path: root/boehm-gc/gc_priv.h

/* 
 * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
 * Copyright (c) 1991-1994 by Xerox Corporation.  All rights reserved.
 * Copyright (c) 1996-1999 by Silicon Graphics.  All rights reserved.
 * Copyright (c) 1999 by Hewlett-Packard Company. All rights reserved.
 *
 *
 * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
 * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
 *
 * Permission is hereby granted to use or copy this program
 * for any purpose,  provided the above notices are retained on all copies.
 * Permission to modify the code and to distribute modified code is granted,
 * provided the above notices are retained, and a notice that the code was
 * modified is included with the above copyright notice.
 */
/* Boehm, February 16, 1996 2:30 pm PST */
 

# ifndef GC_PRIVATE_H
# define GC_PRIVATE_H

#if defined(mips) && defined(SYSTYPE_BSD) && defined(sony_news)
    /* sony RISC NEWS, NEWSOS 4 */
#   define BSD_TIME
/*    typedef long ptrdiff_t;   -- necessary on some really old systems	*/
#endif

#if defined(mips) && defined(SYSTYPE_BSD43)
    /* MIPS RISCOS 4 */
#   define BSD_TIME
#endif

#ifdef BSD_TIME
#   include <sys/types.h>
#   include <sys/time.h>
#   include <sys/resource.h>
#endif /* BSD_TIME */

# ifndef GC_H
#   include "gc.h"
# endif

typedef GC_word word;
typedef GC_signed_word signed_word;

# ifndef GCCONFIG_H
#   include "gcconfig.h"
# endif

# ifndef HEADERS_H
#   include "gc_hdrs.h"
# endif

typedef int GC_bool;
# define TRUE 1
# define FALSE 0

typedef char * ptr_t;	/* A generic pointer to which we can add	*/
			/* byte displacements.				*/
			/* Preferably identical to caddr_t, if it 	*/
			/* exists.					*/
			
#if defined(__STDC__)
#   include <stdlib.h>
#   if !(defined( sony_news ) )
#       include <stddef.h>
#   endif
#   define VOLATILE volatile
#else
#   ifdef MSWIN32
#   	include <stdlib.h>
#   endif
#   define VOLATILE
#endif

#define CONST GC_CONST

#if 0 /* was once defined for AMIGA */
#   define GC_FAR __far
#else
#   define GC_FAR
#endif


/*********************************/
/*                               */
/* Definitions for conservative  */
/* collector                     */
/*                               */
/*********************************/

/*********************************/
/*                               */
/* Easily changeable parameters  */
/*                               */
/*********************************/

#define STUBBORN_ALLOC	/* Define stubborn allocation primitives	*/
#if defined(SRC_M3) || defined(SMALL_CONFIG)
# undef STUBBORN_ALLOC
#endif


/* #define ALL_INTERIOR_POINTERS */
		    /* Forces all pointers into the interior of an 	*/
		    /* object to be considered valid.  Also causes the	*/
		    /* sizes of all objects to be inflated by at least 	*/
		    /* one byte.  This should suffice to guarantee	*/
		    /* that in the presence of a compiler that does	*/
		    /* not perform garbage-collector-unsafe		*/
		    /* optimizations, all portable, strictly ANSI	*/
		    /* conforming C programs should be safely usable	*/
		    /* with malloc replaced by GC_malloc and free	*/
		    /* calls removed.  There are several disadvantages: */
		    /* 1. There are probably no interesting, portable,	*/
		    /*    strictly ANSI	conforming C programs.		*/
		    /* 2. This option makes it hard for the collector	*/
		    /*    to allocate space that is not ``pointed to''  */
		    /*    by integers, etc.  Under SunOS 4.X with a 	*/
		    /*    statically linked libc, we empiricaly		*/
		    /*    observed that it would be difficult to 	*/
		    /*	  allocate individual objects larger than 100K.	*/
		    /* 	  Even if only smaller objects are allocated,	*/
		    /*    more swap space is likely to be needed.       */
		    /*    Fortunately, much of this will never be	*/
		    /*    touched.					*/
		    /* If you can easily avoid using this option, do.	*/
		    /* If not, try to keep individual objects small.	*/
		    
#define PRINTSTATS  /* Print garbage collection statistics          	*/
		    /* For less verbose output, undefine in reclaim.c 	*/

#define PRINTTIMES  /* Print the amount of time consumed by each garbage   */
		    /* collection.                                         */

#define PRINTBLOCKS /* Print object sizes associated with heap blocks,     */
		    /* whether the objects are atomic or composite, and    */
		    /* whether or not the block was found to be empty      */
		    /* during the reclaim phase.  Typically generates       */
		    /* about one screenful per garbage collection.         */
#undef PRINTBLOCKS

#ifdef SILENT
#  ifdef PRINTSTATS
#    undef PRINTSTATS
#  endif
#  ifdef PRINTTIMES
#    undef PRINTTIMES
#  endif
#  ifdef PRINTNBLOCKS
#    undef PRINTNBLOCKS
#  endif
#endif

#if defined(PRINTSTATS) && !defined(GATHERSTATS)
#   define GATHERSTATS
#endif

#ifdef FINALIZE_ON_DEMAND
#   define GC_INVOKE_FINALIZERS()
#else
#   define GC_INVOKE_FINALIZERS() (void)GC_invoke_finalizers()
#endif

#define MERGE_SIZES /* Round up some object sizes, so that fewer distinct */
		    /* free lists are actually maintained.  This applies  */
		    /* only to the top level routines in misc.c, not to   */
		    /* user generated code that calls GC_allocobj and     */
		    /* GC_allocaobj directly.                             */
		    /* Slows down average programs slightly.  May however */
		    /* substantially reduce fragmentation if allocation   */
		    /* request sizes are widely scattered.                */
		    /* May save significant amounts of space for obj_map  */
		    /* entries.						  */

/* ALIGN_DOUBLE requires MERGE_SIZES at present. */
# if defined(ALIGN_DOUBLE) && !defined(MERGE_SIZES)
#   define MERGE_SIZES
# endif

#if defined(ALL_INTERIOR_POINTERS) && !defined(DONT_ADD_BYTE_AT_END)
# define ADD_BYTE_AT_END
#endif


# ifndef LARGE_CONFIG
#   define MINHINCR 16	/* Minimum heap increment, in blocks of HBLKSIZE  */
			/* Must be multiple of largest page size.	  */
#   define MAXHINCR 512	/* Maximum heap increment, in blocks              */
# else
#   define MINHINCR 64
#   define MAXHINCR 4096
# endif

# define TIME_LIMIT 50	   /* We try to keep pause times from exceeding	 */
			   /* this by much. In milliseconds.		 */

# define BL_LIMIT GC_black_list_spacing
			   /* If we need a block of N bytes, and we have */
			   /* a block of N + BL_LIMIT bytes available, 	 */
			   /* and N > BL_LIMIT,				 */
			   /* but all possible positions in it are 	 */
			   /* blacklisted, we just use it anyway (and	 */
			   /* print a warning, if warnings are enabled). */
			   /* This risks subsequently leaking the block	 */
			   /* due to a false reference.  But not using	 */
			   /* the block risks unreasonable immediate	 */
			   /* heap growth.				 */

/*********************************/
/*                               */
/* Stack saving for debugging	 */
/*                               */
/*********************************/

#ifdef SAVE_CALL_CHAIN

/*
 * Number of frames and arguments to save in objects allocated by
 * debugging allocator.
 */
#   define NFRAMES 6	/* Number of frames to save. Even for		*/
			/* alignment reasons.				*/
#   define NARGS 2	/* Mumber of arguments to save for each call.	*/

#   define NEED_CALLINFO

/* Fill in the pc and argument information for up to NFRAMES of my	*/
/* callers.  Ignore my frame and my callers frame.			*/
void GC_save_callers (/* struct callinfo info[NFRAMES] */);

void GC_print_callers (/* struct callinfo info[NFRAMES] */);

#else

# ifdef GC_ADD_CALLER
#   define NFRAMES 1
#   define NARGS 0
#   define NEED_CALLINFO
# endif

#endif

#ifdef NEED_CALLINFO
    struct callinfo {
	word ci_pc;
#	if NARGS > 0
	    word ci_arg[NARGS];	/* bit-wise complement to avoid retention */
#	endif
#	if defined(ALIGN_DOUBLE) && (NFRAMES * (NARGS + 1)) % 2 == 1
	    /* Likely alignment problem. */
	    word ci_dummy;
#	endif
    };
#endif


/*********************************/
/*                               */
/* OS interface routines	 */
/*                               */
/*********************************/

#ifdef BSD_TIME
#   undef CLOCK_TYPE
#   undef GET_TIME
#   undef MS_TIME_DIFF
#   define CLOCK_TYPE struct timeval
#   define GET_TIME(x) { struct rusage rusage; \
			 getrusage (RUSAGE_SELF,  &rusage); \
			 x = rusage.ru_utime; }
#   define MS_TIME_DIFF(a,b) ((double) (a.tv_sec - b.tv_sec) * 1000.0 \
                               + (double) (a.tv_usec - b.tv_usec) / 1000.0)
#else /* !BSD_TIME */
# ifdef MSWIN32
#   include <windows.h>
#   include <winbase.h>
#   define CLOCK_TYPE DWORD
#   define GET_TIME(x) x = GetTickCount()
#   define MS_TIME_DIFF(a,b) ((long)((a)-(b)))
# else /* !MSWIN32, !BSD_TIME */
#   include <time.h>
#   if !defined(__STDC__) && defined(SPARC) && defined(SUNOS4)
      clock_t clock();	/* Not in time.h, where it belongs	*/
#   endif
#   if defined(FREEBSD) && !defined(CLOCKS_PER_SEC)
#     include <machine/limits.h>
#     define CLOCKS_PER_SEC CLK_TCK
#   endif
#   if !defined(CLOCKS_PER_SEC)
#     define CLOCKS_PER_SEC 1000000
/*
 * This is technically a bug in the implementation.  ANSI requires that
 * CLOCKS_PER_SEC be defined.  But at least under SunOS4.1.1, it isn't.
 * Also note that the combination of ANSI C and POSIX is incredibly gross
 * here. The type clock_t is used by both clock() and times().  But on
 * some machines these use different notions of a clock tick,  CLOCKS_PER_SEC
 * seems to apply only to clock.  Hence we use it here.  On many machines,
 * including SunOS, clock actually uses units of microseconds (which are
 * not really clock ticks).
 */
#   endif
#   define CLOCK_TYPE clock_t
#   define GET_TIME(x) x = clock()
#   define MS_TIME_DIFF(a,b) ((unsigned long) \
		(1000.0*(double)((a)-(b))/(double)CLOCKS_PER_SEC))
# endif /* !MSWIN32 */
#endif /* !BSD_TIME */

