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712 lines
20 KiB
C
712 lines
20 KiB
C
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/*
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** $Id: lgc.c,v 2.38.1.1 2007/12/27 13:02:25 roberto Exp $
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** Garbage Collector
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** See Copyright Notice in lua.h
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*/
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#include <string.h>
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#define lgc_c
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#define LUA_CORE
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#include "lua.h"
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#include "ldebug.h"
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#include "ldo.h"
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#include "lfunc.h"
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#include "lgc.h"
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#include "lmem.h"
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#include "lobject.h"
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#include "lstate.h"
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#include "lstring.h"
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#include "ltable.h"
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#include "ltm.h"
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#define GCSTEPSIZE 1024u
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#define GCSWEEPMAX 40
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#define GCSWEEPCOST 10
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#define GCFINALIZECOST 100
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#define maskmarks cast_byte(~(bitmask(BLACKBIT)|WHITEBITS))
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#define makewhite(g,x) \
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((x)->gch.marked = cast_byte(((x)->gch.marked & maskmarks) | luaC_white(g)))
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#define white2gray(x) reset2bits((x)->gch.marked, WHITE0BIT, WHITE1BIT)
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#define black2gray(x) resetbit((x)->gch.marked, BLACKBIT)
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#define stringmark(s) reset2bits((s)->tsv.marked, WHITE0BIT, WHITE1BIT)
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#define isfinalized(u) testbit((u)->marked, FINALIZEDBIT)
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#define markfinalized(u) l_setbit((u)->marked, FINALIZEDBIT)
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#define KEYWEAK bitmask(KEYWEAKBIT)
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#define VALUEWEAK bitmask(VALUEWEAKBIT)
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#define markvalue(g,o) { checkconsistency(o); \
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if (iscollectable(o) && iswhite(gcvalue(o))) reallymarkobject(g,gcvalue(o)); }
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#define markobject(g,t) { if (iswhite(obj2gco(t))) \
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reallymarkobject(g, obj2gco(t)); }
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#define setthreshold(g) (g->GCthreshold = (g->estimate/100) * g->gcpause)
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static void removeentry (Node *n) {
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lua_assert(ttisnil(gval(n)));
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if (iscollectable(gkey(n)))
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setttype(gkey(n), LUA_TDEADKEY); /* dead key; remove it */
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}
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static void reallymarkobject (global_State *g, GCObject *o) {
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lua_assert(iswhite(o) && !isdead(g, o));
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white2gray(o);
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switch (o->gch.tt) {
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case LUA_TSTRING: {
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return;
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}
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case LUA_TUSERDATA: {
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Table *mt = gco2u(o)->metatable;
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gray2black(o); /* udata are never gray */
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if (mt) markobject(g, mt);
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markobject(g, gco2u(o)->env);
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return;
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}
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case LUA_TUPVAL: {
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UpVal *uv = gco2uv(o);
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markvalue(g, uv->v);
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if (uv->v == &uv->u.value) /* closed? */
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gray2black(o); /* open upvalues are never black */
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return;
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}
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case LUA_TFUNCTION: {
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gco2cl(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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gco2h(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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gco2th(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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gco2p(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(0);
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}
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}
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static void marktmu (global_State *g) {
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GCObject *u = g->tmudata;
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if (u) {
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do {
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u = u->gch.next;
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makewhite(g, u); /* may be marked, if left from previous GC */
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reallymarkobject(g, u);
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} while (u != g->tmudata);
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}
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}
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/* move `dead' udata that need finalization to list `tmudata' */
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size_t luaC_separateudata (lua_State *L, int all) {
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global_State *g = G(L);
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size_t deadmem = 0;
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GCObject **p = &g->mainthread->next;
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GCObject *curr;
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while ((curr = *p) != NULL) {
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if (!(iswhite(curr) || all) || isfinalized(gco2u(curr)))
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p = &curr->gch.next; /* don't bother with them */
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else if (fasttm(L, gco2u(curr)->metatable, TM_GC) == NULL) {
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markfinalized(gco2u(curr)); /* don't need finalization */
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p = &curr->gch.next;
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}
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else { /* must call its gc method */
