offsets GC_arrays._modws_valid_offsets
1213 # ifdef STUBBORN_ALLOC
1214 #    define GC_changed_pages GC_arrays._changed_pages
1215 #    define GC_prev_changed_pages GC_arrays._prev_changed_pages
1216 # endif
1217 # define GC_obj_map GC_arrays._obj_map
1218 # define GC_last_heap_addr GC_arrays._last_heap_addr
1219 # define GC_prev_heap_addr GC_arrays._prev_heap_addr
1220 # define GC_words_allocd GC_arrays._words_allocd
1221 # define GC_words_wasted GC_arrays._words_wasted
1222 # define GC_large_free_bytes GC_arrays._large_free_bytes
1223 # define GC_words_finalized GC_arrays._words_finalized
1224 # define GC_non_gc_bytes_at_gc GC_arrays._non_gc_bytes_at_gc
1225 # define GC_mem_freed GC_arrays._mem_freed
1226 # define GC_mark_procs GC_arrays._mark_procs
1227 # define GC_heapsize GC_arrays._heapsize
1228 # define GC_max_heapsize GC_arrays._max_heapsize
1229 # define GC_words_allocd_before_gc GC_arrays._words_allocd_before_gc
1230 # define GC_heap_sects GC_arrays._heap_sects
1231 # define GC_last_stack GC_arrays._last_stack
1232 # ifdef USE_MUNMAP
1233 #   define GC_unmapped_bytes GC_arrays._unmapped_bytes
1234 # endif
1235 # ifdef MSWIN32
1236 #   define GC_heap_bases GC_arrays._heap_bases
1237 # endif
1238 # define GC_static_roots GC_arrays._static_roots
1239 # define GC_root_index GC_arrays._root_index
1240 # define GC_excl_table GC_arrays._excl_table
1241 # define GC_all_nils GC_arrays._all_nils
1242 # define GC_top_index GC_arrays._top_index
1243 # if defined(PROC_VDB) || defined(MPROTECT_VDB)
1244 #   define GC_grungy_pages GC_arrays._grungy_pages
1245 # endif
1246 # ifdef MPROTECT_VDB
1247 #   define GC_dirty_pages GC_arrays._dirty_pages
1248 # endif
1249 # ifdef PROC_VDB
1250 #   define GC_written_pages GC_arrays._written_pages
1251 # endif
1252 # ifdef GATHERSTATS
1253 #   define GC_composite_in_use GC_arrays._composite_in_use
1254 #   define GC_atomic_in_use GC_arrays._atomic_in_use
1255 # endif
1256 # ifdef MERGE_SIZES
1257 #   define GC_size_map GC_arrays._size_map
1258 # endif
1259
1260 # define beginGC_arrays ((ptr_t)(&GC_arrays))
1261 # define endGC_arrays (((ptr_t)(&GC_arrays)) + (sizeof GC_arrays))
1262
1263 /* Object kinds: */
1264 # define MAXOBJKINDS 16
1265
1266 extern struct obj_kind {
1267    ptr_t *ok_freelist;  /* Array of free listheaders for this kind of object */
1268                         /* Point either to GC_arrays or to storage allocated */
1269                         /* with GC_scratch_alloc.                            */
1270    struct hblk **ok_reclaim_list;
1271                         /* List headers for lists of blocks waiting to be */
1272                         /* swept.                                         */
1273    word ok_descriptor;  /* Descriptor template for objects in this      */
1274                         /* block.                                       */
1275    GC_bool ok_relocate_descr;
1276                         /* Add object size in bytes to descriptor       */
1277                         /* template to obtain descriptor.  Otherwise    */
1278                         /* template is used as is.                      */
1279    GC_bool ok_init;   /* Clear objects before putting them on the free list. */
1280 } GC_obj_kinds[MAXOBJKINDS];
1281
1282 # define endGC_obj_kinds (((ptr_t)(&GC_obj_kinds)) + (sizeof GC_obj_kinds))
1283
1284 # define end_gc_area ((ptr_t)endGC_arrays == (ptr_t)(&GC_obj_kinds) ? \
1285                         endGC_obj_kinds : endGC_arrays)
1286
1287 /* Predefined kinds: */
1288 # define PTRFREE 0
1289 # define NORMAL  1
1290 # define UNCOLLECTABLE 2