/* We use bzero and bcopy internally.  They may not be available.	*/
# if defined(SPARC) && defined(SUNOS4)
#   define BCOPY_EXISTS
# endif
# if defined(M68K) && defined(AMIGA)
#   define BCOPY_EXISTS
# endif
# if defined(M68K) && defined(NEXT)
#   define BCOPY_EXISTS
# endif
# if defined(VAX)
#   define BCOPY_EXISTS
# endif
# if defined(AMIGA)
#   include <string.h>
#   define BCOPY_EXISTS
# endif

# ifndef BCOPY_EXISTS
#   include <string.h>
#   define BCOPY(x,y,n) memcpy(y, x, (size_t)(n))
#   define BZERO(x,n)  memset(x, 0, (size_t)(n))
# else
#   define BCOPY(x,y,n) bcopy((char *)(x),(char *)(y),(int)(n))
#   define BZERO(x,n) bzero((char *)(x),(int)(n))
# endif

/* HBLKSIZE aligned allocation.  0 is taken to mean failure 	*/
/* space is assumed to be cleared.				*/
/* In the case os USE_MMAP, the argument must also be a 	*/
/* physical page size.						*/
/* GET_MEM is currently not assumed to retrieve 0 filled space, */
/* though we should perhaps take advantage of the case in which */
/* does.							*/
# ifdef PCR
    char * real_malloc();
#   define GET_MEM(bytes) HBLKPTR(real_malloc((size_t)bytes + GC_page_size) \
				  + GC_page_size-1)
# else
#   ifdef OS2
      void * os2_alloc(size_t bytes);
#     define GET_MEM(bytes) HBLKPTR((ptr_t)os2_alloc((size_t)bytes \
				    + GC_page_size) \
                                    + GC_page_size-1)
#   else
#     if defined(AMIGA) || defined(NEXT) || defined(MACOSX) || defined(DOS4GW)
#       define GET_MEM(bytes) HBLKPTR((size_t) \
				      calloc(1, (size_t)bytes + GC_page_size) \
                                      + GC_page_size-1)
#     else
#	ifdef MSWIN32
          extern ptr_t GC_win32_get_mem();
#         define GET_MEM(bytes) (struct hblk *)GC_win32_get_mem(bytes)
#	else
#	  ifdef MACOS
#	    if defined(USE_TEMPORARY_MEMORY)
		extern Ptr GC_MacTemporaryNewPtr(size_t size,
						 Boolean clearMemory);
#               define GET_MEM(bytes) HBLKPTR( \
		    GC_MacTemporaryNewPtr(bytes + GC_page_size, true) \
		    + GC_page_size-1)
#	    else
#         	    define GET_MEM(bytes) HBLKPTR( \
			NewPtrClear(bytes + GC_page_size) + GC_page_size-1)
#	    endif
#	  else
              extern ptr_t GC_unix_get_mem();
#             define GET_MEM(bytes) (struct hblk *)GC_unix_get_mem(bytes)
#	  endif
#	endif
#     endif
#   endif
# endif

/*
 * Mutual exclusion between allocator/collector routines.
 * Needed if there is more than one allocator thread.
 * FASTLOCK() is assumed to try to acquire the lock in a cheap and
 * dirty way that is acceptable for a few instructions, e.g. by
 * inhibiting preemption.  This is assumed to have succeeded only
 * if a subsequent call to FASTLOCK_SUCCEEDED() returns TRUE.
 * FASTUNLOCK() is called whether or not FASTLOCK_SUCCEEDED().
 * If signals cannot be tolerated with the FASTLOCK held, then
 * FASTLOCK should disable signals.  The code executed under
 * FASTLOCK is otherwise immune to interruption, provided it is
 * not restarted.
 * DCL_LOCK_STATE declares any local variables needed by LOCK and UNLOCK
 * and/or DISABLE_SIGNALS and ENABLE_SIGNALS and/or FASTLOCK.
 * (There is currently no equivalent for FASTLOCK.)
 */  
# ifdef THREADS
#  ifdef PCR_OBSOLETE	/* Faster, but broken with multiple lwp's	*/
#    include  "th/PCR_Th.h"
#    include  "th/PCR_ThCrSec.h"
     extern struct PCR_Th_MLRep GC_allocate_ml;
#    define DCL_LOCK_STATE  PCR_sigset_t GC_old_sig_mask
#    define LOCK() PCR_Th_ML_Acquire(&GC_allocate_ml) 
#    define UNLOCK() PCR_Th_ML_Release(&GC_allocate_ml)
#    define FASTLOCK() PCR_ThCrSec_EnterSys()
     /* Here we cheat (a lot): */
#        define FASTLOCK_SUCCEEDED() (*(int *)(&GC_allocate_ml) == 0)
		/* TRUE if nobody currently holds the lock */
#    define FASTUNLOCK() PCR_ThCrSec_ExitSys()
#  endif
#  ifdef PCR
#    include <base/PCR_Base.h>
#    include <th/PCR_Th.h>
     extern PCR_Th_ML GC_allocate_ml;
#    define DCL_LOCK_STATE \
	 PCR_ERes GC_fastLockRes; PCR_sigset_t GC_old_sig_mask
#    define LOCK() PCR_Th_ML_Acquire(&GC_allocate_ml)
#    define UNLOCK() PCR_Th_ML_Release(&GC_allocate_ml)
#    define FASTLOCK() (GC_fastLockRes = PCR_Th_ML_Try(&GC_allocate_ml))
#    define FASTLOCK_SUCCEEDED() (GC_fastLockRes == PCR_ERes_okay)
#    define FASTUNLOCK()  {\
        if( FASTLOCK_SUCCEEDED() ) PCR_Th_ML_Release(&GC_allocate_ml); }
#  endif
#  ifdef SRC_M3
     extern word RT0u__inCritical;
#    define LOCK() RT0u__inCritical++
#    define UNLOCK() RT0u__inCritical--
#  endif
#  ifdef SOLARIS_THREADS
#    include <thread.h>
#    include <signal.h>
     extern mutex_t GC_allocate_ml;
#    define LOCK() mutex_lock(&GC_allocate_ml);
#    define UNLOCK() mutex_unlock(&GC_allocate_ml);
#  endif
#  if defined(LINUX_THREADS) 
#   if defined(I386)|| defined(POWERPC) || defined(ALPHA) || defined(IA64) \
    || defined(M68K) || defined(SPARC)
#    include <pthread.h>
#    define USE_SPIN_LOCK
#    if defined(I386)
       inline static int GC_test_and_set(volatile unsigned int *addr) {
	  int oldval;
	  /* Note: the "xchg" instruction does not need a "lock" prefix */
	  __asm__ __volatile__("xchgl %0, %1"
		: "=r"(oldval), "=m"(*(addr))
		: "0"(1), "m"(*(addr)));
	  return oldval;
       }
#    endif
#    if defined(IA64)
       inline static int GC_test_and_set(volatile unsigned int *addr) {
	  int oldval;
	  __asm__ __volatile__("xchg4 %0=%1,%2"
		: "=r"(oldval), "=m"(*addr)
		: "r"(1), "1"(*addr));
	  return oldval;
       }
       inline static void GC_clear(volatile unsigned int *addr) {
	 __asm__ __volatile__("st4.rel %0=r0" : "=m" (*addr));
       }
#      define GC_CLEAR_DEFINED
#    endif
#    ifdef SPARC
       inline static int GC_test_and_set(volatile unsigned int *addr) {
	 int oldval;

	 __asm__ __volatile__("ldstub %1,%0"
	 : "=r"(oldval), "=m"(*addr)
	 : "m"(*addr));
	 return oldval;
       }
#    endif
#    ifdef M68K
       /* Contributed by Tony Mantler.  I'm not sure how well it was	*/
       /* tested.							*/
       inline static int GC_test_and_set(volatile unsigned int *addr) {
          char oldval; /* this must be no longer than 8 bits */

          /* The return value is semi-phony. */
          /* 'tas' sets bit 7 while the return */
          /* value pretends bit 0 was set */
          __asm__ __volatile__(
                 "tas %1@; sne %0; negb %0"
                 : "=d" (oldval)
                 : "a" (addr));
          return oldval;
       }
#    endif
#    if defined(POWERPC)
      inline static int GC_test_and_set(volatile unsigned int *addr) {
        int oldval;
        int temp = 1; // locked value

        __asm__ __volatile__(
               "1:\tlwarx %0,0,%3\n"   // load and reserve
               "\tcmpwi %0, 0\n"       // if load is
               "\tbne 2f\n"            //   non-zero, return already set
               "\tstwcx. %2,0,%1\n"    // else store conditional
               "\tbne- 1b\n"           // retry if lost reservation
               "2:\t\n"                // oldval is zero if we set
              : "=&r"(oldval), "=p"(addr)
              : "r"(temp), "1"(addr)
              : "memory");
        return (int)oldval;
      }
      inline static void GC_clear(volatile unsigned int *addr) {
	 __asm__ __volatile__("eieio");
         *(addr) = 0;
      }
#     define GC_CLEAR_DEFINED
#    endif
#    ifdef ALPHA
      inline static int GC_test_and_set(volatile unsigned int * addr)
      {
        unsigned long oldvalue;
        unsigned long temp;

