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030d16c40f
yap-6.3/C/heapgc.c
vsc ab97812ec7 first steps to allow mavars with tabling 
fix trailing for tabling with multiple get_cons


git-svn-id: https://yap.svn.sf.net/svnroot/yap/trunk@1356 b08c6af1-5177-4d33-ba66-4b1c6b8b522a
2005-08-05 14:55:03 +00:00

3649 lines
88 KiB
C
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/*************************************************************************
* *
* YAP Prolog *
* *
* Yap Prolog was developed at NCCUP - Universidade do Porto *
* *
* Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997 *
* *
**************************************************************************
* *
* File: heapgc.c *
* Last rev: *
* mods: *
* comments: Global Stack garbage collector *
* *
*************************************************************************/
#ifdef SCCS
static char SccsId[] = "%W% %G%";
#endif /* SCCS */
#include "absmi.h"
#include "yapio.h"
#include "alloc.h"
#include "attvar.h"
#define EARLY_RESET 1
#if !defined(TABLING)
#define EASY_SHUNTING 1
#endif /* !TABLING */
#define HYBRID_SCHEME 1
/* global variables for garbage collection */
/* in a single gc */
static unsigned long int total_marked; /* number of heap objects marked */
#if DEBUG
#ifdef COROUTINING
static unsigned long int total_smarked;
#endif
#endif
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 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"
#if GC_NO_TAGS
char *bp;
#endif
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;
static void
gc_growtrail(int committed)
{
#if USE_SYSTEM_MALLOC
TR = OldTR;
#endif
if (!Yap_growtrail(64 * 1024L, TRUE)) {
/* could not find more trail */
longjmp(Yap_gc_restore, 2);
}
#if USE_SYSTEM_MALLOC
#if !GC_NO_TAGS
if (committed) {
longjmp(Yap_gc_restore, 2);
}
#endif
longjmp(Yap_gc_restore, 1);
#endif
}
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) {
gc_growtrail(TRUE);
}
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_hash_entry_struct {
UInt timestmp;
CELL* addr;
struct gc_ma_hash_entry_struct *next;
} gc_ma_hash_entry;
static gc_ma_hash_entry gc_ma_hash_table[GC_MAVARS_HASH_SIZE];
static UInt gc_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_hash_entry *gc_ma_h_top;
static inline gc_ma_hash_entry *
GC_ALLOC_NEW_MASPACE(void)
{
gc_ma_hash_entry *new = gc_ma_h_top;
if ((char *)gc_ma_h_top > Yap_TrailTop-1024)
gc_growtrail(FALSE);
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 gc_ma_hash_entry*
gc_lookup_ma_var(CELL *addr, tr_fr_ptr trp) {
unsigned int i = GC_MAVAR_HASH(addr);
gc_ma_hash_entry *nptr, *optr = NULL;
if (gc_ma_hash_table[i].timestmp != gc_timestamp) {
gc_ma_hash_table[i].timestmp = gc_timestamp;
gc_ma_hash_table[i].addr = addr;
gc_ma_hash_table[i].next = NULL;
return NULL;
}
nptr = gc_ma_hash_table+i;
while (nptr) {
optr = nptr;
if (nptr->addr == addr) {
return nptr;
}
nptr = nptr->next;
}
nptr = GC_ALLOC_NEW_MASPACE();
optr->next = nptr;
nptr->addr = addr;
nptr->next = NULL;
return NULL;
}
static inline void
GC_NEW_MAHASH(gc_ma_hash_entry *top) {
UInt time = ++gc_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 = 0L;
time = ++gc_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
}
#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;
}
}
}
}
#if DEBUG && COUNT_CELLS_MARKED
static int
count_cells_marked(void)
{
CELL *current;
int found_marked = 0;
for (current = H - 1; current >= H0; current--) {
if (MARKED_PTR(current)) {
found_marked++;
}
}
return(found_marked);
}
#endif
/* straightforward binary tree scheme that, given a key, finds a
matching dbref */
typedef enum {
db_entry,
cl_entry,
lcl_entry,
li_entry,
dcl_entry
} db_entry_type;
typedef struct db_entry {
CODEADDR val;
db_entry_type db_type;
struct db_entry *left;
CODEADDR lim;
struct db_entry *right;
} *dbentry;
static ADDR db_vec, db_vec0;
typedef struct RB_red_blk_node {
CODEADDR key;
CODEADDR lim;
db_entry_type db_type;
int red; /* if red=0 then the node is black */
struct RB_red_blk_node* left;
struct RB_red_blk_node* right;
struct RB_red_blk_node* parent;
} rb_red_blk_node;
static rb_red_blk_node *db_root, *db_nil;
static rb_red_blk_node *
RBMalloc(UInt size)
{
ADDR new = db_vec;
db_vec += size;
if ((ADDR)db_vec > Yap_TrailTop-1024) {
gc_growtrail(FALSE);
}
return (rb_red_blk_node *)new;
}
static rb_red_blk_node *
RBTreeCreate(void) {
rb_red_blk_node* temp;
/* see the comment in the rb_red_blk_tree structure in red_black_tree.h */
/* for information on nil and root */
temp=db_nil= RBMalloc(sizeof(rb_red_blk_node));
temp->parent=temp->left=temp->right=temp;
temp->red=0;
temp->key=NULL;
temp = RBMalloc(sizeof(rb_red_blk_node));
temp->parent=temp->left=temp->right=db_nil;
temp->key=NULL;
temp->red=0;
return temp;
}
/***********************************************************************/
/* FUNCTION: LeftRotate */
/**/
/* INPUTS: This takes a tree so that it can access the appropriate */
/* root and nil pointers, and the node to rotate on. */
/**/
/* OUTPUT: None */
/**/
/* Modifies Input: tree, x */
/**/
/* EFFECTS: Rotates as described in _Introduction_To_Algorithms by */
/* Cormen, Leiserson, Rivest (Chapter 14). Basically this */
/* makes the parent of x be to the left of x, x the parent of */
/* its parent before the rotation and fixes other pointers */
/* accordingly. */
/***********************************************************************/
static void
LeftRotate(rb_red_blk_node* x) {
rb_red_blk_node* y;
rb_red_blk_node* nil=db_nil;
/* I originally wrote this function to use the sentinel for */
/* nil to avoid checking for nil. However this introduces a */
/* very subtle bug because sometimes this function modifies */
/* the parent pointer of nil. This can be a problem if a */
/* function which calls LeftRotate also uses the nil sentinel */
/* and expects the nil sentinel's parent pointer to be unchanged */
/* after calling this function. For example, when RBDeleteFixUP */
/* calls LeftRotate it expects the parent pointer of nil to be */
/* unchanged. */
y=x->right;
x->right=y->left;
if (y->left != nil) y->left->parent=x; /* used to use sentinel here */
/* and do an unconditional assignment instead of testing for nil */