1291 # ifdef ATOMIC_UNCOLLECTABLE
1292 #   define AUNCOLLECTABLE 3
1293 #   define STUBBORN 4
1294 #   define IS_UNCOLLECTABLE(k) (((k) & ~1) == UNCOLLECTABLE)
1295 # else
1296 #   define STUBBORN 3
1297 #   define IS_UNCOLLECTABLE(k) ((k) == UNCOLLECTABLE)
1298 # endif
1299
1300 extern int GC_n_kinds;
1301
1302 GC_API word GC_fo_entries;
1303
1304 extern word GC_n_heap_sects;    /* Number of separately added heap      */
1305                                 /* sections.                            */
1306
1307 extern word GC_page_size;
1308
1309 # ifdef MSWIN32
1310 extern word GC_n_heap_bases;    /* See GC_heap_bases.   */
1311 # endif
1312
1313 extern word GC_total_stack_black_listed;
1314                         /* Number of bytes on stack blacklist.  */
1315
1316 extern word GC_black_list_spacing;
1317                         /* Average number of bytes between blacklisted  */
1318                         /* blocks. Approximate.                         */
1319                         /* Counts only blocks that are                  */
1320                         /* "stack-blacklisted", i.e. that are           */
1321                         /* problematic in the interior of an object.    */
1322
1323 extern char * GC_invalid_map;
1324                         /* Pointer to the nowhere valid hblk map */
1325                         /* Blocks pointing to this map are free. */
1326
1327 extern struct hblk * GC_hblkfreelist[];
1328                                 /* List of completely empty heap blocks */
1329                                 /* Linked through hb_next field of      */
1330                                 /* header structure associated with     */
1331                                 /* block.                               */
1332
1333 extern GC_bool GC_is_initialized;       /* GC_init() has been run.      */
1334
1335 extern GC_bool GC_objects_are_marked;   /* There are marked objects in  */
1336                                         /* the heap.                    */
1337
1338 #ifndef SMALL_CONFIG
1339   extern GC_bool GC_incremental;
1340                         /* Using incremental/generational collection. */
1341 #else
1342 # define GC_incremental TRUE
1343                         /* Hopefully allow optimizer to remove some code. */
1344 #endif
1345
1346 extern GC_bool GC_dirty_maintained;
1347                                 /* Dirty bits are being maintained,     */
1348                                 /* either for incremental collection,   */
1349                                 /* or to limit the root set.            */
1350
1351 extern word GC_root_size;       /* Total size of registered root sections */
1352
1353 extern GC_bool GC_debugging_started;    /* GC_debug_malloc has been called. */
1354
1355 extern ptr_t GC_least_plausible_heap_addr;
1356 extern ptr_t GC_greatest_plausible_heap_addr;
1357                         /* Bounds on the heap.  Guaranteed valid        */
1358                         /* Likely to include future heap expansion.     */
1359
1360 /* Operations */
1361 # ifndef abs
1362 #   define abs(x)  ((x) < 0? (-(x)) : (x))
1363 # endif
1364
1365
1366 /*  Marks are in a reserved area in                          */
1367 /*  each heap block.  Each word has one mark bit associated  */
1368 /*  with it. Only those corresponding to the beginning of an */
1369 /*  object are used.                                         */
1370
1371
1372 /* Mark bit operations */
1373
1374 /*
1375  * Retrieve, set, clear the mark bit corresponding
1376  * to the nth word in a given heap block.
