527 lines
11 KiB
C
527 lines
11 KiB
C
/*************************************************************************
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* *
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* YAP Prolog *
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* *
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* Yap Prolog was developed at NCCUP - Universidade do Porto *
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* *
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* Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997 *
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* *
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**************************************************************************
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* *
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* File: agc.c *
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* Last rev: *
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* mods: *
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* comments: reclaim unused atoms and functors *
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* *
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*************************************************************************/
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#ifdef SCCS
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static char SccsId[] = "@(#)agc.c 1.3 3/15/90";
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#endif
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#include "absmi.h"
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#include "alloc.h"
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#include "yapio.h"
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#include "iopreds.h"
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#include "attvar.h"
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#ifdef DEBUG
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/* #define DEBUG_RESTORE1 1 */
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/* #define DEBUG_RESTORE2 1 */
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/* #define DEBUG_RESTORE3 1 */
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#define errout Yap_stderr
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#endif
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STATIC_PROTO(void RestoreEntries, (PropEntry *, int));
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STATIC_PROTO(void CleanCode, (PredEntry *));
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static int agc_calls;
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static YAP_ULONG_LONG agc_collected;
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static Int tot_agc_time = 0; /* total time spent in GC */
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static Int tot_agc_recovered = 0; /* number of heap objects in all garbage collections */
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#define AtomMarkedBit 1
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static inline void
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MarkAtomEntry(AtomEntry *ae)
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{
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CELL c = (CELL)(ae->NextOfAE);
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c |= AtomMarkedBit;
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ae->NextOfAE = (Atom)c;
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}
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static inline int
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AtomResetMark(AtomEntry *ae)
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{
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CELL c = (CELL)(ae->NextOfAE);
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if (c & AtomMarkedBit) {
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c &= ~AtomMarkedBit;
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ae->NextOfAE = (Atom)c;
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return TRUE;
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}
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return FALSE;
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}
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static inline Atom
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CleanAtomMarkedBit(Atom a)
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{
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CELL c = (CELL)a;
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c &= ~AtomMarkedBit;
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return (Atom)c;
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}
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static inline Functor
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FuncAdjust(Functor f)
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{
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if (!IsExtensionFunctor(f)) {
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AtomEntry *ae = RepAtom(NameOfFunctor(f));
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MarkAtomEntry(ae);
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}
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return(f);
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}
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static inline Term
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AtomTermAdjust(Term t)
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{
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AtomEntry *ae = RepAtom(AtomOfTerm(t));
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MarkAtomEntry(ae);
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return(t);
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}
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static inline Atom
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AtomAdjust(Atom a)
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{
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AtomEntry *ae;
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if (a == NIL) return(a);
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ae = RepAtom(a);
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MarkAtomEntry(ae);
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return(a);
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}
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#define IsOldCode(P) FALSE
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#define IsOldCodeCellPtr(P) FALSE
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#define IsOldDelay(P) FALSE
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#define IsOldDelayPtr(P) FALSE
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#define IsOldLocalInTR(P) FALSE
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#define IsOldLocalInTRPtr(P) FALSE
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#define IsOldGlobal(P) FALSE
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#define IsOldGlobalPtr(P) FALSE
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#define IsOldTrail(P) FALSE
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#define IsOldTrailPtr(P) FALSE
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#define CharP(X) ((char *)(X))
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#define OrArgAdjust(P)
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#define TabEntryAdjust(P)
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#define IntegerAdjust(D) (D)
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#define AddrAdjust(P) (P)
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#define MFileAdjust(P) (P)
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#define CodeVarAdjust(P) (P)
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#define ConstantAdjust(P) (P)
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#define ArityAdjust(P) (P)
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#define DoubleInCodeAdjust(P)
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#define IntegerInCodeAdjust(P)
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#define OpcodeAdjust(P) (P)
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#define ModuleAdjust(P) (P)
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#define ExternalFunctionAdjust(P) (P)
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#define PredEntryAdjust(P) (P)
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#define AtomEntryAdjust(P) (P)
