mirror of
https://github.com/lua/lua
synced 2024-12-24 03:16:50 +03:00
towards incremental GC
This commit is contained in:
Roberto Ierusalimschy
parent
53c7f86194
commit
366e4af3c9
143
lgc.c
143
lgc.c
@ -1,5 +1,5 @@
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/*
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** $Id: lgc.c,v 1.177 2003/08/27 21:01:44 roberto Exp roberto $
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** $Id: lgc.c,v 1.178 2003/11/17 19:50:05 roberto Exp roberto $
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** Garbage Collector
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** See Copyright Notice in lua.h
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*/
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@ -22,13 +22,6 @@
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#include "ltm.h"
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typedef struct GCState {
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GCObject *tmark; /* list of marked objects to be traversed */
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GCObject *w; /* list of traversed weak tables (to be cleared) */
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global_State *g;
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} GCState;
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#define unblack(x) resetbit((x)->gch.marked, BLACKBIT)
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#define isblack(x) testbit((x)->gch.marked, BLACKBIT)
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@ -46,44 +39,44 @@ typedef struct GCState {
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#define markobject(st,o) { checkconsistency(o); \
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if (iscollectable(o) && !isblack(gcvalue(o))) reallymarkobject(st,gcvalue(o)); }
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#define markobject(g,o) { checkconsistency(o); \
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if (iscollectable(o) && !isblack(gcvalue(o))) reallymarkobject(g,gcvalue(o)); }
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#define condmarkobject(st,o,c) { checkconsistency(o); \
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#define condmarkobject(g,o,c) { checkconsistency(o); \
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if (iscollectable(o) && !isblack(gcvalue(o)) && (c)) \
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reallymarkobject(st,gcvalue(o)); }
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reallymarkobject(g,gcvalue(o)); }
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#define markvalue(st,t) { if (!isblack(valtogco(t))) \
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reallymarkobject(st, valtogco(t)); }
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#define markvalue(g,t) { if (!isblack(valtogco(t))) \
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reallymarkobject(g, valtogco(t)); }
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static void reallymarkobject (GCState *st, GCObject *o) {
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static void reallymarkobject (global_State *g, GCObject *o) {
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lua_assert(!isblack(o));
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blacken(o);
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switch (o->gch.tt) {
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case LUA_TUSERDATA: {
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markvalue(st, gcotou(o)->uv.metatable);
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markvalue(g, gcotou(o)->uv.metatable);
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break;
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}
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case LUA_TFUNCTION: {
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gcotocl(o)->c.gclist = st->tmark;
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st->tmark = o;
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gcotocl(o)->c.gclist = g->gray;
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g->gray = o;
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break;
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}
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case LUA_TTABLE: {
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gcotoh(o)->gclist = st->tmark;
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st->tmark = o;
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gcotoh(o)->gclist = g->gray;
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g->gray = o;
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break;
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}
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case LUA_TTHREAD: {
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gcototh(o)->gclist = st->tmark;
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st->tmark = o;
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gcototh(o)->gclist = g->gray;
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g->gray = o;
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break;
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}
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case LUA_TPROTO: {
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gcotop(o)->gclist = st->tmark;
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st->tmark = o;
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gcotop(o)->gclist = g->gray;
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g->gray = o;
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break;
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}
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default: lua_assert(o->gch.tt == LUA_TSTRING);
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@ -91,11 +84,11 @@ static void reallymarkobject (GCState *st, GCObject *o) {
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}
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static void marktmu (GCState *st) {
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static void marktmu (global_State *g) {
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GCObject *u;
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for (u = st->g->tmudata; u; u = u->gch.next) {
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for (u = g->tmudata; u; u = u->gch.next) {
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unblack(u); /* may be marked, if left from previous GC */
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reallymarkobject(st, u);
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reallymarkobject(g, u);
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}
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}
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@ -132,14 +125,14 @@ size_t luaC_separateudata (lua_State *L) {
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}
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static void traversetable (GCState *st, Table *h) {
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static void traversetable (global_State *g, Table *h) {
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int i;
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int weakkey = 0;
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int weakvalue = 0;
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const TObject *mode;
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markvalue(st, h->metatable);
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lua_assert(h->lsizenode || h->node == st->g->dummynode);
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mode = gfasttm(st->g, h->metatable, TM_MODE);
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markvalue(g, h->metatable);
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lua_assert(h->lsizenode || h->node == g->dummynode);
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mode = gfasttm(g, h->metatable, TM_MODE);
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if (mode && ttisstring(mode)) { /* is there a weak mode? */
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weakkey = (strchr(svalue(mode), 'k') != NULL);
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weakvalue = (strchr(svalue(mode), 'v') != NULL);
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@ -147,23 +140,23 @@ static void traversetable (GCState *st, Table *h) {
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h->marked &= ~(KEYWEAK | VALUEWEAK); /* clear bits */
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h->marked |= cast(lu_byte, (weakkey << KEYWEAKBIT) |
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(weakvalue << VALUEWEAKBIT));
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h->gclist = st->w; /* must be cleared after GC, ... */
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st->w = valtogco(h); /* ... so put in the appropriate list */
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h->gclist = g->weak; /* must be cleared after GC, ... */
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g->weak = valtogco(h); /* ... so put in the appropriate list */
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}
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}
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if (weakkey && weakvalue) return;
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if (!weakvalue) {