1377  *
1378  * (Recall that bit n corresponds to object beginning at word n
1379  * relative to the beginning of the block, including unused words)
1380  */
1381
1382 # define mark_bit_from_hdr(hhdr,n) (((hhdr)->hb_marks[divWORDSZ(n)] \
1383                             >> (modWORDSZ(n))) & (word)1)
1384 # define set_mark_bit_from_hdr(hhdr,n) (hhdr)->hb_marks[divWORDSZ(n)] \
1385                                 |= (word)1 << modWORDSZ(n)
1386
1387 # define clear_mark_bit_from_hdr(hhdr,n) (hhdr)->hb_marks[divWORDSZ(n)] \
1388                                 &= ~((word)1 << modWORDSZ(n))
1389
1390 /* Important internal collector routines */
1391
1392 ptr_t GC_approx_sp();
1393
1394 GC_bool GC_should_collect();
1395 #ifdef PRESERVE_LAST
1396     GC_bool GC_in_last_heap_sect(/* ptr_t */);
1397         /* In last added heap section?  If so, avoid breaking up.       */
1398 #endif
1399 void GC_apply_to_all_blocks(/*fn, client_data*/);
1400                         /* Invoke fn(hbp, client_data) for each         */
1401                         /* allocated heap block.                        */
1402 struct hblk * GC_next_used_block(/* struct hblk * h */);
1403                         /* Return first in-use block >= h       */
1404 struct hblk * GC_prev_block(/* struct hblk * h */);
1405                         /* Return last block <= h.  Returned block      */
1406                         /* is managed by GC, but may or may not be in   */
1407                         /* use.                                         */
1408 void GC_mark_init();
1409 void GC_clear_marks();  /* Clear mark bits for all heap objects. */
1410 void GC_invalidate_mark_state();        /* Tell the marker that marked     */
1411                                         /* objects may point to unmarked   */
1412                                         /* ones, and roots may point to    */
1413                                         /* unmarked objects.               */
1414                                         /* Reset mark stack.               */
1415 void GC_mark_from_mark_stack(); /* Mark from everything on the mark stack. */
1416                                 /* Return after about one pages worth of   */
1417                                 /* work.                                   */
1418 GC_bool GC_mark_stack_empty();
1419 GC_bool GC_mark_some(/* cold_gc_frame */);
1420                         /* Perform about one pages worth of marking     */
1421                         /* work of whatever kind is needed.  Returns    */
1422                         /* quickly if no collection is in progress.     */
1423                         /* Return TRUE if mark phase finished.          */
1424 void GC_initiate_gc();          /* initiate collection.                 */
1425                                 /* If the mark state is invalid, this   */
1426                                 /* becomes full colleection.  Otherwise */
1427                                 /* it's partial.                        */
1428 void GC_push_all(/*b,t*/);      /* Push everything in a range           */
1429                                 /* onto mark stack.                     */
1430 void GC_push_dirty(/*b,t*/);      /* Push all possibly changed          */
1431                                   /* subintervals of [b,t) onto         */
1432                                   /* mark stack.                        */
1433 #ifndef SMALL_CONFIG
1434   void GC_push_conditional(/* ptr_t b, ptr_t t, GC_bool all*/);
1435 #else
1436 # define GC_push_conditional(b, t, all) GC_push_all(b, t)
1437 #endif
1438                                 /* Do either of the above, depending    */
1439                                 /* on the third arg.                    */
1440 void GC_push_all_stack(/*b,t*/);    /* As above, but consider           */
1441                                     /*  interior pointers as valid      */
1442 void GC_push_all_eager(/*b,t*/);    /* Same as GC_push_all_stack, but   */
1443                                     /* ensures that stack is scanned    */
1444                                     /* immediately, not just scheduled  */
1445                                     /* for scanning.                    */
1446 #ifndef THREADS
1447   void GC_push_all_stack_partially_eager(/* bottom, top, cold_gc_frame */);
1448                         /* Similar to GC_push_all_eager, but only the   */
1449                         /* part hotter than cold_gc_frame is scanned    */
