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763b59bb05
yap-6.3/C/heapgc.c
vsc e133c87b3b fix cycle when outputting a choicepoint for retry_c. 
git-svn-id: https://yap.svn.sf.net/svnroot/yap/trunk@699 b08c6af1-5177-4d33-ba66-4b1c6b8b522a
2002-11-20 19:25:45 +00:00

3223 lines
77 KiB
C
Raw Blame History

/*************************************************************************
* *
* 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: Global Stack garbage collector *
* *
*************************************************************************/
#ifdef SCCS
static char SccsId[] = "%W% %G%";
#endif /* SCCS */
#include "absmi.h"
#include "yapio.h"
#define EARLY_RESET 1
#if !defined(TABLING)
#define EASY_SHUNTING 1
#endif
#define HYBRID_SCHEME 1
/* global variables for garbage collection */
#ifndef DEBUG
static
#endif
unsigned int gc_calls = 0; /* number of times GC has been called */
static Int tot_gc_time = 0; /* total time spent in GC */
static Int tot_gc_recovered = 0; /* number of heap objects in all garbage collections */
/* in a single gc */
static Int total_marked; /* number of heap objects marked */
struct gc_ma_h_entry *live_list;
STATIC_PROTO(Int p_inform_gc, (void));
STATIC_PROTO(Int p_gc, (void));
#ifdef EASY_SHUNTING
static choiceptr current_B;
static tr_fr_ptr sTR, sTR0;
static CELL *prev_HB;
#endif
static tr_fr_ptr new_TR;
STATIC_PROTO(void push_registers, (Int, yamop *));
STATIC_PROTO(void marking_phase, (tr_fr_ptr, CELL *, yamop *, CELL *));
STATIC_PROTO(void compaction_phase, (tr_fr_ptr, CELL *, yamop *, CELL *));
STATIC_PROTO(void pop_registers, (Int, yamop *));
STATIC_PROTO(void store_ref_in_dbtable, (DBRef));
STATIC_PROTO(DBRef find_ref_in_dbtable, (DBRef));
STATIC_PROTO(void init_dbtable, (tr_fr_ptr));
STATIC_PROTO(void mark_db_fixed, (CELL *));
STATIC_PROTO(void mark_regs, (tr_fr_ptr));
STATIC_PROTO(void mark_trail, (tr_fr_ptr, tr_fr_ptr, CELL *, choiceptr));
STATIC_PROTO(void mark_environments, (CELL *, OPREG, CELL *));
STATIC_PROTO(void mark_choicepoints, (choiceptr, tr_fr_ptr, int));
STATIC_PROTO(void into_relocation_chain, (CELL *, CELL *));
STATIC_PROTO(void sweep_trail, (choiceptr, tr_fr_ptr));
STATIC_PROTO(void sweep_environments, (CELL *, OPREG, CELL *));
STATIC_PROTO(void sweep_choicepoints, (choiceptr));
STATIC_PROTO(choiceptr update_B_H, (choiceptr, CELL *, CELL *, CELL *));
STATIC_PROTO(void compact_heap, (void));
STATIC_PROTO(void update_relocation_chain, (CELL *, CELL *));
STATIC_PROTO(int is_gc_verbose, (void));
STATIC_PROTO(int is_gc_very_verbose, (void));
#include "heapgc.h"
static int discard_trail_entries = 0;
/* support for hybrid garbage collection scheme */
typedef struct {
CELL *v;
int nof;
} cont;
#ifdef EASY_SHUNTING
#define cont_top0 (cont *)sTR
#else
static cont *cont_top0;
#endif
static cont *cont_top;
inline static void
PUSH_CONTINUATION(CELL *v, int nof) {
cont *x;
if (nof == 0) return;
x = cont_top;
x++;
if ((ADDR)x > Yap_TrailTop-1024)
Yap_growtrail(64 * 1024L);
x->v = v;
x->nof = nof;
cont_top = x;
}
#define POP_CONTINUATION() { \
if (cont_top == cont_top0) \
return; \
else { \
int nof = cont_top->nof; \
cont *x = cont_top; \
\
current = x->v; \
if (nof == 1) \
cont_top = --x; \
else { \
x->nof = nof-1; \
x->v = current+1; \
} \
} \
goto begin; }
#ifdef HYBRID_SCHEME
static CELL_PTR *iptop;
inline static void
PUSH_POINTER(CELL *v) {
if (iptop >= (CELL_PTR *)ASP) return;
*iptop++ = v;
}
inline static void
POP_POINTER(void) {
if (iptop >= (CELL_PTR *)ASP) return;
--iptop;
}
inline static void
POPSWAP_POINTER(CELL_PTR *vp) {
if (iptop >= (CELL_PTR *)ASP) return;
--iptop;
if (vp != iptop)
*vp = *iptop;
}
/*
original code from In Hyuk Choi,
found at http://userpages.umbc.edu/~ichoi1/project/cs441.htm
*/
static inline void
exchange(CELL_PTR * b, Int i, Int j)
{
CELL *t = b[j];
b[j] = b[i];
b[i] = t;
}
static UInt
partition(CELL *a[], Int p, Int r)
{
CELL *x;
UInt i, j;
x = a[p];
i = p+1;
j = r;
while (a[j] > x && i < j) {
j--;
}
while (a[i] < x && i < j) {
i++;
}
while(i < j) {
exchange(a, i, j);
i++;
j--;
while (a[j] > x && i < j) {
j--;
}
while (a[i] < x && i < j) {
i++;
}
}
if (a[i] > x)
i--;
exchange(a, p, i);
return(i);
}
static void
insort(CELL *a[], Int p, Int q)
{
Int j;
for (j = p+1; j <= q; j ++) {
CELL *key;
Int i;
key = a[j];
i = j;
while (i > p && a[i-1] > key) {
a[i] = a[i-1];
i --;
}
a[i] = key;
}
}
static void
quicksort(CELL *a[], Int p, Int r)
{
Int q;
if (p < r) {
if (r - p < 100) {
insort(a, p, r);
return;
}
exchange(a, p, (p+r)/2);
q = partition (a, p, r);
quicksort(a, p, q-1);
quicksort(a, q + 1, r);
}
}
#else
#define PUSH_POINTER(P)
#define POP_POINTER()
#define POPSWAP_POINTER(P)
#endif /* HYBRID_SCHEME */
#ifdef MULTI_ASSIGNMENT_VARIABLES
/*
Based in opt.mavar.h. This is a set of routines to find out if a
ma trail entry has appeared before in the same trail segment. All ma
entries for the same cell are then linked. At the end of mark_trail() only
one will remain.
*/
#define GC_MAVARS_HASH_SIZE 512
typedef struct gc_ma_h_entry {
CELL* addr;
tr_fr_ptr trptr;
struct gc_ma_h_entry* ma_list;
struct gc_ma_h_entry *next;
} gc_ma_h_inner_struct;
extern struct gc_ma_h_entry *live_list;
typedef struct {
UInt timestmp;
struct gc_ma_h_entry val;
} gc_ma_hash_entry;
static gc_ma_hash_entry gc_ma_hash_table[GC_MAVARS_HASH_SIZE];
static UInt timestamp; /* an unsigned int */
static inline unsigned int
GC_MAVAR_HASH(CELL *addr) {
#if SIZEOF_INT_P==8
return((((unsigned int)((CELL)(addr)))>>3)%GC_MAVARS_HASH_SIZE);
#else
return((((unsigned int)((CELL)(addr)))>>2)%GC_MAVARS_HASH_SIZE);
#endif
}
gc_ma_h_inner_struct *gc_ma_h_top;
static inline struct gc_ma_h_entry *
GC_ALLOC_NEW_MASPACE(void)
{
gc_ma_h_inner_struct *new = gc_ma_h_top;
if ((char *)gc_ma_h_top > Yap_TrailTop-1024)
Yap_growtrail(64 * 1024L);
gc_ma_h_top++;
cont_top = (cont *)gc_ma_h_top;
#ifdef EASY_SHUNTING
sTR = (tr_fr_ptr)cont_top;
#else
cont_top0 = cont_top;
#endif
return(new);
}
static inline tr_fr_ptr*
gc_lookup_ma_var(CELL *addr, tr_fr_ptr trp) {
unsigned int i = GC_MAVAR_HASH(addr);
struct gc_ma_h_entry *nptr, *optr;
if (gc_ma_hash_table[i].timestmp != timestamp) {
gc_ma_hash_table[i].timestmp = timestamp;
gc_ma_hash_table[i].val.addr = addr;
gc_ma_hash_table[i].val.next = NULL;
gc_ma_hash_table[i].val.trptr = trp;
gc_ma_hash_table[i].val.ma_list = live_list;
live_list = &(gc_ma_hash_table[i].val);
return(NULL);
}
if (gc_ma_hash_table[i].val.addr == addr) {
return(&(gc_ma_hash_table[i].val.trptr));
}
optr = &(gc_ma_hash_table[i].val);
nptr = gc_ma_hash_table[i].val.next;
while (nptr != NULL) {
if (nptr->addr == addr) {
return(&(nptr->trptr));
}
optr = nptr;
nptr = nptr->next;
}
nptr = GC_ALLOC_NEW_MASPACE();
optr->next = nptr;
nptr->addr = addr;
nptr->trptr = trp;
nptr->ma_list = live_list;
nptr->next = NULL;
live_list = nptr;
return(NULL);
}
static inline void
GC_NEW_MAHASH(gc_ma_h_inner_struct *top) {
UInt time = ++timestamp;
if (time == 0) {
unsigned int i;
/* damn, we overflowed */
for (i = 0; i < GC_MAVARS_HASH_SIZE; i++)
gc_ma_hash_table[i].timestmp = 0;
time = ++timestamp;
}
gc_ma_h_top = top;
cont_top = (cont *)gc_ma_h_top;
#ifdef EASY_SHUNTING
sTR = (tr_fr_ptr)cont_top;
#else
cont_top0 = cont_top;
#endif
live_list = NULL;
}
#endif
/* find all accessible objects on the heap and squeeze out all the rest */
/* push the active registers onto the trail for inclusion during gc */
static void
push_registers(Int num_regs, yamop *nextop)
{
int i;
/* push array entries first */
ArrayEntry *al = DynArrayList;
while (al != NULL) {
if (al->ArrayEArity > 0) {
TrailTerm(TR++) = al->ValueOfVE;
}
al = al->NextArrayE;
}
#ifdef COROUTINING
TrailTerm(TR) = WokenGoals;
TrailTerm(TR+1) = MutableList;
TrailTerm(TR+2) = AttsMutableList;
TrailTerm(TR+3) = DelayedVars;
TR += 4;
#endif
for (i = 1; i <= num_regs; i++)
TrailTerm(TR++) = (CELL) XREGS[i];
/* push any live registers we might have hanging around */
if (nextop->opc == Yap_opcode(_move_back) ||
nextop->opc == Yap_opcode(_skip)) {
CELL *lab = (CELL *)(nextop->u.l.l);
CELL max = lab[0];
Int curr = lab[1];
lab += 2;
if (max) {
CELL i;
for (i=0L; i <= max; i++) {
if (i == 8*CellSize) {
curr = lab[0];
lab++;
}
if (curr & 1) {
TrailTerm(TR++) = XREGS[i];
}
curr >>= 1;
}
}
}
}
/* pop the corrected register values from the trail and update the registers */
static void
pop_registers(Int num_regs, yamop *nextop)
{
int i;
tr_fr_ptr ptr = TR;
/* pop array entries first */
ArrayEntry *al = DynArrayList;
while (al != NULL) {
if (al->ArrayEArity > 0) {
al->ValueOfVE = TrailTerm(ptr++);
}
al = al->NextArrayE;
}
#ifdef COROUTINING
#ifdef MULTI_ASSIGNMENT_VARIABLES
WokenGoals = TrailTerm(ptr++);
MutableList = TrailTerm(ptr++);
AttsMutableList = TrailTerm(ptr++);
DelayedVars = TrailTerm(ptr++);
#endif
#endif
for (i = 1; i <= num_regs; i++)
XREGS[i] = TrailTerm(ptr++);
/* pop any live registers we might have hanging around */
if (nextop->opc == Yap_opcode(_move_back) ||
nextop->opc == Yap_opcode(_skip)) {
CELL *lab = (CELL *)(nextop->u.l.l);
CELL max = lab[0];
Int curr = lab[1];
lab += 2;
if (max) {
CELL i;
for (i=0L; i <= max; i++) {
