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 */
}
}
void GCTM (lua_State *L) {
#else
static void GCTM (lua_State *L) {
#endif /* LUA_REFCOUNT */
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;
#if LUA_REFCOUNT
udata->uv.prev = (GCObject*)&G(L)->mainthread->next;
#endif /* LUA_REFCOUNT */
udata->uv.next = g->mainthread->next; /* return it to `root' list */
#if LUA_REFCOUNT
if (udata->uv.next)
udata->uv.next->uv.prev = obj2gco(udata);
#endif /* LUA_REFCOUNT */
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 */
#if LUA_REFCOUNT
/* We could be in the middle of a stack set, so call the __gc metamethod on
one stack level past the current one. */
L->top++;
/* we're freeing this object, but fake ref count it, because GCTM actually uses it */
udata->uv.ref++;
L->top += 2;
setobj2s(L, L->top - 2, tm);
setuvalue(L, L->top - 1, udata);
luaD_call(L, L->top - 2, 0);
udata->uv.ref--;
L->top--;
setnilvalue2n(L, L->top - 1);
#else
setobj2s(L, L->top, tm);
setuvalue(L, L->top+1, udata);
L->top += 2;
luaD_call(L, L->top - 2, 0);
#endif /* LUA_REFCOUNT */
L->allowhook = oldah; /* restore hooks */
g->GCthreshold = oldt; /* restore threshold */
}
}
/*
** mark an object. Userdata, strings, and closed upvalues are visited
** and turned black here. Other objects are marked gray and added
** to appropriate list to be visited (and turned black) later. (Open
** upvalues are already linked in 'headuv' list.)
*/
static void reallymarkobject (global_State *g, GCObject *o) {
reentry:
white2gray(o);
switch (gch(o)->tt) {
case LUA_TSHRSTR:
case LUA_TLNGSTR: {
gray2black(o);
g->GCmemtrav += sizestring(gco2ts(o));
break;
}
case LUA_TUSERDATA: {
TValue uvalue;
markobject(g, gco2u(o)->metatable); /* mark its metatable */
gray2black(o);
g->GCmemtrav += sizeudata(gco2u(o));
getuservalue(g->mainthread, rawgco2u(o), &uvalue);
if (valiswhite(&uvalue)) { /* markvalue(g, &uvalue); */
o = gcvalue(&uvalue);
goto reentry;
}
break;
}
case LUA_TLCL: {
gco2lcl(o)->gclist = g->gray;
g->gray = o;
break;
}
case LUA_TCCL: {
gco2ccl(o)->gclist = g->gray;
g->gray = o;
break;
}
case LUA_TTABLE: {
linktable(gco2t(o), &g->gray);
break;
}
case LUA_TTHREAD: {
gco2th(o)->gclist = g->gray;
g->gray = o;
break;
}
case LUA_TPROTO: {
gco2p(o)->gclist = g->gray;
g->gray = o;
break;
}
default: lua_assert(0); break;
}
}
static void freeobj (lua_State *L, GCObject *o) {
global_State *g = G(L);
lua_assert(is_robj(o));
switch (o->gch.tt) {
case LUA_TPROTO:
luaF_freeproto(L, gco2p(o));
break;
case LUA_TFUNCTION:
luaF_freeclosure(L, gco2cl(o));
break;
case LUA_TUPVAL:
luaF_freeupval(L, gco2uv(o));
break;
case LUA_TTABLE:
luaH_free(L, gco2h(o));
break;
case LUA_TTHREAD: {
lua_assert(gco2th(o) != L && gco2th(o) != G(L)->mainthread);
luaE_freethread(L, gco2th(o));
break;
}
case LUA_TSTRING: {
G(L)->strt.nuse--;
luaM_freemem(L, o, sizestring(gco2ts(o)));
break;
}
case LUA_TUSERDATA: {
const Udata *udata = rawgco2u(o);
const TValue *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 */
}
luaM_freemem(L, o, sizeudata(gco2u(o)));
break;
}
default:
lua_assert(0);
}
}
void rstack_reject (lua_State *L, GCObject *src) {
RStack *rs = rstack(L);
RObject *robj = rstack_getrobj(rs, src);
lua_assert(robj && src == robj->body);
luaC_link(L, src, src->gch.tt);
switch(src->gch.tt) {
case LUA_TTABLE:
luaH_reject(L, gco2h(src));
break;
case LUA_TUSERDATA:
luaS_rejectu(L, rawgco2u(src));
break;
// TODO: implement
default:
lua_assert(0);
}
robj->body = NULL;
}