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#define GlobalEntryAdjust(P) (P)
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#define BlobTermAdjust(P) (P)
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#define CodeComposedTermAdjust(P) (P)
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#define CellPtoHeapAdjust(P) (P)
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#define PtoAtomHashEntryAdjust(P) (P)
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#define CellPtoHeapCellAdjust(P) (P)
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#define CellPtoTRAdjust(P) (P)
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#define CodeAddrAdjust(P) (P)
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#define ConsultObjAdjust(P) (P)
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#define DelayAddrAdjust(P) (P)
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#define DelayAdjust(P) (P)
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#define GlobalAdjust(P) (P)
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#define DBRefAdjust(P) (P)
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#define DBRefPAdjust(P) (P)
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#define DBTermAdjust(P) (P)
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#define LUIndexAdjust(P) (P)
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#define SIndexAdjust(P) (P)
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#define LocalAddrAdjust(P) (P)
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#define GlobalAddrAdjust(P) (P)
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#define PtoLUCAdjust(P) (P)
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#define PtoStCAdjust(P) (P)
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#define PtoArrayEAdjust(P) (P)
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#define PtoArraySAdjust(P) (P)
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#define PtoGlobalEAdjust(P) (P)
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#define PtoDelayAdjust(P) (P)
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#define PtoGloAdjust(P) (P)
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#define PtoLocAdjust(P) (P)
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#define PtoHeapCellAdjust(P) (P)
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#define PtoOpAdjust(P) (P)
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#define PtoLUClauseAdjust(P) (P)
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#define PtoLUIndexAdjust(P) (P)
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#define PtoDBTLAdjust(P) (P)
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#define PtoPredAdjust(P) (P)
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#define PropAdjust(P) (P)
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#define TrailAddrAdjust(P) (P)
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#define XAdjust(P) (P)
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#define YAdjust(P) (P)
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#define HoldEntryAdjust(P) (P)
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#define recompute_mask(dbr)
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#define rehash(oldcode, NOfE, KindOfEntries)
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#include "rheap.h"
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static void init_reg_copies(void)
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{
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OldASP = ASP;
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OldLCL0 = LCL0;
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OldTR = TR;
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OldGlobalBase = (CELL *)Yap_GlobalBase;
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OldH = H;
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OldH0 = H0;
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OldTrailBase = Yap_TrailBase;
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OldTrailTop = Yap_TrailTop;
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OldHeapBase = Yap_HeapBase;
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OldHeapTop = HeapTop;
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}
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static void
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mark_hash_entry(AtomHashEntry *HashPtr)
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{
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Atom atm;
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atm = HashPtr->Entry;
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if (atm) {
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AtomEntry *at = RepAtom(atm);
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do {
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RestoreAtom(at);
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atm = at->NextOfAE;
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at = RepAtom(CleanAtomMarkedBit(atm));
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} while (!EndOfPAEntr(at));
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}
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}
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static void
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mark_hash_preds(void)
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{
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UInt i;
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for (i = 0; i < PredHashTableSize; i++) {
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PredEntry *p = PredHash[i];
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while (p) {
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Prop nextp = p->NextOfPE = PropAdjust(p->NextOfPE);
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CleanCode(p);
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p = RepPredProp(nextp);
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}
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}
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}
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/*
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* This is the really tough part, to restore the whole of the heap
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*/
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static void
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mark_atoms(void)
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{
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AtomHashEntry *HashPtr = HashChain;
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register int i;
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restore_codes();
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for (i = 0; i < AtomHashTableSize; ++i) {
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mark_hash_entry(HashPtr);
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HashPtr++;
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}
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HashPtr = WideHashChain;
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for (i = 0; i < WideAtomHashTableSize; ++i) {
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mark_hash_entry(HashPtr);
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HashPtr++;
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}
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mark_hash_entry(&INVISIBLECHAIN);
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RestoreAtom(RepAtom(AtomFoundVar));
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RestoreAtom(RepAtom(AtomFreeTerm));
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mark_hash_preds();
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}
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static void
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mark_trail(void)
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{
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register tr_fr_ptr pt;
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pt = TR;
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/* moving the trail is simple */
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while (pt != (tr_fr_ptr)Yap_TrailBase) {
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CELL reg = TrailTerm(pt-1);
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if (!IsVarTerm(reg)) {
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if (IsAtomTerm(reg)) {