        __asm__ __volatile__(
                             "1:     ldl_l %0,%1\n"
                             "       and %0,%3,%2\n"
                             "       bne %2,2f\n"
                             "       xor %0,%3,%0\n"
                             "       stl_c %0,%1\n"
                             "       beq %0,3f\n"
                             "       mb\n"
                             "2:\n"
                             ".section .text2,\"ax\"\n"
                             "3:     br 1b\n"
                             ".previous"
                             :"=&r" (temp), "=m" (*addr), "=&r" (oldvalue)
                             :"Ir" (1), "m" (*addr));

        return oldvalue;
      }
      /* Should probably also define GC_clear, since it needs	*/
      /* a memory barrier ??					*/
#    endif /* ALPHA */
#    ifdef ARM32
      inline static int GC_test_and_set(volatile unsigned int *addr) {
        int oldval;
        /* SWP on ARM is very similar to XCHG on x86.  Doesn't lock the
         * bus because there are no SMP ARM machines.  If/when there are,
         * this code will likely need to be updated. */
        /* See linuxthreads/sysdeps/arm/pt-machine.h in glibc-2.1 */
        __asm__ __volatile__("swp %0, %1, [%2]"
      			     : "=r"(oldval)
      			     : "r"(1), "r"(addr));
        return oldval;
      }
#    endif
#    ifndef GC_CLEAR_DEFINED
       inline static void GC_clear(volatile unsigned int *addr) {
	  /* Try to discourage gcc from moving anything past this. */
	  __asm__ __volatile__(" ");
          *(addr) = 0;
       }
#    endif

     extern volatile unsigned int GC_allocate_lock;
     extern pthread_t GC_lock_holder;
     extern void GC_lock(void);
	/* Allocation lock holder.  Only set if acquired by client through */
	/* GC_call_with_alloc_lock.					   */
#    define SET_LOCK_HOLDER() GC_lock_holder = pthread_self()
#    define NO_THREAD (pthread_t)(-1)
#    define UNSET_LOCK_HOLDER() GC_lock_holder = NO_THREAD
#    define I_HOLD_LOCK() (pthread_equal(GC_lock_holder, pthread_self()))
#    define LOCK() \
		{ if (GC_test_and_set(&GC_allocate_lock)) GC_lock(); }
#    define UNLOCK() \
		GC_clear(&GC_allocate_lock)
     extern VOLATILE GC_bool GC_collecting;
#    define ENTER_GC() \
		{ \
		    GC_collecting = 1; \
		}
#    define EXIT_GC() GC_collecting = 0;
#   else /* LINUX_THREADS on hardware for which we don't know how	*/
	 /* to do test and set.						*/
#    include <pthread.h>
     extern pthread_mutex_t GC_allocate_ml;
#    define LOCK() pthread_mutex_lock(&GC_allocate_ml)
#    define UNLOCK() pthread_mutex_unlock(&GC_allocate_ml)
#   endif
#  endif /* LINUX_THREADS */
#  if defined(HPUX_THREADS)
#    include <pthread.h>
     extern pthread_mutex_t GC_allocate_ml;
#    define LOCK() pthread_mutex_lock(&GC_allocate_ml)
#    define UNLOCK() pthread_mutex_unlock(&GC_allocate_ml)
#  endif
#  if defined(IRIX_THREADS) || defined(IRIX_JDK_THREADS) 
     /* This may also eventually be appropriate for HPUX_THREADS */
#    include <pthread.h>
#    ifndef HPUX_THREADS
	/* This probably should never be included, but I can't test	*/
	/* on Irix anymore.						*/
#       include <mutex.h>
#    endif

#    ifndef HPUX_THREADS
#      if __mips < 3 || !(defined (_ABIN32) || defined(_ABI64)) \
	|| !defined(_COMPILER_VERSION) || _COMPILER_VERSION < 700
#        define GC_test_and_set(addr, v) test_and_set(addr,v)
#      else
#	 define GC_test_and_set(addr, v) __test_and_set(addr,v)
#      endif
#    else
       /* I couldn't find a way to do this inline on HP/UX	*/
#    endif
     extern unsigned long GC_allocate_lock;
	/* This is not a mutex because mutexes that obey the (optional) 	*/
	/* POSIX scheduling rules are subject to convoys in high contention	*/
	/* applications.  This is basically a spin lock.			*/
     extern pthread_t GC_lock_holder;
     extern void GC_lock(void);
	/* Allocation lock holder.  Only set if acquired by client through */
	/* GC_call_with_alloc_lock.					   */
#    define SET_LOCK_HOLDER() GC_lock_holder = pthread_self()
#    define NO_THREAD (pthread_t)(-1)
#    define UNSET_LOCK_HOLDER() GC_lock_holder = NO_THREAD
#    define I_HOLD_LOCK() (pthread_equal(GC_lock_holder, pthread_self()))
#    ifdef HPUX_THREADS
#      define LOCK() { if (!GC_test_and_clear(&GC_allocate_lock)) GC_lock(); }
       /* The following is INCORRECT, since the memory model is too weak. */
#      define UNLOCK() { GC_noop1(&GC_allocate_lock); \
			*(volatile unsigned long *)(&GC_allocate_lock) = 1; }
#    else
#      define LOCK() { if (GC_test_and_set(&GC_allocate_lock, 1)) GC_lock(); }
#      if __mips >= 3 && (defined (_ABIN32) || defined(_ABI64)) \
	   && defined(_COMPILER_VERSION) && _COMPILER_VERSION >= 700
#	    define UNLOCK() __lock_release(&GC_allocate_lock)
#      else
	    /* The function call in the following should prevent the	*/
	    /* compiler from moving assignments to below the UNLOCK.	*/
	    /* This is probably not necessary for ucode or gcc 2.8.	*/
	    /* It may be necessary for Ragnarok and future gcc		*/
	    /* versions.						*/
#           define UNLOCK() { GC_noop1(&GC_allocate_lock); \
			*(volatile unsigned long *)(&GC_allocate_lock) = 0; }
#      endif
#    endif
     extern VOLATILE GC_bool GC_collecting;
#    define ENTER_GC() \
		{ \
		    GC_collecting = 1; \
		}
#    define EXIT_GC() GC_collecting = 0;
#  endif /* IRIX_THREADS || IRIX_JDK_THREADS */
#  ifdef WIN32_THREADS
#    include <windows.h>
     GC_API CRITICAL_SECTION GC_allocate_ml;
#    define LOCK() EnterCriticalSection(&GC_allocate_ml);
#    define UNLOCK() LeaveCriticalSection(&GC_allocate_ml);
#  endif
#  ifndef SET_LOCK_HOLDER
#      define SET_LOCK_HOLDER()
#      define UNSET_LOCK_HOLDER()
#      define I_HOLD_LOCK() FALSE
		/* Used on platforms were locks can be reacquired,	*/
		/* so it doesn't matter if we lie.			*/
#  endif
# else
#    define LOCK()
#    define UNLOCK()
# endif
# ifndef SET_LOCK_HOLDER
#   define SET_LOCK_HOLDER()
#   define UNSET_LOCK_HOLDER()
#   define I_HOLD_LOCK() FALSE
		/* Used on platforms were locks can be reacquired,	*/
		/* so it doesn't matter if we lie.			*/
# endif
# ifndef ENTER_GC
#   define ENTER_GC()
#   define EXIT_GC()
# endif

# ifndef DCL_LOCK_STATE
#   define DCL_LOCK_STATE
# endif
# ifndef FASTLOCK
#   define FASTLOCK() LOCK()
#   define FASTLOCK_SUCCEEDED() TRUE
#   define FASTUNLOCK() UNLOCK()
# endif

/* Delay any interrupts or signals that may abort this thread.  Data	*/
/* structures are in a consistent state outside this pair of calls.	*/
/* ANSI C allows both to be empty (though the standard isn't very	*/
/* clear on that point).  Standard malloc implementations are usually	*/
/* neither interruptable nor thread-safe, and thus correspond to	*/
/* empty definitions.							*/
# ifdef PCR
#   define DISABLE_SIGNALS() \
		 PCR_Th_SetSigMask(PCR_allSigsBlocked,&GC_old_sig_mask)
#   define ENABLE_SIGNALS() \
		PCR_Th_SetSigMask(&GC_old_sig_mask, NIL)
# else
#   if defined(SRC_M3) || defined(AMIGA) || defined(SOLARIS_THREADS) \
	|| defined(MSWIN32) || defined(MACOS) || defined(DJGPP) \
	|| defined(NO_SIGNALS) || defined(IRIX_THREADS) \
	|| defined(IRIX_JDK_THREADS) || defined(LINUX_THREADS) 
			/* Also useful for debugging.		*/
	/* Should probably use thr_sigsetmask for SOLARIS_THREADS. */
#     define DISABLE_SIGNALS()
#     define ENABLE_SIGNALS()
#   else
#     define DISABLE_SIGNALS() GC_disable_signals()
	void GC_disable_signals();
#     define ENABLE_SIGNALS() GC_enable_signals()
	void GC_enable_signals();
#   endif
# endif

/*
 * Stop and restart mutator threads.
 */
# ifdef PCR
#     include "th/PCR_ThCtl.h"
#     define STOP_WORLD() \
 	PCR_ThCtl_SetExclusiveMode(PCR_ThCtl_ExclusiveMode_stopNormal, \
 				   PCR_allSigsBlocked, \
 				   PCR_waitForever)
#     define START_WORLD() \
	PCR_ThCtl_SetExclusiveMode(PCR_ThCtl_ExclusiveMode_null, \
 				   PCR_allSigsBlocked, \
 				   PCR_waitForever);
# else
#   if defined(SOLARIS_THREADS) || defined(WIN32_THREADS) \
	|| defined(IRIX_THREADS) || defined(LINUX_THREADS) \
	|| defined(IRIX_JDK_THREADS) || defined(HPUX_THREADS)
      void GC_stop_world();
      void GC_start_world();
#     define STOP_WORLD() GC_stop_world()
#     define START_WORLD() GC_start_world()
#   else
#     define STOP_WORLD()
#     define START_WORLD()
#   endif
# endif

