gc_priv.h

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/* though we should perhaps take advantage of the case in which */
/* does.							*/
struct hblk;	/* See below.	*/
# 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(NEXT) || defined(MACOSX) || defined(DOS4GW) || \
	 (defined(AMIGA) && !defined(GC_AMIGA_FASTALLOC)) || \
	 (defined(SUNOS5) && !defined(USE_MMAP))
#       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
#	    ifdef MSWINCE
	      extern ptr_t GC_wince_get_mem();
#	      define GET_MEM(bytes) (struct hblk *)GC_wince_get_mem(bytes)
#	    else
#	      if defined(AMIGA) && defined(GC_AMIGA_FASTALLOC)
	        extern void *GC_amiga_get_mem(size_t size);
		define GET_MEM(bytes) HBLKPTR((size_t) \
                  GC_amiga_get_mem((size_t)bytes + GC_page_size) \
		  + GC_page_size-1)
#	      else
                extern ptr_t GC_unix_get_mem();
#               define GET_MEM(bytes) (struct hblk *)GC_unix_get_mem(bytes)
#	      endif
#	    endif
#	  endif
#	endif
#     endif
#   endif
# 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.							*/
/* It probably doesn't make any sense to declare these to be nonempty	*/
/* if the code is being optimized, since signal safety relies on some	*/
/* ordering constraints that are typically not obeyed by optimizing	*/
/* compilers.								*/
# 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(THREADS) || defined(AMIGA)  \
	|| defined(MSWIN32) || defined(MSWINCE) || defined(MACOS) \
	|| defined(DJGPP) || defined(NO_SIGNALS) 
			/* Also useful for debugging.		*/
	/* Should probably use thr_sigsetmask for GC_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(GC_SOLARIS_THREADS) || defined(GC_WIN32_THREADS) \
	|| defined(GC_PTHREADS)
      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)("GC Warning: " msg, (GC_word)(arg))
extern GC_warn_proc GC_current_warn_proc;

/* Get environment entry */
#if !defined(NO_GETENV)
#   define GETENV(name) getenv(name)
#else
#   define GETENV(name) 0
#endif

/*********************************/
/*                               */
/* 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)(signed_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) || (defined(HPUX) && defined(HP_PA))
      /* HPUX/PA seems to use 4K pages with the 64 bit ABI */
#     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_MAXOBJBYTES (CPP_HBLKSIZE/2)
#define MAXOBJBYTES ((word)CPP_MAXOBJBYTES)
#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. */
# define ROUNDED_UP_WORDS(n) \
	BYTES_TO_WORDS((n) + (WORDS_TO_BYTES(1) - 1 + EXTRA_BYTES))
# ifdef ALIGN_DOUBLE
#       define ALIGNED_WORDS(n) \
	    (BYTES_TO_WORDS((n) + WORDS_TO_BYTES(2) - 1 + EXTRA_BYTES) & ~1)
# else
#       define ALIGNED_WORDS(n) ROUNDED_UP_WORDS(n)
# endif
# define SMALL_OBJ(bytes) ((bytes) < (MAXOBJBYTES - EXTRA_BYTES))
# define ADD_SLOP(bytes) ((bytes) + EXTRA_BYTES)
# 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, or				*/
    /* - USE_MARK_BYTES is defined.				*/
#   if defined(USE_MARK_BYTES) || 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  19  /* Collisions likely at 512K blocks,	*/
				/* which is >= 2GB.  Each table takes	*/
				/* 64KB.				*/
# else
#   ifdef SMALL_CONFIG
#     define LOG_PHT_ENTRIES  14 /* Collisions are likely if heap grows	*/
				 /* to more than 16K hblks = 64MB.	*/
				 /* Each hash table occupies 2K bytes.   */
#   else /* default "medium" configuration */
#     define LOG_PHT_ENTRIES  16 /* Collisions are likely if heap grows	*/
				 /* to more than 16K hblks >= 256MB.	*/
				 /* Each hash table occupies 8K bytes.  */
#   endif
# 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))
/* And a dumb but thread-safe version of set_pht_entry_from_index.	*/
/* This sets (many) extra bits.						*/
# define set_pht_entry_from_index_safe(bl, index) \
		(bl)[divWORDSZ(index)] = ONES
	


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

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

#define BITS_PER_HBLK (CPP_HBLKSIZE * 8)

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

# ifdef USE_MARK_BYTES
#   define MARK_BITS_SZ (MARK_BITS_PER_HBLK/2)
	/* Unlike the other case, this is in units of bytes.		*/
	/* We actually allocate only every second mark bit, since we	*/
	/* force all objects to be doubleword aligned.			*/
	/* However, each mark bit is allocated as a byte.		*/
# else
#   define MARK_BITS_SZ (MARK_BITS_PER_HBLK/CPP_WORDSZ)
# endif

/* We maintain layout maps for heap blocks containing objects of a given */
/* size.  Each entry in this map describes a byte offset and has the	 */
/* following type.							 */
typedef unsigned char map_entry_type;

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.				*/
    map_entry_type * 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 	*/