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MarkAtomEntry(RepAtom(AtomOfTerm(reg)));
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}
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}
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pt--;
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}
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}
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static void
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mark_local(void)
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{
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CELL *pt;
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/* Adjusting the local */
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pt = LCL0;
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/* moving the trail is simple */
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while (pt > ASP) {
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CELL reg = *--pt;
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if (!IsVarTerm(reg)) {
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if (IsAtomTerm(reg)
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#ifdef TABLING
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/* assume we cannot have atoms on first page,
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so this must be an arity
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*/
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&& reg > Yap_page_size
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#endif
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) {
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MarkAtomEntry(RepAtom(AtomOfTerm(reg)));
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}
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}
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}
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}
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static CELL *
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mark_global_cell(CELL *pt)
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{
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CELL reg = *pt;
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if (IsVarTerm(reg)) {
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/* skip bitmaps */
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switch(reg) {
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case (CELL)FunctorDouble:
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#if SIZEOF_DOUBLE == 2*SIZEOF_LONG_INT
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return pt + 4;
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#else
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return pt + 3;
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#endif
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case (CELL)FunctorBigInt:
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{
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Int sz = 2 +
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(sizeof(MP_INT)+
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(((MP_INT *)(pt+1))->_mp_alloc*sizeof(mp_limb_t)))/sizeof(CELL);
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return pt + sz;
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}
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case (CELL)FunctorLongInt:
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return pt + 3;
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break;
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}
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} else if (IsAtomTerm(reg)) {
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MarkAtomEntry(RepAtom(AtomOfTerm(reg)));
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return pt+1;
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}
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return pt+1;
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}
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static void
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mark_global(void)
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{
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CELL *pt;
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/*
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* to clean the global now that functors are just variables pointing to
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* the code
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*/
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#if COROUTINING
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pt = (CELL *)DelayTop();
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#else
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pt = H0;
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#endif
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while (pt < H) {
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pt = mark_global_cell(pt);
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}
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}
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static void
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mark_stacks(void)
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{
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mark_trail();
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mark_local();
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mark_global();
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}
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static void
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mark_streams(void)
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{
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int i;
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for (i=0; i < MaxStreams; i++) {
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if (!(Stream[i].status & (Free_Stream_f|Socket_Stream_f|InMemory_Stream_f|Pipe_Stream_f))) {
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/* This is a file, so it has a name */
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AtomEntry *ae = RepAtom(Stream[i].u.file.name);
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MarkAtomEntry(ae);
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ae = RepAtom(AtomOfTerm(Stream[i].u.file.user_name));
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MarkAtomEntry(ae);
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}
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}
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for (i=0;i<NOfFileAliases;i++) {
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AtomEntry *ae = RepAtom(FileAliases[i].name);
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MarkAtomEntry(ae);
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}
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}
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static void
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clean_atom_list(AtomHashEntry *HashPtr)
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{
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Atom atm = HashPtr->Entry;
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Atom *patm = &(HashPtr->Entry);
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while (atm != NIL) {
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AtomEntry *at = RepAtom(atm);
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if (AtomResetMark(at) ||
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at->PropsOfAE != NIL ||
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(AGCHook != NULL && !AGCHook(atm))) {
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patm = &(at->NextOfAE);
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atm = at->NextOfAE;
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} else {
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NOfAtoms--;
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if (IsWideAtom(atm)) {
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#ifdef DEBUG_RESTORE3
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fprintf(errout, "Purged %p:%S\n", at, at->WStrOfAE);
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#endif
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agc_collected += sizeof(AtomEntry)+wcslen(at->WStrOfAE);
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} else {
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#ifdef DEBUG_RESTORE3
