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yap-6.3/C/exo.c
Vitor Santos Costa bda5d56bdf memory recovery
2013-03-19 21:26:22 -05:00

521 lines
13 KiB
C

/*************************************************************************
* *
* YAP Prolog *
* *
* Yap Prolog was developed at NCCUP - Universidade do Porto *
* *
* Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997 *
* *
**************************************************************************
* *
* File: exo.c *
* comments: Exo compilation *
* *
* Last rev: $Date: 2008-07-22 23:34:44 $,$Author: vsc $ * *
* $Log: not supported by cvs2svn $ *
* *
* *
*************************************************************************/
#include "Yap.h"
#include "clause.h"
#include "yapio.h"
#include "eval.h"
#include "tracer.h"
#ifdef YAPOR
#include "or.macros.h"
#endif /* YAPOR */
#ifdef TABLING
#include "tab.macros.h"
#endif /* TABLING */
#if HAVE_STRING_H
#include <string.h>
#endif
//static int exo_write=FALSE;
//void do_write(void) { exo_write=TRUE;}
#define NEXTOP(V,TYPE) ((yamop *)(&((V)->u.TYPE.next)))
#define MAX_ARITY 256
#define FNV32_PRIME 16777619
#define FNV64_PRIME ((UInt)1099511628211)
#define FNV32_OFFSET 2166136261
#define FNV64_OFFSET ((UInt)14695981039346656037)
/* Simple hash function:
first component is the base key.
hash0 spreads extensions coming from different elements.
spread over j quadrants.
*/
static BITS32
HASH(UInt arity, CELL *cl, UInt bnds[], UInt sz)
{
UInt hash;
UInt j=0;
hash = FNV32_OFFSET;
while (j < arity) {
if (bnds[j]) {
unsigned char *i=(unsigned char*)(cl+j);
unsigned char *m=(unsigned char*)(cl+(j+1));
while (i < m) {
hash = hash ^ i[0];
hash = hash * FNV32_PRIME;
i++;
}
}
j++;
}
return hash;
}
static BITS32
NEXT(UInt hash)
{
return (hash*997);
}
/* search for matching elements */
static int
MATCH(CELL *clp, CELL *kvp, UInt arity, UInt bnds[])
{
UInt j = 0;
while (j< arity) {
if ( bnds[j] && clp[j] != kvp[j])
return FALSE;
j++;
}
return TRUE;
}
static void
ADD_TO_TRY_CHAIN(CELL *kvp, CELL *cl, struct index_t *it)
{
BITS32 old = (kvp-it->cls)/it->arity;
BITS32 new = (cl-it->cls)/it->arity;
BITS32 *links = it->links;
BITS32 tmp = links[old]; /* points to the end of the chain */
if (!tmp) {
links[old] = links[new] = new;
} else {
links[new] = links[tmp];
links[tmp] = new;
links[old] = new;
}
}
/* This is the critical routine, it builds the hash table *
* each HT field stores a key pointer which is actually
* a pointer to the point in the clause where one can find the element.
*
* The cls table indexes all elements that can be reached using that key.