y->parent=x->parent;
/* instead of checking if x->parent is the root as in the book, we */
/* count on the root sentinel to implicitly take care of this case */
if( x == x->parent->left) {
x->parent->left=y;
} else {
x->parent->right=y;
}
y->left=x;
x->parent=y;
#ifdef DEBUG_ASSERT
Assert(!db_nil->red,"nil not red in LeftRotate");
#endif
}
/***********************************************************************/
/* FUNCTION: RighttRotate */
/**/
/* INPUTS: This takes a tree so that it can access the appropriate */
/* root and nil pointers, and the node to rotate on. */
/**/
/* OUTPUT: None */
/**/
/* Modifies Input?: tree, y */
/**/
/* EFFECTS: Rotates as described in _Introduction_To_Algorithms by */
/* Cormen, Leiserson, Rivest (Chapter 14). Basically this */
/* makes the parent of x be to the left of x, x the parent of */
/* its parent before the rotation and fixes other pointers */
/* accordingly. */
/***********************************************************************/
static void
RightRotate(rb_red_blk_node* y) {
rb_red_blk_node* x;
rb_red_blk_node* nil=db_nil;
/* I originally wrote this function to use the sentinel for */
/* nil to avoid checking for nil. However this introduces a */
/* very subtle bug because sometimes this function modifies */
/* the parent pointer of nil. This can be a problem if a */
/* function which calls LeftRotate also uses the nil sentinel */
/* and expects the nil sentinel's parent pointer to be unchanged */
/* after calling this function. For example, when RBDeleteFixUP */
/* calls LeftRotate it expects the parent pointer of nil to be */
/* unchanged. */
x=y->left;
y->left=x->right;
if (nil != x->right) x->right->parent=y; /*used to use sentinel here */
/* and do an unconditional assignment instead of testing for nil */
/* instead of checking if x->parent is the root as in the book, we */
/* count on the root sentinel to implicitly take care of this case */
x->parent=y->parent;
if( y == y->parent->left) {
y->parent->left=x;
} else {
y->parent->right=x;
}
x->right=y;
y->parent=x;
#ifdef DEBUG_ASSERT
Assert(!db_nil->red,"nil not red in RightRotate");
#endif
}
/***********************************************************************/
/* FUNCTION: TreeInsertHelp */
/**/
/* INPUTS: tree is the tree to insert into and z is the node to insert */
/**/
/* OUTPUT: none */
/**/
/* Modifies Input: tree, z */
/**/
/* EFFECTS: Inserts z into the tree as if it were a regular binary tree */
/* using the algorithm described in _Introduction_To_Algorithms_ */
/* by Cormen et al. This funciton is only intended to be called */
/* by the RBTreeInsert function and not by the user */
/***********************************************************************/
static void
TreeInsertHelp(rb_red_blk_node* z) {
/* This function should only be called by InsertRBTree (see above) */
rb_red_blk_node* x;
rb_red_blk_node* y;
rb_red_blk_node* nil=db_nil;
z->left=z->right=nil;
y=db_root;
x=db_root->left;
while( x != nil) {
y=x;
if (x->key < z->key) { /* x.key > z.key */
x=x->left;
} else { /* x,key <= z.key */
x=x->right;
}
}
z->parent=y;
if ( (y == db_root) ||
(y->key < z->key)) { /* y.key > z.key */
y->left=z;
} else {
y->right=z;
}
#ifdef DEBUG_ASSERT
Assert(!db_nil->red,"nil not red in TreeInsertHelp");
#endif
}
/* Before calling Insert RBTree the node x should have its key set */
/***********************************************************************/
/* FUNCTION: RBTreeInsert */
/**/
/* INPUTS: tree is the red-black tree to insert a node which has a key */
/* pointed to by key and info pointed to by info. */
/**/
/* OUTPUT: This function returns a pointer to the newly inserted node */
/* which is guarunteed to be valid until this node is deleted. */
/* What this means is if another data structure stores this */
/* pointer then the tree does not need to be searched when this */
/* is to be deleted. */
/**/
/* Modifies Input: tree */
/**/
/* EFFECTS: Creates a node node which contains the appropriate key and */
/* info pointers and inserts it into the tree. */
/***********************************************************************/
static rb_red_blk_node *
RBTreeInsert(CODEADDR key, CODEADDR end, db_entry_type db_type) {
rb_red_blk_node * y;
rb_red_blk_node * x;
rb_red_blk_node * newNode;
x=(rb_red_blk_node*) RBMalloc(sizeof(rb_red_blk_node));
x->key=key;
x->lim=end;
x->db_type=db_type;
TreeInsertHelp(x);
newNode=x;
x->red=1;
while(x->parent->red) { /* use sentinel instead of checking for root */
if (x->parent == x->parent->parent->left) {
y=x->parent->parent->right;
if (y->red) {
x->parent->red=0;
y->red=0;
x->parent->parent->red=1;
x=x->parent->parent;
} else {
if (x == x->parent->right) {
x=x->parent;
LeftRotate(x);
}
x->parent->red=0;
x->parent->parent->red=1;
RightRotate(x->parent->parent);
}
} else { /* case for x->parent == x->parent->parent->right */
y=x->parent->parent->left;
if (y->red) {
x->parent->red=0;
y->red=0;
x->parent->parent->red=1;
x=x->parent->parent;
} else {
if (x == x->parent->left) {
x=x->parent;
RightRotate(x);
}
x->parent->red=0;
x->parent->parent->red=1;
LeftRotate(x->parent->parent);
}
}
}
db_root->left->red=0;
return newNode;
#ifdef DEBUG_ASSERT
Assert(!db_nil->red,"nil not red in RBTreeInsert");
Assert(!db_root->red,"root not red in RBTreeInsert");
#endif
}
/* init the table */
static void
store_in_dbtable(CODEADDR entry, CODEADDR end, db_entry_type db_type)
{
RBTreeInsert(entry, end, db_type);
}
/* find an element in the dbentries table */
static rb_red_blk_node *
find_ref_in_dbtable(CODEADDR entry)
{
rb_red_blk_node *current = db_root->left;
while (current != db_nil) {
if (current->key < entry && current->lim > entry) {
return current;
}
if (entry < current->key)
current = current->right;
else
current = current->left;
}
return current;
}
static void
mark_db_fixed(CELL *ptr) {
rb_red_blk_node *el;
el = find_ref_in_dbtable((CODEADDR)ptr);
if (el != db_nil) {
switch (el->db_type) {
case db_entry:
((DBRef)(el->key))->Flags |= GcFoundMask;
break;
case cl_entry:
((DynamicClause *)(el->key))->ClFlags |= GcFoundMask;
break;
case lcl_entry:
((LogUpdClause *)(el->key))->ClFlags |= GcFoundMask;