/* Abandon ship */
# ifdef PCR
#   define ABORT(s) PCR_Base_Panic(s)
# else
#   ifdef SMALL_CONFIG
#	define ABORT(msg) abort();
#   else
	GC_API void GC_abort();
#       define ABORT(msg) GC_abort(msg);
#   endif
# endif

/* Exit abnormally, but without making a mess (e.g. out of memory) */
# ifdef PCR
#   define EXIT() PCR_Base_Exit(1,PCR_waitForever)
# else
#   define EXIT() (void)exit(1)
# endif

/* Print warning message, e.g. almost out of memory.	*/
# define WARN(msg,arg) (*GC_current_warn_proc)(msg, (GC_word)(arg))
extern GC_warn_proc GC_current_warn_proc;

/*********************************/
/*                               */
/* Word-size-dependent defines   */
/*                               */
/*********************************/

#if CPP_WORDSZ == 32
#  define WORDS_TO_BYTES(x)   ((x)<<2)
#  define BYTES_TO_WORDS(x)   ((x)>>2)
#  define LOGWL               ((word)5)    /* log[2] of CPP_WORDSZ */
#  define modWORDSZ(n) ((n) & 0x1f)        /* n mod size of word	    */
#  if ALIGNMENT != 4
#	define UNALIGNED
#  endif
#endif

#if CPP_WORDSZ == 64
#  define WORDS_TO_BYTES(x)   ((x)<<3)
#  define BYTES_TO_WORDS(x)   ((x)>>3)
#  define LOGWL               ((word)6)    /* log[2] of CPP_WORDSZ */
#  define modWORDSZ(n) ((n) & 0x3f)        /* n mod size of word	    */
#  if ALIGNMENT != 8
#	define UNALIGNED
#  endif
#endif

#define WORDSZ ((word)CPP_WORDSZ)
#define SIGNB  ((word)1 << (WORDSZ-1))
#define BYTES_PER_WORD      ((word)(sizeof (word)))
#define ONES                ((word)(-1))
#define divWORDSZ(n) ((n) >> LOGWL)	   /* divide n by size of word      */

/*********************/
/*                   */
/*  Size Parameters  */
/*                   */
/*********************/

/*  heap block size, bytes. Should be power of 2 */

#ifndef HBLKSIZE
# ifdef SMALL_CONFIG
#   define CPP_LOG_HBLKSIZE 10
# else
#   if CPP_WORDSZ == 32
#     define CPP_LOG_HBLKSIZE 12
#   else
#     define CPP_LOG_HBLKSIZE 13
#   endif
# endif
#else
# if HBLKSIZE == 512
#   define CPP_LOG_HBLKSIZE 9
# endif
# if HBLKSIZE == 1024
#   define CPP_LOG_HBLKSIZE 10
# endif
# if HBLKSIZE == 2048
#   define CPP_LOG_HBLKSIZE 11
# endif
# if HBLKSIZE == 4096
#   define CPP_LOG_HBLKSIZE 12
# endif
# if HBLKSIZE == 8192
#   define CPP_LOG_HBLKSIZE 13
# endif
# if HBLKSIZE == 16384
#   define CPP_LOG_HBLKSIZE 14
# endif
# ifndef CPP_LOG_HBLKSIZE
    --> fix HBLKSIZE
# endif
# undef HBLKSIZE
#endif
# define CPP_HBLKSIZE (1 << CPP_LOG_HBLKSIZE)
# define LOG_HBLKSIZE   ((word)CPP_LOG_HBLKSIZE)
# define HBLKSIZE ((word)CPP_HBLKSIZE)


/*  max size objects supported by freelist (larger objects may be   */
/*  allocated, but less efficiently)                                */

#define CPP_MAXOBJSZ    BYTES_TO_WORDS(CPP_HBLKSIZE/2)
#define MAXOBJSZ ((word)CPP_MAXOBJSZ)
		
# define divHBLKSZ(n) ((n) >> LOG_HBLKSIZE)

# define HBLK_PTR_DIFF(p,q) divHBLKSZ((ptr_t)p - (ptr_t)q)
	/* Equivalent to subtracting 2 hblk pointers.	*/
	/* We do it this way because a compiler should	*/
	/* find it hard to use an integer division	*/
	/* instead of a shift.  The bundled SunOS 4.1	*/
	/* o.w. sometimes pessimizes the subtraction to	*/
	/* involve a call to .div.			*/
 
# define modHBLKSZ(n) ((n) & (HBLKSIZE-1))
 
# define HBLKPTR(objptr) ((struct hblk *)(((word) (objptr)) & ~(HBLKSIZE-1)))

# define HBLKDISPL(objptr) (((word) (objptr)) & (HBLKSIZE-1))

/* Round up byte allocation requests to integral number of words, etc. */
# ifdef ADD_BYTE_AT_END
#   define ROUNDED_UP_WORDS(n) BYTES_TO_WORDS((n) + WORDS_TO_BYTES(1))
#   ifdef ALIGN_DOUBLE
#       define ALIGNED_WORDS(n) (BYTES_TO_WORDS((n) + WORDS_TO_BYTES(2)) & ~1)
#   else
#       define ALIGNED_WORDS(n) ROUNDED_UP_WORDS(n)
#   endif
#   define SMALL_OBJ(bytes) ((bytes) < WORDS_TO_BYTES(MAXOBJSZ))
#   define ADD_SLOP(bytes) ((bytes)+1)
# else
#   define ROUNDED_UP_WORDS(n) BYTES_TO_WORDS((n) + (WORDS_TO_BYTES(1) - 1))
#   ifdef ALIGN_DOUBLE
#       define ALIGNED_WORDS(n) \
			(BYTES_TO_WORDS((n) + WORDS_TO_BYTES(2) - 1) & ~1)
#   else
#       define ALIGNED_WORDS(n) ROUNDED_UP_WORDS(n)
#   endif
#   define SMALL_OBJ(bytes) ((bytes) <= WORDS_TO_BYTES(MAXOBJSZ))
#   define ADD_SLOP(bytes) (bytes)
# endif
# ifndef MIN_WORDS
    /* MIN_WORDS is the size of the smallest allocated object.	*/
    /* 1 and 2 are the only valid values.			*/
    /* 2 must be used if:					*/
    /* - GC_gcj_malloc can be used for objects of requested	*/
    /*   size smaller than 2 words				*/
#   if defined(GC_GCJ_SUPPORT)
#     define MIN_WORDS 2   	/* Smallest allocated object.	*/
#   else
#     define MIN_WORDS 1
#   endif
# endif


/*
 * Hash table representation of sets of pages.  This assumes it is
 * OK to add spurious entries to sets.
 * Used by black-listing code, and perhaps by dirty bit maintenance code.
 */
 
# ifdef LARGE_CONFIG
#   define LOG_PHT_ENTRIES  17
# else
#   define LOG_PHT_ENTRIES  14	/* Collisions are likely if heap grows	*/
				/* to more than 16K hblks = 64MB.	*/
				/* Each hash table occupies 2K bytes.   */
# endif
# define PHT_ENTRIES ((word)1 << LOG_PHT_ENTRIES)
# define PHT_SIZE (PHT_ENTRIES >> LOGWL)
typedef word page_hash_table[PHT_SIZE];

# define PHT_HASH(addr) ((((word)(addr)) >> LOG_HBLKSIZE) & (PHT_ENTRIES - 1))

# define get_pht_entry_from_index(bl, index) \
		(((bl)[divWORDSZ(index)] >> modWORDSZ(index)) & 1)
# define set_pht_entry_from_index(bl, index) \
		(bl)[divWORDSZ(index)] |= (word)1 << modWORDSZ(index)
# define clear_pht_entry_from_index(bl, index) \
		(bl)[divWORDSZ(index)] &= ~((word)1 << modWORDSZ(index))
	


/********************************************/
/*                                          */
/*    H e a p   B l o c k s                 */
/*                                          */
/********************************************/

/*  heap block header */
#define HBLKMASK   (HBLKSIZE-1)

#define BITS_PER_HBLK (HBLKSIZE * 8)

#define MARK_BITS_PER_HBLK (BITS_PER_HBLK/CPP_WORDSZ)
	   /* upper bound                                    */
	   /* We allocate 1 bit/word.  Only the first word   */
	   /* in each object is actually marked.             */

# ifdef ALIGN_DOUBLE
#   define MARK_BITS_SZ (((MARK_BITS_PER_HBLK + 2*CPP_WORDSZ - 1) \
			  / (2*CPP_WORDSZ))*2)
# else
#   define MARK_BITS_SZ ((MARK_BITS_PER_HBLK + CPP_WORDSZ - 1)/CPP_WORDSZ)
# endif
	   /* Upper bound on number of mark words per heap block  */

struct hblkhdr {
    word hb_sz;  /* If in use, size in words, of objects in the block. */
		 /* if free, the size in bytes of the whole block      */
    struct hblk * hb_next; 	/* Link field for hblk free list	 */
    				/* and for lists of chunks waiting to be */
    				/* reclaimed.				 */
    struct hblk * hb_prev;	/* Backwards link for free list.	*/
    word hb_descr;   		/* object descriptor for marking.  See	*/
    				/* mark.h.				*/
    char* hb_map;	/* A pointer to a pointer validity map of the block. */
    		      	/* See GC_obj_map.				     */
    		     	/* Valid for all blocks with headers.		     */
    		     	/* Free blocks point to GC_invalid_map.		     */
    unsigned char hb_obj_kind;
    			 /* Kind of objects in the block.  Each kind 	*/
    			 /* identifies a mark procedure and a set of 	*/
    			 /* list headers.  Sometimes called regions.	*/
    unsigned char hb_flags;
#	define IGNORE_OFF_PAGE	1	/* Ignore pointers that do not	*/
					/* point to the first page of 	*/
					/* this object.			*/
#	define WAS_UNMAPPED 2	/* This is a free block, which has	*/
				/* been unmapped from the address 	*/
				/* space.				*/
				/* GC_remap must be invoked on it	*/
				/* before it can be reallocated.	*/
				/* Only set with USE_MUNMAP.		*/
    unsigned short hb_last_reclaimed;
    				/* Value of GC_gc_no when block was	*/
    				/* last allocated or swept. May wrap.   */
				/* For a free block, this is maintained */
				/* unly for USE_MUNMAP, and indicates	*/
				/* when the header was allocated, or	*/
				/* when the size of the block last	*/
				/* changed.				*/
    word hb_marks[MARK_BITS_SZ];
			    /* Bit i in the array refers to the             */
			    /* object starting at the ith word (header      */
			    /* INCLUDED) in the heap block.                 */
			    /* The lsb of word 0 is numbered 0.		    */
			    /* Unused bits are invalid, and are 	    */
			    /* occasionally set, e.g for uncollectable	    */
			    /* objects.					    */
};

