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tag system replaced by event tables

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This commit is contained in:
Roberto Ierusalimschy
2001-12-05 18:15:18 -02:00
parent 413fc7334b
commit 592a309177
24 changed files with 417 additions and 711 deletions
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121
lgc.c
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@@ -1,5 +1,5 @@
/*
** $Id: lgc.c,v 1.116 2001/11/06 21:41:53 roberto Exp $
** $Id: lgc.c,v 1.1 2001/11/29 22:14:34 rieru Exp rieru $
** Garbage Collector
** See Copyright Notice in lua.h
*/
@@ -30,6 +30,15 @@ typedef struct GCState {
#define strmark(s) {if ((s)->tsv.marked == 0) (s)->tsv.marked = 1;}
/* mark tricks for userdata */
#define isudmarked(u) (u->uv.len & 1)
#define markud(u) (u->uv.len |= 1)
#define unmarkud(u) (u->uv.len--)
/* mark tricks for upvalues (assume that open upvalues are always marked) */
#define isupvalmarked(uv) ((uv)->v != &(uv)->value)
static void markobject (GCState *st, TObject *o);
@@ -66,9 +75,9 @@ static void markclosure (GCState *st, Closure *cl) {
protomark(cl->l.p);
for (i=0; i<cl->l.nupvalues; i++) { /* mark its upvalues */
UpVal *u = cl->l.upvals[i];
if (!u->mark) {
u->mark = 1;
markobject(st, u->v);
if (!isupvalmarked(u)) {
markobject(st, &u->value);
u->v = NULL; /* mark it! */
}
}
}
@@ -90,8 +99,8 @@ static void markobject (GCState *st, TObject *o) {
strmark(tsvalue(o));
break;
case LUA_TUSERDATA:
if (!ismarkedudata(uvalue(o)))
switchudatamark(uvalue(o));
if (!isudmarked(uvalue(o)))
markud(uvalue(o));
break;
case LUA_TFUNCTION:
markclosure(st, clvalue(o));
@@ -112,7 +121,6 @@ static void markstacks (lua_State *L, GCState *st) {
lua_State *L1 = L;
do { /* for each thread */
StkId o, lim;
markobject(st, &L1->gt); /* mark table of globals */
for (o=L1->stack; o<L1->top; o++)
markobject(st, o);
lim = (L1->stack_last - L1->ci->base > MAXSTACK) ? L1->ci->base+MAXSTACK
@@ -124,17 +132,10 @@ static void markstacks (lua_State *L, GCState *st) {
}
static void marktagmethods (global_State *G, GCState *st) {
int t;
for (t=0; t<G->ntag; t++) {
struct TM *tm = &G->TMtable[t];
int e;
if (tm->name) strmark(tm->name);
for (e=0; e<TM_N; e++) {
Closure *cl = tm->method[e];
if (cl) markclosure(st, cl);
}
}
static void markudet (lua_State *L, GCState *st) {
Udata *u;
for (u = G(L)->rootudata; u; u = u->uv.next)
marktable(st, u->uv.eventtable);
}
@@ -152,6 +153,7 @@ static void traversetable (GCState *st, Table *h) {
h->mark = st->toclear; /* put in the appropriate list */
st->toclear = h;
}
marktable(st, h->eventtable);
if (!(mode & LUA_WEAK_VALUE)) {
i = sizearray(h);
while (i--)
@@ -172,11 +174,9 @@ static void traversetable (GCState *st, Table *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 */
markudet(L, st); /* mark userdata's event tables */
while (st->tmark) { /* traverse marked tables */
Table *h = st->tmark; /* get first table from list */
st->tmark = h->mark; /* remove it from list */
traversetable(st, h);
@@ -189,7 +189,7 @@ static int hasmark (const TObject *o) {
case LUA_TSTRING:
return tsvalue(o)->tsv.marked;
case LUA_TUSERDATA:
return ismarkedudata(uvalue(o));
return isudmarked(uvalue(o));
case LUA_TTABLE:
return ismarked(hvalue(o));
case LUA_TFUNCTION:
@@ -261,8 +261,9 @@ static void collectupval (lua_State *L) {
UpVal **v = &G(L)->rootupval;
UpVal *curr;
while ((curr = *v) != NULL) {
if (curr->mark) {
curr->mark = 0;
if (isupvalmarked(curr)) {
lua_assert(curr->v == NULL);
curr->v = &curr->value; /* unmark */
v = &curr->next; /* next */
}
else {