if (i == 8*CellSize) {
curr = lab[0];
lab++;
}
if (curr & 1) {
XREGS[i] = TrailTerm(ptr++);
}
curr >>= 1;
}
}
}
}
#ifdef DEBUG
static int
count_cells_marked(void)
{
CELL *current;
int found_marked = 0;
for (current = H - 1; current >= H0; current--) {
if (MARKED(*current)) {
found_marked++;
}
}
return(found_marked);
}
#endif
/* straightforward binary tree scheme that, given a key, finds a
matching dbref */
typedef struct db_entry {
DBRef val;
struct db_entry *left;
CELL *lim;
struct db_entry *right;
} *dbentry;
static dbentry db_vec, db_vec0;
/* init the table */
static void
store_ref_in_dbtable(DBRef entry)
{
dbentry parent = db_vec0;
dbentry new = db_vec;
if ((ADDR)new > Yap_TrailTop-1024)
Yap_growtrail(64 * 1024L);
new->val = entry;
new->lim = (CELL *)((CODEADDR)entry+Yap_SizeOfBlock((CODEADDR)entry));
new->left = new->right = NULL;
if (db_vec == db_vec0) {
db_vec++;
return;
}
db_vec++;
parent = db_vec0;
beg:
if (entry < parent->val) {
if (parent->right == NULL) {
parent->right = new;
} else {
parent = parent->right;
goto beg;
}
} else {
if (parent->left == NULL) {
parent->left = new;
} else {
parent = parent->left;
goto beg;
}
}
}
/* init the table */
static void
store_cl_in_dbtable(Clause *cl)
{
dbentry parent = db_vec0;
dbentry new = db_vec;
if ((ADDR)new > Yap_TrailTop-1024)
Yap_growtrail(64 * 1024L);
new->val = (DBRef)cl;
new->lim = (CELL *)((CODEADDR)cl + Yap_SizeOfBlock((CODEADDR)cl));
new->left = new->right = NULL;
if (db_vec == db_vec0) {
db_vec++;
return;
}
db_vec++;
parent = db_vec0;
beg:
if ((DBRef)cl < parent->val) {
if (parent->right == NULL) {
parent->right = new;
} else {
parent = parent->right;
goto beg;
}
} else {
if (parent->left == NULL) {
parent->left = new;
} else {
parent = parent->left;
goto beg;
}
}
}
/* find an element in the dbentries table */
static DBRef
find_ref_in_dbtable(DBRef entry)
{
dbentry current = db_vec0;
while (current != NULL) {
if (current->val < entry && current->lim > (CELL *)entry) {
return(current->val);
}
if (entry < current->val)
current = current->right;
else
current = current->left;
}
return(NULL);
}
static void
mark_db_fixed(CELL *ptr) {
DBRef el;
el = find_ref_in_dbtable((DBRef)ptr);
if (el != NULL)
el->Flags |= GcFoundMask;
}
static void
init_dbtable(tr_fr_ptr trail_ptr) {
Clause *cl = DeadClauses;
db_vec0 = db_vec = (dbentry)TR;
while (trail_ptr > (tr_fr_ptr)Yap_TrailBase) {
register CELL trail_cell;
trail_ptr--;
trail_cell = TrailTerm(trail_ptr);
if (!IsVarTerm(trail_cell) && IsPairTerm(trail_cell)) {
CELL *pt0 = RepPair(trail_cell);
/* DB pointer */
CODEADDR entry;
CELL flags;
#ifdef FROZEN_STACKS /* TRAIL */
/* avoid frozen segments */
if (
#ifdef SBA
(ADDR) pt0 >= HeapTop
#else
(ADDR) pt0 >= Yap_TrailBase
#endif
) {
continue;
}
#endif /* FROZEN_STACKS */
flags = Flags((CELL)pt0);
/* for the moment, if all references to the term in the stacks
are only pointers, reset the flag */
entry = ((CODEADDR)pt0 - (CELL) &(((DBRef) NIL)->Flags));
if (FlagOn(DBClMask, flags)) {
store_ref_in_dbtable((DBRef)entry);
} else {
store_cl_in_dbtable((Clause *)entry);
}
}
}
while (cl != NULL) {
store_cl_in_dbtable(cl);
cl = cl->u.NextCl;
}
if (db_vec == db_vec0) {
/* could not find any entries: probably using LOG UPD semantics */
db_vec0 = NULL;
}
}
#ifndef ANALYST
static char *op_names[_std_top + 1] =
{
#define OPCODE(OP,TYPE) #OP
#include "YapOpcodes.h"
#undef OPCODE
};
#endif
#ifdef DEBUG
/* #define INSTRUMENT_GC 1 */
#ifdef INSTRUMENT_GC
typedef enum {
gc_var,
gc_ref,
gc_atom,
gc_int,
gc_num,
gc_list,
gc_appl,
gc_func,
gc_susp
} gc_types;
unsigned long chain[16];
unsigned long env_vars;
unsigned long vars[gc_susp+1];
unsigned long num_bs;
unsigned long old_vars, new_vars;
static CELL *TrueHB;
static void
inc_vars_of_type(CELL *curr,gc_types val) {
if (curr >= H0 && curr < TrueHB) {
old_vars++;
} else if (curr >= TrueHB && curr < H) {
new_vars++;
} else {
return;
}
vars[val]++;
}
static void
put_type_info(unsigned long total)
{
fprintf(Yap_stderr,"[GC] type info for %lu cells\n", total);
fprintf(Yap_stderr,"[GC] %lu vars\n", vars[gc_var]);
fprintf(Yap_stderr,"[GC] %lu refs\n", vars[gc_ref]);
fprintf(Yap_stderr,"[GC] %lu references from env\n", env_vars);
fprintf(Yap_stderr,"[GC] %lu atoms\n", vars[gc_atom]);
fprintf(Yap_stderr,"[GC] %lu small ints\n", vars[gc_int]);
fprintf(Yap_stderr,"[GC] %lu other numbers\n", vars[gc_num]);
fprintf(Yap_stderr,"[GC] %lu lists\n", vars[gc_list]);
fprintf(Yap_stderr,"[GC] %lu compound terms\n", vars[gc_appl]);
fprintf(Yap_stderr,"[GC] %lu functors\n", vars[gc_func]);
fprintf(Yap_stderr,"[GC] %lu suspensions\n", vars[gc_susp]);
}
static void
inc_var(CELL *current, CELL *next)
{
int len = 1;
CELL *mynext=next;
if (ONHEAP(current)) {
if (next == current) {
inc_vars_of_type(current,gc_var);
chain[0]++;
} else {
inc_vars_of_type(current,gc_ref);
while(ONHEAP(mynext) && IsVarTerm(*mynext)) {
CELL *prox = GET_NEXT(*mynext);
if (prox == mynext) {
chain[0]++;
break;
}
len++;
mynext = prox;
}
if (len>=15)
(chain[15])++;
else
(chain[len])++;
}
}
}
#endif /* INSTRUMENT_GC */
int STD_PROTO(vsc_stop,(void));
int
vsc_stop(void) {
return(1);
}
#endif
#ifdef CHECK_GLOBAL
static void
check_global(void) {
CELL *current;
#ifdef INSTRUMENT_GC
vars[gc_var] = 0;
vars[gc_ref] = 0;
vars[gc_atom] = 0;
vars[gc_int] = 0;
vars[gc_num] = 0;
vars[gc_list] = 0;
vars[gc_appl] = 0;
vars[gc_func] = 0;
vars[gc_susp] = 0;
#endif
for (current = H - 1; current >= H0; current--) {
CELL ccurr = *current;
if (MARKED(ccurr)) {
CELL ccell = UNMARK_CELL(ccurr);
if (ccell < (CELL)AtomBase && ccell > EndSpecials && IsVarTerm(ccell)) {
/* oops, we found a blob */
int nofcells = (UNMARK_CELL(*current)-EndSpecials) / sizeof(CELL);
CELL *ptr = current - nofcells ;
current = ptr;
ccurr = *current;
/* process the functor next */
}
if (MARKED(ccurr)) {
printf("Oops, found marked cell at %p\n", current);
break;
}
}
#if INSTRUMENT_GC
if (IsVarTerm(ccurr)) {
if (IsBlobFunctor((Functor)ccurr)) vars[gc_num]++;
else if (ccurr != 0 && ccurr < (CELL)HeapTop) {
/* printf("%p: %s/%d\n", current,
RepAtom(NameOfFunctor((Functor)ccurr))->StrOfAE,
ArityOfFunctor((Functor)ccurr));*/
vars[gc_func]++;
}
else if (IsUnboundVar((CELL)current)) vars[gc_var]++;
else vars[gc_ref]++;
} else if (IsApplTerm(ccurr)) {
/* printf("%p: f->%p\n",current,RepAppl(ccurr)); */
vars[gc_appl]++;
} else if (IsPairTerm(ccurr)) {
/* printf("%p: l->%p\n",current,RepPair(ccurr)); */
vars[gc_list]++;
} else if (IsAtomTerm(ccurr)) {
/* printf("%p: %s\n",current,RepAtom(AtomOfTerm(ccurr))->StrOfAE); */
vars[gc_atom]++;
} else if (IsIntTerm(ccurr)) {
/* printf("%p: %d\n",current,IntOfTerm(ccurr)); */
vars[gc_int]++;
}
#endif
}
#if INSTRUMENT_GC
put_type_info(H-H0);
vars[gc_var] = 0;
vars[gc_ref] = 0;
vars[gc_atom] = 0;
vars[gc_int] = 0;
vars[gc_num] = 0;
vars[gc_list] = 0;
vars[gc_appl] = 0;
vars[gc_func] = 0;
vars[gc_susp] = 0;
#endif
}
#else
#define check_global()
#endif /* CHECK_GLOBAL */
/* mark a heap object and all heap objects accessible from it */
static void
mark_variable(CELL_PTR current)
{
CELL_PTR next;
register CELL ccur;
unsigned int arity;
begin:
ccur = *current;
if (MARKED(ccur)) {
POP_CONTINUATION();
}
MARK(current);
total_marked++;
PUSH_POINTER(current);
next = GET_NEXT(ccur);
if (IsVarTerm(ccur)) {
if (ONHEAP(next)) {
#ifdef EASY_SHUNTING
CELL cnext;
/* do variable shunting between variables in the global */
if (!MARKED((cnext = *next))) {
if (IsVarTerm(cnext) && (CELL)next == cnext) {
/* new global variable to new global variable */
if (current < prev_HB && current >= HB && next >= HB && next < prev_HB) {
#ifdef INSTRUMENT_GC
inc_var(current, current);
#endif
*next = (CELL)current;
*current = MARK_CELL((CELL)current);
POP_CONTINUATION();
} else {
/* can't help here */
#ifdef INSTRUMENT_GC
inc_var(current, next);
#endif
current = next;
}
} else {
/* binding to a determinate reference */
if (next >= HB && current < LCL0 && cnext != TermFoundVar) {
*current = cnext;
total_marked--;
POP_POINTER();
} else {
#ifdef INSTRUMENT_GC
inc_var(current, next);
#endif
current = next;
}
}
} else if (IsVarTerm(cnext) &&
UNMARK_CELL(cnext) != (CELL)next &&
current < LCL0) {
/* This step is possible because we clean up the trail */
*current = UNMARK_CELL(cnext);
total_marked--;
POP_POINTER();
} else
#endif
/* what I'd do without variable shunting */
{
#ifdef INSTRUMENT_GC
inc_var(current, next);
#endif
current = next;
}
goto begin;
}
#ifdef DEBUG
else if (next < (CELL *)AtomBase || next < (CELL *)HeapTop)
fprintf(Yap_stderr, "ooops while marking %lx, %p at %p\n", (unsigned long int)ccur, current, next);
#endif
#ifdef INSTRUMENT_GC
else
inc_var(current, next);
#endif
POP_CONTINUATION();
} else if (IsPairTerm(ccur)) {
#ifdef INSTRUMENT_GC
inc_vars_of_type(current,gc_list);
#endif
if (ONHEAP(next)) {
PUSH_CONTINUATION(next+1,1);
current = next;
goto begin;
} else if (ONCODE(next)) {
mark_db_fixed(RepPair(ccur));
}
POP_CONTINUATION();
} else if (IsApplTerm(ccur)) {
register CELL cnext = *next;
#ifdef INSTRUMENT_GC
if (!IsExtensionFunctor((Functor)cnext))
inc_vars_of_type(current,gc_appl);
else
inc_vars_of_type(current,gc_num);