1450                         /* immediately.  Needed to endure that callee-  */
1451                         /* save registers are not missed.               */
1452 #else
1453   /* In the threads case, we push part of the current thread stack      */
1454   /* with GC_push_all_eager when we push the registers.  This gets the  */
1455   /* callee-save registers that may disappear.  The remainder of the    */
1456   /* stacks are scheduled for scanning in *GC_push_other_roots, which   */
1457   /* is thread-package-specific.                                        */
1458 #endif
1459 void GC_push_current_stack(/* ptr_t cold_gc_frame */);
1460                         /* Push enough of the current stack eagerly to  */
1461                         /* ensure that callee-save registers saved in   */
1462                         /* GC frames are scanned.                       */
1463                         /* In the non-threads case, schedule entire     */
1464                         /* stack for scanning.                          */
1465 void GC_push_roots(/* GC_bool all, ptr_t cold_gc_frame */);
1466                         /* Push all or dirty roots.     */
1467 extern void (*GC_push_other_roots)();
1468                         /* Push system or application specific roots    */
1469                         /* onto the mark stack.  In some environments   */
1470                         /* (e.g. threads environments) this is          */
1471                         /* predfined to be non-zero.  A client supplied */
1472                         /* replacement should also call the original    */
1473                         /* function.                                    */
1474 extern void (*GC_start_call_back)(/* void */);
1475                         /* Called at start of full collections.         */
1476                         /* Not called if 0.  Called with allocation     */
1477                         /* lock held.                                   */
1478                         /* 0 by default.                                */
1479 void GC_push_regs();    /* Push register contents onto mark stack.      */
1480                         /* If NURSERY is defined, the default push      */
1481                         /* action can be overridden with GC_push_proc   */
1482 void GC_remark();       /* Mark from all marked objects.  Used  */
1483                         /* only if we had to drop something.    */
1484
1485 # ifdef NURSERY
1486     extern void (*GC_push_proc)(ptr_t);
1487 # endif
1488 # if defined(MSWIN32)
1489   void __cdecl GC_push_one();
1490 # else
1491   void GC_push_one(/*p*/);    /* If p points to an object, mark it    */
1492                               /* and push contents on the mark stack  */
1493 # endif
1494 void GC_push_one_checked(/*p*/); /* Ditto, omits plausibility test      */
1495 void GC_push_marked(/* struct hblk h, hdr * hhdr */);
1496                 /* Push contents of all marked objects in h onto        */
1497                 /* mark stack.                                          */
1498 #ifdef SMALL_CONFIG
1499 # define GC_push_next_marked_dirty(h) GC_push_next_marked(h)
1500 #else
1501   struct hblk * GC_push_next_marked_dirty(/* h */);
1502                 /* Invoke GC_push_marked on next dirty block above h.   */
1503                 /* Return a pointer just past the end of this block.    */
1504 #endif /* !SMALL_CONFIG */
1505 struct hblk * GC_push_next_marked(/* h */);
1506                 /* Ditto, but also mark from clean pages.       */
1507 struct hblk * GC_push_next_marked_uncollectable(/* h */);
1508                 /* Ditto, but mark only from uncollectable pages.       */
1509 GC_bool GC_stopped_mark(); /* Stop world and mark from all roots        */
1510                         /* and rescuers.                        */
1511 void GC_clear_hdr_marks(/* hhdr */);  /* Clear the mark bits in a header */
1512 void GC_set_hdr_marks(/* hhdr */);  /* Set the mark bits in a header */
1513 void GC_add_roots_inner();
1514 GC_bool GC_is_static_root(/* ptr_t p */);
1515                 /* Is the address p in one of the registered static     */
1516                 /* root sections?                                       */
1517 void GC_register_dynamic_libraries();
1518                 /* Add dynamic library data sections to the root set. */
1519
1520 /* Machine dependent startup routines */
1521 ptr_t GC_get_stack_base();
