/*
** traverse one gray object, turning it to black (except for threads,
** which are always gray).
*/
static void propagatemark (global_State *g) {
lu_mem size;
GCObject *o = g->gray;
lua_assert(isgray(o));
gray2black(o);
switch (gch(o)->tt) {
case LUA_TTABLE: {
Table *h = gco2t(o);
g->gray = h->gclist; /* remove from 'gray' list */
size = traversetable(g, h);
break;
}
case LUA_TLCL: {
LClosure *cl = gco2lcl(o);
g->gray = cl->gclist; /* remove from 'gray' list */
size = traverseLclosure(g, cl);
break;
}
case LUA_TCCL: {
CClosure *cl = gco2ccl(o);
g->gray = cl->gclist; /* remove from 'gray' list */
size = traverseCclosure(g, cl);
break;
}
case LUA_TTHREAD: {
lua_State *th = gco2th(o);
g->gray = th->gclist; /* remove from 'gray' list */
th->gclist = g->grayagain;
g->grayagain = o; /* insert into 'grayagain' list */
black2gray(o);
size = traversestack(g, th);
break;
}
case LUA_TPROTO: {
Proto *p = gco2p(o);
g->gray = p->gclist; /* remove from 'gray' list */
size = traverseproto(g, p);
break;
}
default: lua_assert(0); return;
}
g->GCmemtrav += size;
}
void luaC_callGCTM (lua_State *L) {
lu_byte oldah = L->allowhook;
L->allowhook = 0; /* stop debug hooks during GC tag methods */
L->top++; /* reserve space to keep udata while runs its gc method */
#if LUA_REFCOUNT
while (G(L)->tmudata_head.next != (GCObject*)&G(L)->tmudata_tail) {
GCObject *o = G(L)->tmudata_head.next;
Udata *udata = gcotou(o);
G(L)->tmudata_head.next = udata->uv.next; /* remove udata from `tmudata' */
udata->uv.prev = (GCObject*)&G(L)->rootudata_head;
udata->uv.next = G(L)->rootudata_head.next;
if (udata->uv.next)
udata->uv.next->uv.prev = o;
G(L)->rootudata_head.next = o;
#else !LUA_REFCOUNT
while (G(L)->tmudata != NULL) {
GCObject *o = G(L)->tmudata;
Udata *udata = gcotou(o);
G(L)->tmudata = udata->uv.next; /* remove udata from `tmudata' */
udata->uv.next = G(L)->rootudata; /* return it to `root' list */
G(L)->rootudata = o;
#endif LUA_REFCOUNT
setuvalue(L->top - 1, udata); /* keep a reference to it */
unmark(o);
markfinalized(udata);
do1gcTM(L, udata);
}
L->top--;
L->allowhook = oldah; /* restore hooks */
}
void luaC_sweep (lua_State *L, int all) {
if (all) all = 256; /* larger than any mark */
#if LUA_REFCOUNT
sweeplist(L, &G(L)->rootudata_head.next, (GCObject*)&G(L)->rootudata_tail, all);
#else !LUA_REFCOUNT
sweeplist(L, &G(L)->rootudata, NULL, all);
#endif LUA_REFCOUNT
sweepstrings(L, all);
#if LUA_REFCOUNT
sweeplist(L, &G(L)->rootgc_head.next, (GCObject*)&G(L)->rootgc_tail, all);
#else !LUA_REFCOUNT
sweeplist(L, &G(L)->rootgc, NULL, all);
#endif LUA_REFCOUNT
}
/* mark root set */
static void markroot (GCState *st, lua_State *L) {
int i;
global_State *g = st->g;
markobject(st, defaultmeta(L));
for (i = 0; i < LUA_NTYPES; i++)
{
markobject(st, defaultmetatypes(L, i));
}
markobject(st, registry(L));
traversestack(st, g->mainthread);
if (L != g->mainthread) /* another thread is running? */
markvalue(st, L); /* cannot collect it */
if (G(L)->userGCFunction)
{
st->L = g->mainthread;
G(L)->userGCFunction(st);
}
}