use arrays to implement catch and throw instead of record
cleanup queues at top-level and at catch-throw. git-svn-id: https://yap.svn.sf.net/svnroot/yap/trunk@69 b08c6af1-5177-4d33-ba66-4b1c6b8b522a
This commit is contained in:
vsc
parent
08ebcf94be
commit
97d882c1a7
87
C/arrays.c
87
C/arrays.c
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@ -771,6 +771,36 @@ p_create_static_array(void)
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}
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}
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/* has a static array associated (+Name) */
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static Int
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p_has_static_array(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 (FALSE);
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}
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else if (IsAtomTerm(t)) {
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/* Create a named array */
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AtomEntry *ae = RepAtom(AtomOfTerm(t));
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StaticArrayEntry *pp;
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READ_LOCK(ae->ARWLock);
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pp = RepStaticArrayProp(ae->PropOfAE);
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while (!EndOfPAEntr(pp) && pp->KindOfPE != ArrayProperty)
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pp = RepStaticArrayProp(pp->NextOfPE);
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if (EndOfPAEntr(pp) || pp->ValueOfVE.ints == NULL) {
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READ_UNLOCK(ae->ARWLock);
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return (FALSE);
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} else {
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READ_UNLOCK(ae->ARWLock);
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return(TRUE);
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}
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} else {
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return (FALSE);
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}
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}
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/* resize a static array (+Name, + Size, +Props) */
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/* does not work for mmap arrays yet */
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static Int
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@ -1369,7 +1399,7 @@ p_assign_static(void)
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Error(INSTANTIATION_ERROR,t3,"assign_static");
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return (FALSE);
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}
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if (indx < 0 || indx >= - ptr->ArrayEArity) {
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if (indx < 0 || indx >= - ptr->ArrayEArity) {
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WRITE_UNLOCK(ptr->ArRWLock);
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Error(DOMAIN_ERROR_ARRAY_OVERFLOW,t2,"assign_static");
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}
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@ -1543,6 +1573,60 @@ p_sync_mmapped_arrays(void)
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return(TRUE);
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}
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/*
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This is a hack, to steal the first element of a key.
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It first fetches the first element in the chain, and then erases it
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through its reference.
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Be careful when using this routine. It is especially evil because if
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the term is ground it should be copied to the stack, as space for
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the entry may be deleted. For the moment, the terms I want are just
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integers, so no problemo, amigo.
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*/
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static Term
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StealFirstFromDB(DBRef ref)
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{
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Term TermDB, out;
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if ((TermDB = FetchTermFromDB(ref,3)) == (CELL)0) {
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/* oops, we are in trouble, not enough stack space */
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return(TermNil);
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}
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if (IsVarTerm(TermDB) || !IsApplTerm(TermDB))
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/* it's not a wonderful world afterall */
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return(TermNil);
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out = ArgOfTerm(1,TermDB);
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/* now, return what once was there, only nevermore */
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return(out);
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}
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Int
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SetDBForThrow(Term Message)
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{
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Term cut_pt_term;
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Atom a = FullLookupAtom("$catch_queue");
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AtomEntry *ae = RepAtom(a);
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StaticArrayEntry *ptr;
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DBRef ref;
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READ_LOCK(ae->ARWLock);
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ptr = RepStaticArrayProp(ae->PropOfAE);
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while (!EndOfPAEntr(ptr) && ptr->KindOfPE != ArrayProperty)
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ptr = RepStaticArrayProp(ptr->NextOfPE);
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READ_UNLOCK(ae->ARWLock);
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ref = ptr->ValueOfVE.terms[0];
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cut_pt_term = StealFirstFromDB(ref);
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if (IsVarTerm(cut_pt_term) || !IsIntegerTerm(cut_pt_term)) {
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/* ooops, babe we are in trouble */
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return(-1);
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}
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/* OK, we've got the place to cut to, next store the new throw */
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ptr->ValueOfVE.terms[1] = StoreTermInDB(Message,3);
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return(IntegerOfTerm(cut_pt_term));
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}
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void
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InitArrayPreds(void)
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{
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@ -1558,5 +1642,6 @@ InitArrayPreds(void)