break;
case li_entry:
((LogUpdIndex *)(el->key))->ClFlags |= GcFoundMask;
break;
case dcl_entry:
((DeadClause *)(el->key))->ClFlags |= GcFoundMask;
break;
}
}
}
static void
init_dbtable(tr_fr_ptr trail_ptr) {
DeadClause *cl = DeadClauses;
db_vec0 = db_vec = (ADDR)TR;
db_root = RBTreeCreate();
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 */
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 = *pt0;
/* for the moment, if all references to the term in the stacks
are only pointers, reset the flag */
if (FlagOn(DBClMask, flags)) {
DBRef dbr = DBStructFlagsToDBStruct(pt0);
store_in_dbtable((CODEADDR)dbr,
(CODEADDR)dbr+sizeof(DBStruct)+sizeof(CELL)*dbr->DBT.NOfCells,
db_entry);
} else if (flags & LogUpdMask) {
if (flags & IndexMask) {
LogUpdIndex *li = ClauseFlagsToLogUpdIndex(pt0);
store_in_dbtable((CODEADDR)li, (CODEADDR)li+li->ClSize, li_entry);
} else {
LogUpdClause *cli = ClauseFlagsToLogUpdClause(pt0);
store_in_dbtable((CODEADDR)cli, (CODEADDR)cli+cli->ClSize, lcl_entry);
}
} else {
DynamicClause *dcl = ClauseFlagsToDynamicClause(pt0);
store_in_dbtable((CODEADDR)dcl, (CODEADDR)dcl+dcl->ClSize, dcl_entry);
}
}
}
while (cl != NULL) {
store_in_dbtable((CODEADDR)cl, (CODEADDR)cl+cl->ClSize, dcl_entry);
cl = cl->NextCl;
}
if (db_vec == db_vec0) {
/* could not find any entries: probably using LOG UPD semantics */
db_vec0 = NULL;
}
}
#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,"%% type info for %lu cells\n", total);
fprintf(Yap_stderr,"%% %lu vars\n", vars[gc_var]);
fprintf(Yap_stderr,"%% %lu refs\n", vars[gc_ref]);
fprintf(Yap_stderr,"%% %lu references from env\n", env_vars);
fprintf(Yap_stderr,"%% %lu atoms\n", vars[gc_atom]);
fprintf(Yap_stderr,"%% %lu small ints\n", vars[gc_int]);
fprintf(Yap_stderr,"%% %lu other numbers\n", vars[gc_num]);
fprintf(Yap_stderr,"%% %lu lists\n", vars[gc_list]);
fprintf(Yap_stderr,"%% %lu compound terms\n", vars[gc_appl]);
fprintf(Yap_stderr,"%% %lu functors\n", vars[gc_func]);
fprintf(Yap_stderr,"%% %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_PTR(current)) {
CELL ccell = UNMARK_CELL(ccurr);
if (
ccell < MAX_SPECIALS_TAG && /* two first pages */
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_PTR(current)) {
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)Yap_GlobalBase || ccurr > (CELL)Yap_TrailTop)) {
/* printf("%p: %s/%d\n", current,
RepAtom(NameOfFunctor((Functor)ccurr))->StrOfAE,
ArityOfFunctor((Functor)ccurr));*/
vars[gc_func]++;
}
else if (IsUnboundVar(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_PTR(current)) {
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 */
cnext = *next;
if (!MARKED_PTR(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;
#if GC_NO_TAGS
UNMARK(next);
MARK(current);
*current = (CELL)current;
#else
*current = MARK_CELL((CELL)current);
#endif
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) {
#if GC_NO_TAGS
UNMARK(current);
#endif
*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);
#if GC_NO_TAGS
UNMARK(current);
#endif
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 *)Yap_GlobalBase || next > (CELL *)Yap_TrailTop) {
fprintf(Yap_stderr, "ooops while marking %lx, %p at %p\n", (unsigned long int)ccur, current, next);
#endif
} else {
#ifdef COROUTING
total_smarked++;
#endif
#ifdef INSTRUMENT_GC
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_PTR(next) || !ONHEAP(next) )
POP_CONTINUATION();
if (next < H0) POP_CONTINUATION();
if (IsExtensionFunctor((Functor)cnext)) {
switch (cnext) {
case (CELL)FunctorLongInt:
MARK(next);
#if GC_NO_TAGS
MARK(next+2);
#endif
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);
#if GC_NO_TAGS
MARK(next+3);
#endif
#elif GC_NO_TAGS
MARK(next+2);
#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);
}
#if GC_NO_TAGS
MARK(next+i);
#endif
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;
#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
mark_db_fixed((CELL *)gc_ENV[E_CP]);
/* for each saved variable */
if (size > EnvSizeInCells) {
int tsize = size - EnvSizeInCells;
currv = sizeof(CELL)*8-tsize%(sizeof(CELL)*8);
if (pvbmap != NULL) {
pvbmap += tsize/(sizeof(CELL)*8);
bmap = *pvbmap;
} else {
bmap = -1L;
}
bmap = (Int)(((CELL)bmap) << currv);
}
for (saved_var = gc_ENV - size; saved_var < gc_ENV - EnvSizeInCells; saved_var++) {
if (currv == sizeof(CELL)*8) {
if (pvbmap) {
pvbmap--;
bmap = *pvbmap;
} else {
bmap = -1L;
}
currv = 0;
}
/* we may have already been here */
if (bmap < 0 && !MARKED_PTR(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_PTR(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]));
#if defined(ANALYST) || defined(DEBUG)
fprintf(Yap_stderr,"ENV %p-%p(%d) %s\n", gc_ENV, pvbmap, size-EnvSizeInCells, Yap_op_names[op]);
#else
fprintf(Yap_stderr,"ENV %p-%p(%d) %d\n", gc_ENV, pvbmap, size-EnvSizeInCells, (int)op);
#endif
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_hash_entry *)cont_top0);
while (trail_base < trail_ptr) {
register CELL trail_cell;
trail_cell = TrailTerm(trail_base);
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_PTR(hp)) {
#ifdef EARLY_RESET
/* reset to be a variable */
RESET_VARIABLE(hp);
discard_trail_entries++;
RESET_VARIABLE(&TrailTerm(trail_base));
#ifdef FROZEN_STACKS
RESET_VARIABLE(&TrailVal(trail_base));
#endif
#else
/* if I have no early reset I have to follow the trail chain */
mark_external_reference(&TrailTerm(trail_base));
UNMARK(&TrailTerm(trail_base));
#endif /* EARLY_RESET */
} else if (hp < (CELL *)Yap_GlobalBase || hp > (CELL *)Yap_TrailTop) {
/* 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_base));
#ifdef FROZEN_STACKS
RESET_VARIABLE(&TrailVal(trail_base));
#endif
discard_trail_entries++;
} else {
if (trail_cell == (CELL)trail_base)
discard_trail_entries++;
#ifdef FROZEN_STACKS
else
mark_external_reference(&TrailVal(trail_base));
#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, TRUE);
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_hash_entry *)(nsTR+3);
RESET_VARIABLE(cptr);
MARK(cptr);
}
#endif
}
} else if (IsPairTerm(trail_cell)) {
/* can safely ignore this */
}
#if MULTI_ASSIGNMENT_VARIABLES
else {
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.
