From 26bf2adaceb18877d836174226d2bfdc3f1fc512 Mon Sep 17 00:00:00 2001
From: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Tue, 6 Nov 2001 19:41:53 -0200
Subject: optimizations for space in LClosures and time cleanning weak tables
---
lgc.c | 100 ++++++++++++++++++++++++++++++++++--------------------------------
1 file changed, 52 insertions(+), 48 deletions(-)
(limited to 'lgc.c')
diff --git a/lgc.c b/lgc.c
index abace987..d41b6d51 100644
--- a/lgc.c
+++ b/lgc.c
@@ -1,5 +1,5 @@
/*
-** $Id: lgc.c,v 1.114 2001/10/25 19:14:14 roberto Exp roberto $
+** $Id: lgc.c,v 1.115 2001/10/31 19:58:11 roberto Exp $
** Garbage Collector
** See Copyright Notice in lua.h
*/
@@ -22,6 +22,7 @@
typedef struct GCState {
Table *tmark; /* list of marked tables to be visited */
+ Table *toclear; /* list of visited weak tables (to be cleared after GC) */
} GCState;
@@ -65,10 +66,10 @@ static void markclosure (GCState *st, Closure *cl) {
lua_assert(cl->l.nupvalues == cl->l.p->nupvalues);
protomark(cl->l.p);
for (i=0; i<cl->l.nupvalues; i++) { /* mark its upvalues */
- UpVal *u = cl->l.upvals[i].heap;
- if (u && !u->marked) {
- u->marked = 1;
- markobject(st, &u->val);
+ TObject *u = cl->l.upvals[i];
+ if (isclosed(u)) {
+ ttype(u-1) = LUA_TNIL; /* temporary value (to mark as visited) */
+ markobject(st, u);
}
}
}
@@ -148,6 +149,10 @@ static void removekey (Node *n) {
static void traversetable (GCState *st, Table *h) {
int i;
int mode = h->weakmode;
+ if (mode) { /* weak table? must be cleared after GC... */
+ h->mark = st->toclear; /* put in the appropriate list */
+ st->toclear = h;
+ }
if (!(mode & LUA_WEAK_VALUE)) {
i = sizearray(h);
while (i--)
@@ -167,17 +172,15 @@ static void traversetable (GCState *st, Table *h) {
}
-static void markall (lua_State *L) {
- GCState st;
- st.tmark = NULL;
- marktagmethods(G(L), &st); /* mark tag methods */
- markstacks(L, &st); /* mark all stacks */
- marktable(&st, G(L)->type2tag);
- markobject(&st, &G(L)->registry);
- while (st.tmark) { /* mark tables */
- Table *h = st.tmark; /* get first table from list */
- st.tmark = h->mark; /* remove it from list */
- traversetable(&st, h);
+static void markall (lua_State *L, GCState *st) {
+ marktagmethods(G(L), st); /* mark tag methods */
+ markstacks(L, st); /* mark all stacks */
+ marktable(st, G(L)->type2tag);
+ markobject(st, &G(L)->registry);
+ while (st->tmark) { /* mark tables */
+ Table *h = st->tmark; /* get first table from list */
+ st->tmark = h->mark; /* remove it from list */
+ traversetable(st, h);
}
}
@@ -198,30 +201,27 @@ static int hasmark (const TObject *o) {
}
-static void cleardeadnodes (Table *h) {
- int i;
- 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)) || !hasmark(key(n))) {
- setnilvalue(val(n)); /* remove value ... */
- removekey(n); /* ... and key */
+/*
+** clear (set to nil) keys and values from weaktables that were collected
+*/
+static void cleartables (Table *h) {
+ for (; h; h = h->mark) {
+ int i;
+ lua_assert(h->weakmode);
+ 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)) || !hasmark(key(n))) {
+ setnilvalue(val(n)); /* remove value ... */
+ removekey(n); /* ... and key */
+ }
}
- }
-}
-
-
-static void cleartables (global_State *G) {
- Table *h;
- for (h = G->roottable; h; h = h->next) {
- if (h->weakmode && ismarked(h))
- cleardeadnodes(h);
}
}
@@ -284,16 +284,17 @@ static void collecttable (lua_State *L) {
static void collectupval (lua_State *L) {
- UpVal **v = &G(L)->rootupval;
- UpVal *curr;
+ TObject **v = &G(L)->rootupval;
+ TObject *curr;
while ((curr = *v) != NULL) {
- if (curr->marked) {
- curr->marked = 0;
- v = &curr->next;
+ if (ttype(curr) == LUA_TNIL) { /* was marked? */
+ ttype(curr) = LUA_HEAPUPVAL; /* unmark */
+ v = &vvalue(curr); /* next */
}
else {
- *v = curr->next;
- luaM_freelem(L, curr);
+ lua_assert(ttype(curr) == LUA_HEAPUPVAL);
+ *v = vvalue(curr); /* next */
+ luaM_freearray(L, curr, 2, TObject);
}
}
}
@@ -411,8 +412,11 @@ void luaC_collect (lua_State *L, int all) {
void luaC_collectgarbage (lua_State *L) {
- markall(L);
- cleartables(G(L));
+ GCState st;
+ st.tmark = NULL;
+ st.toclear = NULL;
+ markall(L, &st);
+ cleartables(st.toclear);
luaC_collect(L, 0);
checkMbuffer(L);
G(L)->GCthreshold = 2*G(L)->nblocks; /* new threshold */
--
cgit v1.2.3-55-g6feb