*
* Insert:
* j = first
* not match cij -> insert, open new chain
* match ci..j ck..j -> find j = minarg(cij \= c2j),
* else j = +inf -> c2+ci
* Lookup:
* j= first
* not match cij -> fail
* match ci..j ck..j -> find j = minarg(cij \= c2j)
* else
*/
static int
INSERT(CELL *cl, struct index_t *it, UInt arity, UInt base, UInt bnds[])
{
CELL *kvp;
BITS32 hash;
int coll_count = 0;
hash = HASH(arity, cl, bnds, it->hsize);
next:
kvp = EXO_OFFSET_TO_ADDRESS(it, it->key [hash % it->hsize]);
if (kvp == NULL) {
/* simple case, new entry */
it->nentries++;
it->key[hash % it->hsize ] = EXO_ADDRESS_TO_OFFSET(it, cl);
return TRUE;
} else if (MATCH(kvp, cl, arity, bnds)) {
it->ntrys++;
ADD_TO_TRY_CHAIN(kvp, cl, it);
return TRUE;
} else {
coll_count++;
if (coll_count == 32)
return FALSE;
it->ncollisions++;
// printf("#");
hash = NEXT(hash);
//if (exo_write) printf("N=%ld\n", hash);
goto next;
}
}
static yamop *
LOOKUP(struct index_t *it, UInt arity, UInt j, UInt bnds[])
{
CACHE_REGS
CELL *kvp;
BITS32 hash;
/* j is the firs bound element */
/* check if we match */
hash = HASH(arity, XREGS+1, bnds, it->hsize);
next:
/* loop to insert element */
kvp = EXO_OFFSET_TO_ADDRESS(it, it->key[hash % it->hsize]);
if (kvp == NULL) {
/* simple case, no element */
return FAILCODE;
} else if (MATCH(kvp, XREGS+1, arity, bnds)) {
S = kvp;
if (!it->is_key && it->links[(S-it->cls)/arity])
return it->code;
else
return NEXTOP(NEXTOP(it->code,lp),lp);
} else {
/* collision */
hash = NEXT(hash);
goto next;
}
}
static int
fill_hash(UInt bmap, struct index_t *it, UInt bnds[])
{
UInt i;
UInt arity = it->arity;
CELL *cl = it->cls;
for (i=0; i < it->nels; i++) {
if (!INSERT(cl, it, arity, 0, bnds))
return FALSE;
cl += arity;
}
for (i=0; i < it->hsize; i++) {
if (it->key[i]) {
UInt offset = it->key[i]/arity;
UInt last = it->links[offset];
if (last) {
/* the chain used to point straight to the last, and the last back to the origibal first */
it->links[offset] = it->links[last];
it->links[last] = 0;
}
}
}
return TRUE;
}
static struct index_t *
add_index(struct index_t **ip, UInt bmap, PredEntry *ap, UInt count, UInt bnds[])
{
CACHE_REGS
UInt ncls = ap->cs.p_code.NOfClauses, j;
CELL *base = NULL;
struct index_t *i;
size_t sz;
yamop *ptr;
sz = (CELL)NEXTOP(NEXTOP((yamop*)NULL,lp),lp)+ap->ArityOfPE*(CELL)NEXTOP((yamop *)NULL,x) +(CELL)NEXTOP(NEXTOP((yamop *)NULL,p),l);
if (!(i = (struct index_t *)Yap_AllocCodeSpace(sizeof(struct index_t)+sz))) {
CACHE_REGS
save_machine_regs();
LOCAL_Error_Size = 3*ncls*sizeof(CELL);
LOCAL_ErrorMessage = "not enough space to index";
Yap_Error(OUT_OF_HEAP_ERROR, TermNil, LOCAL_ErrorMessage);
return NULL;
}
i->is_key = FALSE;
i->next = *ip;
i->prev = NULL;
i->nels = ncls;
i->arity = ap->ArityOfPE;
i->ap = ap;
i->bmap = bmap;
i->is_key = FALSE;
i->hsize = 2*ncls;
if (count) {
if (!(base = (CELL *)Yap_AllocCodeSpace(sizeof(BITS32)*(ncls+i->hsize)))) {
CACHE_REGS
save_machine_regs();
LOCAL_Error_Size = sizeof(CELL)*(ncls+i->hsize);
LOCAL_ErrorMessage = "not enough space to generate indices";
Yap_FreeCodeSpace((void *)i);