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InitCPred("$sync_mmapped_arrays", 0, p_sync_mmapped_arrays, SafePredFlag);
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InitCPred("$compile_array_refs", 0, p_compile_array_refs, SafePredFlag);
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InitCPred("$array_refs_compiled", 0, p_array_refs_compiled, SafePredFlag);
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InitCPred("$has_static_array", 1, p_has_static_array, TestPredFlag|SafePredFlag);
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}
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133
C/dbase.c
133
C/dbase.c
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@ -114,7 +114,7 @@ typedef struct {
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} SFKeep;
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#endif
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typedef struct
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typedef struct idb_queue
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{
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Functor id; /* identify this as being pointed to by a DBRef */
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Term EntryTerm; /* cell bound to itself */
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@ -123,6 +123,8 @@ typedef struct
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rwlock_t QRWLock; /* a simple lock to protect this entry */
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#endif
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DBRef FirstInQueue, LastInQueue;
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Int age; /* the number of catches when we created the queue */
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struct idb_queue *next, *prev;
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} db_queue;
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#define HashFieldMask ((CELL)0xffL)
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@ -263,7 +265,6 @@ STATIC_PROTO(Int p_dequeue, (void));
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STATIC_PROTO(Int p_first_age, (void));
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STATIC_PROTO(Int p_db_nb_to_ref, (void));
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STATIC_PROTO(Int p_last_age, (void));
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STATIC_PROTO(Term StealFirstFromDB, (Atom, Int));
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#if OS_HANDLES_TR_OVERFLOW
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#define check_trail(x)
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@ -3451,24 +3452,6 @@ p_erase(void)
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return (TRUE);
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}
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/* erase(+Ref) */
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static Int
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p_smash(void)
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{
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Term t1 = Deref(ARG1);
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if (IsVarTerm(t1)) {
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Error(INSTANTIATION_ERROR, t1, "erase");
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return (FALSE);
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}
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if (!IsDBRefTerm(t1)) {
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Error(TYPE_ERROR_DBREF, t1, "erase");
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return (FALSE);
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}
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EraseEntry(DBRefOfTerm(t1));
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return (TRUE);
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}
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/* eraseall(+Key) */
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static Int
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p_eraseall(void)
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@ -3799,7 +3782,7 @@ p_init_queue(void)
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db_queue *dbq;
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Term t;
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while ((dbq = (db_queue *)AllocDBSpace(sizeof(db_queue))) == NIL) {
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while ((dbq = (db_queue *)AllocDBSpace(sizeof(db_queue))) == NULL) {
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if (!growheap(FALSE)) {
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Abort("[ SYSTEM ERROR: YAP failed to reserve space in growheap ]\n");
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return(FALSE);
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@ -3808,12 +3791,17 @@ p_init_queue(void)
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dbq->id = FunctorDBRef;
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dbq->EntryTerm = MkAtomTerm(AbsAtom((AtomEntry *)dbq));
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dbq->Flags = DBClMask;
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dbq->FirstInQueue = dbq->LastInQueue = NIL;
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dbq->FirstInQueue = dbq->LastInQueue = NULL;
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dbq->next = DBQueues;
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dbq->prev = NULL;
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DBQueues = dbq;
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dbq->age = IntOfTerm(GetValue(AtomCatch));
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INIT_RWLOCK(dbq->QRWLock);
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t = MkDBRefTerm((DBRef)dbq);
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return(unify(ARG1, t));
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}
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static Int
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p_enqueue(void)
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{
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@ -3887,6 +3875,12 @@ p_dequeue(void)
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WRITE_LOCK(father_key->QRWLock);
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if ((cur_instance = father_key->FirstInQueue) == NIL) {
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/* an empty queue automatically goes away */
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if (father_key == DBQueues)
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DBQueues = father_key->next;
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else
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father_key->prev->next = father_key->next;
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if (father_key->next != NULL)
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father_key->next->prev = father_key->prev;
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WRITE_UNLOCK(father_key->QRWLock);
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FreeDBSpace((char *) father_key);
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return(FALSE);
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@ -3907,77 +3901,34 @@ p_dequeue(void)
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}
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}
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/*
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This is a hack, to steal the first element of a key.