#endif
if (ONCODE(next)) {
if ((Functor)cnext == FunctorDBRef) {
DBRef tref = DBRefOfTerm(ccur);
/* make sure the reference is marked as in use */
if ((tref->Flags & ErasedMask) &&
tref->Parent != NULL &&
tref->Parent->KindOfPE & LogUpdDBBit) {
*current = MkDBRefTerm(DBErasedMarker);
MARK(current);
} else {
tref->Flags |= GcFoundMask;
}
} else {
mark_db_fixed(next);
}
POP_CONTINUATION();
}
if ( MARKED(cnext) || !ONHEAP(next) )
POP_CONTINUATION();
if (next < H0) POP_CONTINUATION();
if (IsExtensionFunctor((Functor)cnext)) {
switch (cnext) {
case (CELL)FunctorLongInt:
MARK(next);
total_marked += 3;
PUSH_POINTER(next);
PUSH_POINTER(next+1);
PUSH_POINTER(next+2);
POP_CONTINUATION();
case (CELL)FunctorDouble:
MARK(next);
total_marked += 2+SIZEOF_DOUBLE/SIZEOF_LONG_INT;
PUSH_POINTER(next);
PUSH_POINTER(next+1);
PUSH_POINTER(next+2);
#if SIZEOF_DOUBLE==2*SIZEOF_LONG_INT
PUSH_POINTER(next+3);
#endif
POP_CONTINUATION();
#ifdef USE_GMP
case (CELL)FunctorBigInt:
MARK(next);
/* size is given by functor + friends */
total_marked += 2+
(sizeof(MP_INT)+
(((MP_INT *)(next+1))->_mp_alloc*sizeof(mp_limb_t)))/CellSize;
{
int i;
PUSH_POINTER(next);
for (i = 1; i <= (sizeof(MP_INT)+
(((MP_INT *)(next+1))->_mp_alloc*sizeof(mp_limb_t)))/CellSize;
i++)
PUSH_POINTER(next+i);
PUSH_POINTER(next+i);
}
POP_CONTINUATION();
#endif
default:
POP_CONTINUATION();
}
}
if (next < H0) POP_CONTINUATION();
#ifdef INSTRUMENT_GC
inc_vars_of_type(next,gc_func);
#endif
arity = ArityOfFunctor((Functor)(cnext));
MARK(next);
++total_marked;
PUSH_POINTER(next);
current = next+1;
PUSH_CONTINUATION(current+1,arity-1);
goto begin;
}
#ifdef INSTRUMENT_GC
else if (IsAtomTerm(ccur))
inc_vars_of_type(current,gc_atom);
else
inc_vars_of_type(current, gc_int);
#endif
POP_CONTINUATION();
}
void
Yap_mark_variable(CELL_PTR current)
{
mark_variable(current);
}
static void
mark_external_reference(CELL *ptr) {
CELL reg = *ptr;
/* first, mark variables in environments */
if (IsVarTerm(reg)) {
if (ONHEAP(reg)) {
#ifdef HYBRID_SCHEME
CELL_PTR *old = iptop;
#endif
mark_variable(ptr);
total_marked--;
POPSWAP_POINTER(old);
} else {
MARK(ptr);
}
} else if (IsApplTerm(reg)) {
CELL *next = RepAppl(reg);
if (ONHEAP(next)) {
#ifdef HYBRID_SCHEME
CELL_PTR *old = iptop;
#endif
mark_variable(ptr);
total_marked--;
POPSWAP_POINTER(old);
} else {
MARK(ptr);
if (ONCODE(next)) {
if ((Functor)(*next) == FunctorDBRef) {
DBRef tref = DBRefOfTerm(reg);
/* make sure the reference is marked as in use */
if ((tref->Flags & ErasedMask) &&
tref->Parent != NULL &&
tref->Parent->KindOfPE & LogUpdDBBit) {
*ptr = MkDBRefTerm(DBErasedMarker);
MARK(ptr);
} else {
tref->Flags |= GcFoundMask;
}
} else {
mark_db_fixed(next);
}
}
}
} else if (IsPairTerm(reg)) {
CELL *next = RepPair(reg);
if (ONHEAP(next)) {
#ifdef HYBRID_SCHEME
CELL_PTR *old = iptop;
#endif
mark_variable(ptr);
total_marked--;
POPSWAP_POINTER(old);
} else {
MARK(ptr);
if (ONCODE(next)) {
mark_db_fixed(next);
}
}
} else {
/* atom or integer */
MARK(ptr);
}
}
/*
* mark all heap objects accessible from the trail (which includes the active
* general purpose registers)
*/
void
Yap_mark_external_reference(CELL *ptr) {
mark_external_reference(ptr);
}
static void
mark_regs(tr_fr_ptr old_TR)
{
tr_fr_ptr trail_ptr;
/* first, whatever we dumped on the trail. Easier just to do
the registers separately? */
for (trail_ptr = old_TR; trail_ptr < TR; trail_ptr++)
mark_external_reference(&TrailTerm(trail_ptr));
}
#ifdef COROUTINING
static void
mark_delays(CELL *max)
{
CELL *ptr = (CELL *)Yap_GlobalBase;
for (; ptr < max; ptr++) {
mark_external_reference(ptr);
}
}
#endif
/* mark all heap objects accessible from a chain of environments */
static void
mark_environments(CELL_PTR gc_ENV, OPREG size, CELL *pvbmap)
{
CELL_PTR saved_var;
while (gc_ENV != NULL) { /* no more environments */
Int bmap = 0;
int currv = 0;
Clause *cl;
#ifdef DEBUG
if (size < 0 || size > 512)
fprintf(Yap_stderr,"Oops, env size for %p is %ld\n", gc_ENV, (unsigned long int)size);
#endif
if ((cl = (Clause *)find_ref_in_dbtable((DBRef)gc_ENV[E_CP])) != NULL) {
cl->ClFlags |= GcFoundMask;
}
/* for each saved variable */
if (size > EnvSizeInCells) {
int tsize = size - EnvSizeInCells;
currv = sizeof(CELL)*8-tsize%(sizeof(CELL)*8);
pvbmap += tsize/(sizeof(CELL)*8);
bmap = *pvbmap;
bmap = (Int)(((CELL)bmap) << currv);
}
for (saved_var = gc_ENV - size; saved_var < gc_ENV - EnvSizeInCells; saved_var++) {
if (currv == sizeof(CELL)*8) {
pvbmap--;
bmap = *pvbmap;
currv = 0;
}
/* we may have already been here */
if (bmap < 0 && !MARKED(*saved_var)) {
#ifdef INSTRUMENT_GC
Term ccur = *saved_var;
if (IsVarTerm(ccur)) {
int len = 1;
CELL *mynext= GET_NEXT(ccur);
if (ONHEAP(mynext)) {
env_vars++;
while(ONHEAP(mynext) && IsVarTerm(*mynext)) {
CELL *prox = GET_NEXT(*mynext);
if (prox == mynext) {
chain[0]++;
break;
}
len++;
mynext = prox;
}
if (len>=15)
(chain[15])++;
else
(chain[len])++;
}
}
#endif
mark_external_reference(saved_var);
}
bmap <<= 1;
currv++;
}
/* have we met this environment before?? */
/* we use the B field in the environment to tell whether we have
been here before or not.
We do it at the end because we don't want to lose any variables
that would have been trimmed at the first environment visit.
*/
if (MARKED(gc_ENV[E_CB]))
return;
MARK(gc_ENV+E_CB);
size = EnvSize((CELL_PTR) (gc_ENV[E_CP])); /* size = EnvSize(CP) */
pvbmap = EnvBMap((CELL_PTR) (gc_ENV[E_CP]));
#if 0
if (size < 0) {
PredEntry *pe = EnvPreg(gc_ENV[E_CP]);
op_numbers op = Yap_op_from_opcode(ENV_ToOp(gc_ENV[E_CP]));
fprintf(Yap_stderr,"ENV %p-%p(%d) %s\n", gc_ENV, pvbmap, size-EnvSizeInCells, op_names[op]);
if (pe->ArityOfPE)
fprintf(Yap_stderr," %s/%d\n", RepAtom(NameOfFunctor(pe->FunctorOfPred))->StrOfAE, pe->ArityOfPE);
else
fprintf(Yap_stderr," %s\n", RepAtom((Atom)(pe->FunctorOfPred))->StrOfAE);
}
#endif
gc_ENV = (CELL_PTR) gc_ENV[E_E]; /* link to prev
* environment */
}
}
/*
Cleaning the trail should be quick and simple, right? Well, not
really :-(. The problem is that the trail includes a dumping ground
of the WAM registers and of extra choice-point fields, which need
to be cleaned from somewhere.
And cleaning the trail itself is not easy. The problem is that we
may not have cleaned the trail after cuts. If we naively followed
these pointers, we could have direct references to the global
stack! A solution is to verify whether we are poiting at a
legitimate trail entry. Unfortunately this requires some extra work
following choice-points.
*/
static void
mark_trail(tr_fr_ptr trail_ptr, tr_fr_ptr trail_base, CELL *gc_H, choiceptr gc_B)
{
#ifdef EASY_SHUNTING
tr_fr_ptr begsTR = NULL, endsTR = NULL;
#endif
cont *old_cont_top0 = cont_top0;
GC_NEW_MAHASH((gc_ma_h_inner_struct *)cont_top0);
while (trail_ptr > trail_base) {
register CELL trail_cell;
trail_ptr--;
trail_cell = TrailTerm(trail_ptr);
if (IsVarTerm(trail_cell)) {
CELL *hp = (CELL *)trail_cell;
/* if a variable older than the current CP has not been marked yet,
than its new binding is not accessible and we can reset it. Note
we must use gc_H to avoid trouble with dangling variables
in the heap */
if (((hp < gc_H && hp >= H0) || (hp > (CELL *)gc_B && hp < LCL0) ) && !MARKED(*hp)) {
#ifdef EARLY_RESET
/* reset to be a variable */
RESET_VARIABLE(hp);
discard_trail_entries++;
RESET_VARIABLE(&TrailTerm(trail_ptr));
#ifdef FROZEN_STACKS
RESET_VARIABLE(&TrailVal(trail_ptr));
#endif
#else
/* if I have no early reset I have to follow the trail chain */
mark_external_reference(&TrailTerm(trail_ptr));
UNMARK(&TrailTerm(trail_ptr));
#endif /* EARLY_RESET */
} else if (hp < (CELL *)HeapTop) {
/* I decided to allow pointers from the Heap back into the trail.
The point of doing so is to have dynamic arrays */
mark_external_reference(hp);
} else if ((hp < (CELL *)gc_B && hp >= gc_H) || hp > (CELL *)Yap_TrailBase) {
/* clean the trail, avoid dangling pointers! */
RESET_VARIABLE(&TrailTerm(trail_ptr));
#ifdef FROZEN_STACKS
RESET_VARIABLE(&TrailVal(trail_ptr));
#endif
discard_trail_entries++;
} else {
if (trail_cell == (CELL)trail_ptr)
discard_trail_entries++;
#ifdef FROZEN_STACKS
else
mark_external_reference(&TrailVal(trail_ptr));
#endif
#ifdef EASY_SHUNTING
if (hp < gc_H && hp >= H0) {
tr_fr_ptr nsTR = (tr_fr_ptr)cont_top0;
CELL *cptr = (CELL *)trail_cell;
if ((ADDR)nsTR > Yap_TrailTop-1024)
Yap_growtrail(64 * 1024L);
TrailTerm(nsTR) = (CELL)NULL;
TrailTerm(nsTR+1) = *hp;
TrailTerm(nsTR+2) = trail_cell;
if (begsTR == NULL)
begsTR = nsTR;
else
TrailTerm(endsTR) = (CELL)nsTR;
endsTR = nsTR;
cont_top = (cont *)(nsTR+3);
sTR = (tr_fr_ptr)cont_top;
gc_ma_h_top = (gc_ma_h_inner_struct *)(nsTR+3);
RESET_VARIABLE(cptr);
MARK(cptr);
}
#endif
}
} else if (IsPairTerm(trail_cell)) {
/* can safely ignore this */
}
#if MULTI_ASSIGNMENT_VARIABLES
else {
tr_fr_ptr *lkp;
CELL *cptr = RepAppl(trail_cell);
/* This is a bit complex. The idea is that we may have several
trailings for the same mavar in the same trail segment. Essentially,
the problem arises because of !. What we want is to ignore all but
the last entry, or in this case, all but the first entry with the last
value.