*/
if (!gc_lookup_ma_var(cptr, trail_base)) {
/* check whether this is the first time we see it*/
if (HEAP_PTR(trail_cell)) {
/* fool the gc into thinking this is a variable */
TrailTerm(trail_base) = (CELL)cptr;
mark_external_reference(&(TrailTerm(trail_base)));
/* reset the gc to believe the original tag */
TrailTerm(trail_base) = AbsAppl((CELL *)TrailTerm(trail_base));
}
trail_base++;
mark_external_reference(&(TrailTerm(trail_base)));
trail_base ++;
if (HEAP_PTR(trail_cell)) {
/* fool the gc into thinking this is a variable */
TrailTerm(trail_base) = (CELL)cptr;
mark_external_reference(&(TrailTerm(trail_base)));
/* reset the gc to believe the original tag */
TrailTerm(trail_base) = AbsAppl((CELL *)TrailTerm(trail_base));
}
} else {
/* we can safely ignore this little monster */
discard_trail_entries += 3;
RESET_VARIABLE(&TrailTerm(trail_base));
#ifdef FROZEN_STACKS
RESET_VARIABLE(&TrailVal(trail_base));
#endif
trail_base++;
RESET_VARIABLE(&TrailTerm(trail_base));
#ifdef FROZEN_STACKS
RESET_VARIABLE(&TrailVal(trail_base));
#endif
trail_base++;
RESET_VARIABLE(&TrailTerm(trail_base));
#ifdef FROZEN_STACKS
RESET_VARIABLE(&TrailVal(trail_base));
#endif
}
}
#endif
trail_base++;
}
#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
#define init_substitution_pointer(GCB, SUBS_PTR, DEP_FR) \
if (DepFr_leader_cp(DEP_FR) == GCB) { \
/* GCB is a generator-consumer node */ \
/* never here if batched scheduling */ \
SUBS_PTR = (CELL *) (GEN_CP(GCB) + 1); \
SUBS_PTR += SgFr_arity(GEN_CP(GCB)->cp_sg_fr); \
} else { \
SUBS_PTR = (CELL *) (CONS_CP(GCB) + 1); \
}
#endif /* TABLING */
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)
{
yamop *lu_cl0 = NEXTOP(PredLogUpdClause0->CodeOfPred,ld),
*lu_cl = NEXTOP(PredLogUpdClause->CodeOfPred,ld),
*su_cl = NEXTOP(PredStaticClause->CodeOfPred,ld);
#ifdef TABLING
dep_fr_ptr depfr = LOCAL_top_dep_fr;
#endif /* TABLING */
#ifdef EASY_SHUNTING
HB = H;
#endif
while (gc_B != NULL) {
op_numbers opnum;
register OPCODE op;
yamop *rtp = gc_B->cp_ap;
mark_db_fixed((CELL *)rtp);
mark_db_fixed((CELL *)(gc_B->cp_cp));
#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 /* TABLING */
{
op = rtp->opc;
opnum = Yap_op_from_opcode(op);
}
if (very_verbose) {
PredEntry *pe = Yap_PredForChoicePt(gc_B);
#if defined(ANALYST) || defined(DEBUG)
if (pe == NULL) {
fprintf(Yap_stderr,"%% marked %ld (%s)\n", total_marked, Yap_op_names[opnum]);
} else if (pe->ArityOfPE) {
fprintf(Yap_stderr,"%% %s/%d marked %ld (%s)\n", RepAtom(NameOfFunctor(pe->FunctorOfPred))->StrOfAE, pe->ArityOfPE, total_marked, Yap_op_names[opnum]);
} else {
fprintf(Yap_stderr,"%% %s marked %ld (%s)\n", RepAtom((Atom)(pe->FunctorOfPred))->StrOfAE, total_marked, Yap_op_names[opnum]);
}
#else
if (pe == NULL) {
fprintf(Yap_stderr,"%% marked %ld (%u)\n", total_marked, (unsigned int)opnum);
} else if (pe->ArityOfPE) {
fprintf(Yap_stderr,"%% %s/%d marked %ld (%u)\n", RepAtom(NameOfFunctor(pe->FunctorOfPred))->StrOfAE, pe->ArityOfPE, total_marked, (unsigned int)opnum);
} else {
fprintf(Yap_stderr,"%% %s marked %ld (%u)\n", RepAtom((Atom)(pe->FunctorOfPred))->StrOfAE, total_marked, (unsigned int)opnum);
}
#endif
}
{
/* 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 */
}
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.bmap
#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 /* TABLING */
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 */
restart_cp:
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 _retry_c:
case _retry_userc:
if (gc_B->cp_ap == RETRY_C_RECORDED_K_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 _jump:
rtp = rtp->u.l.l;
op = rtp->opc;
opnum = Yap_op_from_opcode(op);
goto restart_cp;
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_load_answer:
{
CELL *vars_ptr, vars;
vars_ptr = (CELL *) (LOAD_CP(gc_B) + 1);
vars = *vars_ptr++;
while (vars--) {
mark_external_reference(vars_ptr);
vars_ptr++;
}
}
nargs = 0;
break;
case _table_try_answer:
case _table_retry_me:
case _table_trust_me:
case _table_retry:
case _table_trust:
{
CELL *vars_ptr, vars;
vars_ptr = (CELL *)(GEN_CP(gc_B) + 1);
nargs = rtp->u.ld.s;
while (nargs--) {
mark_external_reference(vars_ptr);
vars_ptr++;
}
vars = *vars_ptr++;
while (vars--) {
mark_external_reference(vars_ptr);
vars_ptr++;
}
}
nargs = 0;
break;
case _table_completion:
{
CELL *vars_ptr, vars;
vars_ptr = (CELL *)(GEN_CP(gc_B) + 1);
nargs = SgFr_arity(GEN_CP(gc_B)->cp_sg_fr);
while (nargs--) {
mark_external_reference(vars_ptr);
vars_ptr++;
}
vars = *vars_ptr++;
while (vars--) {
mark_external_reference(vars_ptr);
vars_ptr++;
}
}
nargs = 0;
break;
case _table_answer_resolution:
{
CELL *vars_ptr, vars;
init_substitution_pointer(gc_B, vars_ptr, CONS_CP(gc_B)->cp_dep_fr);
vars = *vars_ptr++;
while (vars--) {
mark_external_reference(vars_ptr);
vars_ptr++;
}
}
nargs = 0;
break;
case _trie_retry_null:
case _trie_trust_null:
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:
case _trie_retry_extension:
case _trie_trust_extension:
case _trie_retry_float:
case _trie_trust_float:
case _trie_retry_long:
case _trie_trust_long:
{
CELL *vars_ptr;
int heap_arity, vars_arity, subs_arity;