1522 void GC_register_data_segments();
1523
1524 /* Black listing: */
1525 void GC_bl_init();
1526 # ifndef ALL_INTERIOR_POINTERS
1527     void GC_add_to_black_list_normal(/* bits, maybe source */);
1528                         /* Register bits as a possible future false     */
1529                         /* reference from the heap or static data       */
1530 #   ifdef PRINT_BLACK_LIST
1531 #     define GC_ADD_TO_BLACK_LIST_NORMAL(bits, source) \
1532                         GC_add_to_black_list_normal(bits, source)
1533 #   else
1534 #     define GC_ADD_TO_BLACK_LIST_NORMAL(bits, source) \
1535                         GC_add_to_black_list_normal(bits)
1536 #   endif
1537 # else
1538 #   ifdef PRINT_BLACK_LIST
1539 #     define GC_ADD_TO_BLACK_LIST_NORMAL(bits, source) \
1540                         GC_add_to_black_list_stack(bits, source)
1541 #   else
1542 #     define GC_ADD_TO_BLACK_LIST_NORMAL(bits, source) \
1543                         GC_add_to_black_list_stack(bits)
1544 #   endif
1545 # endif
1546
1547 void GC_add_to_black_list_stack(/* bits, maybe source */);
1548 struct hblk * GC_is_black_listed(/* h, len */);
1549                         /* If there are likely to be false references   */
1550                         /* to a block starting at h of the indicated    */
1551                         /* length, then return the next plausible       */
1552                         /* starting location for h that might avoid     */
1553                         /* these false references.                      */
1554 void GC_promote_black_lists();
1555                         /* Declare an end to a black listing phase.     */
1556 void GC_unpromote_black_lists();
1557                         /* Approximately undo the effect of the above.  */
1558                         /* This actually loses some information, but    */
1559                         /* only in a reasonably safe way.               */
1560 word GC_number_stack_black_listed(/*struct hblk *start, struct hblk *endp1 */);
1561                         /* Return the number of (stack) blacklisted     */
1562                         /* blocks in the range for statistical          */
1563                         /* purposes.                                    */
1564
1565 ptr_t GC_scratch_alloc(/*bytes*/);
1566                                 /* GC internal memory allocation for    */
1567                                 /* small objects.  Deallocation is not  */
1568                                 /* possible.                            */
1569
1570 /* Heap block layout maps: */
1571 void GC_invalidate_map(/* hdr */);
1572                                 /* Remove the object map associated     */
1573                                 /* with the block.  This identifies     */
1574                                 /* the block as invalid to the mark     */
1575                                 /* routines.                            */
1576 GC_bool GC_add_map_entry(/*sz*/);
1577                                 /* Add a heap block map for objects of  */
1578                                 /* size sz to obj_map.                  */
1579                                 /* Return FALSE on failure.             */
1580 void GC_register_displacement_inner(/*offset*/);
1581                                 /* Version of GC_register_displacement  */
1582                                 /* that assumes lock is already held    */
1583                                 /* and signals are already disabled.    */
1584
1585 /*  hblk allocation: */
1586 void GC_new_hblk(/*size_in_words, kind*/);
1587                                 /* Allocate a new heap block, and build */
1588                                 /* a free list in it.                   */
1589 struct hblk * GC_allochblk(/*size_in_words, kind*/);
1590                                 /* Allocate a heap block, clear it if   */
1591                                 /* for composite objects, inform        */
1592                                 /* the marker that block is valid       */
1593                                 /* for objects of indicated size.       */
1594                                 /* sz < 0 ==> atomic.                   */
1595 void GC_freehblk();             /* Deallocate a heap block and mark it  */
1596                                 /* as invalid.                          */
1597
1598 /*  Misc GC: */
1599 void GC_init_inner();
1600 GC_bool GC_expand_hp_inner();