/*  heap block body */

# define DISCARD_WORDS 0
	/* Number of words to be dropped at the beginning of each block	*/
	/* Must be a multiple of WORDSZ.  May reasonably be nonzero	*/
	/* on machines that don't guarantee longword alignment of	*/
	/* pointers, so that the number of false hits is minimized.	*/
	/* 0 and WORDSZ are probably the only reasonable values.	*/

# define BODY_SZ ((HBLKSIZE-WORDS_TO_BYTES(DISCARD_WORDS))/sizeof(word))

struct hblk {
#   if (DISCARD_WORDS != 0)
        word garbage[DISCARD_WORDS];
#   endif
    word hb_body[BODY_SZ];
};

# define HDR_WORDS ((word)DISCARD_WORDS)
# define HDR_BYTES ((word)WORDS_TO_BYTES(DISCARD_WORDS))

# define OBJ_SZ_TO_BLOCKS(sz) \
    divHBLKSZ(HDR_BYTES + WORDS_TO_BYTES(sz) + HBLKSIZE-1)
    /* Size of block (in units of HBLKSIZE) needed to hold objects of	*/
    /* given sz (in words).						*/

/* Object free list link */
# define obj_link(p) (*(ptr_t *)(p))

/* The type of mark procedures.  This really belongs in gc_mark.h.	*/
/* But we put it here, so that we can avoid scanning the mark proc	*/
/* table.								*/
typedef struct ms_entry * (*mark_proc)(/* word * addr,
					  struct ms_entry *mark_stack_ptr,
					  struct ms_entry *mark_stack_limit,
					  word env */);
# define LOG_MAX_MARK_PROCS 6
# define MAX_MARK_PROCS (1 << LOG_MAX_MARK_PROCS)

/* Root sets.  Logically private to mark_rts.c.  But we don't want the	*/
/* tables scanned, so we put them here.					*/
/* MAX_ROOT_SETS is the maximum number of ranges that can be 	*/
/* registered as static roots. 					*/
# ifdef LARGE_CONFIG
#   define MAX_ROOT_SETS 4096
# else
#   ifdef PCR
#     define MAX_ROOT_SETS 1024
#   else
#     ifdef MSWIN32
#	define MAX_ROOT_SETS 512
	    /* Under NT, we add only written pages, which can result 	*/
	    /* in many small root sets.					*/
#     else
#       define MAX_ROOT_SETS 64
#     endif
#   endif
# endif

# define MAX_EXCLUSIONS (MAX_ROOT_SETS/4)
/* Maximum number of segments that can be excluded from root sets.	*/

/*
 * Data structure for excluded static roots.
 */
struct exclusion {
    ptr_t e_start;
    ptr_t e_end;
};

/* Data structure for list of root sets.				*/
/* We keep a hash table, so that we can filter out duplicate additions.	*/
/* Under Win32, we need to do a better job of filtering overlaps, so	*/
/* we resort to sequential search, and pay the price.			*/
struct roots {
	ptr_t r_start;
	ptr_t r_end;
#	ifndef MSWIN32
	  struct roots * r_next;
#	endif
	GC_bool r_tmp;
	  	/* Delete before registering new dynamic libraries */
};

#ifndef MSWIN32
    /* Size of hash table index to roots.	*/
#   define LOG_RT_SIZE 6
#   define RT_SIZE (1 << LOG_RT_SIZE) /* Power of 2, may be != MAX_ROOT_SETS */
#endif

/* Lists of all heap blocks and free lists	*/
/* as well as other random data structures	*/
/* that should not be scanned by the		*/
/* collector.					*/
/* These are grouped together in a struct	*/
/* so that they can be easily skipped by the	*/
/* GC_mark routine.				*/
/* The ordering is weird to make GC_malloc	*/
/* faster by keeping the important fields	*/
/* sufficiently close together that a		*/
/* single load of a base register will do.	*/
/* Scalars that could easily appear to		*/
/* be pointers are also put here.		*/
/* The main fields should precede any 		*/
/* conditionally included fields, so that	*/
/* gc_inl.h will work even if a different set	*/
/* of macros is defined when the client is	*/
/* compiled.					*/

struct _GC_arrays {
  word _heapsize;
  word _max_heapsize;
  word _requested_heapsize;	/* Heap size due to explicit expansion */
  ptr_t _last_heap_addr;
  ptr_t _prev_heap_addr;
  word _large_free_bytes;
	/* Total bytes contained in blocks on large object free */
	/* list.						*/
  word _words_allocd_before_gc;
		/* Number of words allocated before this	*/
		/* collection cycle.				*/
  word _words_allocd;
  	/* Number of words allocated during this collection cycle */
  word _words_wasted;
  	/* Number of words wasted due to internal fragmentation	*/
  	/* in large objects, or due to dropping blacklisted     */
	/* blocks, since last gc.  Approximate.                 */
  word _words_finalized;
  	/* Approximate number of words in objects (and headers)	*/
  	/* That became ready for finalization in the last 	*/
  	/* collection.						*/
  word _non_gc_bytes_at_gc;
  	/* Number of explicitly managed bytes of storage 	*/
  	/* at last collection.					*/
  word _mem_freed;
  	/* Number of explicitly deallocated words of memory	*/
  	/* since last collection.				*/
  ptr_t _scratch_end_ptr;
  ptr_t _scratch_last_end_ptr;
	/* Used by headers.c, and can easily appear to point to	*/
	/* heap.						*/
  mark_proc _mark_procs[MAX_MARK_PROCS];
  	/* Table of user-defined mark procedures.  There is	*/
	/* a small number of these, which can be referenced	*/
	/* by DS_PROC mark descriptors.  See gc_mark.h.		*/
  ptr_t _objfreelist[MAXOBJSZ+1];
			  /* free list for objects */
  ptr_t _aobjfreelist[MAXOBJSZ+1];
			  /* free list for atomic objs 	*/

  ptr_t _uobjfreelist[MAXOBJSZ+1];
			  /* uncollectable but traced objs 	*/
			  /* objects on this and auobjfreelist  */
			  /* are always marked, except during   */
			  /* garbage collections.		*/
# ifdef ATOMIC_UNCOLLECTABLE
    ptr_t _auobjfreelist[MAXOBJSZ+1];
# endif
			  /* uncollectable but traced objs 	*/

# ifdef GATHERSTATS
    word _composite_in_use;
   		/* Number of words in accessible composite	*/
		/* objects.					*/
    word _atomic_in_use;
   		/* Number of words in accessible atomic		*/
		/* objects.					*/
# endif
# ifdef USE_MUNMAP
    word _unmapped_bytes;
# endif
# ifdef MERGE_SIZES
    unsigned _size_map[WORDS_TO_BYTES(MAXOBJSZ+1)];
    	/* Number of words to allocate for a given allocation request in */
    	/* bytes.							 */
# endif 

# ifdef STUBBORN_ALLOC
    ptr_t _sobjfreelist[MAXOBJSZ+1];
# endif
  			  /* free list for immutable objects	*/
  ptr_t _obj_map[MAXOBJSZ+1];
                       /* If not NIL, then a pointer to a map of valid  */
    		       /* object addresses. _obj_map[sz][i] is j if the	*/
    		       /* address block_start+i is a valid pointer      */
    		       /* to an object at				*/
    		       /* block_start+i&~3 - WORDS_TO_BYTES(j).		*/
    		       /* (If ALL_INTERIOR_POINTERS is defined, then	*/
    		       /* instead ((short *)(hb_map[sz])[i] is j if	*/
    		       /* block_start+WORDS_TO_BYTES(i) is in the	*/
    		       /* interior of an object starting at		*/
    		       /* block_start+WORDS_TO_BYTES(i-j)).		*/
    		       /* It is OBJ_INVALID if				*/
    		       /* block_start+WORDS_TO_BYTES(i) is not		*/
    		       /* valid as a pointer to an object.              */
    		       /* We assume all values of j <= OBJ_INVALID.	*/
    		       /* The zeroth entry corresponds to large objects.*/
#   ifdef ALL_INTERIOR_POINTERS
#	define map_entry_type short
#       define OBJ_INVALID 0x7fff
#	define MAP_ENTRY(map, bytes) \
		(((map_entry_type *)(map))[BYTES_TO_WORDS(bytes)])
#	define MAP_ENTRIES BYTES_TO_WORDS(HBLKSIZE)
#	define MAP_SIZE (MAP_ENTRIES * sizeof(map_entry_type))
#	define OFFSET_VALID(displ) TRUE
#	define CPP_MAX_OFFSET (HBLKSIZE - HDR_BYTES - 1)
#	define MAX_OFFSET ((word)CPP_MAX_OFFSET)
#   else
#	define map_entry_type char
#       define OBJ_INVALID 0x7f
#	define MAP_ENTRY(map, bytes) \
		(map)[bytes]
#	define MAP_ENTRIES HBLKSIZE
#	define MAP_SIZE MAP_ENTRIES
#	define CPP_MAX_OFFSET (WORDS_TO_BYTES(OBJ_INVALID) - 1)	
#	define MAX_OFFSET ((word)CPP_MAX_OFFSET)
# 	define VALID_OFFSET_SZ \
	  (CPP_MAX_OFFSET > WORDS_TO_BYTES(CPP_MAXOBJSZ)? \
	   CPP_MAX_OFFSET+1 \
	   : WORDS_TO_BYTES(CPP_MAXOBJSZ)+1)
  	char _valid_offsets[VALID_OFFSET_SZ];
				/* GC_valid_offsets[i] == TRUE ==> i 	*/
				/* is registered as a displacement.	*/
#	define OFFSET_VALID(displ) GC_valid_offsets[displ]
  	char _modws_valid_offsets[sizeof(word)];
				/* GC_valid_offsets[i] ==>		  */
				/* GC_modws_valid_offsets[i%sizeof(word)] */
#   endif
# ifdef STUBBORN_ALLOC
    page_hash_table _changed_pages;
        /* Stubborn object pages that were changes since last call to	*/
	/* GC_read_changed.						*/
    page_hash_table _prev_changed_pages;
        /* Stubborn object pages that were changes before last call to	*/
	/* GC_read_changed.						*/
# endif
# if defined(PROC_VDB) || defined(MPROTECT_VDB)
    page_hash_table _grungy_pages; /* Pages that were dirty at last 	   */
				     /* GC_read_dirty.			   */
# endif
# ifdef MPROTECT_VDB
    VOLATILE page_hash_table _dirty_pages;	
			/* Pages dirtied since last GC_read_dirty. */
# endif
# ifdef PROC_VDB
    page_hash_table _written_pages;	/* Pages ever dirtied	*/
# endif
# ifdef LARGE_CONFIG
#   if CPP_WORDSZ > 32
#     define MAX_HEAP_SECTS 4096 	/* overflows at roughly 64 GB	   */
#   else
#     define MAX_HEAP_SECTS 768		/* Separately added heap sections. */
#   endif
# else
#   define MAX_HEAP_SECTS 256
# endif
  struct HeapSect {
      ptr_t hs_start; word hs_bytes;
  } _heap_sects[MAX_HEAP_SECTS];
# ifdef MSWIN32
    ptr_t _heap_bases[MAX_HEAP_SECTS];
    		/* Start address of memory regions obtained from kernel. */
# endif
  struct roots _static_roots[MAX_ROOT_SETS];
# ifndef MSWIN32
    struct roots * _root_index[RT_SIZE];
# endif
  struct exclusion _excl_table[MAX_EXCLUSIONS];
  /* Block header index; see gc_headers.h */
  bottom_index * _all_nils;
  bottom_index * _top_index [TOP_SZ];
#ifdef SAVE_CALL_CHAIN
  struct callinfo _last_stack[NFRAMES];	/* Stack at last garbage collection.*/
  					/* Useful for debugging	mysterious  */
  					/* object disappearances.	    */
  					/* In the multithreaded case, we    */
  					/* currently only save the calling  */
  					/* stack.			    */
#endif
};