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deadmem += sizeudata(gco2u(curr));
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markfinalized(gco2u(curr));
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*p = curr->gch.next;
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/* link `curr' at the end of `tmudata' list */
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if (g->tmudata == NULL) /* list is empty? */
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g->tmudata = curr->gch.next = curr; /* creates a circular list */
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else {
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curr->gch.next = g->tmudata->gch.next;
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g->tmudata->gch.next = curr;
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g->tmudata = curr;
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}
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}
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}
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return deadmem;
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}
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static int 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 TValue *mode;
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if (h->metatable)
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markobject(g, h->metatable);
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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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if (weakkey || weakvalue) { /* is really weak? */
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h->marked &= ~(KEYWEAK | VALUEWEAK); /* clear bits */
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h->marked |= cast_byte((weakkey << KEYWEAKBIT) |
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(weakvalue << VALUEWEAKBIT));
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h->gclist = g->weak; /* must be cleared after GC, ... */
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g->weak = obj2gco(h); /* ... so put in the appropriate list */
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}
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}
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if (weakkey && weakvalue) return 1;
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if (!weakvalue) {
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i = h->sizearray;
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while (i--)
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markvalue(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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lua_assert(ttype(gkey(n)) != LUA_TDEADKEY || ttisnil(gval(n)));
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if (ttisnil(gval(n)))
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removeentry(n); /* remove empty entries */
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else {
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lua_assert(!ttisnil(gkey(n)));
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if (!weakkey) markvalue(g, gkey(n));
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if (!weakvalue) markvalue(g, gval(n));
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}
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}
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return weakkey || weakvalue;
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}
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/*
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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 (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 literals */
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markvalue(g, &f->k[i]);
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for (i=0; i<f->sizeupvalues; i++) { /* mark upvalue names */
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if (f->upvalues[i])
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stringmark(f->upvalues[i]);
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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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markobject(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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stringmark(f->locvars[i].varname);
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}
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}
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static void traverseclosure (global_State *g, Closure *cl) {
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markobject(g, cl->c.env);
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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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markvalue(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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markobject(g, cl->l.p);
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for (i=0; i<cl->l.nupvalues; i++) /* mark its upvalues */
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markobject(g, cl->l.upvals[i]);
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}
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}
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static void checkstacksizes (lua_State *L, StkId max) {
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int ci_used = cast_int(L->ci - L->base_ci); /* number of `ci' in use */
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int s_used = cast_int(max - L->stack); /* part of stack in use */
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if (L->size_ci > LUAI_MAXCALLS) /* handling overflow? */
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return; /* do not touch the stacks */
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if (4*ci_used < L->size_ci && 2*BASIC_CI_SIZE < L->size_ci)
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luaD_reallocCI(L, L->size_ci/2); /* still big enough... */
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condhardstacktests(luaD_reallocCI(L, ci_used + 1));
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if (4*s_used < L->stacksize &&
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2*(BASIC_STACK_SIZE+EXTRA_STACK) < L->stacksize)
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luaD_reallocstack(L, L->stacksize/2); /* still big enough... */
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condhardstacktests(luaD_reallocstack(L, s_used));
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}
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static void traversestack (global_State *g, lua_State *l) {
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StkId o, lim;
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CallInfo *ci;
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markvalue(g, gt(l));
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lim = l->top;
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for (ci = l->base_ci; ci <= l->ci; ci++) {
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lua_assert(ci->top <= l->stack_last);
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if (lim < ci->top) lim = ci->top;
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}
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for (o = l->stack; o < l->top; o++)
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markvalue(g, o);
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for (; o <= lim; o++)
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setnilvalue(o);
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checkstacksizes(l, lim);
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}
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/*
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** traverse one gray object, turning it to black.
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** Returns `quantity' traversed.