1601 void GC_start_reclaim(/*abort_if_found*/);
1602                                 /* Restore unmarked objects to free     */
1603                                 /* lists, or (if abort_if_found is      */
1604                                 /* TRUE) report them.                   */
1605                                 /* Sweeping of small object pages is    */
1606                                 /* largely deferred.                    */
1607 void GC_continue_reclaim(/*size, kind*/);
1608                                 /* Sweep pages of the given size and    */
1609                                 /* kind, as long as possible, and       */
1610                                 /* as long as the corr. free list is    */
1611                                 /* empty.                               */
1612 void GC_reclaim_or_delete_all();
1613                                 /* Arrange for all reclaim lists to be  */
1614                                 /* empty.  Judiciously choose between   */
1615                                 /* sweeping and discarding each page.   */
1616 GC_bool GC_reclaim_all(/* GC_stop_func f*/);
1617                                 /* Reclaim all blocks.  Abort (in a     */
1618                                 /* consistent state) if f returns TRUE. */
1619 GC_bool GC_block_empty(/* hhdr */); /* Block completely unmarked?       */
1620 GC_bool GC_never_stop_func();   /* Returns FALSE.               */
1621 GC_bool GC_try_to_collect_inner(/* GC_stop_func f */);
1622                                 /* Collect; caller must have acquired   */
1623                                 /* lock and disabled signals.           */
1624                                 /* Collection is aborted if f returns   */
1625                                 /* TRUE.  Returns TRUE if it completes  */
1626                                 /* successfully.                        */
1627 # define GC_gcollect_inner() \
1628         (void) GC_try_to_collect_inner(GC_never_stop_func)
1629 void GC_finish_collection();    /* Finish collection.  Mark bits are    */
1630                                 /* consistent and lock is still held.   */
1631 GC_bool GC_collect_or_expand(/* needed_blocks */);
1632                                 /* Collect or expand heap in an attempt */
1633                                 /* make the indicated number of free    */
1634                                 /* blocks available.  Should be called  */
1635                                 /* until the blocks are available or    */
1636                                 /* until it fails by returning FALSE.   */
1637 GC_API void GC_init();          /* Initialize collector.                */
1638 void GC_collect_a_little_inner(/* int n */);
1639                                 /* Do n units worth of garbage          */
1640                                 /* collection work, if appropriate.     */
1641                                 /* A unit is an amount appropriate for  */
1642                                 /* HBLKSIZE bytes of allocation.        */
1643 ptr_t GC_generic_malloc(/* bytes, kind */);
1644                                 /* Allocate an object of the given      */
1645                                 /* kind.  By default, there are only    */
1646                                 /* a few kinds: composite(pointerfree), */
1647                                 /* atomic, uncollectable, etc.          */
1648                                 /* We claim it's possible for clever    */
1649                                 /* client code that understands GC      */
1650                                 /* internals to add more, e.g. to       */
1651                                 /* communicate object layout info       */
1652                                 /* to the collector.                    */
1653 ptr_t GC_generic_malloc_ignore_off_page(/* bytes, kind */);
1654                                 /* As above, but pointers past the      */
1655                                 /* first page of the resulting object   */
1656                                 /* are ignored.                         */
1657 ptr_t GC_generic_malloc_inner(/* bytes, kind */);
1658                                 /* Ditto, but I already hold lock, etc. */
1659 ptr_t GC_generic_malloc_words_small GC_PROTO((size_t words, int kind));
1660                                 /* As above, but size in units of words */
1661                                 /* Bypasses MERGE_SIZES.  Assumes       */