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It first fetches the first element in the chain, and then erases it
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through its reference.
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Be careful when using this routine. It is especially evil because if
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the term is ground it should be copied to the stack, as space for
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the entry may be deleted. For the moment, the terms I want are just
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integers, so no problemo, amigo.
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*/
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static Term
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StealFirstFromDB(Atom key, Int arity)
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static Int
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p_clean_queues(void)
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{
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Prop AtProp;
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Register DBRef ref;
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Term TermDB;
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Term out;
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Int myage = IntOfTerm(ARG1);
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db_queue *ptr;
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YAPEnterCriticalSection();
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ptr = DBQueues;
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while (ptr) {
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if (ptr->age >= myage) {
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DBRef cur_instance;
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db_queue *optr = ptr;
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/* get the DB property */
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if ((AtProp = FindDBProp(RepAtom(key), 0, arity)) == NIL) {
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return(TermNil);
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while ((cur_instance = ptr->FirstInQueue)) {
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/* release space for cur_instance */
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ptr->FirstInQueue = (DBRef)(cur_instance->Parent);
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ErasePendingRefs(cur_instance);
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FreeDBSpace((char *) cur_instance);
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}
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ptr = ptr->next;
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FreeDBSpace((char *) optr);
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} else
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break;
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}
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/* get the first entry */
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#ifdef KEEP_OLD_ENTRIES_HANGING_ABOUT
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ref = RepDBProp(AtProp)->FirstNEr;
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#else
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ref = RepDBProp(AtProp)->First;
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#endif
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/* is there anyone home ? */
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while (ref != NIL
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&& (ref->Flags & (DBCode | ErasedMask)))
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ref = NextDBRef(ref);
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if (ref == NIL) {
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return(TermNil);
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}
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/* get our fine term */
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if ((TermDB = GetDBTerm(ref)) == (CELL)0) {
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/* oops, we are in trouble, not enough stack space */
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return(TermNil);
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}
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if (IsVarTerm(TermDB) || !IsApplTerm(TermDB))
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/* it's not a wonderful world afterall */
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return(TermNil);
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out = ArgOfTerm(1,TermDB);
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/* next, make it disappear from the DB */
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EraseEntry(ref);
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/* now, return what once was there, only nevermore */
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return(out);
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}
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Int
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SetDBForThrow(Term Message)
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{
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Term cut_pt_term;
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/* who's gonna catch us? */
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DBModule = 0;
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cut_pt_term = StealFirstFromDB(AtomCatch, 0);
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if (IsVarTerm(cut_pt_term) || !IsIntegerTerm(cut_pt_term)) {
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/* ooops, babe we are in trouble */
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return(-1);
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}
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/* OK, we've got the place to cut to, next store the new throw */
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if (record(MkFirst, MkAtomTerm(AtomThrow), Message, TermNil) == NIL)
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return (-1);
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else
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/* off we go, to see the wizard of Oz */
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return(IntegerOfTerm(cut_pt_term));
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if (ptr)
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ptr->prev = NULL;
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DBQueues = ptr;
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YAPLeaveCriticalSection();
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return(TRUE);
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}
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/* given a key, find the clock number for the first entry */
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@ -4187,7 +4138,6 @@ InitDBPreds(void)
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InitCPred("$recordzp", 4, p_drcdzp, SafePredFlag|SyncPredFlag);
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InitCPred("$recordaifnot", 3, p_rcdaifnot, SafePredFlag|SyncPredFlag);
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InitCPred("$recordzifnot", 3, p_rcdzifnot, SafePredFlag|SyncPredFlag);
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InitCPred("$db_smash", 1, p_smash, SafePredFlag|SyncPredFlag);