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*/
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static l_mem propagatemark (global_State *g) {
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GCObject *o = g->gray;
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lua_assert(isgray(o));
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gray2black(o);
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switch (o->gch.tt) {
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case LUA_TTABLE: {
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Table *h = gco2h(o);
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g->gray = h->gclist;
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if (traversetable(g, h)) /* table is weak? */
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black2gray(o); /* keep it gray */
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return sizeof(Table) + sizeof(TValue) * h->sizearray +
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sizeof(Node) * sizenode(h);
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}
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case LUA_TFUNCTION: {
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Closure *cl = gco2cl(o);
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g->gray = cl->c.gclist;
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traverseclosure(g, cl);
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return (cl->c.isC) ? sizeCclosure(cl->c.nupvalues) :
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sizeLclosure(cl->l.nupvalues);
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}
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case LUA_TTHREAD: {
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lua_State *th = gco2th(o);
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g->gray = th->gclist;
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th->gclist = g->grayagain;
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g->grayagain = o;
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black2gray(o);
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traversestack(g, th);
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return sizeof(lua_State) + sizeof(TValue) * th->stacksize +
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sizeof(CallInfo) * th->size_ci;
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}
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case LUA_TPROTO: {
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Proto *p = gco2p(o);
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g->gray = p->gclist;
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traverseproto(g, p);
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return sizeof(Proto) + sizeof(Instruction) * p->sizecode +
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sizeof(Proto *) * p->sizep +
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sizeof(TValue) * p->sizek +
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sizeof(int) * p->sizelineinfo +
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sizeof(LocVar) * p->sizelocvars +
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sizeof(TString *) * p->sizeupvalues;
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}
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default: lua_assert(0); return 0;
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}
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}
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static size_t propagateall (global_State *g) {
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size_t m = 0;
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while (g->gray) m += propagatemark(g);
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return m;
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}
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/*
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** The next function tells whether a key or value can be cleared from
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** a weak table. Non-collectable objects are never removed from weak
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** tables. Strings behave as `values', so are never removed too. for
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** other objects: if really collected, cannot keep them; for userdata
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** being finalized, keep them in keys, but not in values
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*/
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static int iscleared (const TValue *o, int iskey) {
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if (!iscollectable(o)) return 0;
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if (ttisstring(o)) {