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i = h->sizearray;
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while (i--)
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markobject(st, &h->array[i]);
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markobject(g, &h->array[i]);
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}
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i = sizenode(h);
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while (i--) {
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Node *n = gnode(h, i);
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if (!ttisnil(gval(n))) {
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lua_assert(!ttisnil(gkey(n)));
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condmarkobject(st, gkey(n), !weakkey);
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condmarkobject(st, gval(n), !weakvalue);
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condmarkobject(g, gkey(n), !weakkey);
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condmarkobject(g, gval(n), !weakvalue);
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}
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}
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}
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@ -173,7 +166,7 @@ static void traversetable (GCState *st, Table *h) {
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** All marks are conditional because a GC may happen while the
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** prototype is still being created
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*/
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static void traverseproto (GCState *st, Proto *f) {
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static void traverseproto (global_State *g, Proto *f) {
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int i;
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if (f->source) stringmark(f->source);
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for (i=0; i<f->sizek; i++) { /* mark literal strings */
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@ -186,7 +179,7 @@ static void traverseproto (GCState *st, Proto *f) {
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}
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for (i=0; i<f->sizep; i++) { /* mark nested protos */
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if (f->p[i])
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markvalue(st, f->p[i]);
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markvalue(g, f->p[i]);
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}
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for (i=0; i<f->sizelocvars; i++) { /* mark local-variable names */
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if (f->locvars[i].varname)
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@ -196,22 +189,22 @@ static void traverseproto (GCState *st, Proto *f) {
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static void traverseclosure (GCState *st, Closure *cl) {
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static void traverseclosure (global_State *g, Closure *cl) {
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if (cl->c.isC) {
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int i;
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for (i=0; i<cl->c.nupvalues; i++) /* mark its upvalues */
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markobject(st, &cl->c.upvalue[i]);
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markobject(g, &cl->c.upvalue[i]);
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}
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else {
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int i;
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lua_assert(cl->l.nupvalues == cl->l.p->nups);
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markvalue(st, hvalue(&cl->l.g));
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markvalue(st, cl->l.p);
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markvalue(g, hvalue(&cl->l.g));
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markvalue(g, cl->l.p);
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for (i=0; i<cl->l.nupvalues; i++) { /* mark its upvalues */
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UpVal *u = cl->l.upvals[i];
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if (!isblack(valtogco(u))) {
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blacken(valtogco(u));
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markobject(st, &u->value);
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markobject(g, &u->value);
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}
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}
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}
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@ -230,48 +223,48 @@ static void checkstacksizes (lua_State *L, StkId max) {
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}
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static void traversestack (GCState *st, lua_State *L1) {
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static void traversestack (global_State *g, lua_State *L1) {
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StkId o, lim;
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CallInfo *ci;
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markobject(st, gt(L1));
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markobject(g, gt(L1));
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lim = L1->top;
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for (ci = L1->base_ci; ci <= L1->ci; ci++) {
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lua_assert(ci->top <= L1->stack_last);
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if (lim < ci->top) lim = ci->top;
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}
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for (o = L1->stack; o < L1->top; o++)
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markobject(st, o);
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markobject(g, o);
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for (; o <= lim; o++)
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setnilvalue(o);
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checkstacksizes(L1, lim);
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}
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static void propagatemarks (GCState *st) {
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while (st->tmark) { /* traverse marked objects */
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switch (st->tmark->gch.tt) {
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static void propagatemarks (global_State *g) {
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while (g->gray) { /* traverse marked objects */
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switch (g->gray->gch.tt) {
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case LUA_TTABLE: {
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Table *h = gcotoh(st->tmark);
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st->tmark = h->gclist;
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traversetable(st, h);
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Table *h = gcotoh(g->gray);
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g->gray = h->gclist;
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traversetable(g, h);
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break;
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}
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case LUA_TFUNCTION: {
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Closure *cl = gcotocl(st->tmark);
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st->tmark = cl->c.gclist;
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traverseclosure(st, cl);
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Closure *cl = gcotocl(g->gray);
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g->gray = cl->c.gclist;
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traverseclosure(g, cl);
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break;
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}
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case LUA_TTHREAD: {
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lua_State *th = gcototh(st->tmark);
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st->tmark = th->gclist;
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traversestack(st, th);
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lua_State *th = gcototh(g->gray);
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g->gray = th->gclist;
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traversestack(g, th);
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break;
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}
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case LUA_TPROTO: {
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Proto *p = gcotop(st->tmark);
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st->tmark = p->gclist;
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traverseproto(st, p);
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Proto *p = gcotop(g->gray);
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g->gray = p->gclist;