Problem: we can only mark when we know it is the *last*.
Solution: we keep a list of all found entries and search in the end
*/
if (!(lkp = gc_lookup_ma_var(cptr, trail_ptr))) {
if (HEAP_PTR(trail_cell)) {
/* fool the gc into thinking this is a variable */
TrailTerm(trail_ptr) = (CELL)cptr;
mark_external_reference(&(TrailTerm(trail_ptr)));
/* reset the gc to believe the original tag */
TrailTerm(trail_ptr) = AbsAppl((CELL *)TrailTerm(trail_ptr));
}
trail_ptr --;
} else {
tr_fr_ptr trp = (*lkp)-1;
TrailTerm(trp) = TrailTerm(trail_ptr-1);
/* we can safely ignore this little monster */
discard_trail_entries += 2;
RESET_VARIABLE(&TrailTerm(trail_ptr));
#ifdef FROZEN_STACKS
RESET_VARIABLE(&TrailVal(trail_ptr));
#endif
trail_ptr--;
RESET_VARIABLE(&TrailTerm(trail_ptr));
#ifdef FROZEN_STACKS
RESET_VARIABLE(&TrailVal(trail_ptr));
#endif
}
}
#endif
}
#if MULTI_ASSIGNMENT_VARIABLES
while (live_list != NULL) {
CELL trail_cell = TrailTerm(live_list->trptr-1);
CELL trail_cell2 = TrailTerm(live_list->trptr);
if (HEAP_PTR(trail_cell)) {
mark_external_reference(&TrailTerm(live_list->trptr-1));
}
#ifdef FROZEN_STACKS
if (HEAP_PTR(TrailVal(trail_ptr))) {
mark_external_reference(&TrailVal(trail_ptr));
}
#endif
/*
swap the two so that the sweep_trail() knows we have
a multi-assignment binding
*/
TrailTerm(live_list->trptr) = TrailTerm(live_list->trptr-1);
TrailTerm(live_list->trptr-1) = trail_cell2;
#ifdef FROZEN_STACKS
if (HEAP_PTR(TrailVal(trail_ptr-1))) {
mark_external_reference(&TrailVal(trail_ptr-1));
}
#endif
live_list = live_list->ma_list;
}
#endif
#ifdef EASY_SHUNTING
sTR = (tr_fr_ptr)old_cont_top0;
while (begsTR != NULL) {
tr_fr_ptr newsTR = (tr_fr_ptr)TrailTerm(begsTR);
TrailTerm(sTR) = TrailTerm(begsTR+1);
TrailTerm(sTR+1) = TrailTerm(begsTR+2);
begsTR = newsTR;
sTR += 2;
}
#else
cont_top0 = old_cont_top0;
#endif
cont_top = cont_top0;
}
/*
* mark all heap objects accessible from each choicepoint & its chain of
* environments
*/
#ifdef TABLING
#ifdef TABLING_BATCHED_SCHEDULING
#define init_substitution_pointer(GCB, SUBS_PTR, DEP_FR) \
SUBS_PTR = (CELL *) (CONS_CP(GCB) + 1)
#else /* TABLING_LOCAL_SCHEDULING */
#define init_substitution_pointer(GCB, SUBS_PTR, DEP_FR) \
SUBS_PTR = (CELL *) (CONS_CP(GCB) + 1); \
if (DepFr_leader_cp(DEP_FR) == GCB) \
SUBS_PTR += SgFr_arity(GEN_CP_SG_FR(GCB))
#endif /* TABLING_SCHEDULING */
#endif
static void
mark_slots(CELL *ptr)
{
Int ns = IntOfTerm(*ptr);
ptr++;
while (ns > 0) {
mark_external_reference(ptr);
ptr++;
ns--;
}
}
static void
mark_choicepoints(register choiceptr gc_B, tr_fr_ptr saved_TR, int very_verbose)
{
#ifdef TABLING
dep_fr_ptr depfr = LOCAL_top_dep_fr;
#endif
#ifdef EASY_SHUNTING
HB = H;
#endif
while (gc_B != NULL) {
op_numbers opnum;
register OPCODE op;
yamop *rtp = gc_B->cp_ap;
Clause *cl;
if ((cl = (Clause *)find_ref_in_dbtable((DBRef)rtp)) != NULL) {
cl->ClFlags |= GcFoundMask;
}
if ((cl = (Clause *)find_ref_in_dbtable((DBRef)(gc_B->cp_b))) != NULL) {
cl->ClFlags |= GcFoundMask;
}
#ifdef EASY_SHUNTING
current_B = gc_B;
prev_HB = HB;
#endif
HB = gc_B->cp_h;
#ifdef INSTRUMENT_GC
num_bs++;
#endif
#ifdef TABLING
/* include consumers */
if (depfr != NULL && gc_B >= DepFr_cons_cp(depfr)) {
gc_B = DepFr_cons_cp(depfr);
depfr = DepFr_next(depfr);
continue;
}
if (rtp == NULL) {
opnum = _table_completion;
} else
#endif
{
op = rtp->opc;
opnum = Yap_op_from_opcode(op);
}
if (very_verbose) {
switch (opnum) {
case _retry_c:
case _or_else:
case _or_last:
case _Nstop:
case _switch_last:
case _switch_l_list:
case _retry_userc:
case _trust_logical_pred:
case _retry_profiled:
case _count_retry:
{
Atom at;
Int arity;
SMALLUNSGN mod;
if (Yap_PredForCode((CODEADDR)gc_B->cp_ap, &at, &arity, &mod)) {
if (arity)
fprintf(Yap_stderr,"[GC] %s/%d marked %d (%s)\n", RepAtom(at)->StrOfAE, arity, total_marked, op_names[opnum]);
else
fprintf(Yap_stderr,"[GC] %s marked %d (%s)\n", RepAtom(at)->StrOfAE, total_marked, op_names[opnum]);
} else
fprintf(Yap_stderr,"[GC] marked %d (%s)\n", total_marked, op_names[opnum]);
}
break;
#ifdef TABLING
case _table_completion:
case _table_answer_resolution:
{
PredEntry *pe = ENV_ToP(gc_B->cp_cp);
op_numbers caller_op = Yap_op_from_opcode(ENV_ToOp(gc_B->cp_cp));
/* first condition checks if this was a meta-call */
if ((caller_op != _call && caller_op != _fcall) || pe == NULL) {
fprintf(Yap_stderr,"[GC] marked %d (%s)\n", total_marked, op_names[opnum]);
} else
fprintf(Yap_stderr,"[GC] %s/%d marked %d (%s)\n", RepAtom(NameOfFunctor(pe->FunctorOfPred))->StrOfAE, pe->ArityOfPE, total_marked, op_names[opnum]);
}
break;
case _trie_retry_var:
case _trie_trust_var:
case _trie_retry_val:
case _trie_trust_val:
case _trie_retry_atom:
case _trie_trust_atom:
case _trie_retry_list:
case _trie_trust_list:
case _trie_retry_struct:
case _trie_trust_struct:
fprintf(Yap_stderr,"[GC] marked %d (%s)\n", total_marked, op_names[opnum]);
break;
#endif
default:
{
PredEntry *pe = (PredEntry *)gc_B->cp_ap->u.ld.p;
if (pe == NULL) {
fprintf(Yap_stderr,"[GC] marked %d (%s)\n", total_marked, op_names[opnum]);
} else
if (pe->ArityOfPE)
fprintf(Yap_stderr,"[GC] %s/%d marked %d (%s)\n", RepAtom(NameOfFunctor(pe->FunctorOfPred))->StrOfAE, pe->ArityOfPE, total_marked, op_names[opnum]);
else
fprintf(Yap_stderr,"[GC] %s marked %d (%s)\n", RepAtom((Atom)(pe->FunctorOfPred))->StrOfAE, total_marked, op_names[opnum]);
}
}
}
{
/* find out how many cells are still alive in the trail */
#ifndef FROZEN_STACKS
UInt d0 = discard_trail_entries, diff, orig;
orig = saved_TR-gc_B->cp_tr;
#endif
mark_trail(saved_TR, gc_B->cp_tr, gc_B->cp_h, gc_B);
saved_TR = gc_B->cp_tr;
#ifndef FROZEN_STACKS
diff = discard_trail_entries-d0;
gc_B->cp_tr = (tr_fr_ptr)(orig-diff);
#endif /* FROZEN_STACKS */
}
restart_cp:
if (opnum == _or_else || opnum == _or_last) {
/* ; choice point */
mark_environments((CELL_PTR) (gc_B->cp_a1),
#ifdef YAPOR
-gc_B->cp_cp->u.ldl.s / ((OPREG)sizeof(CELL)),
(CELL *)(gc_B->cp_cp->u.ldl.bl)
#else
-gc_B->cp_cp->u.sla.s / ((OPREG)sizeof(CELL)),
gc_B->cp_cp->u.sla.l2
#endif
);
} else {
/* choicepoint with arguments */
register CELL_PTR saved_reg;
OPREG nargs;
if (opnum == _Nstop)
mark_environments((CELL_PTR) gc_B->cp_env,
EnvSizeInCells,
NULL);
else
#ifdef TABLING
if (opnum != _table_completion)
#endif
mark_environments((CELL_PTR) gc_B->cp_env,
EnvSize((CELL_PTR) (gc_B->cp_cp)),
EnvBMap((CELL_PTR) (gc_B->cp_cp)));
/* extended choice point */
switch (opnum) {
case _Nstop:
mark_slots(gc_B->cp_env);
if (gc_B->cp_b != NULL) {
nargs = 0;
break;
} else {
/* this is the last choice point, the work is done ;-) */
return;
}
case _switch_last:
case _switch_l_list:
nargs = rtp->u.slll.s;
break;
case _retry_c:
case _retry_userc:
if (gc_B->cp_ap == RETRY_C_RECORDED_CODE
|| gc_B->cp_ap == RETRY_C_RECORDED_K_CODE
|| gc_B->cp_ap == RETRY_C_DRECORDED_CODE
|| gc_B->cp_ap == RETRY_C_RECORDEDP_CODE) {
/* we have a reference from the choice-point stack to a term */
choiceptr old_b = B;
DBRef ref;
B = gc_B;
ref = (DBRef)EXTRA_CBACK_ARG(3,1);
if (IsVarTerm((CELL)ref))
ref->Flags |= GcFoundMask;
else {
if (ONCODE((CELL)ref)) {
mark_db_fixed(RepAppl((CELL)ref));
}
}
B = old_b;
}
nargs = rtp->u.lds.s+rtp->u.lds.extra;
break;
case _trust_logical_pred:
case _retry_profiled:
case _count_retry:
rtp = NEXTOP(rtp,l);
op = rtp->opc;
opnum = Yap_op_from_opcode(op);
goto restart_cp;
case _trust_fail:
nargs = 0;
break;
#ifdef TABLING
case _table_answer_resolution:
{
CELL *answ_fr;
CELL vars;
/* fetch the solution */
init_substitution_pointer(gc_B, answ_fr, CONS_CP(gc_B)->ccp_dep_fr);
vars = *answ_fr++;
while (vars--) {
mark_external_reference(answ_fr);
answ_fr++;
}
nargs = 0;
}
break;
case _table_completion:
{
register gen_cp_ptr gcp = GEN_CP(gc_B);
int nargs;
#ifdef TABLING_BATCHED_SCHEDULING
nargs = gcp->gcp_sg_fr->subgoal_arity;
#else
nargs = gcp->gcp_dep_fr->subgoal_frame->subgoal_arity;
#endif
saved_reg = (CELL *)(gcp+1)+nargs;
nargs = *saved_reg++;
while (nargs--) {
mark_external_reference(saved_reg);
saved_reg++;
}
}
nargs = 0;
break;
case _table_retry_me:
case _table_trust_me:
{
register gen_cp_ptr gcp = GEN_CP(gc_B);
int nargs = rtp->u.ld.s;
/* for each saved register */
for (saved_reg = (CELL *)(gcp+1);
/* assumes we can count registers in CP this