1662                                 /* words <= MAXOBJSZ.                   */
1663 ptr_t GC_generic_malloc_inner_ignore_off_page(/* bytes, kind */);
1664                                 /* Allocate an object, where            */
1665                                 /* the client guarantees that there     */
1666                                 /* will always be a pointer to the      */
1667                                 /* beginning of the object while the    */
1668                                 /* object is live.                      */
1669 ptr_t GC_allocobj(/* sz_inn_words, kind */);
1670                                 /* Make the indicated                   */
1671                                 /* free list nonempty, and return its   */
1672                                 /* head.                                */
1673
1674 void GC_init_headers();
1675 GC_bool GC_install_header(/*h*/);
1676                                 /* Install a header for block h.        */
1677                                 /* Return FALSE on failure.             */
1678 GC_bool GC_install_counts(/*h, sz*/);
1679                                 /* Set up forwarding counts for block   */
1680                                 /* h of size sz.                        */
1681                                 /* Return FALSE on failure.             */
1682 void GC_remove_header(/*h*/);
1683                                 /* Remove the header for block h.       */
1684 void GC_remove_counts(/*h, sz*/);
1685                                 /* Remove forwarding counts for h.      */
1686 hdr * GC_find_header(/*p*/);    /* Debugging only.                      */
1687
1688 void GC_finalize();     /* Perform all indicated finalization actions   */
1689                         /* on unmarked objects.                         */
1690                         /* Unreachable finalizable objects are enqueued */
1691                         /* for processing by GC_invoke_finalizers.      */
1692                         /* Invoked with lock.                           */
1693
1694 void GC_add_to_heap(/*p, bytes*/);
1695                         /* Add a HBLKSIZE aligned chunk to the heap.    */
1696
1697 void GC_print_obj(/* ptr_t p */);
1698                         /* P points to somewhere inside an object with  */
1699                         /* debugging info.  Print a human readable      */
1700                         /* description of the object to stderr.         */
1701 ptr_t GC_debug_object_start(/* ptr_t p */);
1702                         /* P points to the start of an object that may  */
1703                         /* have debug info at its head.  Return the     */
1704                         /* start of the real data.                      */
1705 extern void (*GC_check_heap)();
1706                         /* Check that all objects in the heap with      */
1707                         /* debugging info are intact.  Print            */
1708                         /* descriptions of any that are not.            */
1709 extern void (*GC_print_heap_obj)(/* ptr_t p */);
1710                         /* If possible print s followed by a more       */
1711                         /* detailed description of the object           */
1712                         /* referred to by p.                            */
1713
1714 /* Memory unmapping: */
1715 #ifdef USE_MUNMAP
1716   void GC_unmap_old(void);
1717   void GC_merge_unmapped(void);
1718   void GC_unmap(ptr_t start, word bytes);
1719   void GC_remap(ptr_t start, word bytes);
1720   void GC_unmap_gap(ptr_t start1, word bytes1, ptr_t start2, word bytes2);
1721 #endif
1722
1723 /* Virtual dirty bit implementation:            */
1724 /* Each implementation exports the following:   */
1725 void GC_read_dirty();   /* Retrieve dirty bits. */
1726 GC_bool GC_page_was_dirty(/* struct hblk * h  */);
1727                         /* Read retrieved dirty bits.   */
1728 GC_bool GC_page_was_ever_dirty(/* struct hblk * h  */);
1729                         /* Could the page contain valid heap pointers?  */
1730 void GC_is_fresh(/* struct hblk * h, word number_of_blocks  */);
1731                         /* Assert the region currently contains no      */
1732                         /* valid pointers.                              */
1733 void GC_write_hint(/* struct hblk * h  */);
1734                         /* h is about to be written.    */
1735 void GC_dirty_init();