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InitCPred("erase", 1, p_erase, SafePredFlag|SyncPredFlag);
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InitCPred("erased", 1, p_erased, TestPredFlag | SafePredFlag|SyncPredFlag);
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InitCPred("instance", 2, p_instance, SyncPredFlag);
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@ -4199,6 +4149,7 @@ InitDBPreds(void)
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InitCPred("$db_key", 2, p_db_key, 0);
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InitCPred("$db_enqueue", 2, p_enqueue, SyncPredFlag);
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InitCPred("$db_dequeue", 2, p_dequeue, SyncPredFlag);
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InitCPred("$db_clean_queues", 1, p_clean_queues, SyncPredFlag);
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InitCPred("$db_first_age", 2, p_first_age, TestPredFlag|SafePredFlag|SyncPredFlag);
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InitCPred("$db_nb_to_ref", 3, p_db_nb_to_ref, TestPredFlag|SafePredFlag);
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InitCPred("$db_last_age", 2, p_last_age, TestPredFlag|SafePredFlag|SyncPredFlag);
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1
C/init.c
1
C/init.c
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@ -820,6 +820,7 @@ InitCodes(void)
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heap_regs->no_of_modules = 1;
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heap_regs->primitives_module = 0;
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heap_regs->user_module = 1;
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heap_regs->db_queues = NULL;
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heap_regs->atom_abol = LookupAtom("$abol");
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AtomAltNot = LookupAtom("not");
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heap_regs->atom_append = LookupAtom ("append");
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|
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4
C/save.c
4
C/save.c
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@ -944,6 +944,10 @@ restore_codes(void)
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heap_regs->dead_clauses = (Clause *)
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AddrAdjust((ADDR)(heap_regs->dead_clauses));
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}
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if (heap_regs->db_queues != NULL) {
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heap_regs->db_queues = (struct idb_queue *)
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AddrAdjust((ADDR)(heap_regs->db_queues));
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}
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heap_regs->retry_recorded_code =
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PtoOpAdjust(heap_regs->retry_recorded_code);
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heap_regs->retry_recorded_k_code =
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|
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@ -1099,7 +1099,7 @@ ProcessSIGINT(void)
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if (in_readline) {
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/* readline must eat a newline, otherwise we will
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have to wait before we do the Abort() */
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} else {
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} else if (!(PrologMode & CritMode)) {
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#endif
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#if defined(__MINGW32__) || _MSC_VER
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/* we can't do a direct abort, so ask the system to do it for us */
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|
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4
H/Heap.h
4
H/Heap.h
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|
@ -10,7 +10,7 @@
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* File: Heap.h *
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* mods: *
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* comments: Heap Init Structure *
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* version: $Id: Heap.h,v 1.4 2001-06-08 13:38:42 vsc Exp $ *
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* version: $Id: Heap.h,v 1.5 2001-06-08 19:10:43 vsc Exp $ *
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*************************************************************************/
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/* information that can be stored in Code Space */
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|
@ -133,6 +133,7 @@ typedef struct various_codes {
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#endif
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int primitives_module;
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int user_module;
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struct idb_queue *db_queues;
|
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Atom
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atom_abol,
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atom_alarm,
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|
|
@ -316,6 +317,7 @@ typedef struct various_codes {
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#define ModuleName heap_regs->module_name
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#define PrimitivesModule heap_regs->primitives_module
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#define UserModule heap_regs->user_module
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#define DBQueues heap_regs->db_queues
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#define NoOfModules heap_regs->no_of_modules
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#define AtomAbol heap_regs->atom_abol
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#define AtomAlarm heap_regs->atom_alarm
|
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|
|
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|
|
@ -16,6 +16,7 @@
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|
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<h2>Yap-4.3.19:</h2>
|
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<ul>
|
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<li>FIXED: change catch and throw to use arrays.</li>
|
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<li>CLEANUP: split TRAIL_REF.</li>
|
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<li>FIXED: give correct type to FreeBlocks.</li>
|
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<li>FIXED: give correct type to alias list.</li>
|
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|
|
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81
pl/boot.yap
81
pl/boot.yap
|
|
@ -43,6 +43,7 @@ true :- true. % otherwise, $$compile will ignore this clause.
|
|||
),
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'$set_yap_flags'(10,0),
|
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'$set_value'('$gc',on),
|
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'$init_catch',
|
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prompt(' ?- '),
|
||||
(
|
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'$get_value'('$break',0)
|
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|
|
@ -61,13 +62,25 @@ true :- true. % otherwise, $$compile will ignore this clause.