way */
saved_reg < (CELL *)(gcp+1) + nargs;
saved_reg++) {
mark_external_reference(saved_reg);
}
nargs = *saved_reg++;
while (nargs--) {
mark_external_reference(saved_reg);
saved_reg++;
}
}
nargs = 0;
break;
case _trie_retry_var:
case _trie_trust_var:
case _trie_retry_val:
case _trie_trust_val:
case _trie_retry_atom:
case _trie_trust_atom:
case _trie_retry_list:
case _trie_trust_list:
case _trie_retry_struct:
case _trie_trust_struct:
{
CELL *aux_ptr;
int heap_arity;
int vars_arity;
int subs_arity;
/* fetch the solution */
aux_ptr = (CELL *)(gc_B+1);
heap_arity = *aux_ptr;
vars_arity = *(aux_ptr + heap_arity + 1);
subs_arity = *(aux_ptr + heap_arity + 2);
if (heap_arity) {
int i;
aux_ptr += heap_arity + subs_arity + vars_arity + 1;
for (i = 0; i < heap_arity + subs_arity + vars_arity + 1; i++) {
mark_external_reference(aux_ptr);
aux_ptr--;
}
} else {
int i;
aux_ptr += 2 + subs_arity + vars_arity;
for (i = 0; i < vars_arity; i++) {
mark_external_reference(aux_ptr);
aux_ptr--;
}
for (i = 1; i < subs_arity; i++) {
aux_ptr--;
mark_external_reference(aux_ptr);
}
}
}
nargs = 0;
break;
#endif
#ifdef DEBUG
case _retry_me:
case _trust_me:
case _profiled_retry_me:
case _profiled_trust_me:
case _count_retry_me:
case _count_trust_me:
case _retry_me0:
case _trust_me0:
case _retry_me1:
case _trust_me1:
case _retry_me2:
case _trust_me2:
case _retry_me3:
case _trust_me3:
case _retry_me4:
case _trust_me4:
case _retry_and_mark:
case _profiled_retry_and_mark:
case _count_retry_and_mark:
case _retry:
case _trust_in:
case _trust:
case _retry_first:
case _trust_first_in:
case _trust_first:
case _retry_tail:
case _trust_tail_in:
case _trust_tail:
case _retry_head:
case _trust_head_in:
case _trust_head:
nargs = rtp->u.ld.s;
break;
default:
fprintf(Yap_stderr, "OOps in GC: Unexpected opcode: %d\n", opnum);
nargs = 0;
#else
default:
nargs = rtp->u.ld.s;
#endif
}
/* for each saved register */
for (saved_reg = &gc_B->cp_a1;
/* assumes we can count registers in CP this
way */
saved_reg < &gc_B->cp_a1 + nargs;
saved_reg++) {
mark_external_reference(saved_reg);
}
}
gc_B = gc_B->cp_b;
}
}
/*
* insert a cell which points to a heap object into relocation chain of that
* object
*/
static void
into_relocation_chain(CELL_PTR current, CELL_PTR next)
{
#ifdef TAGS_FAST_OPS
register CELL ccur = *current, cnext = *next;
if (IsVarTerm(ccur)) {
*current = ( MARKED(ccur) ? MARK_CELL(UNMARKED(cnext)) :
UNMARKED(cnext) );
*next = (MARKED(cnext) ? MBIT : 0) | RBIT | (Int) current;
} else if (IsPairTerm(ccur)) {
*current = ( MARKED(ccur) ? MARK_CELL(UNMARKED(cnext)) :
UNMARKED(cnext) );
*next = AbsPair((CELL *)
((MARKED(cnext) ? MBIT : 0) | RBIT | (Int) current));
} else if (IsApplTerm(ccur)) {
*current = ( MARKED(ccur) ? MARK_CELL(UNMARKED(cnext)) :
UNMARKED(cnext) );
*next = AbsAppl((CELL *)
((MARKED(cnext) ? MBIT : 0) | RBIT | (Int) current));
} else {
fprintf(Yap_stderr," OH MY GOD !!!!!!!!!!!!\n");
}
#else
CELL current_tag;
current_tag = TAG(*current);
*current = (*current & MBIT) | (*next & ~MBIT);
#if INVERT_RBIT
*next = ((*next & MBIT) | (CELL) current | current_tag) & ~RBIT;
#else
*next = (*next & MBIT) | RBIT | (CELL) current | current_tag;
#endif
#endif
}
/* insert trail cells which point to heap objects into relocation chains */
static void
sweep_trail(choiceptr gc_B, tr_fr_ptr old_TR)
{
tr_fr_ptr trail_ptr, dest;
Int OldHeapUsed = HeapUsed;
#ifdef DEBUG
Int hp_entrs = 0, hp_erased = 0, hp_not_in_use = 0,
hp_in_use_erased = 0, code_entries = 0;
#endif
Clause **cptr, *cl;
#ifndef FROZEN_STACKS
/*
adjust cp_tr pointers,
we don't compress TR if we have freeze.
*/
{
Int size = old_TR-(tr_fr_ptr)Yap_TrailBase;
size -= discard_trail_entries;
while (gc_B != NULL) {
size -= (UInt)(gc_B->cp_tr);
gc_B->cp_tr = (tr_fr_ptr)Yap_TrailBase+size;
gc_B = gc_B->cp_b;
}
}
#endif /* FROZEN_STACKS */
/* first, whatever we dumped on the trail. Easier just to do
the registers separately? */
for (trail_ptr = old_TR; trail_ptr < TR; trail_ptr++) {
if (MARKED(TrailTerm(trail_ptr))) {
UNMARK(&TrailTerm(trail_ptr));
if (HEAP_PTR(TrailTerm(trail_ptr))) {
into_relocation_chain(&TrailTerm(trail_ptr), GET_NEXT(TrailTerm(trail_ptr)));
}
}
}
/* next, follows the real trail entries */
trail_ptr = (tr_fr_ptr)Yap_TrailBase;
dest = trail_ptr;
while (trail_ptr < old_TR) {
register CELL trail_cell;
trail_cell = TrailTerm(trail_ptr);
#ifndef FROZEN_STACKS
/* recover a trail cell */
if (trail_cell == (CELL)trail_ptr) {
TrailTerm(dest) = trail_cell;
trail_ptr++;
/* just skip cell */
} else
#endif
{
TrailTerm(dest) = trail_cell;
if (IsVarTerm(trail_cell)) {
/* we need to check whether this is a honest to god trail entry */
if ((CELL *)trail_cell < H && MARKED(*(CELL *)trail_cell) && (CELL *)trail_cell >= H0) {
if (HEAP_PTR(trail_cell)) {
into_relocation_chain(&TrailTerm(dest), GET_NEXT(trail_cell));
}
#ifdef FROZEN_STACKS
/* it is complex to recover cells with frozen segments */
TrailVal(dest) = TrailVal(trail_ptr);
if (MARKED(TrailVal(dest))) {
UNMARK(&TrailVal(dest));
if (HEAP_PTR(TrailVal(dest))) {
into_relocation_chain(&TrailVal(dest), GET_NEXT(TrailVal(dest)));
}
}
#endif
} else if ((CELL *)trail_cell < (CELL *)HeapTop) {
/* we may have pointers from the heap back into the cell */
CELL *next = GET_NEXT(*CellPtr(trail_cell));
UNMARK(CellPtr(trail_cell));
if (HEAP_PTR(*CellPtr(trail_cell))) {
into_relocation_chain(CellPtr(trail_cell),next);
}
#ifdef FROZEN_STACKS
/* it is complex to recover cells with frozen segments */
TrailVal(dest) = TrailVal(trail_ptr);
if (MARKED(TrailVal(dest))) {
UNMARK(&TrailVal(dest));
if (HEAP_PTR(TrailVal(dest))) {
into_relocation_chain(&TrailVal(dest), GET_NEXT(TrailVal(dest)));
}
}
#endif
}
} else if (IsPairTerm(trail_cell)) {
CELL *pt0 = RepPair(trail_cell);
CELL flags;
#ifdef FROZEN_STACKS /* TRAIL */
/* process all segments */
if (
#ifdef SBA
(ADDR) pt0 >= HeapTop
#else
(ADDR) pt0 >= Yap_TrailBase
#endif
) {
trail_ptr++;
dest++;
continue;
}
#endif /* FROZEN_STACKS */
flags = Flags((CELL)pt0);
#ifdef DEBUG
hp_entrs++;
if (!FlagOn(GcFoundMask, flags)) {
hp_not_in_use++;
if (!FlagOn(DBClMask, flags)) {
code_entries++;
}
if (FlagOn(ErasedMask, flags)) {
hp_erased++;
}
} else {
if (FlagOn(ErasedMask, flags)) {
hp_in_use_erased++;
}
}
#endif
if (!FlagOn(GcFoundMask, flags)) {
if (FlagOn(DBClMask, flags)) {
DBRef dbr = (DBRef) ((CELL)pt0 - (CELL) &(((DBRef) NIL)->Flags));
dbr->Flags &= ~InUseMask;
DEC_DBREF_COUNT(dbr);
if (dbr->Flags & ErasedMask) {
Yap_ErDBE(dbr);
}
} else {
Clause *cl = ClauseFlagsToClause((CELL)pt0);
int erase;
DEC_CLREF_COUNT(cl);
cl->ClFlags &= ~InUseMask;
erase = (cl->ClFlags & ErasedMask)
#if defined(YAPOR) || defined(THREADS)
&& (cl->ref_count == 0)
#endif
;
if (erase) {
/* at this point,
no one is accessing the clause */
Yap_ErCl(cl);
}
}
RESET_VARIABLE(&TrailTerm(dest));
discard_trail_entries++;
} else {
Flags((CELL)pt0) = ResetFlag(GcFoundMask, flags);
}
#if MULTI_ASSIGNMENT_VARIABLES
} else {
CELL trail_cell = TrailTerm(trail_ptr);
CELL *ptr;
CELL old = TrailTerm(trail_ptr+1);
if (MARKED(trail_cell))
ptr = RepAppl(UNMARK_CELL(trail_cell));
else
ptr = RepAppl(trail_cell);
TrailTerm(dest) = old;
TrailTerm(dest+1) = trail_cell;
if (MARKED(old)) {
UNMARK(&TrailTerm(dest));
if (HEAP_PTR(old)) {
into_relocation_chain(&TrailTerm(dest), GET_NEXT(old));
}
}
#ifdef FROZEN_STACKS
TrailVal(dest) = TrailVal(trail_ptr);
if (MARKED(TrailVal(dest))) {
UNMARK(&TrailVal(dest));
if (HEAP_PTR(TrailVal(dest))) {
into_relocation_chain(&TrailVal(dest), GET_NEXT(TrailTerm(dest)));
}
}
#endif
dest++;
if (MARKED(trail_cell)) {
UNMARK(&TrailTerm(dest));
if (HEAP_PTR(trail_cell)) {
into_relocation_chain(&TrailTerm(dest), GET_NEXT(trail_cell));
}
}
trail_ptr++;
#ifdef FROZEN_STACKS
TrailVal(dest) = TrailVal(trail_ptr);
if (MARKED(TrailVal(dest))) {
UNMARK(&TrailVal(dest));
if (HEAP_PTR(TrailVal(dest))) {
into_relocation_chain(&TrailVal(dest), GET_NEXT(TrailTerm(dest)));
}
}
#endif
#endif
}
trail_ptr++;
dest++;
}
}
new_TR = dest;
if (is_gc_verbose()) {
if (old_TR != (tr_fr_ptr)Yap_TrailBase)
fprintf(Yap_stderr,
"[GC] Trail: discarded %d (%ld%%) cells out of %ld\n",
discard_trail_entries,
(unsigned long int)(discard_trail_entries*100/(old_TR-(tr_fr_ptr)Yap_TrailBase)),
