LUA_API void lua_close (lua_State *L) {
L = G(L)->mainthread; /* only the main thread can be closed */
lua_lock(L);
luaF_close(L, L->stack); /* close all upvalues for this thread */
luaC_separateudata(L, 1); /* separate udata that have GC metamethods */
L->errfunc = 0; /* no error function during GC metamethods */
do { /* repeat until no more errors */
L->ci = L->base_ci;
L->base = L->top = L->ci->base;
L->nCcalls = L->baseCcalls = 0;
} while (luaD_rawrunprotected(L, callallgcTM, NULL) != 0);
lua_assert(G(L)->tmudata == NULL);
luai_userstateclose(L);
close_state(L);
}
static void mark (lua_State *L) {
GCState st;
GCObject *wkv;
st.g = G(L);
st.tmark = NULL;
st.wkv = st.wk = st.wv = NULL;
markroot(&st, L);
propagatemarks(&st); /* mark all reachable objects */
cleartablevalues(st.wkv);
cleartablevalues(st.wv);
wkv = st.wkv; /* keys must be cleared after preserving udata */
st.wkv = NULL;
st.wv = NULL;
luaC_separateudata(L); /* separate userdata to be preserved */
marktmu(&st); /* mark `preserved' userdata */
propagatemarks(&st); /* remark, to propagate `preserveness' */
cleartablekeys(wkv);
/* `propagatemarks' may resuscitate some weak tables; clear them too */
cleartablekeys(st.wk);
cleartablevalues(st.wv);
cleartablekeys(st.wkv);
cleartablevalues(st.wkv);
}
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) */
#if LUAPLUS_EXTENSIONS
if (G(L)->userGCFunction)
G(L)->userGCFunction(L);
#endif /* LUAPLUS_EXTENSIONS */
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' */
#if LUA_REFCOUNT
cleartable(L, g->weak); /* remove collected objects from weak tables */
#else
cleartable(g->weak); /* remove collected objects from weak tables */
#endif /* LUA_REFCOUNT */
/* 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 */
}