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( exists('~/prolog.ini') -> [-'~/prolog.ini'] ; true )
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),
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'$clean_catch_and_throw',
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'$db_clean_queues'(0),
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'$startup_reconsult',
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'$startup_goals'
|
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;
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true
|
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).
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|
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%
|
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'$init_catch' :-
|
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% initialise access to the catch queue
|
||||
( '$has_static_array'('$catch_queue') ->
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true
|
||||
;
|
||||
static_array('$catch_queue',2, term)
|
||||
),
|
||||
update_array('$catch_queue', 0, '$'),
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update_array('$catch_queue', 1, '$').
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|
||||
|
||||
%
|
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% encapsulate $cut_by because of co-routining.
|
||||
%
|
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'$cut_by'(X) :- '$$cut_by'(X).
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||||
|
|
@ -1122,9 +1135,9 @@ catch(G,C,A) :-
|
|||
'$catch'(G,C,A).
|
||||
|
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'$catch'(G,C,A) :-
|
||||
'$get_value'('$catch_counter', I),
|
||||
'$get_value'('$catch', I),
|
||||
I1 is I+1,
|
||||
'$set_value'('$catch_counter', I1),
|
||||
'$set_value'('$catch', I1),
|
||||
'$current_module'(M),
|
||||
'$catch'(G,C,A,I,M).
|
||||
|
||||
|
|
@ -1134,23 +1147,35 @@ catch(G,C,A) :-
|
|||
'$catch_call'(X,G,I).
|
||||
% someone sent us a throw.
|
||||
'$catch'(_,C,A,_,M) :-
|
||||
('$recorded'('$throw',X,R)->true),
|
||||
erase(R),
|
||||
array_element('$catch_queue', 1, X), X \= '$',
|
||||
update_array('$catch_queue', 1, '$'),
|
||||
array_element('$catch_queue', 0, catch(_,Lev,Q)),
|
||||
update_array('$catch_queue', 0, Q),
|
||||
'$db_clean_queues'(Lev),
|
||||
( C=X -> '$current_module'(_,M), '$execute'(A) ; throw(X)).
|
||||
% normal exit: make sure we only erase what we should erase!
|
||||
'$catch'(_,_,_,I,_) :-
|
||||
'$recorded'('$catch','$catch'(_,J),R), J >= I,
|
||||
erase(R), fail.
|
||||
array_element('$catch_queue', 0, OldCatch),
|
||||
'$erase_catch_elements'(OldCatch, I, Catch),
|
||||
update_array('$catch_queue', 0, Catch),
|
||||
fail.
|
||||
|
||||
'$erase_catch_elements'(catch(X, J, P), I, Catch) :-
|
||||
J >= I, !,
|
||||
'$erase_catch_elements'(P, I, Catch).
|
||||
'$erase_catch_elements'(Catch, _, Catch).
|
||||
|
||||
'$catch_call'(X,G,I) :-
|
||||
'$recorda'('$catch','$catch'(X,I),_),
|
||||
array_element('$catch_queue', 0, OldCatch),
|
||||
update_array('$catch_queue', 0, catch(X,I,OldCatch)),
|
||||
'$execute'(G),
|
||||
( % on exit remove the catch
|
||||
('$recorded'('$catch','$catch'(X,I),R)->true),
|
||||
erase(R)
|
||||
array_element('$catch_queue', 0, catch(X,I,Catch)),
|
||||
update_array('$catch_queue', 0, Catch)
|
||||
;
|
||||
% on backtracking reinstate the catch before backtracking to G
|
||||
'$recorda'('$catch','$catch'(X,I),_),
|
||||
array_element('$catch_queue', 0, Catch),
|
||||
update_array('$catch_queue', 0, catch(X,I,Catch)),
|
||||
fail
|
||||
).
