/*
** barrier that moves collector forward, that is, mark the white object
** being pointed by a black object. (If in sweep phase, clear the black
** object to white [sweep it] to avoid other barrier calls for this
** same object.)
*/
void luaC_barrier_ (lua_State *L, GCObject *o, GCObject *v) {
global_State *g = G(L);
lua_assert(isblack(o) && iswhite(v) && !isdead(g, v) && !isdead(g, o));
if (keepinvariant(g)) /* must keep invariant? */
reallymarkobject(g, v); /* restore invariant */
else { /* sweep phase */
lua_assert(issweepphase(g));
makewhite(g, o); /* mark main obj. as white to avoid other barriers */
}
}
static void marktmu (global_State *g) {
GCObject *u = g->tmudata;
if (u) {
do {
u = u->gch.next;
makewhite(g, u); /* may be marked, if left from previous GC */
reallymarkobject(g, u);
} while (u != g->tmudata);
}
}
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 */
}
/*
** barrier that moves collector forward, that is, mark the white object
** being pointed by a black object.
*/
void luaC_barrier_ (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(isgenerational(g) || g->gcstate != GCSpause);
lua_assert(gch(o)->tt != LUA_TTABLE);
if (keepinvariant(g)) /* must keep invariant? */
reallymarkobject(g, v); /* restore invariant */
else { /* sweep phase */
lua_assert(issweepphase(g));
makewhite(g, o); /* mark main obj. as white to avoid other barriers */
}
}
/*
** Traverse an ephemeron table and link it to proper list. Returns true
** iff any object was marked during this traversal (which implies that
** convergence has to continue). During propagation phase, keep table
** in 'grayagain' list, to be visited again in the atomic phase. In
** the atomic phase, if table has any white->white entry, it has to
** be revisited during ephemeron convergence (as that key may turn
** black). Otherwise, if it has any white key, table has to be cleared
** (in the atomic phase).
*/
static int traverseephemeron (global_State *g, Table *h) {
int marked = 0; /* true if an object is marked in this traversal */
int hasclears = 0; /* true if table has white keys */
int hasww = 0; /* true if table has entry "white-key -> white-value" */
Node *n, *limit = gnodelast(h);
unsigned int i;
/* traverse array part */
for (i = 0; i < h->sizearray; i++) {
if (valiswhite(&h->array[i])) {
marked = 1;
reallymarkobject(g, gcvalue(&h->array[i]));
}
}
/* traverse hash part */
for (n = gnode(h, 0); n < limit; n++) {
checkdeadkey(n);
if (ttisnil(gval(n))) /* entry is empty? */
removeentry(n); /* remove it */
else if (iscleared(g, gkey(n))) { /* key is not marked (yet)? */
hasclears = 1; /* table must be cleared */
if (valiswhite(gval(n))) /* value not marked yet? */
hasww = 1; /* white-white entry */
}
else if (valiswhite(gval(n))) { /* value not marked yet? */
marked = 1;
reallymarkobject(g, gcvalue(gval(n))); /* mark it now */
}
}
/* link table into proper list */
if (g->gcstate == GCSpropagate)
linkgclist(h, g->grayagain); /* must retraverse it in atomic phase */
else if (hasww) /* table has white->white entries? */
linkgclist(h, g->ephemeron); /* have to propagate again */
else if (hasclears) /* table has white keys? */
linkgclist(h, g->allweak); /* may have to clean white keys */
return marked;
}
static int traverseephemeron (global_State *g, Table *h) {
int marked = 0; /* true if an object is marked in this traversal */
int hasclears = 0; /* true if table has white keys */