Yap_Error(OUT_OF_HEAP_ERROR, TermNil, LOCAL_ErrorMessage);
return NULL;
}
bzero(base, sizeof(CELL)*(ncls+i->hsize));
}
i->size = sizeof(CELL)*(ncls+i->hsize)+sz+sizeof(struct index_t);
i->key = (CELL *)base;
i->links = (CELL *)(base+i->hsize);
i->ncollisions = i->nentries = i->ntrys = 0;
i->cls = (CELL *)((ADDR)ap->cs.p_code.FirstClause+2*sizeof(struct index_t *));
*ip = i;
while (count) {
if (!fill_hash(bmap, i, bnds)) {
size_t sz;
i->hsize += ncls;
if (i->is_key) {
sz = i->hsize*sizeof(BITS32);
} else {
sz = (ncls+i->hsize)*sizeof(BITS32);
}
if (base != realloc(base, sz))
return FALSE;
bzero(base, sz);
i->key = (CELL *)base;
i->links = (CELL *)(base+i->hsize);
i->ncollisions = i->nentries = i->ntrys = 0;
continue;
}
fprintf(stderr, "entries=%ld collisions=%ld trys=%ld\n", i->nentries, i->ncollisions, i->ntrys);
if (!i->ntrys && !i->is_key) {
i->is_key = TRUE;
if (base != realloc(base, i->hsize*sizeof(BITS32)))
return FALSE;
}
/* our hash table is just too large */
if (( i->nentries+i->ncollisions )*10 < i->hsize) {
size_t sz;
i->hsize = ( i->nentries+i->ncollisions )*10;
if (i->is_key) {
sz = i->hsize*sizeof(BITS32);
} else {
sz = (ncls+i->hsize)*sizeof(BITS32);
}
if (base != realloc(base, sz))
return FALSE;
bzero(base, sz);
i->key = (CELL *)base;
i->links = (CELL *)(base+i->hsize);
i->ncollisions = i->nentries = i->ntrys = 0;
} else {
break;
}
}
ptr = (yamop *)(i+1);
i->code = ptr;
if (count)
ptr->opc = Yap_opcode(_try_exo);
else
ptr->opc = Yap_opcode(_try_all_exo);
ptr->u.lp.l = (yamop *)i;
ptr->u.lp.p = ap;
ptr = NEXTOP(ptr, lp);
if (count)
ptr->opc = Yap_opcode(_retry_exo);
else
ptr->opc = Yap_opcode(_retry_all_exo);
ptr->u.lp.p = ap;
ptr->u.lp.l = (yamop *)i;
ptr = NEXTOP(ptr, lp);
for (j = 0; j < i->arity; j++) {
ptr->opc = Yap_opcode(_get_atom_exo);
#if PRECOMPUTE_REGADDRESS
ptr->u.x.x = (CELL) (XREGS + (j+1));
#else
ptr->u.x.x = j+1;
#endif
ptr = NEXTOP(ptr, x);
}
ptr->opc = Yap_opcode(_procceed);
ptr->u.p.p = ap;
ptr = NEXTOP(ptr, p);
ptr->opc = Yap_opcode(_Ystop);
ptr->u.l.l = i->code;
Yap_inform_profiler_of_clause((char *)(i->code), (char *)NEXTOP(ptr,l), ap, GPROF_INDEX);
return i;
}
yamop *
Yap_ExoLookup(PredEntry *ap USES_REGS)
{
UInt arity = ap->ArityOfPE;
UInt bmap = 0L, bit = 1, count = 0, j, j0 = 0;
struct index_t **ip = (struct index_t **)(ap->cs.p_code.FirstClause);
struct index_t *i = *ip;
for (j=0; j< arity; j++, bit<<=1) {
Term t = Deref(XREGS[j+1]);
if (!IsVarTerm(t)) {
bmap += bit;
LOCAL_ibnds[j] = TRUE;
if (!count) j0= j;
count++;
} else {
LOCAL_ibnds[j] = FALSE;
}
XREGS[j+1] = t;
}
while (i) {
// if (i->is_key && (i->bmap & bmap) == i->bmap) {
// break;
// }
if (i->bmap == bmap) {
break;
}
ip = &i->next;
i = i->next;
}
if (!i) {
i = add_index(ip, bmap, ap, count, LOCAL_ibnds);
}
if (count)
return LOOKUP(i, arity, j0, LOCAL_ibnds);
else
return i->code;
}
CELL
Yap_NextExo(choiceptr cptr, struct index_t *it)
{
CACHE_REGS
CELL offset = ADDRESS_TO_LINK(it,(CELL *)((CELL *)(B+1))[it->arity]);
CELL next = it->links[offset];
((CELL *)(B+1))[it->arity] = (CELL)LINK_TO_ADDRESS(it, next);