|
||||
|
||||
|
|
@ -1161,9 +1186,9 @@ catch(G,C,A) :-
|
|||
% also avoids module preprocessing and goal_expansion
|
||||
%
|
||||
'$system_catch'(G,C,A) :-
|
||||
'$get_value'('$catch_counter', I),
|
||||
'$get_value'('$catch', I),
|
||||
I1 is I+1,
|
||||
'$set_value'('$catch_counter', I1),
|
||||
'$set_value'('$catch', I1),
|
||||
'$current_module'(M),
|
||||
'$system_catch'(G,C,A,I,M).
|
||||
|
||||
|
|
@ -1173,8 +1198,11 @@ catch(G,C,A) :-
|
|||
'$system_catch_call'(X,G,I).
|
||||
% someone sent us a throw.
|
||||
'$system_catch'(_,C,A,_,M0) :-
|
||||
('$recorded'('$throw',X,R)->true),
|
||||
erase(R),
|
||||
array_element('$catch_queue', 1, X), X \= '$',
|
||||
update_array('$catch_queue', 1, '$'),
|
||||
array_element('$catch_queue', 0, catch(_,Lev,Q)),
|
||||
'$db_clean_queues'(Lev),
|
||||
update_array('$catch_queue', 0, Q),
|
||||
( C=X ->
|
||||
'$current_module'(_,M0),
|
||||
(A = M:G -> '$mod_switch'(M,G) ; '$mod_switch'(M0,A))
|
||||
|
|
@ -1183,27 +1211,30 @@ catch(G,C,A) :-
|
|||
).
|
||||
% normal exit: make sure we only erase what we should erase!
|
||||
'$system_catch'(_,_,_,I,_) :-
|
||||
'$recorded'('$catch','$catch'(_,J),R), J >= I,
|
||||
erase(R), fail.
|
||||
array_element('$catch_queue', 0, OldCatch),
|
||||
'$erase_catch_elements'(OldCatch, I, Catch),
|
||||
update_array('$catch_queue', 0, Catch),
|
||||
fail.
|
||||
|
||||
'$system_catch_call'(X,G,I) :-
|
||||
'$recorda'('$catch','$catch'(X,I),_),
|
||||
array_element('$catch_queue', 0, OldCatch),
|
||||
update_array('$catch_queue', 0, catch(X,I,OldCatch)),
|
||||
'$execute0'(G),
|
||||
( % on exit remove the catch
|
||||
('$recorded'('$catch','$catch'(X,I),R)->true),
|
||||
erase(R)
|
||||
array_element('$catch_queue', 0, catch(X,I,Catch)),
|
||||
update_array('$catch_queue', 0, Catch)
|
||||
;
|
||||
% on backtracking reinstate the catch before backtracking to G
|
||||
'$recorda'('$catch','$catch'(X,I),_),
|
||||
array_element('$catch_queue', 0, Catch),
|
||||
update_array('$catch_queue', 0, catch(X,I,Catch)),
|
||||
fail
|
||||
).
|
||||
|
||||
throw(A) :-
|
||||
% fetch the point to jump to
|
||||
'$recorded'('$catch','$catch'(X,_),R), !,
|
||||
erase(R),
|
||||
array_element('$catch_queue', 0, catch(X,_,_)), !,
|
||||
% now explain why we are jumping.
|
||||
'$recordz'('$throw',A,_),
|
||||
update_array('$catch_queue', 1, A),
|
||||
'$$cut_by'(X),
|
||||
fail.
|
||||
throw(G) :-
|
||||
|
|
@ -1218,7 +1249,7 @@ throw(G) :-
|
|||
throw(error(type_error(list,S),T)).
|
||||
|
||||
'$clean_catch_and_throw' :-
|
||||
'$set_value'('$catch_counter', 0),
|
||||
'$set_value'('$catch', 0),
|
||||
fail.
|
||||
'$clean_catch_and_throw' :-
|
||||
'$recorded'('$catch',_,R),
|
||||
|
|
|
|||
Reference in New Issue