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stringmark(rawtsvalue(o)); /* strings are `values', so are never weak */
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return 0;
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}
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return iswhite(gcvalue(o)) ||
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(ttisuserdata(o) && (!iskey && isfinalized(uvalue(o))));
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}
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/*
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** clear collected entries from weaktables
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*/
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static void cleartable (GCObject *l) {
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while (l) {
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Table *h = gco2h(l);
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int i = h->sizearray;
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lua_assert(testbit(h->marked, VALUEWEAKBIT) ||
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testbit(h->marked, KEYWEAKBIT));
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if (testbit(h->marked, VALUEWEAKBIT)) {
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while (i--) {
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TValue *o = &h->array[i];
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if (iscleared(o, 0)) /* value was collected? */
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setnilvalue(o); /* remove value */
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}
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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)) && /* non-empty entry? */
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(iscleared(key2tval(n), 1) || iscleared(gval(n), 0))) {
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setnilvalue(gval(n)); /* remove value ... */
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removeentry(n); /* remove entry from table */
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}
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}
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l = h->gclist;
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}
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}
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static void freeobj (lua_State *L, GCObject *o) {
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switch (o->gch.tt) {
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case LUA_TPROTO: luaF_freeproto(L, gco2p(o)); break;
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case LUA_TFUNCTION: luaF_freeclosure(L, gco2cl(o)); break;
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case LUA_TUPVAL: luaF_freeupval(L, gco2uv(o)); break;
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case LUA_TTABLE: luaH_free(L, gco2h(o)); break;
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case LUA_TTHREAD: {
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lua_assert(gco2th(o) != L && gco2th(o) != G(L)->mainthread);
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luaE_freethread(L, gco2th(o));
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break;
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}
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case LUA_TSTRING: {
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G(L)->strt.nuse--;
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luaM_freemem(L, o, sizestring(gco2ts(o)));
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break;
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}
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case LUA_TUSERDATA: {
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luaM_freemem(L, o, sizeudata(gco2u(o)));
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break;
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}
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default: lua_assert(0);
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}
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}
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#define sweepwholelist(L,p) sweeplist(L,p,MAX_LUMEM)
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static GCObject **sweeplist (lua_State *L, GCObject **p, lu_mem count) {
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GCObject *curr;
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global_State *g = G(L);
|
||
|
int deadmask = otherwhite(g);
|
||
|
while ((curr = *p) != NULL && count-- > 0) {
|
||
|
if (curr->gch.tt == LUA_TTHREAD) /* sweep open upvalues of each thread */
|
||
|
sweepwholelist(L, &gco2th(curr)->openupval);
|
||
|
if ((curr->gch.marked ^ WHITEBITS) & deadmask) { /* not dead? */