int prop = 0; /* true if table has entry "white-key -> white-value" */
Node *n, *limit = gnodelast(h);
int i;
/* traverse array part (numeric keys are 'strong') */
for (i = 0; i < h->sizearray; i++) {
if (valiswhite(&h->array[i])) {
marked = 1;
reallymarkobject(g, gcvalue(&h->array[i]));
}
}
/* traverse hash part */
for (n = gnode(h, 0); n < limit; n++) {
checkdeadkey(n);
if (ttisnil(gval(n))) /* entry is empty? */
removeentry(n); /* remove it */
else if (iscleared(g, gkey(n))) { /* key is not marked (yet)? */
hasclears = 1; /* table must be cleared */
if (valiswhite(gval(n))) /* value not marked yet? */
prop = 1; /* must propagate again */
}
else if (valiswhite(gval(n))) { /* value not marked yet? */
marked = 1;
reallymarkobject(g, gcvalue(gval(n))); /* mark it now */
}
}
if (prop)
linktable(h, &g->ephemeron); /* have to propagate again */
else if (hasclears) /* does table have white keys? */
linktable(h, &g->allweak); /* may have to clean white keys */
else /* no white keys */
linktable(h, &g->grayagain); /* no need to clean */
return marked;
}
static void marktmu (GCState *st) {
GCObject *u;
#if LUA_REFCOUNT
for (u = st->g->tmudata_head.next; u != (GCObject*)&st->g->tmudata_tail; u = u->gch.next) {
#else !LUA_REFCOUNT
for (u = st->g->tmudata; u; u = u->gch.next) {
#endif LUA_REFCOUNT
unmark(u); /* may be marked, if left from previous GC */
reallymarkobject(st, u);
}
}
/* move `dead' udata that need finalization to list `tmudata' */
size_t luaC_separateudata (lua_State *L) {
size_t deadmem = 0;
#if LUA_REFCOUNT
GCObject **p = &G(L)->rootudata_head.next;
#else !LUA_REFCOUNT
GCObject **p = &G(L)->rootudata;
#endif LUA_REFCOUNT
GCObject *curr;
GCObject *collected = NULL; /* to collect udata with gc event */
#if !LUA_REFCOUNT
GCObject **lastcollected = &collected;
while ((curr = *p) != NULL) {
lua_assert(curr->gch.tt == LUA_TUSERDATA);
#else LUA_REFCOUNT
while ((curr = *p) != (GCObject*)&G(L)->rootudata_tail) {
#endif LUA_REFCOUNT
if (ismarked(curr) || isfinalized(gcotou(curr)))
p = &curr->gch.next; /* don't bother with them */
else if (fasttm(L, gcotou(curr)->uv.metatable, TM_GC) == NULL) {
markfinalized(gcotou(curr)); /* don't need finalization */
p = &curr->gch.next;
}
else { /* must call its gc method */
deadmem += sizeudata(gcotou(curr)->uv.len);
*p = curr->gch.next;
#if LUA_REFCOUNT
Unlink(curr);
curr->gch.next = (GCObject*)&G(L)->tmudata_tail; /* link `curr' at the end of `collected' list */
curr->gch.prev = G(L)->tmudata_tail.prev;
G(L)->tmudata_tail.prev->gch.next = curr;
G(L)->tmudata_tail.prev = curr;
#else !LUA_REFCOUNT
curr->gch.next = NULL; /* link `curr' at the end of `collected' list */
*lastcollected = curr;
lastcollected = &curr->gch.next;
#endif LUA_REFCOUNT
}
}
/* insert collected udata with gc event into `tmudata' list */
#if LUA_REFCOUNT
// *lastcollected = G(L)->tmudata_head.next;
// G(L)->tmudata_head.next = collected;
#else !LUA_REFCOUNT
*lastcollected = G(L)->tmudata;
G(L)->tmudata = collected;
#endif LUA_REFCOUNT
return deadmem;
}
static void removekey (lua_State *L, Node *n) {
(void)L;
setnilvalue(gval(n)); /* remove corresponding value ... */
if (iscollectable(gkey(n)))
setttype(gkey(n), LUA_TNONE); /* dead key; remove it */
}
void luaC_marknew (lua_State *L, GCObject *o) {
global_State *g = G(L);
o->gch.marked = luaC_white(g);
if (g->gcstate == GCSpropagate)
reallymarkobject(g, o); /* mark new objects as gray during propagate state. */
}