GC_API GC_FAR struct _GC_arrays GC_arrays; 

# define GC_objfreelist GC_arrays._objfreelist
# define GC_aobjfreelist GC_arrays._aobjfreelist
# define GC_uobjfreelist GC_arrays._uobjfreelist
# ifdef ATOMIC_UNCOLLECTABLE
#   define GC_auobjfreelist GC_arrays._auobjfreelist
# endif
# define GC_sobjfreelist GC_arrays._sobjfreelist
# define GC_valid_offsets GC_arrays._valid_offsets
# define GC_modws_valid_offsets GC_arrays._modws_valid_offsets
# ifdef STUBBORN_ALLOC
#    define GC_changed_pages GC_arrays._changed_pages
#    define GC_prev_changed_pages GC_arrays._prev_changed_pages
# endif
# define GC_obj_map GC_arrays._obj_map
# define GC_last_heap_addr GC_arrays._last_heap_addr
# define GC_prev_heap_addr GC_arrays._prev_heap_addr
# define GC_words_allocd GC_arrays._words_allocd
# define GC_words_wasted GC_arrays._words_wasted
# define GC_large_free_bytes GC_arrays._large_free_bytes
# define GC_words_finalized GC_arrays._words_finalized
# define GC_non_gc_bytes_at_gc GC_arrays._non_gc_bytes_at_gc
# define GC_mem_freed GC_arrays._mem_freed
# define GC_scratch_end_ptr GC_arrays._scratch_end_ptr
# define GC_scratch_last_end_ptr GC_arrays._scratch_last_end_ptr
# define GC_mark_procs GC_arrays._mark_procs
# define GC_heapsize GC_arrays._heapsize
# define GC_max_heapsize GC_arrays._max_heapsize
# define GC_requested_heapsize GC_arrays._requested_heapsize
# define GC_words_allocd_before_gc GC_arrays._words_allocd_before_gc
# define GC_heap_sects GC_arrays._heap_sects
# define GC_last_stack GC_arrays._last_stack
# ifdef USE_MUNMAP
#   define GC_unmapped_bytes GC_arrays._unmapped_bytes
# endif
# ifdef MSWIN32
#   define GC_heap_bases GC_arrays._heap_bases
# endif
# define GC_static_roots GC_arrays._static_roots
# define GC_root_index GC_arrays._root_index
# define GC_excl_table GC_arrays._excl_table
# define GC_all_nils GC_arrays._all_nils
# define GC_top_index GC_arrays._top_index
# if defined(PROC_VDB) || defined(MPROTECT_VDB)
#   define GC_grungy_pages GC_arrays._grungy_pages
# endif
# ifdef MPROTECT_VDB
#   define GC_dirty_pages GC_arrays._dirty_pages
# endif
# ifdef PROC_VDB
#   define GC_written_pages GC_arrays._written_pages
# endif
# ifdef GATHERSTATS
#   define GC_composite_in_use GC_arrays._composite_in_use
#   define GC_atomic_in_use GC_arrays._atomic_in_use
# endif
# ifdef MERGE_SIZES
#   define GC_size_map GC_arrays._size_map
# endif

# define beginGC_arrays ((ptr_t)(&GC_arrays))
# define endGC_arrays (((ptr_t)(&GC_arrays)) + (sizeof GC_arrays))

#define USED_HEAP_SIZE (GC_heapsize - GC_large_free_bytes)

/* Object kinds: */
# define MAXOBJKINDS 16

extern struct obj_kind {
   ptr_t *ok_freelist;	/* Array of free listheaders for this kind of object */
   			/* Point either to GC_arrays or to storage allocated */
   			/* with GC_scratch_alloc.			     */
   struct hblk **ok_reclaim_list;
   			/* List headers for lists of blocks waiting to be */
   			/* swept.					  */
   word ok_descriptor;  /* Descriptor template for objects in this	*/
   			/* block.					*/
   GC_bool ok_relocate_descr;
   			/* Add object size in bytes to descriptor 	*/
   			/* template to obtain descriptor.  Otherwise	*/
   			/* template is used as is.			*/
   GC_bool ok_init;   /* Clear objects before putting them on the free list. */
} GC_obj_kinds[MAXOBJKINDS];

# define endGC_obj_kinds (((ptr_t)(&GC_obj_kinds)) + (sizeof GC_obj_kinds))

# define end_gc_area ((ptr_t)endGC_arrays == (ptr_t)(&GC_obj_kinds) ? \
			endGC_obj_kinds : endGC_arrays)

/* Predefined kinds: */
# define PTRFREE 0
# define NORMAL  1
# define UNCOLLECTABLE 2
# ifdef ATOMIC_UNCOLLECTABLE
#   define AUNCOLLECTABLE 3
#   define STUBBORN 4
#   define IS_UNCOLLECTABLE(k) (((k) & ~1) == UNCOLLECTABLE)
# else
#   define STUBBORN 3
#   define IS_UNCOLLECTABLE(k) ((k) == UNCOLLECTABLE)
# endif

extern int GC_n_kinds;

GC_API word GC_fo_entries;

extern word GC_n_heap_sects;	/* Number of separately added heap	*/
				/* sections.				*/

extern word GC_page_size;

# ifdef MSWIN32
extern word GC_n_heap_bases;	/* See GC_heap_bases.	*/
# endif

extern word GC_total_stack_black_listed;
			/* Number of bytes on stack blacklist. 	*/

extern word GC_black_list_spacing;
			/* Average number of bytes between blacklisted	*/
			/* blocks. Approximate.				*/
			/* Counts only blocks that are 			*/
			/* "stack-blacklisted", i.e. that are 		*/
			/* problematic in the interior of an object.	*/

extern char * GC_invalid_map;
			/* Pointer to the nowhere valid hblk map */
			/* Blocks pointing to this map are free. */

extern struct hblk * GC_hblkfreelist[];
				/* List of completely empty heap blocks	*/
				/* Linked through hb_next field of 	*/
				/* header structure associated with	*/
				/* block.				*/

extern GC_bool GC_is_initialized;	/* GC_init() has been run.	*/

extern GC_bool GC_objects_are_marked;	/* There are marked objects in  */
					/* the heap.			*/

#ifndef SMALL_CONFIG
  extern GC_bool GC_incremental;
			/* Using incremental/generational collection. */
#else
# define GC_incremental FALSE
			/* Hopefully allow optimizer to remove some code. */
#endif

extern GC_bool GC_dirty_maintained;
				/* Dirty bits are being maintained, 	*/
				/* either for incremental collection,	*/
				/* or to limit the root set.		*/

extern word GC_root_size;	/* Total size of registered root sections */

extern GC_bool GC_debugging_started;	/* GC_debug_malloc has been called. */ 

extern ptr_t GC_least_plausible_heap_addr;
extern ptr_t GC_greatest_plausible_heap_addr;
			/* Bounds on the heap.  Guaranteed valid	*/
			/* Likely to include future heap expansion.	*/
			
/* Operations */
# ifndef abs
#   define abs(x)  ((x) < 0? (-(x)) : (x))
# endif


/*  Marks are in a reserved area in                          */
/*  each heap block.  Each word has one mark bit associated  */
/*  with it. Only those corresponding to the beginning of an */
/*  object are used.                                         */


/* Mark bit operations */

/*
 * Retrieve, set, clear the mark bit corresponding
 * to the nth word in a given heap block.
 *
 * (Recall that bit n corresponds to object beginning at word n
 * relative to the beginning of the block, including unused words)
 */