|
||
|
lua_assert(!isdead(g, curr) || testbit(curr->gch.marked, FIXEDBIT));
|
||
|
makewhite(g, curr); /* make it white (for next cycle) */
|
||
|
p = &curr->gch.next;
|
||
|
}
|
||
|
else { /* must erase `curr' */
|
||
|
lua_assert(isdead(g, curr) || deadmask == bitmask(SFIXEDBIT));
|
||
|
*p = curr->gch.next;
|
||
|
if (curr == g->rootgc) /* is the first element of the list? */
|
||
|
g->rootgc = curr->gch.next; /* adjust first */
|
||
|
freeobj(L, curr);
|
||
|
}
|
||
|
}
|
||
|
return p;
|
||
|
}
|
||
|
|
||
|
|
||
|
static void checkSizes (lua_State *L) {
|
||
|
global_State *g = G(L);
|
||
|
/* check size of string hash */
|
||
|
if (g->strt.nuse < cast(lu_int32, g->strt.size/4) &&
|
||
|
g->strt.size > MINSTRTABSIZE*2)
|
||
|
luaS_resize(L, g->strt.size/2); /* table is too big */
|
||
|
/* check size of buffer */
|
||
|
if (luaZ_sizebuffer(&g->buff) > LUA_MINBUFFER*2) { /* buffer too big? */
|
||
|
size_t newsize = luaZ_sizebuffer(&g->buff) / 2;
|
||
|
luaZ_resizebuffer(L, &g->buff, newsize);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
|
||
|
static void GCTM (lua_State *L) {
|
||
|
global_State *g = G(L);
|
||
|
GCObject *o = g->tmudata->gch.next; /* get first element */
|
||
|
Udata *udata = rawgco2u(o);
|
||
|
const TValue *tm;
|
||
|
/* remove udata from `tmudata' */
|
||
|
if (o == g->tmudata) /* last element? */
|
||
|
g->tmudata = NULL;
|
||
|
else
|
||
|
g->tmudata->gch.next = udata->uv.next;
|
||
|
udata->uv.next = g->mainthread->next; /* return it to `root' list */
|
||
|
g->mainthread->next = o;
|
||
|
makewhite(g, o);
|
||
|
tm = fasttm(L, udata->uv.metatable, TM_GC);
|
||
|
if (tm != NULL) {
|
||
|
lu_byte oldah = L->allowhook;
|
||
|
lu_mem oldt = g->GCthreshold;
|
||
|
L->allowhook = 0; /* stop debug hooks during GC tag method */
|
||
|
g->GCthreshold = 2*g->totalbytes; /* avoid GC steps */
|
||
|
setobj2s(L, L->top, tm);
|
||
|
setuvalue(L, L->top+1, udata);
|
||
|
L->top += 2;
|
||
|
luaD_call(L, L->top - 2, 0);
|
||
|
L->allowhook = oldah; /* restore hooks */
|
||
|
g->GCthreshold = oldt; /* restore threshold */
|
||
|
}
|
||
|
}
|
||
|
|
||
|
|
||
|
/*
|
||
|
** Call all GC tag methods
|
||
|
*/
|
||
|
void luaC_callGCTM (lua_State *L) {
|
||
|
while (G(L)->tmudata)
|
||
|
GCTM(L);
|
||
|
}
|
||
|
|
||
|
|
||
|
void luaC_freeall (lua_State *L) {
|
||
|
global_State *g = G(L);
|
||
|
int i;
|
||
|
g->currentwhite = WHITEBITS | bitmask(SFIXEDBIT); /* mask to collect all elements */
|
||
|
sweepwholelist(L, &g->rootgc);
|
||
|
for (i = 0; i < g->strt.size; i++) /* free all string lists */
|
||
|
sweepwholelist(L, &g->strt.hash[i]);
|
||
|
}
|
||
|
|
||
|
|
||
|
static void markmt (global_State *g) {
|
||
|
int i;
|
||
|
for (i=0; i<NUM_TAGS; i++)
|
||
|
if (g->mt[i]) markobject(g, g->mt[i]);
|
||
|
}
|
||
|
|
||
|
|
||
|
/* mark root set */
|
||
|
static void markroot (lua_State *L) {
|
||
|
global_State *g = G(L);
|
||
|
g->gray = NULL;
|
||
|
g->grayagain = NULL;
|
||
|
g->weak = NULL;
|
||
|
markobject(g, g->mainthread);
|
||
|
/* make global table be traversed before main stack */
|
||
|
markvalue(g, gt(g->mainthread));
|
||
|
markvalue(g, registry(L));
|
||
|
markmt(g);
|
||
|
g->gcstate = GCSpropagate;
|
||
|
}
|
||
|
|
||
|
|
||
|
static void remarkupvals (global_State *g) {
|
||
|
UpVal *uv;
|
||
|
for (uv = g->uvhead.u.l.next; uv != &g->uvhead; uv = uv->u.l.next) {
|
||
|
lua_assert(uv->u.l.next->u.l.prev == uv && uv->u.l.prev->u.l.next == uv);
|
||
|
if (isgray(obj2gco(uv)))
|
||
|
markvalue(g, uv->v);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
|
||
|
static void atomic (lua_State *L) {
|
||
|
global_State *g = G(L);
|
||
|
size_t udsize; /* total size of userdata to be finalized */
|
||
|
/* remark occasional upvalues of (maybe) dead threads */
|
||
|
remarkupvals(g);
|
||
|
/* traverse objects cautch by write barrier and by 'remarkupvals' */
|
||
|
propagateall(g);
|
||
|
/* remark weak tables */
|
||
|
g->gray = g->weak;
|
||
|
g->weak = NULL;
|
||
|
lua_assert(!iswhite(obj2gco(g->mainthread)));
|
||
|
markobject(g, L); /* mark running thread */
|
||
|
markmt(g); /* mark basic metatables (again) */
|
||
|
propagateall(g);
|
||
|
/* remark gray again */
|
||
|
g->gray = g->grayagain;
|
||
|
g->grayagain = NULL;
|
||
|
propagateall(g);
|
||
|
udsize = luaC_separateudata(L, 0); /* separate userdata to be finalized */
|
||
|
marktmu(g); /* mark `preserved' userdata */
|
||
|
udsize += propagateall(g); /* remark, to propagate `preserveness' */
|
||
|
cleartable(g->weak); /* remove collected objects from weak tables */
|
||
|
/* flip current white */
|
||
|
g->currentwhite = cast_byte(otherwhite(g));
|
||
|
g->sweepstrgc = 0;
|
||
|
g->sweepgc = &g->rootgc;
|
||
|
g->gcstate = GCSsweepstring;
|
||
|
g->estimate = g->totalbytes - udsize; /* first estimate */
|
||
|
}
|
||
|
|
||
|
|
||
|
static l_mem singlestep (lua_State *L) {
|
