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yap-6.3/H/heapgc.h

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/*************************************************************************
* *
* YAP Prolog *
* *
* Yap Prolog was developed at NCCUP - Universidade do Porto *
* *
* Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997 *
* *
**************************************************************************
* *
* File: heapgc.c *
* Last rev: *
* mods: *
* comments: Header for Global Stack garbage collector *
* *
*************************************************************************/
/* macros used by garbage collection */
#if TAG_64BITS
#define MaskAdr (~0x7L)
#endif
/* return pointer from object pointed to by ptr (remove tag & mark) */
#ifdef TAGS_FAST_OPS
#define GET_NEXT(val) ((CELL *)(IsVarTerm((val)) ? \
(val) & MaskAdr : \
( IsPairTerm((val)) ? \
Unsigned(RepPair((val))) & MaskAdr : \
( IsApplTerm((val)) ? \
Unsigned(RepAppl((val))) & MaskAdr : \
(val) & MaskAdr \
) \
) \
) \
)
#else
#ifdef TAG_LOW_BITS_32
#define GET_NEXT(val) ((CELL *) ((val) & ~LowTagBits))
#else
#define GET_NEXT(val) ((CELL *) ((val) & MaskAdr))
#endif
#endif
/* is ptr a pointer to the heap? */
#define ONHEAP(ptr) (CellPtr(ptr) >= H0 && CellPtr(ptr) < H)
/* is ptr a pointer to code space? */
#if USE_SYSTEM_MALLOC
#define ONCODE(ptr) (Addr(ptr) < Yap_GlobalBase || Addr(ptr) > Yap_TrailTop)
#else
#define ONCODE(ptr) (Addr(ptr) < HeapTop && Addr(ptr) >= Yap_HeapBase)
#endif
/* is val pointing to something bound to the heap? */
#define GCIsPrimitiveTerm(X) (/* not really needed !IsVarTerm(X) && */ IsAtomOrIntTerm(X))
/* Does X point to an object in the heap */
#define HEAP_PTR(val) (!GCIsPrimitiveTerm(val) && ONHEAP(GET_NEXT(val)))
/*
Heap_trail_entry must be very careful. We are looking at a valid
trail entry if: it was between H0 and HB or between B and LCLO
(that is, if it was covered by choicepoints at the time), and if it
was a heap pointer.
We can join the two conditions: (H0 =< val < HB || ((B < val < LCL0)
&& H0 <= *DETAG(val) < H))
*/
#define HEAP_TRAIL_ENTRY(val) ((IsVarTerm(val)) && \
((H0 <= CellPtr(val) && CellPtr(val)\
< cp_H) || \
(CellPtr(B) < CellPtr(val) && CellPtr(val) <= \
LCL0 && HEAP_PTR(val))))
#if !defined(YAPOR) && !defined(THREADS)
extern char *Yap_bp;
#endif
#define MARK_BIT 1
#define RMARK_BIT 2
#define mcell(X) Yap_bp[(X)-(CELL *)Yap_GlobalBase]
static inline Int
MARKED_PTR(CELL* ptr)
{
return mcell(ptr) & MARK_BIT;
}
static inline Int
UNMARKED_MARK(CELL* ptr, char *bp)
{
Int pos = ptr - (CELL *)Yap_GlobalBase;
char t = bp[pos];
if (t & MARK_BIT) {
return TRUE;
}
bp[pos] = t | MARK_BIT;
return FALSE;
}
static inline void
MARK(CELL* ptr)
{
mcell(ptr) = mcell(ptr) | MARK_BIT;
}
static inline void
UNMARK(CELL* ptr)
{
mcell(ptr) = mcell(ptr) & ~MARK_BIT;
}
/* not really that useful */
#define MAY_UNMARK(X)
#define UNMARK_CELL(X) (X)
static inline void
RMARK(CELL* ptr)
{
mcell(ptr) = mcell(ptr) | RMARK_BIT;
}
static inline void
UNRMARK(CELL* ptr)
{
mcell(ptr) = mcell(ptr) & ~RMARK_BIT;
}
static inline int
RMARKED(CELL* ptr)
{
return mcell(ptr) & RMARK_BIT;
}
/* is the object pointed to by ptr marked as in a relocation chain? */
#if LONG_ADDRESSES
#ifdef TAG_LOW_BITS_32
#define TAG(X) ((X) & LowTagBits)
#else
#ifdef TAG_64BITS
#define TAG(X) ((X) & MKTAG(0x0,0x7))
#else
#define TAG(X) ((X) & 0x80000003L)
#endif
#endif
#else
#define TAG(X) ((X) & 0x98000000L)
#endif
typedef CELL *CELL_PTR;
#define ENVSIZE(E) EnvSize(((CELL *)E)[E_CP])
void STD_PROTO(Yap_mark_variable, (CELL *));
void STD_PROTO(Yap_mark_external_reference, (CELL *));
void STD_PROTO(Yap_inc_mark_variable, (void));