@@ -289,26 +290,27 @@ static void collecttable (lua_State *L) {
}
static void collectudata (lua_State *L, int keep) {
static Udata *collectudata (lua_State *L, int keep) {
Udata **p = &G(L)->rootudata;
Udata *curr;
Udata *collected = NULL;
while ((curr = *p) != NULL) {
if (ismarkedudata(curr)) {
switchudatamark(curr); /* unmark */
if (isudmarked(curr)) {
unmarkud(curr);
p = &curr->uv.next;
}
else { /* collect */
int tag = curr->uv.tag;
const TObject *tm = fasttm(L, curr->uv.eventtable, TM_GC);
*p = curr->uv.next;
if (keep || /* must keep all of them (to close state)? */
luaT_gettm(G(L), tag, TM_GC)) { /* or is there a GC tag method? */
curr->uv.next = G(L)->TMtable[tag].collected; /* chain udata ... */
G(L)->TMtable[tag].collected = curr; /* ... to call its TM later */
if (keep || tm != NULL) {
curr->uv.next = collected;
collected = curr;
}
else /* no tag method; delete udata */
else /* no gc action; delete udata */
luaM_free(L, curr, sizeudata(curr->uv.len));
}
}
return collected;
}
@@ -347,14 +349,14 @@ static void checkMbuffer (lua_State *L) {
}
static void callgcTM (lua_State *L, const TObject *obj) {
Closure *tm = luaT_gettmbyObj(G(L), obj, TM_GC);
if (tm != NULL) {
static void callgcTM (lua_State *L, Udata *udata) {
const TObject *tm = fasttm(L, udata->uv.eventtable, TM_GC);
if (tm != NULL && ttype(tm) == LUA_TFUNCTION) {
int oldah = L->allowhooks;
StkId top = L->top;
L->allowhooks = 0; /* stop debug hooks during GC tag methods */
setclvalue(top, tm);
setobj(top+1, obj);
setobj(top, tm);
setuvalue(top+1, udata);
L->top += 2;
luaD_call(L, top);
L->top = top; /* restore top */
@@ -363,53 +365,52 @@ static void callgcTM (lua_State *L, const TObject *obj) {
}
static void callgcTMudata (lua_State *L) {
int tag;
static void callgcTMudata (lua_State *L, Udata *c) {
luaD_checkstack(L, 3);
for (tag=G(L)->ntag-1; tag>=0; tag--) { /* for each tag (in reverse order) */
Udata *udata;
while ((udata = G(L)->TMtable[tag].collected) != NULL) {
G(L)->TMtable[tag].collected = udata->uv.next; /* remove it from list */
udata->uv.next = G(L)->rootudata; /* resurect it */
G(L)->rootudata = udata;
setuvalue(L->top, udata);
L->top++; /* keep it in stack to avoid being (recursively) collected */
callgcTM(L, L->top-1);
uvalue(L->top-1)->uv.tag = 0; /* default tag (udata is `finalized') */
L->top--;
}
L->top++; /* reserve space to keep udata while runs its gc method */
while (c != NULL) {
Udata *udata = c;
c = udata->uv.next; /* remove udata from list */
udata->uv.next = G(L)->rootudata; /* resurect it */
G(L)->rootudata = udata;
setuvalue(L->top - 1, udata);
callgcTM(L, udata);
/* mark udata as finalized (default event table) */
uvalue(L->top-1)->uv.eventtable = hvalue(defaultet(L));
}
L->top--;
}
void luaC_callallgcTM (lua_State *L) {
if (G(L)->rootudata) { /* avoid problems with incomplete states */
collectudata(L, 1); /* collect all udata into tag lists */
callgcTMudata(L); /* call their GC tag methods */
Udata *c = collectudata(L, 1); /* collect all udata */
callgcTMudata(L, c); /* call their GC tag methods */
}
}
void luaC_collect (lua_State *L, int all) {
collectudata(L, 0);
Udata *luaC_collect (lua_State *L, int all) {
Udata *c = collectudata(L, 0);
collectstrings(L, all);
collecttable(L);
collectproto(L);
collectupval(L);
collectclosures(L);
return c;
}
void luaC_collectgarbage (lua_State *L) {
Udata *c;
GCState st;
st.tmark = NULL;
st.toclear = NULL;
markall(L, &st);
cleartables(st.toclear);
luaC_collect(L, 0);
c = luaC_collect(L, 0);
checkMbuffer(L);
G(L)->GCthreshold = 2*G(L)->nblocks; /* new threshold */
callgcTMudata(L);
callgcTM(L, &luaO_nilobject);
callgcTMudata(L, c);
}