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fprintf(stderr, "Purged %p:%s patm=%p %p\n", at, at->StrOfAE, patm, at->NextOfAE);
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#endif
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agc_collected += sizeof(AtomEntry)+strlen(at->StrOfAE);
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}
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*patm = atm = at->NextOfAE;
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Yap_FreeCodeSpace((char *)at);
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}
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}
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}
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/*
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* This is the really tough part, to restore the whole of the heap
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*/
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static void
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clean_atoms(void)
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{
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AtomHashEntry *HashPtr = HashChain;
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register int i;
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AtomResetMark(AtomFoundVar);
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AtomResetMark(AtomFreeTerm);
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for (i = 0; i < AtomHashTableSize; ++i) {
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clean_atom_list(HashPtr);
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HashPtr++;
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}
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HashPtr = WideHashChain;
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for (i = 0; i < WideAtomHashTableSize; ++i) {
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clean_atom_list(HashPtr);
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HashPtr++;
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}
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clean_atom_list(&INVISIBLECHAIN);
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}
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static void
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atom_gc(void)
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{
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int gc_verbose = Yap_is_gc_verbose();
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int gc_trace = 0;
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UInt time_start, agc_time;
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#if defined(YAPOR) || defined(THREADS)
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return;
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#endif
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if (Yap_GetValue(AtomGcTrace) != TermNil)
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gc_trace = 1;
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agc_calls++;
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agc_collected = 0;
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if (gc_trace) {
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fprintf(Yap_stderr, "%% agc:\n");
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} else if (gc_verbose) {
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fprintf(Yap_stderr, "%% Start of atom garbage collection %d:\n", agc_calls);
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}
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time_start = Yap_cputime();
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/* get the number of active registers */
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YAPEnterCriticalSection();
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init_reg_copies();
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mark_stacks();
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mark_streams();
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mark_atoms();
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clean_atoms();
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AGcLastCall = NOfAtoms;
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YAPLeaveCriticalSection();
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agc_time = Yap_cputime()-time_start;
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tot_agc_time += agc_time;
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tot_agc_recovered += agc_collected;
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if (gc_verbose) {
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fprintf(Yap_stderr, "%% Collected %lld bytes.\n", agc_collected);
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fprintf(Yap_stderr, "%% GC %d took %g sec, total of %g sec doing GC so far.\n", agc_calls, (double)agc_time/1000, (double)tot_agc_time/1000);
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}
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}
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void
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Yap_atom_gc(void)
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{
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atom_gc();
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}
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static Int
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p_atom_gc(void)
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{
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#ifndef FIXED_STACKS
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atom_gc();
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#endif /* FIXED_STACKS */
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return TRUE;
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}
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static Int
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p_inform_agc(void)
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{
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Term tn = MkIntegerTerm(tot_agc_time);
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Term tt = MkIntegerTerm(agc_calls);
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Term ts = MkIntegerTerm(tot_agc_recovered);
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return(Yap_unify(tn, ARG2) && Yap_unify(tt, ARG1) && Yap_unify(ts, ARG3));
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}
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static Int
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p_agc_threshold(void)
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{
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Term t = Deref(ARG1);
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if (IsVarTerm(t)) {
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return Yap_unify(ARG1, MkIntegerTerm(AGcThreshold));
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} else if (!IsIntegerTerm(t)) {
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Yap_Error(TYPE_ERROR_INTEGER,t,"prolog_flag/2 agc_margin");
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return FALSE;
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} else {
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Int i = IntegerOfTerm(t);
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if (i<0) {
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Yap_Error(DOMAIN_ERROR_NOT_LESS_THAN_ZERO,t,"prolog_flag/2 agc_margin");
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return FALSE;
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} else {
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AGcThreshold = i;
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return TRUE;
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}
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}
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}
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void
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Yap_init_agc(void)
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{
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Yap_InitCPred("$atom_gc", 0, p_atom_gc, HiddenPredFlag);
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Yap_InitCPred("$inform_agc", 3, p_inform_agc, HiddenPredFlag);
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Yap_InitCPred("$agc_threshold", 1, p_agc_threshold, HiddenPredFlag|SafePredFlag);
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}
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