vars_ptr = (CELL *)(gc_B + 1);
heap_arity = *vars_ptr;
vars_arity = *(vars_ptr + heap_arity + 1);
subs_arity = *(vars_ptr + heap_arity + 2);
vars_ptr += heap_arity + subs_arity + vars_arity + 2;
if (vars_arity) {
while (vars_arity--) {
mark_external_reference(vars_ptr);
vars_ptr--;
}
}
if (subs_arity) {
while (subs_arity--) {
mark_external_reference(vars_ptr);
vars_ptr--;
}
}
vars_ptr -= 2;
if (heap_arity) {
while (heap_arity--) {
if (*vars_ptr == 0)
break; /* term extension mark: float/longint */
mark_external_reference(vars_ptr);
vars_ptr--;
}
}
}
nargs = 0;
break;
#endif /* TABLING */
case _profiled_retry_and_mark:
case _count_retry_and_mark:
case _retry_and_mark:
ClauseCodeToDynamicClause(gc_B->cp_ap)->ClFlags |= GcFoundMask;
case _retry2:
nargs = 2;
break;
case _retry3:
nargs = 3;
break;
case _retry4:
nargs = 4;
break;
#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:
case _trust:
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
}
if (gc_B->cp_ap == lu_cl0 ||
gc_B->cp_ap == lu_cl ||
gc_B->cp_ap == su_cl) {
CELL *pt = (CELL *)IntegerOfTerm(gc_B->cp_args[1]);
mark_db_fixed(pt);
}
/* 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 inline void
into_relocation_chain(CELL_PTR current, CELL_PTR next)
{
#ifdef TAGS_FAST_OPS
register CELL ccur = *current, cnext = *next;
if (IsVarTerm(ccur)) {
#if GC_NO_TAGS
RMARK(next);
*current = UNMARKED(cnext);
#else
*current = ( MARKED(ccur) ? MARK_CELL(UNMARKED(cnext)) :
UNMARKED(cnext) );
*next = (MARKED(cnext) ? MBIT : 0) | RBIT | (Int) current;
#endif
} else if (IsPairTerm(ccur)) {
#if GC_NO_TAGS
*next = current;
#else
*current = ( MARKED(ccur) ? MARK_CELL(UNMARKED(cnext)) :
UNMARKED(cnext) );
*next = AbsPair((CELL *)
((MARKED(cnext) ? MBIT : 0) | RBIT | (Int) current));
#endif
} else if (IsApplTerm(ccur)) {
#if GC_NO_TAGS
*next = AbsPair((CELL *)current);
#else
*current = ( MARKED(ccur) ? MARK_CELL(UNMARKED(cnext)) :
UNMARKED(cnext) );
*next = AbsAppl((CELL *)
((MARKED(cnext) ? MBIT : 0) | RBIT | (Int) current));
#endif
} else {
fprintf(Yap_stderr," OH MY GOD !!!!!!!!!!!!\n");
}
#else
CELL current_tag;
current_tag = TAG(*current);
#if GC_NO_TAGS
if (RMARKED(next))
RMARK(current);
else
UNRMARK(current);
*current = *next;
*next = (CELL) current | current_tag;
RMARK(next);
#else
*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 /* GC_NO_TAGS */
#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;
#if !USE_MALLOC
Int OldHeapUsed = HeapUsed;
#endif
#ifdef DEBUG
Int hp_entrs = 0, hp_erased = 0, hp_not_in_use = 0,
hp_in_use_erased = 0, code_entries = 0;
#endif
#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_PTR(&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_PTR((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_PTR(&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 *)Yap_GlobalBase ||
(CELL *)trail_cell > (CELL *)Yap_TrailTop) {
/* 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_PTR(&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 >= Yap_GlobalBase
#else
(ADDR) pt0 >= Yap_TrailBase
#endif
) {
trail_ptr++;
dest++;
continue;
}
#endif /* FROZEN_STACKS */
flags = *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 {
if (flags & LogUpdMask) {
if (flags & IndexMask) {
LogUpdIndex *indx = ClauseFlagsToLogUpdIndex(pt0);
int erase;
DEC_CLREF_COUNT(indx);
indx->ClFlags &= ~InUseMask;
erase = (indx->ClFlags & ErasedMask
&& !indx->ClRefCount);
if (erase) {
/* at this point,
no one is accessing the clause */
Yap_ErLogUpdIndex(indx, NULL);
}
} else {
LogUpdClause *cl = ClauseFlagsToLogUpdClause(pt0);
int erase;
DEC_CLREF_COUNT(cl);
cl->ClFlags &= ~InUseMask;
erase = ((cl->ClFlags & ErasedMask) && !cl->ClRefCount);
if (erase) {
/* at this point,
no one is accessing the clause */
Yap_ErLogUpdCl(cl);
}
}
} else {
DynamicClause *cl = ClauseFlagsToDynamicClause(pt0);
int erase;
DEC_CLREF_COUNT(cl);
cl->ClFlags &= ~InUseMask;
erase = (cl->ClFlags & ErasedMask)
#if defined(YAPOR) || defined(THREADS)
&& (cl->ClRefCount == 0)
#endif
;
if (erase) {
/* at this point,
no one is accessing the clause */
Yap_ErCl(cl);
}
}
}
RESET_VARIABLE(&TrailTerm(dest));
discard_trail_entries++;
} else {
*pt0 = ResetFlag(GcFoundMask, flags);
}
#if MULTI_ASSIGNMENT_VARIABLES
} else {
CELL trail_cell = TrailTerm(trail_ptr+2);
CELL *ptr;
CELL old = TrailTerm(trail_ptr+1);
/* be sure we don't overwrite before we read */
Int marked_ptr = MARKED_PTR(&TrailTerm(trail_ptr+2));
Int marked_old = MARKED_PTR(&TrailTerm(trail_ptr+1));
#ifdef FROZEN_STACKS
Int marked_val_old = MARKED_PTR(&TrailVal(trail_ptr+1));
Int marked_val_ptr = MARKED_PTR(&TrailVal(trail_ptr+2));
#endif
if (marked_ptr)
ptr = RepAppl(UNMARK_CELL(trail_cell));
else
ptr = RepAppl(trail_cell);
TrailTerm(dest+1) = old;
if (marked_old) {
UNMARK(&TrailTerm(dest+1));
if (HEAP_PTR(old)) {
into_relocation_chain(&TrailTerm(dest+1), GET_NEXT(old));
}
}
TrailTerm(dest+2) = TrailTerm(dest) = trail_cell;
#ifdef FROZEN_STACKS
TrailVal(dest+1) = TrailVal(trail_ptr+1);
if (marked_val_old) {
UNMARK(&TrailVal(dest+1));
if (HEAP_PTR(TrailVal(dest+1))) {
into_relocation_chain(&TrailVal(dest+1), GET_NEXT(TrailTerm(dest+1)));
}
}