S = it->cls+it->arity*offset;
return next;
}
static Int
p_exodb_get_space( USES_REGS1 )
{ /* '$number_of_clauses'(Predicate,M,N) */
Term t = Deref(ARG1);
Term mod = Deref(ARG2);
Term tn = Deref(ARG3);
UInt arity;
Prop pe;
PredEntry *ap;
MegaClause *mcl;
UInt ncls;
UInt required;
struct index_t **li;
if (IsVarTerm(mod) || !IsAtomTerm(mod)) {
return(FALSE);
}
if (IsAtomTerm(t)) {
Atom a = AtomOfTerm(t);
arity = 0;
pe = PredPropByAtom(a, mod);
} else if (IsApplTerm(t)) {
register Functor f = FunctorOfTerm(t);
arity = ArityOfFunctor(f);
pe = PredPropByFunc(f, mod);
} else {
return FALSE;
}
if (EndOfPAEntr(pe))
return FALSE;
ap = RepPredProp(pe);
if (ap->PredFlags & (DynamicPredFlag|LogUpdatePredFlag
#ifdef TABLING
|TabledPredFlag
#endif /* TABLING */
)) {
Yap_Error(PERMISSION_ERROR_MODIFY_STATIC_PROCEDURE,t,"dbload_get_space/4");
return FALSE;
}
if (IsVarTerm(tn) || !IsIntegerTerm(tn)) {
return FALSE;
}
ncls = IntegerOfTerm(tn);
if (ncls <= 1) {
return FALSE;
}
required = ncls*arity*sizeof(CELL)+sizeof(MegaClause)+2*sizeof(struct index_t *);
while (!(mcl = (MegaClause *)Yap_AllocCodeSpace(required))) {
if (!Yap_growheap(FALSE, required, NULL)) {
/* just fail, the system will keep on going */
return FALSE;
}
}
Yap_ClauseSpace += required;
/* cool, it's our turn to do the conversion */
mcl->ClFlags = MegaMask|ExoMask;
mcl->ClSize = required;
mcl->ClPred = ap;
mcl->ClItemSize = arity*sizeof(CELL);
mcl->ClNext = NULL;
li = (struct index_t **)(mcl->ClCode);
li[0] = li[1] = NULL;
ap->cs.p_code.FirstClause =
ap->cs.p_code.LastClause =
mcl->ClCode;
ap->PredFlags |= MegaClausePredFlag|SourcePredFlag;
ap->cs.p_code.NOfClauses = ncls;
if (ap->PredFlags & (SpiedPredFlag|CountPredFlag|ProfiledPredFlag)) {
ap->OpcodeOfPred = Yap_opcode(_spy_pred);
} else {
ap->OpcodeOfPred = Yap_opcode(_enter_exo);
}
ap->CodeOfPred = ap->cs.p_code.TrueCodeOfPred = (yamop *)(&(ap->OpcodeOfPred));
return Yap_unify(ARG4, MkIntegerTerm((Int)mcl));
}
#define DerefAndCheck(t, V) \
t = Deref(V); if(IsVarTerm(t) || !(IsAtomOrIntTerm(t))) Yap_Error(TYPE_ERROR_ATOM, t0, "load_db");
static int
store_exo(yamop *pc, UInt arity, Term t0)
{
Term t;
CELL *tp = RepAppl(t0)+1,
*cpc = (CELL *)pc;
UInt i;
for (i = 0; i< arity; i++) {
DerefAndCheck(t, tp[0]);
*cpc = t;
tp++;
cpc++;
}
return TRUE;
}
static Int
p_exoassert( USES_REGS1 )
{ /* '$number_of_clauses'(Predicate,M,N) */
Term thandle = Deref(ARG2);
Term tn = Deref(ARG3);
PredEntry *pe;
MegaClause *mcl;
Int n;
if (IsVarTerm(thandle) || !IsIntegerTerm(thandle)) {
return FALSE;
}
mcl = (MegaClause *)IntegerOfTerm(thandle);
if (IsVarTerm(tn) || !IsIntegerTerm(tn)) {
return FALSE;
}
n = IntegerOfTerm(tn);
pe = mcl->ClPred;
return store_exo((yamop *)((ADDR)mcl->ClCode+2*sizeof(struct index_t *)+n*(mcl->ClItemSize)),pe->ArityOfPE, Deref(ARG1));
}
void
Yap_InitExoPreds(void)
{
CACHE_REGS
Term cm = CurrentModule;
CurrentModule = DBLOAD_MODULE;
Yap_InitCPred("exo_db_get_space", 4, p_exodb_get_space, 0L);
Yap_InitCPred("exoassert", 3, p_exoassert, 0L);
CurrentModule = cm;
}