# define mark_bit_from_hdr(hhdr,n) (((hhdr)->hb_marks[divWORDSZ(n)] \
			    >> (modWORDSZ(n))) & (word)1)
# define set_mark_bit_from_hdr(hhdr,n) (hhdr)->hb_marks[divWORDSZ(n)] \
				|= (word)1 << modWORDSZ(n)

# define clear_mark_bit_from_hdr(hhdr,n) (hhdr)->hb_marks[divWORDSZ(n)] \
				&= ~((word)1 << modWORDSZ(n))

/* Important internal collector routines */

ptr_t GC_approx_sp();

GC_bool GC_should_collect();

void GC_apply_to_all_blocks(/*fn, client_data*/);
			/* Invoke fn(hbp, client_data) for each 	*/
			/* allocated heap block.			*/
struct hblk * GC_next_used_block(/* struct hblk * h */);
			/* Return first in-use block >= h	*/
struct hblk * GC_prev_block(/* struct hblk * h */);
			/* Return last block <= h.  Returned block	*/
			/* is managed by GC, but may or may not be in	*/
			/* use.						*/
void GC_mark_init();
void GC_clear_marks();	/* Clear mark bits for all heap objects. */
void GC_invalidate_mark_state();	/* Tell the marker that	marked 	   */
					/* objects may point to	unmarked   */
					/* ones, and roots may point to	   */
					/* unmarked objects.		   */
					/* Reset mark stack.		   */
void GC_mark_from_mark_stack(); /* Mark from everything on the mark stack. */
				/* Return after about one pages worth of   */
				/* work.				   */
GC_bool GC_mark_stack_empty();
GC_bool GC_mark_some(/* cold_gc_frame */);
			/* Perform about one pages worth of marking	*/
			/* work of whatever kind is needed.  Returns	*/
			/* quickly if no collection is in progress.	*/
			/* Return TRUE if mark phase finished.		*/
void GC_initiate_gc();		/* initiate collection.			*/
				/* If the mark state is invalid, this	*/
				/* becomes full colleection.  Otherwise */
				/* it's partial.			*/
void GC_push_all(/*b,t*/);	/* Push everything in a range 		*/
				/* onto mark stack.			*/
void GC_push_dirty(/*b,t*/);      /* Push all possibly changed	 	*/
				  /* subintervals of [b,t) onto		*/
				  /* mark stack.			*/
#ifndef SMALL_CONFIG
  void GC_push_conditional(/* ptr_t b, ptr_t t, GC_bool all*/);
#else
# define GC_push_conditional(b, t, all) GC_push_all(b, t)
#endif
                                /* Do either of the above, depending	*/
				/* on the third arg.			*/
void GC_push_all_stack(/*b,t*/);    /* As above, but consider		*/
				    /*  interior pointers as valid  	*/
void GC_push_all_eager(/*b,t*/);    /* Same as GC_push_all_stack, but   */
				    /* ensures that stack is scanned	*/
				    /* immediately, not just scheduled  */
				    /* for scanning.			*/
#ifndef THREADS
  void GC_push_all_stack_partially_eager(/* bottom, top, cold_gc_frame */);
			/* Similar to GC_push_all_eager, but only the	*/
			/* part hotter than cold_gc_frame is scanned	*/
			/* immediately.  Needed to endure that callee-	*/
			/* save registers are not missed.		*/
#else
  /* In the threads case, we push part of the current thread stack	*/
  /* with GC_push_all_eager when we push the registers.  This gets the  */
  /* callee-save registers that may disappear.  The remainder of the	*/
  /* stacks are scheduled for scanning in *GC_push_other_roots, which	*/
  /* is thread-package-specific.					*/
#endif
void GC_push_current_stack(/* ptr_t cold_gc_frame */);
			/* Push enough of the current stack eagerly to	*/
			/* ensure that callee-save registers saved in	*/
			/* GC frames are scanned.			*/
			/* In the non-threads case, schedule entire	*/
			/* stack for scanning.				*/
void GC_push_roots(/* GC_bool all, ptr_t cold_gc_frame */);
			/* Push all or dirty roots.	*/
extern void (*GC_push_other_roots)();
			/* Push system or application specific roots	*/
			/* onto the mark stack.  In some environments	*/
			/* (e.g. threads environments) this is		*/
			/* predfined to be non-zero.  A client supplied */
			/* replacement should also call the original	*/
			/* function.					*/
extern void (*GC_start_call_back)(/* void */);
			/* Called at start of full collections.		*/
			/* Not called if 0.  Called with allocation 	*/
			/* lock held.					*/
			/* 0 by default.				*/
void GC_push_regs();	/* Push register contents onto mark stack.	*/
			/* If NURSERY is defined, the default push	*/
			/* action can be overridden with GC_push_proc	*/
void GC_remark();	/* Mark from all marked objects.  Used	*/
		 	/* only if we had to drop something.	*/

# ifdef NURSERY
    extern void (*GC_push_proc)(ptr_t);
# endif
# if defined(MSWIN32)
  void __cdecl GC_push_one();
# else
  void GC_push_one(/*p*/);    /* If p points to an object, mark it    */
                              /* and push contents on the mark stack  */
# endif
void GC_push_one_checked(/*p*/); /* Ditto, omits plausibility test	*/
void GC_push_marked(/* struct hblk h, hdr * hhdr */);
		/* Push contents of all marked objects in h onto	*/
		/* mark stack.						*/
#ifdef SMALL_CONFIG
# define GC_push_next_marked_dirty(h) GC_push_next_marked(h)
#else
  struct hblk * GC_push_next_marked_dirty(/* h */);
		/* Invoke GC_push_marked on next dirty block above h.	*/
		/* Return a pointer just past the end of this block.	*/
#endif /* !SMALL_CONFIG */
struct hblk * GC_push_next_marked(/* h */);
		/* Ditto, but also mark from clean pages.	*/
struct hblk * GC_push_next_marked_uncollectable(/* h */);
		/* Ditto, but mark only from uncollectable pages.	*/
GC_bool GC_stopped_mark(); /* Stop world and mark from all roots	*/
			/* and rescuers.			*/
void GC_clear_hdr_marks(/* hhdr */);  /* Clear the mark bits in a header */
void GC_set_hdr_marks(/* hhdr */);  /* Set the mark bits in a header */
void GC_add_roots_inner();
GC_bool GC_is_static_root(/* ptr_t p */);
		/* Is the address p in one of the registered static	*/
		/* root sections?					*/
void GC_register_dynamic_libraries();
		/* Add dynamic library data sections to the root set. */

/* Machine dependent startup routines */
ptr_t GC_get_stack_base();
void GC_register_data_segments();

/* Black listing: */
void GC_bl_init(); 	
# ifndef ALL_INTERIOR_POINTERS
    void GC_add_to_black_list_normal(word /* bits, maybe source */);
			/* Register bits as a possible future false	*/
			/* reference from the heap or static data	*/
#   ifdef PRINT_BLACK_LIST
#     define GC_ADD_TO_BLACK_LIST_NORMAL(bits, source) \
			GC_add_to_black_list_normal((word) bits, source)
#   else
#     define GC_ADD_TO_BLACK_LIST_NORMAL(bits, source) \
			GC_add_to_black_list_normal((word) bits)
#   endif
# else
#   ifdef PRINT_BLACK_LIST
#     define GC_ADD_TO_BLACK_LIST_NORMAL(bits, source) \
			GC_add_to_black_list_stack((word) bits, source)
#   else
#     define GC_ADD_TO_BLACK_LIST_NORMAL(bits, source) \
			GC_add_to_black_list_stack((word) bits)
#   endif
# endif

void GC_add_to_black_list_stack(/* bits, maybe source */);
struct hblk * GC_is_black_listed(/* h, len */);
			/* If there are likely to be false references	*/
			/* to a block starting at h of the indicated    */
			/* length, then return the next plausible	*/
			/* starting location for h that might avoid	*/
			/* these false references.			*/
void GC_promote_black_lists();
			/* Declare an end to a black listing phase.	*/
void GC_unpromote_black_lists();
			/* Approximately undo the effect of the above.	*/
			/* This actually loses some information, but	*/
			/* only in a reasonably safe way.		*/
word GC_number_stack_black_listed(/*struct hblk *start, struct hblk *endp1 */);
			/* Return the number of (stack) blacklisted	*/
			/* blocks in the range for statistical		*/
			/* purposes.					*/
		 	
ptr_t GC_scratch_alloc(/*bytes*/);
				/* GC internal memory allocation for	*/
				/* small objects.  Deallocation is not  */
				/* possible.				*/
	
/* Heap block layout maps: */			
void GC_invalidate_map(/* hdr */);
				/* Remove the object map associated	*/
				/* with the block.  This identifies	*/
				/* the block as invalid to the mark	*/
				/* routines.				*/
GC_bool GC_add_map_entry(/*sz*/);
				/* Add a heap block map for objects of	*/
				/* size sz to obj_map.			*/
				/* Return FALSE on failure.		*/
void GC_register_displacement_inner(/*offset*/);
				/* Version of GC_register_displacement	*/
				/* that assumes lock is already held	*/
				/* and signals are already disabled.	*/

/*  hblk allocation: */		
void GC_new_hblk(/*size_in_words, kind*/);
				/* Allocate a new heap block, and build */
				/* a free list in it.			*/				
struct hblk * GC_allochblk(/*size_in_words, kind*/);
				/* Allocate a heap block, clear it if	*/
				/* for composite objects, inform	*/
				/* the marker that block is valid	*/
				/* for objects of indicated size.	*/
				/* sz < 0 ==> atomic.			*/ 
void GC_freehblk();		/* Deallocate a heap block and mark it  */
				/* as invalid.				*/
				