TrailVal(dest+2) = TrailVal(trail_ptr+2);
if (marked_val_ptr) {
UNMARK(&TrailVal(dest+2));
if (HEAP_PTR(TrailVal(dest+2))) {
into_relocation_chain(&TrailVal(dest+2), GET_NEXT(TrailTerm(dest+2)));
}
}
#endif
if (marked_ptr) {
UNMARK(&TrailTerm(dest));
UNMARK(&TrailTerm(dest+2));
if (HEAP_PTR(trail_cell)) {
into_relocation_chain(&TrailTerm(dest), GET_NEXT(trail_cell));
into_relocation_chain(&TrailTerm(dest+2), GET_NEXT(trail_cell));
}
}
trail_ptr += 2;
dest += 2;
#endif
}
trail_ptr++;
dest++;
}
}
new_TR = dest;
if (is_gc_verbose()) {
if (old_TR != (tr_fr_ptr)Yap_TrailBase)
fprintf(Yap_stderr,
"%% 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,
"%% 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,
"%% 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
#if !USE_SYSTEM_MALLOC
fprintf(Yap_stderr,
"%% 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);
#endif
}
{
DeadClause **cptr;
DeadClause *cl;
cptr = &(DeadClauses);
cl = DeadClauses;
while (cl != NULL) {
if (!(cl->ClFlags & GcFoundMask)) {
char *ocl = (char *)cl;
cl = cl->NextCl;
*cptr = cl;
Yap_FreeCodeSpace(ocl);
} else {
cl->ClFlags &= ~GcFoundMask;
cptr = &(cl->NextCl);
cl = cl->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);
if (pvbmap != NULL) {
pvbmap += tsize/(sizeof(CELL)*8);
bmap = *pvbmap;
} else {
bmap = -1L;
}
bmap = (Int)(((CELL)bmap) << currv);
}
for (saved_var = gc_ENV - size; saved_var < gc_ENV - EnvSizeInCells; saved_var++) {
if (currv == sizeof(CELL)*8) {
if (pvbmap != NULL) {
pvbmap--;
bmap = *pvbmap;
} else {
bmap = -1L;
}
currv = 0;
}
if (bmap < 0) {
CELL env_cell = *saved_var;
if (MARKED_PTR(saved_var)) {
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_PTR(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_PTR(ptr)) {
UNMARK(ptr);
if (HEAP_PTR(cp_cell)) {
into_relocation_chain(ptr, GET_NEXT(cp_cell));
}
}
ptr++;
ns--;
}
}
static void
sweep_b(choiceptr gc_B, UInt arity)
{
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 + arity;
saved_reg++) {
CELL cp_cell = *saved_reg;
if (MARKED_PTR(saved_reg)) {
UNMARK(saved_reg);
if (HEAP_PTR(cp_cell)) {
into_relocation_chain(saved_reg, GET_NEXT(cp_cell));
}
}
}
}
/*
* 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 /* TABLING */
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 /* TABLING */
{
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.bmap
#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;
case _jump:
rtp = rtp->u.l.l;
op = rtp->opc;
opnum = Yap_op_from_opcode(op);
goto restart_cp;
#ifdef TABLING
case _table_load_answer:
{
CELL *vars_ptr, vars;
sweep_environments(gc_B->cp_env, EnvSize((CELL_PTR) (gc_B->cp_cp)), EnvBMap((CELL_PTR) (gc_B->cp_cp)));
vars_ptr = (CELL *) (LOAD_CP(gc_B) + 1);
vars = *vars_ptr++;
while (vars--) {
CELL cp_cell = *vars_ptr;
if (MARKED_PTR(vars_ptr)) {
UNMARK(vars_ptr);
if (HEAP_PTR(cp_cell)) {
into_relocation_chain(vars_ptr, GET_NEXT(cp_cell));
}
}
vars_ptr++;
}
}
break;
case _table_try_answer:
case _table_retry_me:
case _table_trust_me:
case _table_retry:
case _table_trust:
{
int nargs;
CELL *vars_ptr, vars;
sweep_environments(gc_B->cp_env, EnvSize((CELL_PTR) (gc_B->cp_cp)), EnvBMap((CELL_PTR) (gc_B->cp_cp)));
vars_ptr = (CELL *)(GEN_CP(gc_B) + 1);
nargs = rtp->u.ld.s;
while(nargs--) {
CELL cp_cell = *vars_ptr;
if (MARKED_PTR(vars_ptr)) {
UNMARK(vars_ptr);
if (HEAP_PTR(cp_cell)) {
into_relocation_chain(vars_ptr, GET_NEXT(cp_cell));
}
}
vars_ptr++;
}
vars = *vars_ptr++;
while (vars--) {
CELL cp_cell = *vars_ptr;
if (MARKED_PTR(vars_ptr)) {
UNMARK(vars_ptr);
if (HEAP_PTR(cp_cell)) {
into_relocation_chain(vars_ptr, GET_NEXT(cp_cell));
}
}
vars_ptr++;
}
}
break;
case _table_completion:
{
int nargs;
CELL *vars_ptr, vars;
sweep_environments(gc_B->cp_env, EnvSize((CELL_PTR) (gc_B->cp_cp)), EnvBMap((CELL_PTR) (gc_B->cp_cp)));
vars_ptr = (CELL *)(GEN_CP(gc_B) + 1);
nargs = SgFr_arity(GEN_CP(gc_B)->cp_sg_fr);
while(nargs--) {
CELL cp_cell = *vars_ptr;
if (MARKED_PTR(vars_ptr)) {
UNMARK(vars_ptr);
if (HEAP_PTR(cp_cell)) {
into_relocation_chain(vars_ptr, GET_NEXT(cp_cell));
}
}
vars_ptr++;
}
vars = *vars_ptr++;
while (vars--) {
CELL cp_cell = *vars_ptr;
if (MARKED_PTR(vars_ptr)) {
UNMARK(vars_ptr);
if (HEAP_PTR(cp_cell)) {
into_relocation_chain(vars_ptr, GET_NEXT(cp_cell));
}
}
vars_ptr++;
}
}
break;
case _table_answer_resolution:
{
CELL *vars_ptr, vars;
sweep_environments(gc_B->cp_env, EnvSize((CELL_PTR) (gc_B->cp_cp)), EnvBMap((CELL_PTR) (gc_B->cp_cp)));
init_substitution_pointer(gc_B, vars_ptr, CONS_CP(gc_B)->cp_dep_fr);
vars = *vars_ptr++;
while (vars--) {
CELL cp_cell = *vars_ptr;
if (MARKED_PTR(vars_ptr)) {
UNMARK(vars_ptr);
if (HEAP_PTR(cp_cell)) {
into_relocation_chain(vars_ptr, GET_NEXT(cp_cell));
}
}
vars_ptr++;
}
}
break;
case _trie_retry_null:
case _trie_trust_null:
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:
case _trie_retry_extension:
case _trie_trust_extension:
case _trie_retry_float:
case _trie_trust_float:
case _trie_retry_long:
case _trie_trust_long:
{
CELL *vars_ptr;
int heap_arity, vars_arity, subs_arity;
sweep_environments(gc_B->cp_env, EnvSize((CELL_PTR) (gc_B->cp_cp)), EnvBMap((CELL_PTR) (gc_B->cp_cp)));