||
|
global_State *g = G(L);
|
||
|
/*lua_checkmemory(L);*/
|
||
|
switch (g->gcstate) {
|
||
|
case GCSpause: {
|
||
|
markroot(L); /* start a new collection */
|
||
|
return 0;
|
||
|
}
|
||
|
case GCSpropagate: {
|
||
|
if (g->gray)
|
||
|
return propagatemark(g);
|
||
|
else { /* no more `gray' objects */
|
||
|
atomic(L); /* finish mark phase */
|
||
|
return 0;
|
||
|
}
|
||
|
}
|
||
|
case GCSsweepstring: {
|
||
|
lu_mem old = g->totalbytes;
|
||
|
sweepwholelist(L, &g->strt.hash[g->sweepstrgc++]);
|
||
|
if (g->sweepstrgc >= g->strt.size) /* nothing more to sweep? */
|
||
|
g->gcstate = GCSsweep; /* end sweep-string phase */
|
||
|
lua_assert(old >= g->totalbytes);
|
||
|
g->estimate -= old - g->totalbytes;
|
||
|
return GCSWEEPCOST;
|
||
|
}
|
||
|
case GCSsweep: {
|
||
|
lu_mem old = g->totalbytes;
|
||
|
g->sweepgc = sweeplist(L, g->sweepgc, GCSWEEPMAX);
|
||
|
if (*g->sweepgc == NULL) { /* nothing more to sweep? */
|
||
|
checkSizes(L);
|
||
|
g->gcstate = GCSfinalize; /* end sweep phase */
|
||
|
}
|
||
|
lua_assert(old >= g->totalbytes);
|
||
|
g->estimate -= old - g->totalbytes;
|
||
|
return GCSWEEPMAX*GCSWEEPCOST;
|
||
|
}
|
||
|
case GCSfinalize: {
|
||
|
if (g->tmudata) {
|
||
|
GCTM(L);
|
||
|
if (g->estimate > GCFINALIZECOST)
|
||
|
g->estimate -= GCFINALIZECOST;
|
||
|
return GCFINALIZECOST;
|
||
|
}
|
||
|
else {
|
||
|
g->gcstate = GCSpause; /* end collection */
|
||
|
g->gcdept = 0;
|
||
|
return 0;
|
||
|
}
|
||
|
}
|
||
|
default: lua_assert(0); return 0;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
|
||
|
void luaC_step (lua_State *L) {
|
||
|
global_State *g = G(L);
|
||
|
l_mem lim = (GCSTEPSIZE/100) * g->gcstepmul;
|
||
|
if (lim == 0)
|
||
|
lim = (MAX_LUMEM-1)/2; /* no limit */
|
||
|
g->gcdept += g->totalbytes - g->GCthreshold;
|
||
|
do {
|
||
|
lim -= singlestep(L);
|
||
|
if (g->gcstate == GCSpause)
|
||
|
break;
|
||
|
} while (lim > 0);
|
||
|
if (g->gcstate != GCSpause) {
|
||
|
if (g->gcdept < GCSTEPSIZE)
|
||
|
g->GCthreshold = g->totalbytes + GCSTEPSIZE; /* - lim/g->gcstepmul;*/
|
||
|
else {
|
||
|
g->gcdept -= GCSTEPSIZE;
|
||
|
g->GCthreshold = g->totalbytes;
|
||
|
}
|
||
|
}
|
||
|
else {
|
||
|
lua_assert(g->totalbytes >= g->estimate);
|
||
|
setthreshold(g);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
|
||
|
void luaC_fullgc (lua_State *L) {
|
||
|
global_State *g = G(L);
|
||
|
if (g->gcstate <= GCSpropagate) {
|
||
|
/* reset sweep marks to sweep all elements (returning them to white) */
|
||
|
g->sweepstrgc = 0;
|
||
|
g->sweepgc = &g->rootgc;
|
||
|
/* reset other collector lists */
|
||
|
g->gray = NULL;
|
||
|
g->grayagain = NULL;
|
||
|
g->weak = NULL;
|
||
|
g->gcstate = GCSsweepstring;
|
||
|
}
|
||
|
lua_assert(g->gcstate != GCSpause && g->gcstate != GCSpropagate);
|
||
|
/* finish any pending sweep phase */
|
||
|
while (g->gcstate != GCSfinalize) {
|
||
|
lua_assert(g->gcstate == GCSsweepstring || g->gcstate == GCSsweep);
|
||
|
singlestep(L);
|
||
|
}
|
||
|
markroot(L);
|
||
|
while (g->gcstate != GCSpause) {
|
||
|
singlestep(L);
|
||
|
}
|
||
|
setthreshold(g);
|
||
|
}
|
||
|
|
||
|
|
||
|
void luaC_barrierf (lua_State *L, GCObject *o, GCObject *v) {
|
||
|
global_State *g = G(L);
|
||
|
lua_assert(isblack(o) && iswhite(v) && !isdead(g, v) && !isdead(g, o));
|
||
|
lua_assert(g->gcstate != GCSfinalize && g->gcstate != GCSpause);
|
||
|
lua_assert(ttype(&o->gch) != LUA_TTABLE);
|
||
|
/* must keep invariant? */
|
||
|
if (g->gcstate == GCSpropagate)
|
||
|
reallymarkobject(g, v); /* restore invariant */
|
||
|
else /* don't mind */
|
||
|
makewhite(g, o); /* mark as white just to avoid other barriers */
|
||
|
}
|
||
|
|
||
|
|
||
|
void luaC_barrierback (lua_State *L, Table *t) {
|
||
|
global_State *g = G(L);
|
||
|
GCObject *o = obj2gco(t);
|
||
|
lua_assert(isblack(o) && !isdead(g, o));
|
||
|
lua_assert(g->gcstate != GCSfinalize && g->gcstate != GCSpause);
|
||
|
black2gray(o); /* make table gray (again) */
|
||
|
t->gclist = g->grayagain;
|
||
|
g->grayagain = o;
|
||
|
}
|
||
|
|
||
|
|
||
|
void luaC_link (lua_State *L, GCObject *o, lu_byte tt) {
|
||
|
global_State *g = G(L);
|
||
|
o->gch.next = g->rootgc;
|
||
|
g->rootgc = o;
|
||
|
o->gch.marked = luaC_white(g);
|
||
|
o->gch.tt = tt;
|
||
|
}
|
||
|
|
||
|
|
||
|
void luaC_linkupval (lua_State *L, UpVal *uv) {
|
||
|
global_State *g = G(L);
|
||
|
GCObject *o = obj2gco(uv);
|
||
|
o->gch.next = g->rootgc; /* link upvalue into `rootgc' list */
|
||
|
g->rootgc = o;
|
||
|
if (isgray(o)) {
|
||
|
if (g->gcstate == GCSpropagate) {
|
||
|
gray2black(o); /* closed upvalues need barrier */
|
||
|
luaC_barrier(L, uv, uv->v);
|
||
|
}
|
||
|
else { /* sweep phase: sweep it (turning it into white) */
|
||
|
makewhite(g, o);
|
||
|
lua_assert(g->gcstate != GCSfinalize && g->gcstate != GCSpause);
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|