/*  Misc GC: */
void GC_init_inner();
GC_bool GC_expand_hp_inner();
void GC_start_reclaim(/*abort_if_found*/);
				/* Restore unmarked objects to free	*/
				/* lists, or (if abort_if_found is	*/
				/* TRUE) report them.			*/
				/* Sweeping of small object pages is	*/
				/* largely deferred.			*/
void GC_continue_reclaim(/*size, kind*/);
				/* Sweep pages of the given size and	*/
				/* kind, as long as possible, and	*/
				/* as long as the corr. free list is    */
				/* empty.				*/
void GC_reclaim_or_delete_all();
				/* Arrange for all reclaim lists to be	*/
				/* empty.  Judiciously choose between	*/
				/* sweeping and discarding each page.	*/
GC_bool GC_reclaim_all(/* GC_stop_func f*/);
				/* Reclaim all blocks.  Abort (in a	*/
				/* consistent state) if f returns TRUE. */
GC_bool GC_block_empty(/* hhdr */); /* Block completely unmarked? 	*/
GC_bool GC_never_stop_func();	/* Returns FALSE.		*/
GC_bool GC_try_to_collect_inner(/* GC_stop_func f */);
				/* Collect; caller must have acquired	*/
				/* lock and disabled signals.		*/
				/* Collection is aborted if f returns	*/
				/* TRUE.  Returns TRUE if it completes	*/
				/* successfully.			*/
# define GC_gcollect_inner() \
	(void) GC_try_to_collect_inner(GC_never_stop_func)
void GC_finish_collection();	/* Finish collection.  Mark bits are	*/
				/* consistent and lock is still held.	*/
GC_bool GC_collect_or_expand(/* needed_blocks */);
				/* Collect or expand heap in an attempt */
				/* make the indicated number of free	*/
				/* blocks available.  Should be called	*/
				/* until the blocks are available or	*/
				/* until it fails by returning FALSE.	*/
GC_API void GC_init();		/* Initialize collector.		*/
void GC_collect_a_little_inner(/* int n */);
				/* Do n units worth of garbage 		*/
				/* collection work, if appropriate.	*/
				/* A unit is an amount appropriate for  */
				/* HBLKSIZE bytes of allocation.	*/
ptr_t GC_generic_malloc(word bytes, int kind);
				/* Allocate an object of the given	*/
				/* kind.  By default, there are only	*/
				/* a few kinds: composite(pointerfree), */
				/* atomic, uncollectable, etc.		*/
				/* We claim it's possible for clever	*/
				/* client code that understands GC	*/
				/* internals to add more, e.g. to	*/
				/* communicate object layout info	*/
				/* to the collector.			*/
ptr_t GC_generic_malloc_ignore_off_page(/* bytes, kind */);
				/* As above, but pointers past the 	*/
				/* first page of the resulting object	*/
				/* are ignored.				*/
ptr_t GC_generic_malloc_inner(word bytes, int kind);
				/* Ditto, but I already hold lock, etc.	*/
ptr_t GC_generic_malloc_words_small GC_PROTO((size_t words, int kind));
				/* As above, but size in units of words */
				/* Bypasses MERGE_SIZES.  Assumes	*/
				/* words <= MAXOBJSZ.			*/
ptr_t GC_generic_malloc_inner_ignore_off_page(/* bytes, kind */);
				/* Allocate an object, where		*/
				/* the client guarantees that there	*/
				/* will always be a pointer to the 	*/
				/* beginning of the object while the	*/
				/* object is live.			*/
ptr_t GC_allocobj(/* sz_inn_words, kind */);
				/* Make the indicated 			*/
				/* free list nonempty, and return its	*/
				/* head.				*/

void GC_init_headers();
struct hblkhdr * GC_install_header(/*h*/);
				/* Install a header for block h.	*/
				/* Return 0 on failure, or the header	*/
				/* otherwise.				*/
GC_bool GC_install_counts(/*h, sz*/);
				/* Set up forwarding counts for block	*/
				/* h of size sz.			*/
				/* Return FALSE on failure.		*/
void GC_remove_header(/*h*/);
				/* Remove the header for block h.	*/
void GC_remove_counts(/*h, sz*/);
				/* Remove forwarding counts for h.	*/
hdr * GC_find_header(ptr_t /*p*/);	/* Debugging only.			*/

void GC_finalize();	/* Perform all indicated finalization actions	*/
			/* on unmarked objects.				*/
			/* Unreachable finalizable objects are enqueued	*/
			/* for processing by GC_invoke_finalizers.	*/
			/* Invoked with lock.				*/
			
void GC_add_to_heap(/*p, bytes*/);
			/* Add a HBLKSIZE aligned chunk to the heap.	*/

void GC_print_obj(/* ptr_t p */);
			/* P points to somewhere inside an object with	*/
			/* debugging info.  Print a human readable	*/
			/* description of the object to stderr.		*/
extern void (*GC_check_heap)();
			/* Check that all objects in the heap with 	*/
			/* debugging info are intact.  Print 		*/
			/* descriptions of any that are not.		*/
extern void (*GC_print_heap_obj)(/* ptr_t p */);
			/* If possible print s followed by a more	*/
			/* detailed description of the object 		*/
			/* referred to by p.				*/
			
/* Memory unmapping: */
#ifdef USE_MUNMAP
  void GC_unmap_old(void);
  void GC_merge_unmapped(void);
  void GC_unmap(ptr_t start, word bytes);
  void GC_remap(ptr_t start, word bytes);
  void GC_unmap_gap(ptr_t start1, word bytes1, ptr_t start2, word bytes2);
#endif

/* Virtual dirty bit implementation:		*/
/* Each implementation exports the following:	*/
void GC_read_dirty();	/* Retrieve dirty bits.	*/
GC_bool GC_page_was_dirty(/* struct hblk * h  */);
			/* Read retrieved dirty bits.	*/
GC_bool GC_page_was_ever_dirty(/* struct hblk * h  */);
			/* Could the page contain valid heap pointers?	*/
void GC_is_fresh(/* struct hblk * h, word number_of_blocks  */);
			/* Assert the region currently contains no	*/
			/* valid pointers.				*/
void GC_write_hint(/* struct hblk * h  */);
			/* h is about to be written.	*/
void GC_dirty_init();

/* Slow/general mark bit manipulation: */
GC_API GC_bool GC_is_marked();
void GC_clear_mark_bit();
void GC_set_mark_bit();

/* Stubborn objects: */
void GC_read_changed();	/* Analogous to GC_read_dirty */
GC_bool GC_page_was_changed(/* h */);	/* Analogous to GC_page_was_dirty */
void GC_clean_changing_list();	/* Collect obsolete changing list entries */
void GC_stubborn_init();

/* Debugging print routines: */
void GC_print_block_list();
void GC_print_hblkfreelist();
void GC_print_heap_sects();
void GC_print_static_roots();
void GC_dump();

#ifdef KEEP_BACK_PTRS
   void GC_store_back_pointer(ptr_t source, ptr_t dest);
   void GC_marked_for_finalization(ptr_t dest);
#  define GC_STORE_BACK_PTR(source, dest) GC_store_back_pointer(source, dest)
#  define GC_MARKED_FOR_FINALIZATION(dest) GC_marked_for_finalization(dest)
#else
#  define GC_STORE_BACK_PTR(source, dest) 
#  define GC_MARKED_FOR_FINALIZATION(dest)
#endif

/* Make arguments appear live to compiler */
# ifdef __WATCOMC__
  void GC_noop(void*, ...);
# else
  GC_API void GC_noop();
# endif

void GC_noop1(/* word arg */);

/* Logging and diagnostic output: 	*/
GC_API void GC_printf GC_PROTO((char * format, long, long, long, long, long, long));
			/* A version of printf that doesn't allocate,	*/
			/* is restricted to long arguments, and		*/
			/* (unfortunately) doesn't use varargs for	*/
			/* portability.  Restricted to 6 args and	*/
			/* 1K total output length.			*/
			/* (We use sprintf.  Hopefully that doesn't	*/
			/* allocate for long arguments.)  		*/
# define GC_printf0(f) GC_printf(f, 0l, 0l, 0l, 0l, 0l, 0l)
# define GC_printf1(f,a) GC_printf(f, (long)a, 0l, 0l, 0l, 0l, 0l)
# define GC_printf2(f,a,b) GC_printf(f, (long)a, (long)b, 0l, 0l, 0l, 0l)
# define GC_printf3(f,a,b,c) GC_printf(f, (long)a, (long)b, (long)c, 0l, 0l, 0l)
# define GC_printf4(f,a,b,c,d) GC_printf(f, (long)a, (long)b, (long)c, \
					    (long)d, 0l, 0l)
# define GC_printf5(f,a,b,c,d,e) GC_printf(f, (long)a, (long)b, (long)c, \
					      (long)d, (long)e, 0l)
# define GC_printf6(f,a,b,c,d,e,g) GC_printf(f, (long)a, (long)b, (long)c, \
						(long)d, (long)e, (long)g)

void GC_err_printf(/* format, a, b, c, d, e, f */);
# define GC_err_printf0(f) GC_err_puts(f)
# define GC_err_printf1(f,a) GC_err_printf(f, (long)a, 0l, 0l, 0l, 0l, 0l)
# define GC_err_printf2(f,a,b) GC_err_printf(f, (long)a, (long)b, 0l, 0l, 0l, 0l)
# define GC_err_printf3(f,a,b,c) GC_err_printf(f, (long)a, (long)b, (long)c, \
						  0l, 0l, 0l)
# define GC_err_printf4(f,a,b,c,d) GC_err_printf(f, (long)a, (long)b, \
						    (long)c, (long)d, 0l, 0l)
# define GC_err_printf5(f,a,b,c,d,e) GC_err_printf(f, (long)a, (long)b, \
						      (long)c, (long)d, \
						      (long)e, 0l)
# define GC_err_printf6(f,a,b,c,d,e,g) GC_err_printf(f, (long)a, (long)b, \
							(long)c, (long)d, \
							(long)e, (long)g)
			/* Ditto, writes to stderr.			*/
			
void GC_err_puts(/* char *s */);
			/* Write s to stderr, don't buffer, don't add	*/
			/* newlines, don't ...				*/


#   ifdef GC_ASSERTIONS
#	define GC_ASSERT(expr) if(!(expr)) {\
		GC_err_printf2("Assertion failure: %s:%ld\n", \
				__FILE__, (unsigned long)__LINE__); \
		ABORT("assertion failure"); }
#   else 
#	define GC_ASSERT(expr)
#   endif

# endif /* GC_PRIVATE_H */