vars_ptr = (CELL *)(gc_B + 1);
heap_arity = *vars_ptr;
vars_arity = *(vars_ptr + heap_arity + 1);
subs_arity = *(vars_ptr + heap_arity + 2);
vars_ptr += heap_arity + subs_arity + vars_arity + 2;
if (vars_arity) {
while (vars_arity--) {
CELL cp_cell = *vars_ptr;
if (MARKED_PTR(vars_ptr)) {
UNMARK(vars_ptr);
if (HEAP_PTR(cp_cell)) {
into_relocation_chain(vars_ptr, GET_NEXT(cp_cell));
}
}
vars_ptr--;
}
}
if (subs_arity) {
while (subs_arity--) {
CELL cp_cell = *vars_ptr;
if (MARKED_PTR(vars_ptr)) {
UNMARK(vars_ptr);
if (HEAP_PTR(cp_cell)) {
into_relocation_chain(vars_ptr, GET_NEXT(cp_cell));
}
}
vars_ptr--;
}
}
vars_ptr -= 2;
if (heap_arity) {
while (heap_arity--) {
CELL cp_cell = *vars_ptr;
if (*vars_ptr == 0)
break; /* term extension mark: float/longint */
if (MARKED_PTR(vars_ptr)) {
UNMARK(vars_ptr);
if (HEAP_PTR(cp_cell)) {
into_relocation_chain(vars_ptr, GET_NEXT(cp_cell));
}
}
vars_ptr--;
}
}
}
break;
#endif /* TABLING */
case _retry2:
sweep_b(gc_B, 2);
break;
case _retry3:
sweep_b(gc_B, 3);
break;
case _retry4:
sweep_b(gc_B, 4);
break;
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_PTR(saved_reg)) {
UNMARK(saved_reg);
if (HEAP_PTR(cp_cell)) {
into_relocation_chain(saved_reg, GET_NEXT(cp_cell));
}
}
}
}
/* continue to clean environments and arguments */
default:
sweep_b(gc_B,rtp->u.ld.s);
}
/* 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(current)) {
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(current)) {
CELL current_tag;
next = GET_NEXT(ccur);
current_tag = TAG(ccur);
#if GC_NO_TAGS
ccur = *current = *next;
if (RMARKED(next))
RMARK(current);
else
UNRMARK(current);
*next = (CELL) dest | current_tag;
UNRMARK(next);
#else
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 /* GC_NO_TAGS */
}
#endif /* TAGS_FAST_OPS */
}
#ifdef TABLING
static dep_fr_ptr gl_depfr;
#endif /* TABLING */
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 /* TABLING */
}
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 /* TABLING */
dest = (CELL_PTR) H0 + total_marked - 1;
for (current = H - 1; current >= H0; current--) {
if (MARKED_PTR(current)) {
CELL ccell = UNMARK_CELL(*current);
if (
ccell < MAX_SPECIALS_TAG && /* two first pages */
ccell > EndSpecials && IsVarTerm(ccell)
) {
/* oops, we found a blob */
int nofcells = (UNMARK_CELL(*current)-EndSpecials) / sizeof(CELL);
CELL *ptr = current - nofcells ;
if (MARKED_PTR(ptr)) {
#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];
#if GC_NO_TAGS
MARK(ptr+1);
#endif
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 */
#if GC_NO_TAGS
UNRMARK(current);
*current = (CELL) dest; /* no tag */
#else
*current = (*current & MBIT) | (CELL) dest; /* no tag */
#endif
}
}
dest--;
} else {
in_garbage++;
}
}
if (in_garbage)
H0[0] = in_garbage;
#ifdef DEBUG
if (total_marked != found_marked)
fprintf(Yap_stderr,"%% Upward (%d): %ld total against %ld found\n",
GcCalls,
(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_PTR(current)) {
CELL uccur = UNMARK_CELL(ccur);
if (
uccur < MAX_SPECIALS_TAG && /* two first pages */
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,"%% Downward (%d): %ld total against %ld found\n",
GcCalls,
(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 /* TABLING */
}
#ifdef HYBRID_SCHEME
static void
adjust_cp_hbs(void)
{
#ifdef TABLING
dep_fr_ptr depfr = LOCAL_top_dep_fr;
#endif /* TABLING */
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 /* TABLING */
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 < MAX_SPECIALS_TAG && /* two first pages */
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];
#if GC_NO_TAGS
MARK(ptr+1);
#endif
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 */
#if GC_NO_TAGS
*current = (CELL) (H0+(iptr-ibase)); /* no tag */
#else
*current = (*current & MBIT) | (CELL) (H0+(iptr-ibase)); /* no tag */
#endif
}
}
}
#ifdef DEBUG
if (total_marked != found_marked)
fprintf(Yap_stderr,"%% Upward (%d): %ld total against %ld found\n",
GcCalls,
(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 < MAX_SPECIALS_TAG && 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,"%% Downward (%d): %ld total against %ld found\n",
GcCalls,
(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 /* TABLING */
}
#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 */
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(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
#ifdef COROUTINING
-total_smarked
#endif
!= iptop-(CELL_PTR *)H && iptop < (CELL_PTR *)ASP -1024)
fprintf(Yap_stderr,"%% Oops on iptop-H (%ld) vs %ld\n", (unsigned long int)(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,"%% 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 HYBRID_SCHEME
int effectiveness = (((H-H0)-total_marked)*100)/(H-H0);
fprintf(stderr,"%% 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;
int gc_verbose;
tr_fr_ptr old_TR = NULL;
UInt m_time, c_time, time_start, gc_time;
CELL *max;
Int effectiveness;
int gc_trace;
if (setjmp(Yap_gc_restore) == 2) {
/* we cannot recover, fail system */
Yap_Error(OUT_OF_TRAIL_ERROR,TermNil,"could not expand trail during garbage collection");
}
heap_cells = H-H0;