(unsigned long int)(old_TR-(tr_fr_ptr)Yap_TrailBase));
#ifdef DEBUG
if (hp_entrs > 0)
fprintf(Yap_stderr,
"[GC] Trail: unmarked %ld dbentries (%ld%%) out of %ld\n",
(long int)hp_not_in_use,
(long int)(hp_not_in_use*100/hp_entrs),
(long int)hp_entrs);
if (hp_in_use_erased > 0 && hp_erased > 0)
fprintf(Yap_stderr,
"[GC] Trail: deleted %ld dbentries (%ld%%) out of %ld\n",
(long int)hp_erased,
(long int)(hp_erased*100/(hp_erased+hp_in_use_erased)),
(long int)(hp_erased+hp_in_use_erased));
#endif
fprintf(Yap_stderr,
"[GC] Heap: recovered %ld bytes (%ld%%) out of %ld\n",
(unsigned long int)(OldHeapUsed-HeapUsed),
(unsigned long int)((OldHeapUsed-HeapUsed)/(OldHeapUsed/100)),
(unsigned long int)OldHeapUsed);
}
cptr = &(DeadClauses);
cl = DeadClauses;
while (cl != NULL) {
if (!(cl->ClFlags & GcFoundMask)) {
char *ocl = (char *)cl;
cl = cl->u.NextCl;
*cptr = cl;
Yap_FreeCodeSpace(ocl);
} else {
cl->ClFlags &= ~GcFoundMask;
cptr = &(cl->u.NextCl);
cl = cl->u.NextCl;
}
}
}
/*
* insert cells of a chain of environments which point to heap objects into
* relocation chains
*/
static void
sweep_environments(CELL_PTR gc_ENV, OPREG size, CELL *pvbmap)
{
CELL_PTR saved_var;
while (gc_ENV != NULL) { /* no more environments */
Int bmap = 0;
int currv = 0;
/* for each saved variable */
if (size > EnvSizeInCells) {
int tsize = size - EnvSizeInCells;
currv = sizeof(CELL)*8-tsize%(sizeof(CELL)*8);
pvbmap += tsize/(sizeof(CELL)*8);
bmap = *pvbmap;
bmap = (Int)(((CELL)bmap) << currv);
}
for (saved_var = gc_ENV - size; saved_var < gc_ENV - EnvSizeInCells; saved_var++) {
if (currv == sizeof(CELL)*8) {
pvbmap--;
bmap = *pvbmap;
currv = 0;
}
if (bmap < 0) {
CELL env_cell = *saved_var;
if (MARKED(env_cell)) {
UNMARK(saved_var);
if (HEAP_PTR(env_cell)) {
into_relocation_chain(saved_var, GET_NEXT(env_cell));
}
}
}
bmap <<= 1;
currv++;
}
/* have we met this environment before?? */
/* we use the B field in the environment to tell whether we have
been here before or not
*/
if (!MARKED(gc_ENV[E_CB]))
return;
UNMARK(gc_ENV+E_CB);
size = EnvSize((CELL_PTR) (gc_ENV[E_CP])); /* size = EnvSize(CP) */
pvbmap = EnvBMap((CELL_PTR) (gc_ENV[E_CP]));
gc_ENV = (CELL_PTR) gc_ENV[E_E]; /* link to prev
* environment */
}
}
static void
sweep_slots(CELL *ptr)
{
Int ns = IntOfTerm(*ptr);
ptr++;
while (ns > 0) {
CELL cp_cell = *ptr;
if (MARKED(cp_cell)) {
UNMARK(ptr);
if (HEAP_PTR(cp_cell)) {
into_relocation_chain(ptr, GET_NEXT(cp_cell));
}
}
ptr++;
ns--;
}
}
/*
* insert cells of each choicepoint & its chain of environments which point
* to heap objects into relocation chains
*/
static void
sweep_choicepoints(choiceptr gc_B)
{
#ifdef TABLING
dep_fr_ptr depfr = LOCAL_top_dep_fr;
#endif
while(gc_B != NULL) {
yamop *rtp = gc_B->cp_ap;
register OPCODE op;
op_numbers opnum;
#ifdef TABLING
/* include consumers */
if (depfr != NULL && gc_B >= DepFr_cons_cp(depfr)) {
gc_B = DepFr_cons_cp(depfr);
depfr = DepFr_next(depfr);
continue;
}
if (rtp == NULL) {
opnum = _table_completion;
} else
#endif
{
op = rtp->opc;
opnum = Yap_op_from_opcode(op);
}
restart_cp:
/*
* fprintf(Yap_stderr,"sweeping cps: %x, %x, %x\n",
* *gc_B,CP_Extra(gc_B),CP_Nargs(gc_B));
*/
/* any choice point */
switch (opnum) {
case _Nstop:
/* end of the road, say bye bye! */
sweep_environments(gc_B->cp_env,
EnvSizeInCells,
NULL);
sweep_slots(gc_B->cp_env);
if (gc_B->cp_b != NULL) {
break;
} else
return;
case _trust_fail:
sweep_environments(gc_B->cp_env,
EnvSizeInCells,
NULL);
break;
case _or_else:
case _or_last:
sweep_environments((CELL_PTR)(gc_B->cp_a1),
#ifdef YAPOR
-gc_B->cp_cp->u.ldl.s / ((OPREG)sizeof(CELL)),
(CELL *)(gc_B->cp_cp->u.ldl.bl)
#else
-gc_B->cp_cp->u.sla.s / ((OPREG)sizeof(CELL)),
gc_B->cp_cp->u.sla.l2
#endif
);
break;
case _trust_logical_pred:
case _retry_profiled:
case _count_retry:
rtp = NEXTOP(rtp,l);
op = rtp->opc;
opnum = Yap_op_from_opcode(op);
goto restart_cp;
#ifdef TABLING
case _table_answer_resolution:
{
CELL *answ_fr;
CELL vars;
sweep_environments(gc_B->cp_env,
EnvSize((CELL_PTR) (gc_B->cp_cp)),
EnvBMap((CELL_PTR) (gc_B->cp_cp)));
/* fetch the solution */
init_substitution_pointer(gc_B, answ_fr, CONS_CP(gc_B)->ccp_dep_fr);
vars = *answ_fr++;
while (vars--) {
CELL cp_cell = *answ_fr;
if (MARKED(cp_cell)) {
UNMARK(answ_fr);
if (HEAP_PTR(cp_cell)) {
into_relocation_chain(answ_fr, GET_NEXT(cp_cell));
}
}
answ_fr++;
}
}
break;
case _table_completion:
{
register gen_cp_ptr gcp = GEN_CP(gc_B);
#ifdef TABLING_BATCHED_SCHEDULING
int nargs = gcp->gcp_sg_fr->subgoal_arity;
#else
int nargs = gcp->gcp_dep_fr->subgoal_frame->subgoal_arity;
#endif
CELL *saved_reg;
saved_reg = (CELL *)(gcp+1)+nargs;
nargs = *saved_reg++;
while (nargs--) {
CELL cp_cell = *saved_reg;
if (MARKED(cp_cell)) {
UNMARK(saved_reg);
if (HEAP_PTR(cp_cell)) {
into_relocation_chain(saved_reg, GET_NEXT(cp_cell));
}
}
saved_reg++;
}
}
break;
case _table_retry_me:
case _table_trust_me:
{
register gen_cp_ptr gcp = GEN_CP(gc_B);
int nargs;
CELL *saved_reg;
sweep_environments(gc_B->cp_env,
EnvSize((CELL_PTR) (gc_B->cp_cp)),
EnvBMap((CELL_PTR) (gc_B->cp_cp)));
nargs = rtp->u.ld.s;
/* for each saved register */
for (saved_reg = (CELL *)(gcp+1);
/* assumes we can count registers in CP this
way */
saved_reg < (CELL *)(gcp+1) + nargs;
saved_reg++) {
CELL cp_cell = *saved_reg;
if (MARKED(cp_cell)) {
UNMARK(saved_reg);
if (HEAP_PTR(cp_cell)) {
into_relocation_chain(saved_reg, GET_NEXT(cp_cell));
}
}
}
saved_reg = (CELL *)(gcp+1) + nargs;
nargs = *saved_reg++;
while (nargs--) {
CELL cp_cell = *saved_reg;
if (MARKED(cp_cell)) {
UNMARK(saved_reg);
if (HEAP_PTR(cp_cell)) {
into_relocation_chain(saved_reg, GET_NEXT(cp_cell));
}
}
saved_reg++;
}
}
break;
case _trie_retry_var:
case _trie_trust_var:
case _trie_retry_val:
case _trie_trust_val:
case _trie_retry_atom:
case _trie_trust_atom:
case _trie_retry_list:
case _trie_trust_list:
case _trie_retry_struct:
case _trie_trust_struct:
{
CELL *aux_ptr;
int heap_arity;
int vars_arity;
int subs_arity;
sweep_environments(gc_B->cp_env,
EnvSize((CELL_PTR) (gc_B->cp_cp)),
EnvBMap((CELL_PTR) (gc_B->cp_cp)));
/* fetch the solution */
aux_ptr = (CELL *)(gc_B+1);
heap_arity = *aux_ptr;
vars_arity = *(aux_ptr + heap_arity + 1);
subs_arity = *(aux_ptr + heap_arity + 2);
if (heap_arity) {
int i;
aux_ptr += heap_arity + subs_arity + vars_arity + 1;
for (i = 0; i < heap_arity + subs_arity + vars_arity + 1; i++) {
CELL cp_cell = *aux_ptr;
if (MARKED(cp_cell)) {
UNMARK(aux_ptr);
if (HEAP_PTR(cp_cell)) {
into_relocation_chain(aux_ptr, GET_NEXT(cp_cell));
}
}
aux_ptr--;
}
} else {
int i;
aux_ptr += 2 + subs_arity + vars_arity;
for (i = 0; i < vars_arity; i++) {
CELL cp_cell = *aux_ptr;
if (MARKED(cp_cell)) {
UNMARK(aux_ptr);
if (HEAP_PTR(cp_cell)) {
into_relocation_chain(aux_ptr, GET_NEXT(cp_cell));
}
}
aux_ptr--;
}
for (i = 1; i < subs_arity; i++) {
CELL cp_cell = *--aux_ptr;
if (MARKED(cp_cell)) {
UNMARK(aux_ptr);
if (HEAP_PTR(cp_cell)) {
into_relocation_chain(aux_ptr, GET_NEXT(cp_cell));
}
}
}
}
}
break;
#endif
case _retry_c:
case _retry_userc:
{
register CELL_PTR saved_reg;
/* for each extra saved register */
for (saved_reg = &(gc_B->cp_a1)+rtp->u.lds.s;
saved_reg < &(gc_B->cp_a1)+rtp->u.lds.s+rtp->u.lds.extra;
saved_reg++) {
CELL cp_cell = *saved_reg;
if (MARKED(cp_cell)) {
UNMARK(saved_reg);
if (HEAP_PTR(cp_cell)) {
into_relocation_chain(saved_reg, GET_NEXT(cp_cell));
}
}
}
}
/* continue to clean environments and arguments */
default:
{
register CELL_PTR saved_reg;
sweep_environments(gc_B->cp_env,
EnvSize((CELL_PTR) (gc_B->cp_cp)),
EnvBMap((CELL_PTR) (gc_B->cp_cp)));
/* for each saved register */
for (saved_reg = &gc_B->cp_a1;
saved_reg < &gc_B->cp_a1 + rtp->u.ld.s;
saved_reg++) {
CELL cp_cell = *saved_reg;
if (MARKED(cp_cell)) {
UNMARK(saved_reg);
if (HEAP_PTR(cp_cell)) {
into_relocation_chain(saved_reg, GET_NEXT(cp_cell));
}
}
}
}
}
/* link to prev choicepoint */
gc_B = gc_B->cp_b;
}
}
/* update a relocation chain to point all its cells to new location of object */
static void
update_relocation_chain(CELL_PTR current, CELL_PTR dest)
{
CELL_PTR next;
CELL ccur = *current;
#ifdef TAGS_FAST_OPS
while (RMARKED(ccur)) {
register CELL cnext;
next = GET_NEXT(ccur);
cnext = *next;
if (IsVarTerm(ccur)) {
ccur = *current = (MARKED_VAR(ccur) ?
