nik/lush
1
1
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

new API for weak mode

Browse Source
This commit is contained in:
Roberto Ierusalimschy
2002-08-06 14:06:56 -03:00
parent a2fa48a570
commit 634344d61f
9 changed files with 88 additions and 65 deletions
Download Patch File Download Diff File Expand all files Collapse all files

63
lgc.c
View File

@@ -1,5 +1,5 @@
/*
** $Id: lgc.c,v 1.143 2002/07/17 16:25:13 roberto Exp $
** $Id: lgc.c,v 1.144 2002/08/05 14:50:39 roberto Exp roberto $
** Garbage Collector
** See Copyright Notice in lua.h
*/
@@ -35,12 +35,6 @@ typedef struct GCState {
#define ismarked(x) ((x)->mark != (x))
/* `Table.flag' bits to indicate whether table is key-weak and/or value-weak */
#define KEYWEAKBIT (TM_MODE+1) /* ORDER TM */
#define VALUEWEAKBIT (TM_MODE+2)
#define KEYWEAK (1<<KEYWEAKBIT)
#define VALUEWEAK (1<<VALUEWEAKBIT)
/* mark tricks for userdata */
#define isudmarked(u) (u->uv.len & 1)
@@ -221,19 +215,15 @@ static void removekey (Node *n) {
static void traversetable (GCState *st, Table *h) {
int i;
const TObject *mode;
int weakkey = 0;
int weakvalue = 0;
marktable(st, h->metatable);
lua_assert(h->lsizenode || h->node == G(st->L)->dummynode);
mode = fasttm(st->L, h->metatable, TM_MODE);
if (mode && ttisstring(mode)) { /* weak table? */
if (h->mode & (WEAKKEY | WEAKVALUE)) { /* weak table? */
weakkey = h->mode & WEAKKEY;
weakvalue = h->mode & WEAKVALUE;
h->mark = st->toclear; /* must be cleared after GC, ... */
st->toclear = h; /* ...put in the appropriate list */
weakkey = (strchr(svalue(mode), 'k') != NULL);
weakvalue = (strchr(svalue(mode), 'v') != NULL);
h->flags &= ~(KEYWEAK | VALUEWEAK); /* clear bits */
h->flags |= (weakkey << KEYWEAKBIT) | (weakvalue << VALUEWEAKBIT);
st->toclear = h; /* ... so put in the appropriate list */
}
if (!weakvalue) {
i = sizearray(h);
@@ -284,14 +274,14 @@ static int hasmark (const TObject *o) {
static void cleartablekeys (GCState *st) {
Table *h;
for (h = st->toclear; h; h = h->mark) {
int i;
if (!(h->flags & KEYWEAK)) continue;
lua_assert(strchr(svalue(fasttm(st->L, h->metatable, TM_MODE)), 'k'));
i = sizenode(h);
while (i--) {
Node *n = node(h, i);
if (!hasmark(key(n)))
removekey(n); /* ... and key */
lua_assert(h->mode & (WEAKKEY | WEAKVALUE));
if ((h->mode & WEAKKEY)) { /* table may have collected keys? */
int i = sizenode(h);
while (i--) {
Node *n = node(h, i);
if (!hasmark(key(n))) /* key was collected? */
removekey(n); /* remove entry from table */
}
}
}
}
@@ -303,20 +293,19 @@ static void cleartablekeys (GCState *st) {
static void cleartablevalues (GCState *st) {
Table *h;
for (h = st->toclear; h; h = h->mark) {
int i;
if (!(h->flags & VALUEWEAK)) continue;
lua_assert(strchr(svalue(fasttm(st->L, h->metatable, TM_MODE)), 'v'));
i = sizearray(h);
while (i--) {
TObject *o = &h->array[i];
if (!hasmark(o))
setnilvalue(o); /* remove value */
}
i = sizenode(h);
while (i--) {
Node *n = node(h, i);
if (!hasmark(val(n)))
removekey(n); /* ... and key */
if ((h->mode & WEAKVALUE)) { /* table may have collected values? */
int i = sizearray(h);
while (i--) {
TObject *o = &h->array[i];
if (!hasmark(o)) /* value was collected? */
setnilvalue(o); /* remove value */
}
i = sizenode(h);
while (i--) {
Node *n = node(h, i);
if (!hasmark(val(n))) /* value was collected? */
removekey(n); /* remove entry from table */
}
}
}
}