gc_verbose = is_gc_verbose();
effectiveness = 0;
gc_trace = FALSE;
#if COROUTINING
max = (CELL *)DelayTop();
while (H0 - max < 1024+(2*NUM_OF_ATTS)) {
if (!Yap_growglobal(&current_env)) {
Yap_Error(OUT_OF_STACK_ERROR, TermNil, Yap_ErrorMessage);
return 0;
}
max = (CELL *)DelayTop();
}
#else
max = NULL;
#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;
#if !GC_NO_TAGS
/* sanity check: can we still do garbage_collection ? */
if ((CELL)Yap_TrailTop & (MBIT|RBIT)) {
/* oops, we can't */
if (gc_verbose) {
fprintf(Yap_stderr, "%% TrailTop at %p clashes with gc bits: %lx\n", Yap_TrailTop, (unsigned long int)(MBIT|RBIT));
fprintf(Yap_stderr, "%% garbage collection disallowed\n");
}
return(0);
}
#endif
if (gc_trace) {
fprintf(Yap_stderr, "%% gc\n");
} else if (gc_verbose) {
fprintf(Yap_stderr, "%% Start of garbage collection %d:\n", GcCalls);
#ifndef EARLY_RESET
fprintf(Yap_stderr, "%% no early reset in trail\n");
#endif
fprintf(Yap_stderr, "%% Global: %8ld cells (%p-%p)\n", (long int)heap_cells,H0,H);
fprintf(Yap_stderr, "%% Local:%8ld cells (%p-%p)\n", (unsigned long int)(LCL0-ASP),LCL0,ASP);
fprintf(Yap_stderr, "%% Trail:%8ld cells (%p-%p)\n",
(unsigned long int)(TR-(tr_fr_ptr)Yap_TrailBase),Yap_TrailBase,TR);
}
#if !USE_SYSTEM_MALLOC
if (HeapTop >= Yap_GlobalBase - MinHeapGap) {
*--ASP = (CELL)current_env;
if (!Yap_growheap(FALSE, MinHeapGap, NULL)) {
Yap_Error(OUT_OF_HEAP_ERROR, TermNil, Yap_ErrorMessage);
return FALSE;
}
current_env = (CELL *)*ASP;
ASP++;
#if COROUTINING
max = (CELL *)DelayTop();
#endif
}
#endif
time_start = Yap_cputime();
total_marked = 0;
#ifdef COROUTING
total_smarked = 0;
#endif
discard_trail_entries = 0;
#if GC_NO_TAGS
{
UInt alloc_sz = (CELL *)Yap_TrailTop-(CELL*)Yap_GlobalBase;
bp = Yap_PreAllocCodeSpace();
while (bp+alloc_sz > (char *)AuxSp) {
/* not enough space */
*--ASP = (CELL)current_env;
bp = (char *)Yap_ExpandPreAllocCodeSpace(alloc_sz, NULL);
if (!bp)
return 0;
current_env = (CELL *)*ASP;
ASP++;
#if COROUTINING
max = (CELL *)DelayTop();
#endif
}
memset((void *)bp, 0, alloc_sz);
}
#endif /* GC_NO_TAGS */
#ifdef HYBRID_SCHEME
iptop = (CELL_PTR *)H;
#endif
/* get the number of active registers */
YAPEnterCriticalSection();
OldTR = (tr_fr_ptr)(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) {
if (heap_cells > 1000000)
effectiveness = (heap_cells-total_marked)/(heap_cells/100);
else
effectiveness = 100*(heap_cells-total_marked)/heap_cells;
} else
effectiveness = 0;
if (gc_verbose) {
fprintf(Yap_stderr, "%% 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, "%% chain[%d]=%lu\n", i, chain[i]);
}
}
put_type_info((unsigned long int)total_marked);
fprintf(Yap_stderr,"%% %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,"%% %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, "%% Compress: took %g sec\n", (double)(c_time-time_start)/1000);
}
gc_time += (c_time-time_start);
TotGcTime += gc_time;
TotGcRecovered += heap_cells-total_marked;
if (gc_verbose) {
fprintf(Yap_stderr, "%% GC %d took %g sec, total of %g sec doing GC so far.\n", GcCalls, (double)gc_time/1000, (double)TotGcTime/1000);
fprintf(Yap_stderr, "%% 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(TotGcTime);
}
static Int
p_inform_gc(void)
{
Term tn = MkIntegerTerm(TotGcTime);
Term tt = MkIntegerTerm(GcCalls);
Term ts = MkIntegerTerm((TotGcRecovered*sizeof(CELL)));
return(Yap_unify(tn, ARG2) && Yap_unify(tt, ARG1) && Yap_unify(ts, ARG3));
}
static int
call_gc(UInt gc_lim, Int predarity, CELL *current_env, yamop *nextop)
{
UInt gc_margin = MinStackGap;
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 (IsIntegerTerm(Tgc_margin = Yap_GetValue(AtomGcMargin)) &&
gc_margin > 0) {
gc_margin = (UInt)IntegerOfTerm(Tgc_margin);
} else {
/* only go exponential for the first 8 calls */
if (GcCalls < 8)
gc_margin <<= GcCalls;
else {
/* next grow linearly */
gc_margin <<= 8;
/* don't do this: it forces the system to ask for ever more stack!!
gc_margin *= GcCalls;
*/
}
}
if (gc_margin < gc_lim)
gc_margin = gc_lim;
GcCalls++;
if (gc_on && !(Yap_PrologMode & InErrorMode)) {
effectiveness = do_gc(predarity, current_env, nextop);
if (effectiveness > 90) {
while (gc_margin < H-H0)
gc_margin <<= 1;
}
} else {
effectiveness = 0;
}
/* expand the stack if effectiveness is less than 20 % */
if (ASP - H < gc_margin/sizeof(CELL) ||
effectiveness < 20) {
return Yap_growstack(gc_margin);
}
/*
* debug for(save_total=1; save_total<=N; ++save_total)
* plwrite(XREGS[save_total],Yap_DebugPutc,0);
*/
return TRUE;
}
int
Yap_gc(Int predarity, CELL *current_env, yamop *nextop)
{
int res;
Yap_PrologMode |= GCMode;
res=call_gc(4096, predarity, current_env, nextop);
Yap_PrologMode &= ~GCMode;
return res;
}
int
Yap_gcl(UInt gc_lim, Int predarity, CELL *current_env, yamop *nextop)
{
return call_gc(gc_lim+CalculateStackGap()*sizeof(CELL), predarity, current_env, nextop);
}
static Int
p_gc(void)
{
do_gc(0, ENV, P);
return(TRUE);
}
void
Yap_init_gc(void)
{
Yap_InitCPred("$gc", 0, p_gc, HiddenPredFlag);
Yap_InitCPred("$inform_gc", 3, p_inform_gc, HiddenPredFlag);
}
void
Yap_inc_mark_variable()
{
total_marked++;
}
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