ENSURE_MARKED(cnext) :
UNMARKED(cnext) );
*next = (MARKED(cnext) ? MBIT : 0) | (Int) dest;
} else if (IsPairTerm(ccur)) {
ccur = *current = (MARKED_COMP(ccur) ?
ENSURE_MARKED(cnext) :
UNMARKED(cnext) );
*next = AbsPair((CELL *)
((MARKED(cnext) ? MBIT : 0) |
(Int) dest));
} else if (IsApplTerm(ccur)) {
ccur = *current = (MARKED_COMP(ccur) ?
ENSURE_MARKED(cnext) :
UNMARKED(cnext) );
*next = AbsAppl((CELL *)
((MARKED(cnext) ? MBIT : 0) |
(Int) dest));
}
#ifdef DEBUG
else {
Yap_Error(SYSTEM_ERROR, TermNil, "ATOMIC in a GC relocation chain");
}
#endif
}
#else /* TAGS_FAST_OPS */
while (RMARKED(ccur)) {
CELL current_tag;
next = GET_NEXT(ccur);
current_tag = TAG(ccur);
ccur = *current = (ccur & MBIT) | (*next & ~MBIT);
#if INVERT_RBIT
*next = (*next & MBIT) | (CELL) dest | current_tag | RBIT;
#else
*next = (*next & MBIT) | (CELL) dest | current_tag;
#endif
}
#endif /* TAGS_FAST_OPS */
}
#ifdef TABLING
static dep_fr_ptr gl_depfr;
#endif
static inline choiceptr
update_B_H( choiceptr gc_B, CELL *current, CELL *dest, CELL *odest) {
/* also make the value of H in a choicepoint
coherent with the new global
*/
while (gc_B && current <= gc_B->cp_h) {
if (gc_B->cp_h == current) {
gc_B->cp_h = dest;
} else {
gc_B->cp_h = odest;
}
gc_B = gc_B->cp_b;
#ifdef TABLING
if (gl_depfr != NULL && gc_B >= DepFr_cons_cp(gl_depfr)) {
gc_B = DepFr_cons_cp(gl_depfr);
gl_depfr = DepFr_next(gl_depfr);
}
#endif
}
return(gc_B);
}
/*
* move marked objects on the heap upwards over unmarked objects, and reset
* all pointers to point to new locations
*/
static void
compact_heap(void)
{
CELL_PTR dest, current, next;
#ifdef DEBUG
Int found_marked = 0;
#endif /* DEBUG */
choiceptr gc_B = B;
int in_garbage = 0;
/*
* upward phase - scan heap from high to low, setting marked upward
* ptrs to point to what will be the new locations of the
* objects pointed to
*/
#ifdef TABLING
gl_depfr = LOCAL_top_dep_fr;
#endif
dest = (CELL_PTR) H0 + total_marked - 1;
for (current = H - 1; current >= H0; current--) {
if (MARKED(*current)) {
CELL ccell = UNMARK_CELL(*current);
if (ccell < (CELL)AtomBase && ccell > EndSpecials && IsVarTerm(ccell)
) {
/* oops, we found a blob */
int nofcells = (UNMARK_CELL(*current)-EndSpecials) / sizeof(CELL);
CELL *ptr = current - nofcells ;
CELL func = ptr[0];
if (MARKED(func)) {
#ifdef DEBUG
found_marked+=nofcells;
#endif /* DEBUG */
gc_B = update_B_H(gc_B, current, dest, dest+1);
/* this one's being used */
/* first swap the tag so that it will be seen by the next step */
{
CELL tmp = current[0];
current[0] = ptr[1];
ptr[1] = tmp;
}
if (in_garbage > 0) {
current[1] = in_garbage;
in_garbage = 0;
}
dest -= nofcells;
current = ptr;
/* process the functor next */
} else {
/* skip the term */
in_garbage += nofcells+1;
current = ptr;
continue;
}
} else{
gc_B = update_B_H(gc_B, current, dest, dest+1);
}
if (in_garbage > 0) {
current[1] = in_garbage;
in_garbage = 0;
}
#ifdef DEBUG
found_marked++;
#endif /* DEBUG */
update_relocation_chain(current, dest);
if (HEAP_PTR(*current)) {
next = GET_NEXT(*current);
if (next < current) /* push into reloc.
* chain */
into_relocation_chain(current, next);
else if (current == next) /* cell pointing to
* itself */
*current = (*current & MBIT) | (CELL) dest; /* no tag */
}
dest--;
} else {
in_garbage++;
}
}
if (in_garbage)
H0[0] = in_garbage;
#ifdef DEBUG
if (total_marked != found_marked)
fprintf(Yap_stderr,"[GC] Upward (%d): %ld total against %ld found\n",
gc_calls,
(unsigned long int)total_marked,
(unsigned long int)found_marked);
found_marked = 0;
#endif
/*
* downward phase - scan heap from low to high, moving marked objects
* to their new locations & setting downward pointers to pt to new
* locations
*/
dest = (CELL_PTR) H0;
for (current = H0; current < H; current++) {
CELL ccur = *current;
if (MARKED(ccur)) {
CELL uccur = UNMARK_CELL(ccur);
if (uccur < (CELL)AtomBase && uccur > EndSpecials && IsVarTerm(uccur)) {
/* oops, we found a blob */
int nofcells = (uccur-EndSpecials) / sizeof(CELL) , i;
*dest++ = current[nofcells-1];
current ++;
for (i = 0; i < nofcells-2; i++) {
*dest++ = *current++;
}
*dest++ = ccur;
#ifdef DEBUG
found_marked += nofcells;
#endif
continue;
}
#ifdef DEBUG
found_marked++;
#endif
update_relocation_chain(current, dest);
ccur = *current;
next = GET_NEXT(ccur);
if (HEAP_PTR(ccur) && /* move current cell &
* push */
next > current) { /* into relocation chain */
*dest = ccur;
into_relocation_chain(dest, next);
UNMARK(dest);
} else {
/* just move current cell */
*dest = ccur = UNMARK_CELL(ccur);
}
/* next cell, please */
dest++;
} else {
current += (ccur-1);
}
}
#ifdef DEBUG
if (total_marked != found_marked)
fprintf(Yap_stderr,"[GC] Downward (%d): %ld total against %ld found\n",
gc_calls,
(unsigned long int)total_marked,
(unsigned long int)found_marked);
#endif
H = dest; /* reset H */
HB = B->cp_h;
#ifdef TABLING
if (B_FZ == (choiceptr)LCL0)
H_FZ = H0;
else
H_FZ = B_FZ->cp_h;
#endif
}
#ifdef HYBRID_SCHEME
static void
adjust_cp_hbs(void)
{
#ifdef TABLING
dep_fr_ptr depfr = LOCAL_top_dep_fr;
#endif
choiceptr gc_B = B;
CELL_PTR *top = iptop-1, *base = (CELL_PTR *)H;
while (gc_B != NULL) {
CELL *gc_H = gc_B->cp_h;
CELL_PTR *nbase = base;
if (top[0] <= gc_H) {
if (top[0] == gc_H)
gc_B->cp_h = H0+(top-base);
else
gc_B->cp_h = H0+((top+1)-base);
} else while (TRUE) {
CELL_PTR *nxt = nbase+(top-nbase)/2;
if (nxt[0] > gc_H) {
if (nbase == top) {
if (nbase == base) {
gc_B->cp_h = H0;
break;
} else {
Yap_Error(SYSTEM_ERROR,TermNil,"Bug in Garbage collector");
return;
}
}
top = nxt;
} else if (nxt[0] < gc_H && nxt[1] < gc_H) {
nbase = nxt+1;
} else {
if (nxt[0] == gc_H) {
gc_B->cp_h = H0+(nxt-base);
top = nxt;
break;
} else {
gc_B->cp_h = H0+((nxt-base)+1);
top = nxt;
break;
}
}
}
#ifdef TABLING
if (depfr != NULL && gc_B >= DepFr_cons_cp(depfr)) {
gc_B = DepFr_cons_cp(depfr);
depfr = DepFr_next(depfr);
} else
#endif
gc_B = gc_B->cp_b;
}
}
/*
* move marked objects on the heap upwards over unmarked objects, and reset
* all pointers to point to new locations
*/
static void
icompact_heap(void)
{
CELL_PTR *iptr, *ibase = (CELL_PTR *)H;
#ifdef DEBUG
Int found_marked = 0;
#endif /* DEBUG */
/*
* upward phase - scan heap from high to low, setting marked upward
* ptrs to point to what will be the new locations of the
* objects pointed to
*/
for (iptr = iptop - 1; iptr >= ibase; iptr--) {
CELL ccell;
CELL_PTR current;
current = *iptr;
ccell = UNMARK_CELL(*current);
if (ccell < (CELL)AtomBase && ccell > EndSpecials && IsVarTerm(ccell)
) {
/* oops, we found a blob */
int nofcells = (UNMARK_CELL(*current)-EndSpecials) / sizeof(CELL);
CELL *ptr = current - nofcells ;
iptr -= nofcells;
#ifdef DEBUG
found_marked+=nofcells;
#endif /* DEBUG */
/* this one's being used */
/* first swap the tag so that it will be seen by the next step */
{
CELL tmp = current[0];
current[0] = ptr[1];
ptr[1] = tmp;
}
current = ptr;
}
#ifdef DEBUG
found_marked++;
#endif /* DEBUG */
update_relocation_chain(current, H0+(iptr-ibase));
if (HEAP_PTR(*current)) {
CELL_PTR next;
next = GET_NEXT(*current);
if (next < current) /* push into reloc.