1736
1737 /* Slow/general mark bit manipulation: */
1738 GC_API GC_bool GC_is_marked();
1739 void GC_clear_mark_bit();
1740 void GC_set_mark_bit();
1741
1742 /* Stubborn objects: */
1743 void GC_read_changed(); /* Analogous to GC_read_dirty */
1744 GC_bool GC_page_was_changed(/* h */);   /* Analogous to GC_page_was_dirty */
1745 void GC_clean_changing_list();  /* Collect obsolete changing list entries */
1746 void GC_stubborn_init();
1747
1748 /* Debugging print routines: */
1749 void GC_print_block_list();
1750 void GC_print_hblkfreelist();
1751 void GC_print_heap_sects();
1752 void GC_print_static_roots();
1753 void GC_dump();
1754
1755 #ifdef KEEP_BACK_PTRS
1756    void GC_store_back_pointer(ptr_t source, ptr_t dest);
1757    void GC_marked_for_finalization(ptr_t dest);
1758 #  define GC_STORE_BACK_PTR(source, dest) GC_store_back_pointer(source, dest)
1759 #  define GC_MARKED_FOR_FINALIZATION(dest) GC_marked_for_finalization(dest)
1760 #else
1761 #  define GC_STORE_BACK_PTR(source, dest)
1762 #  define GC_MARKED_FOR_FINALIZATION(dest)
1763 #endif
1764
1765 /* Make arguments appear live to compiler */
1766 # ifdef __WATCOMC__
1767   void GC_noop(void*, ...);
1768 # else
1769   GC_API void GC_noop();
1770 # endif
1771
1772 void GC_noop1(/* word arg */);
1773
1774 /* Logging and diagnostic output:       */
1775 GC_API void GC_printf GC_PROTO((char * format, long, long, long, long, long, long));
1776                         /* A version of printf that doesn't allocate,   */
1777                         /* is restricted to long arguments, and         */
1778                         /* (unfortunately) doesn't use varargs for      */
1779                         /* portability.  Restricted to 6 args and       */
1780                         /* 1K total output length.                      */
1781                         /* (We use sprintf.  Hopefully that doesn't     */
1782                         /* allocate for long arguments.)                */
1783 # define GC_printf0(f) GC_printf(f, 0l, 0l, 0l, 0l, 0l, 0l)
1784 # define GC_printf1(f,a) GC_printf(f, (long)a, 0l, 0l, 0l, 0l, 0l)
1785 # define GC_printf2(f,a,b) GC_printf(f, (long)a, (long)b, 0l, 0l, 0l, 0l)
1786 # define GC_printf3(f,a,b,c) GC_printf(f, (long)a, (long)b, (long)c, 0l, 0l, 0l)
1787 # define GC_printf4(f,a,b,c,d) GC_printf(f, (long)a, (long)b, (long)c, \
1788                                             (long)d, 0l, 0l)
1789 # define GC_printf5(f,a,b,c,d,e) GC_printf(f, (long)a, (long)b, (long)c, \
1790                                               (long)d, (long)e, 0l)
1791 # define GC_printf6(f,a,b,c,d,e,g) GC_printf(f, (long)a, (long)b, (long)c, \
1792                                                 (long)d, (long)e, (long)g)
1793
1794 void GC_err_printf(/* format, a, b, c, d, e, f */);
1795 # define GC_err_printf0(f) GC_err_puts(f)
1796 # define GC_err_printf1(f,a) GC_err_printf(f, (long)a, 0l, 0l, 0l, 0l, 0l)
1797 # define GC_err_printf2(f,a,b) GC_err_printf(f, (long)a, (long)b, 0l, 0l, 0l, 0l)
1798 # define GC_err_printf3(f,a,b,c) GC_err_printf(f, (long)a, (long)b, (long)c, \
1799                                                   0l, 0l, 0l)
1800 # define GC_err_printf4(f,a,b,c,d) GC_err_printf(f, (long)a, (long)b, \
1801                                                     (long)c, (long)d, 0l, 0l)
1802 # define GC_err_printf5(f,a,b,c,d,e) GC_err_printf(f, (long)a, (long)b, \
1803                                                       (long)c, (long)d, \
1804                                                       (long)e, 0l)
1805 # define GC_err_printf6(f,a,b,c,d,e,g) GC_err_printf(f, (long)a, (long)b, \
1806                                                         (long)c, (long)d, \
1807                                                         (long)e, (long)g)
1808                         /* Ditto, writes to stderr.                     */
1809
1810 void GC_err_puts(/* char *s */);
1811                         /* Write s to stderr, don't buffer, don't add   */
1812                         /* newlines, don't ...                          */
1813
1814
1815 #   ifdef GC_ASSERTIONS
1816 #       define GC_ASSERT(expr) if(!(expr)) {\
1817                 GC_err_printf2("Assertion failure: %s:%ld\n", \
1818                                 __FILE__, (unsigned long)__LINE__); \
1819                 ABORT("assertion failure"); }
1820 #   else
1821 #       define GC_ASSERT(expr)
1822 #   endif
1823
1824 # endif /* GC_PRIVATE_H */