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traverseproto(g, p);
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break;
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}
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default: lua_assert(0);
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@ -437,28 +430,26 @@ void luaC_sweep (lua_State *L, int all) {
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/* mark root set */
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static void markroot (GCState *st, lua_State *L) {
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global_State *g = st->g;
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markobject(st, defaultmeta(L));
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markobject(st, registry(L));
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traversestack(st, g->mainthread);
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static void markroot (global_State *g, lua_State *L) {
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markobject(g, defaultmeta(L));
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markobject(g, registry(L));
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traversestack(g, g->mainthread);
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if (L != g->mainthread) /* another thread is running? */
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markvalue(st, L); /* cannot collect it */
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markvalue(g, L); /* cannot collect it */
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}
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static size_t mark (lua_State *L) {
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size_t deadmem;
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GCState st;
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st.g = G(L);
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st.tmark = NULL;
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st.w = NULL;
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markroot(&st, L);
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propagatemarks(&st); /* mark all reachable objects */
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global_State *g = G(L);
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lua_assert(g->gray == NULL);
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g->weak = NULL;
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markroot(g, L);
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propagatemarks(g); /* mark all reachable objects */
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deadmem = luaC_separateudata(L); /* separate userdata to be preserved */
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marktmu(&st); /* mark `preserved' userdata */
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propagatemarks(&st); /* remark, to propagate `preserveness' */
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cleartable(st.w); /* remove collected objects from weak tables */
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marktmu(g); /* mark `preserved' userdata */
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propagatemarks(g); /* remark, to propagate `preserveness' */
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cleartable(g->weak); /* remove collected objects from weak tables */
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return deadmem;
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}
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8
lgc.h
8
lgc.h
@ -1,5 +1,5 @@
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/*
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** $Id: lgc.h,v 1.21 2003/07/29 19:25:37 roberto Exp roberto $
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** $Id: lgc.h,v 1.22 2003/11/17 19:50:05 roberto Exp roberto $
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** Garbage Collector
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** See Copyright Notice in lua.h
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*/
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@ -23,15 +23,15 @@
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/*
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** Layout for bit use in `marked' field:
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** bit 0 - object is white (not used yet)
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** bit 0 - object is gray
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** bit 1 - object is black
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** bit 2 - For userdata: is finalized;
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for tables: has weak keys
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** bit 3 - for tables: has weak values
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** bit 4 - for strings: is fixed (should not be collected)
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** bit 4 - object is fixed (should not be collected)
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*/
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#define WHITEBIT 0
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#define GRAYBIT 0
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#define BLACKBIT 1
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#define FINALIZEDBIT 2
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#define KEYWEAKBIT 2
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@ -1,5 +1,5 @@
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/*
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** $Id: lobject.h,v 1.160 2003/04/28 19:26:16 roberto Exp roberto $
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** $Id: lobject.h,v 1.161 2003/08/27 21:01:44 roberto Exp roberto $
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** Type definitions for Lua objects
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** See Copyright Notice in lua.h
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*/
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@ -252,6 +252,7 @@ typedef struct LocVar {
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typedef struct UpVal {
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CommonHeader;
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GCObject *gclist;
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TObject *v; /* points to stack or to its own value */
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TObject value; /* the value (when closed) */
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} UpVal;
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4
lstate.c
4
lstate.c
@ -1,5 +1,5 @@
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/*
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** $Id: lstate.c,v 1.126 2003/09/04 20:19:07 roberto Exp roberto $
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** $Id: lstate.c,v 1.127 2003/10/02 20:31:17 roberto Exp roberto $
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** Global State
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** See Copyright Notice in lua.h
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*/
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@ -167,6 +167,8 @@ LUA_API lua_State *lua_newstate (lua_Alloc f, void *ud) {
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g->panic = NULL;
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g->rootgc = NULL;
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g->rootudata = NULL;
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g->gray = NULL;
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g->weak = NULL;
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g->tmudata = NULL;
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setnilvalue(gkey(g->dummynode));
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setnilvalue(gval(g->dummynode));
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4
lstate.h
4
lstate.h
@ -1,5 +1,5 @@
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/*
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** $Id: lstate.h,v 1.111 2003/07/16 20:49:02 roberto Exp roberto $
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** $Id: lstate.h,v 1.112 2003/10/02 20:31:17 roberto Exp roberto $
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** Global State
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** See Copyright Notice in lua.h
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*/
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@ -100,6 +100,8 @@ typedef struct global_State {
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stringtable strt; /* hash table for strings */
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GCObject *rootgc; /* list of (almost) all collectable objects */
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GCObject *rootudata; /* (separated) list of all userdata */
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GCObject *gray; /* list of gray objects */
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GCObject *weak; /* list of weak tables (to be cleared) */
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GCObject *tmudata; /* list of userdata to be GC */
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lua_Alloc realloc; /* function to reallocate memory */
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void *ud; /* auxiliary data to `realloc' */
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