* chain */
into_relocation_chain(current, next);
else if (current == next) /* cell pointing to
* itself */
*current = (*current & MBIT) | (CELL) (H0+(iptr-ibase)); /* no tag */
}
}
#ifdef DEBUG
if (total_marked != found_marked)
fprintf(Yap_stderr,"[GC] Upward (%d): %ld total against %ld found\n",
gc_calls,
(unsigned long int)total_marked,
(unsigned long int)found_marked);
found_marked = 0;
#endif
/*
* downward phase - scan heap from low to high, moving marked objects
* to their new locations & setting downward pointers to pt to new
* locations
*/
for (iptr = ibase; iptr < iptop; iptr++) {
CELL_PTR next;
CELL *current = *iptr;
CELL ccur = *current;
CELL_PTR dest = H0+(iptr-ibase);
CELL uccur = UNMARK_CELL(ccur);
if (uccur < (CELL)AtomBase && uccur > EndSpecials && IsVarTerm(uccur)) {
/* oops, we found a blob */
int nofcells = (uccur-EndSpecials) / sizeof(CELL) , i;
*dest++ = current[nofcells-1];
current ++;
for (i = 0; i < nofcells-2; i++) {
*dest++ = *current++;
}
*dest = ccur;
iptr += nofcells-1;
#ifdef DEBUG
found_marked += nofcells;
#endif
continue;
}
#ifdef DEBUG
found_marked++;
#endif
update_relocation_chain(current, dest);
ccur = *current;
next = GET_NEXT(ccur);
if (HEAP_PTR(ccur) && /* move current cell &
* push */
next > current) { /* into relocation chain */
*dest = ccur;
into_relocation_chain(dest, next);
UNMARK(dest);
} else {
/* just move current cell */
*dest = ccur = UNMARK_CELL(ccur);
}
}
#ifdef DEBUG
if (total_marked != found_marked)
fprintf(Yap_stderr,"[GC] Downward (%d): %ld total against %ld found\n",
gc_calls,
(unsigned long int)total_marked,
(unsigned long int)found_marked);
#endif
H = H0+(iptop-ibase); /* reset H */
HB = B->cp_h;
#ifdef TABLING
if (B_FZ == (choiceptr)LCL0)
H_FZ = H0;
else
H_FZ = B_FZ->cp_h;
#endif
}
#endif /* HYBRID_SCHEME */
#ifdef EASY_SHUNTING
static void
set_conditionals(tr_fr_ptr sTR) {
while (sTR != sTR0) {
CELL *cptr;
sTR -= 2;
cptr = (CELL *)TrailTerm(sTR+1);
*cptr = TrailTerm(sTR);
}
}
#endif
/*
* mark all objects on the heap that are accessible from active registers,
* the trail, environments, and choicepoints
*/
static void
marking_phase(tr_fr_ptr old_TR, CELL *current_env, yamop *curp, CELL *max)
{
#ifdef EASY_SHUNTING
current_B = B;
#endif
init_dbtable(old_TR);
#ifdef EASY_SHUNTING
sTR0 = (tr_fr_ptr)db_vec;
sTR = (tr_fr_ptr)db_vec;
#else
cont_top0 = (cont *)db_vec;
#endif
cont_top = (cont *)db_vec;
/* These two must be marked first so that our trail optimisation won't lose
values */
#ifdef COROUTINING
Yap_mark_all_suspended_goals();
#endif
mark_regs(old_TR); /* active registers & trail */
#ifdef COROUTINING
mark_delays(max);
#endif
/* active environments */
mark_environments(current_env, EnvSize(curp), EnvBMap((CELL *)curp));
mark_choicepoints(B, old_TR, is_gc_very_verbose()); /* choicepoints, and environs */
#ifdef EASY_SHUNTING
set_conditionals(sTR);
#endif
}
#ifdef COROUTINING
static void
sweep_delays(CELL *max)
{
CELL *ptr = (CELL *)Yap_GlobalBase;
while (ptr < max) {
if (MARKED(*ptr)) {
UNMARK(ptr);
if (HEAP_PTR(*ptr)) {
into_relocation_chain(ptr, GET_NEXT(*ptr));
}
}
ptr++;
}
}
#endif
/*
* move marked heap objects upwards over unmarked objects, and reset all
* pointers to point to new locations
*/
static void
compaction_phase(tr_fr_ptr old_TR, CELL *current_env, yamop *curp, CELL *max)
{
#ifdef COROUTINING
sweep_delays(max);
#endif
sweep_environments(current_env, EnvSize(curp), EnvBMap((CELL *)curp));
sweep_choicepoints(B);
sweep_trail(B, old_TR);
#ifdef HYBRID_SCHEME
#ifdef DEBUG
if (total_marked != iptop-(CELL_PTR *)H && iptop < (CELL_PTR *)ASP -1024)
fprintf(Yap_stderr,"[GC] Oops on iptop-H (%d) vs %d\n", iptop-(CELL_PTR *)H, total_marked);
#endif
if (iptop < (CELL_PTR *)ASP && 10*total_marked < H-H0) {
#ifdef INSTRUMENT_GC
int effectiveness = (((H-H0)-total_marked)*100)/(H-H0);
fprintf(Yap_stderr,"[GC] using pointers (%d)\n", effectiveness);
#endif
quicksort((CELL_PTR *)H, 0, (iptop-(CELL_PTR *)H)-1);
adjust_cp_hbs();
icompact_heap();
} else
#endif /* HYBRID_SCHEME */
{
#ifdef DEBUG
#ifdef HYBID_SCHEME
int effectiveness = (((H-H0)-total_marked)*100)/(H-H0);
fprintf(stderr,"[GC] not using pointers (%d) ASP: %p, ip %p (expected %p) \n", effectiveness, ASP, iptop, H+total_marked);
#endif
#endif
compact_heap();
}
}
static Int
do_gc(Int predarity, CELL *current_env, yamop *nextop)
{
Int heap_cells = H-H0;
int gc_verbose = is_gc_verbose();
tr_fr_ptr old_TR;
Int m_time, c_time, time_start, gc_time;
#if COROUTINING
CELL *max = (CELL *)Yap_ReadTimedVar(DelayedVars);
#else
CELL *max = NULL;
#endif
Int effectiveness = 0;
int gc_trace = FALSE;
#if COROUTINING
if (H0 - max < 1024+(2*NUM_OF_ATTS)) {
if (!Yap_growglobal(&current_env)) {
Yap_Error(SYSTEM_ERROR, TermNil, Yap_ErrorMessage);
return FALSE;
}
}
#endif
#ifdef INSTRUMENT_GC
{
int i;
for (i=0; i<16; i++)
chain[i]=0;
vars[gc_var] = 0;
vars[gc_ref] = 0;
vars[gc_atom] = 0;
vars[gc_int] = 0;
vars[gc_num] = 0;
vars[gc_list] = 0;
vars[gc_appl] = 0;
vars[gc_func] = 0;
vars[gc_susp] = 0;
env_vars = 0;
old_vars = new_vars = 0;
TrueHB = HB;
num_bs = 0;
}
#endif
#ifdef DEBUG
check_global();
#endif
if (Yap_GetValue(AtomGcTrace) != TermNil)
gc_trace = 1;
/* sanity check: can we still do garbage_collection ? */
if ((CELL)Yap_TrailTop & (MBIT|RBIT)) {
/* oops, we can't */
if (gc_verbose) {
fprintf(Yap_stderr, "[GC] TrailTop at %p clashes with gc bits: %lx\n", Yap_TrailTop, (unsigned long int)(MBIT|RBIT));
fprintf(Yap_stderr, "[GC] garbage collection disallowed\n");
}
return(0);
}
gc_calls++;
if (gc_trace) {
fprintf(Yap_stderr, "[gc]\n");
} else if (gc_verbose) {
fprintf(Yap_stderr, "[GC] Start of garbage collection %d:\n", gc_calls);
#ifndef EARLY_RESET
fprintf(Yap_stderr, "[GC] no early reset in trail\n");
#endif
fprintf(Yap_stderr, "[GC] Global: %8ld cells (%p-%p)\n", (long int)heap_cells,H0,H);
fprintf(Yap_stderr, "[GC] Local:%8ld cells (%p-%p)\n", (unsigned long int)(LCL0-ASP),LCL0,ASP);
fprintf(Yap_stderr, "[GC] Trail:%8ld cells (%p-%p)\n",
(unsigned long int)(TR-(tr_fr_ptr)Yap_TrailBase),Yap_TrailBase,TR);
}
if (HeapTop >= Yap_GlobalBase - MinHeapGap) {
*--ASP = (CELL)current_env;
if (!Yap_growheap(FALSE)) {
Yap_Error(SYSTEM_ERROR, TermNil, Yap_ErrorMessage);
return(FALSE);
}
current_env = (CELL *)*ASP;
ASP++;
}
time_start = Yap_cputime();
total_marked = 0;
discard_trail_entries = 0;
#ifdef HYBRID_SCHEME
iptop = (CELL_PTR *)H;
#endif
/* get the number of active registers */
YAPEnterCriticalSection();
old_TR = TR;
push_registers(predarity, nextop);
marking_phase(old_TR, current_env, nextop, max);
m_time = Yap_cputime();
gc_time = m_time-time_start;
if (heap_cells)
effectiveness = ((heap_cells-total_marked)*100)/heap_cells;
else
effectiveness = 0;
if (gc_verbose) {
fprintf(Yap_stderr, "[GC] Mark: Recovered %ld cells of %ld (%ld%%) in %g sec\n",
(long int)(heap_cells-total_marked), (long int)heap_cells, (long int)effectiveness, (double)(m_time-time_start)/1000);
#ifdef INSTRUMENT_GC
{
int i;
for (i=0; i<16; i++) {
if (chain[i]) {
fprintf(Yap_stderr, "[GC] chain[%d]=%lu\n", i, chain[i]);
}
}
put_type_info((unsigned long int)total_marked);
fprintf(Yap_stderr,"[GC] %lu/%ld before and %lu/%ld after\n", old_vars, (unsigned long int)(B->cp_h-H0), new_vars, (unsigned long int)(H-B->cp_h));
fprintf(Yap_stderr,"[GC] %ld choicepoints\n", num_bs);
}
#endif
}
time_start = m_time;
compaction_phase(old_TR, current_env, nextop, max);
TR = old_TR;
pop_registers(predarity, nextop);
TR = new_TR;
YAPLeaveCriticalSection();
c_time = Yap_cputime();
if (gc_verbose) {
fprintf(Yap_stderr, "[GC] Compress: took %g sec\n", (double)(c_time-time_start)/1000);
}
gc_time += (c_time-time_start);
tot_gc_time += gc_time;
tot_gc_recovered += heap_cells-total_marked;
if (gc_verbose) {
fprintf(Yap_stderr, "[GC] GC %d took %g sec, total of %g sec doing GC so far.\n", gc_calls, (double)gc_time/1000, (double)tot_gc_time/1000);
fprintf(Yap_stderr, "[GC] Left %ld cells free in stacks.\n",
(unsigned long int)(ASP-H));
}
check_global();
return(effectiveness);
}
static int
is_gc_verbose(void)
{
#ifdef INSTRUMENT_GC
/* always give info when we are debugging gc */
return(TRUE);
#else
return(Yap_GetValue(AtomGcVerbose) != TermNil ||
Yap_GetValue(AtomGcVeryVerbose) != TermNil);
#endif
}
int
Yap_is_gc_verbose(void)
{
return is_gc_verbose();
}
static int
is_gc_very_verbose(void)
{
return(Yap_GetValue(AtomGcVeryVerbose) != TermNil);
}
Int
Yap_total_gc_time(void)
{
return(tot_gc_time);
}
static Int
p_inform_gc(void)
{
Term tn = MkIntegerTerm(tot_gc_time);
Term tt = MkIntegerTerm(gc_calls);
Term ts = MkIntegerTerm((tot_gc_recovered*sizeof(CELL)));
return(Yap_unify(tn, ARG2) && Yap_unify(tt, ARG1) && Yap_unify(ts, ARG3));
}
int
Yap_gc(Int predarity, CELL *current_env, yamop *nextop)
{
Int gc_margin = 128;
Term Tgc_margin;
Int effectiveness = 0;
int gc_on = FALSE;
#if defined(YAPOR) || defined(THREADS)
if (NOfThreads != 1) {
Yap_Error(SYSTEM_ERROR,TermNil,"cannot perform garbage collection: more than a worker/thread running");
return(FALSE);
}
#endif
if (Yap_GetValue(AtomGc) != TermNil)
gc_on = TRUE;
if (IsIntTerm(Tgc_margin = Yap_GetValue(AtomGcMargin)))
gc_margin = IntOfTerm(Tgc_margin);
else {
if (gc_calls < 8)
gc_margin <<= gc_calls;
else
gc_margin <<= 8;
}
if (gc_margin < 0 || gc_margin > 4000)
gc_margin = (LCL0 - H0) >> 9;
gc_margin = gc_margin << 8;
if (gc_on)
effectiveness = do_gc(predarity, current_env, nextop);
if (effectiveness > 90) {
while (gc_margin < H-H0)
gc_margin <<= 1;
}
/* expand the stack if effectiveness is less than 20 % */
if (ASP - H < gc_margin || !gc_on || effectiveness < 20) {
Int gap = CalculateStackGap();
if (ASP-H > gc_margin)
gc_margin = (ASP-H)+gap;
else
gc_margin = 8 * (gc_margin - (ASP - H));
gc_margin = ((gc_margin >> 16) + 1) << 16;
if (gc_margin < gap)
gc_margin = gap;
while (gc_margin >= gap && !Yap_growstack(gc_margin))
gc_margin = gc_margin/2;
check_global();
return(gc_margin >= gap);
}
/*
* debug for(save_total=1; save_total<=N; ++save_total)
* plwrite(XREGS[save_total],Yap_DebugPutc,0);
*/
return ( TRUE );
}
static Int
p_gc(void)
{
do_gc(0, ENV, P);
return(TRUE);
}
void
Yap_init_gc(void)
{
Yap_InitCPred("$gc", 0, p_gc, 0);
Yap_InitCPred("$inform_gc", 3, p_inform_gc, 0);
}
void
Yap_inc_mark_variable()
{
total_marked++;
}
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