/*
** clear entries with unmarked keys from all weaktables in list 'l' up
** to element 'f'
*/
static void clearkeys (global_State *g, GCObject *l, GCObject *f) {
for (; l != f; l = gco2t(l)->gclist) {
Table *h = gco2t(l);
Node *n, *limit = gnodelast(h);
for (n = gnode(h, 0); n < limit; n++) {
if (!ttisnil(gval(n)) && (iscleared(g, gkey(n)))) {
setnilvalue(gval(n)); /* remove value ... */
removeentry(n); /* and remove entry from table */
}
}
}
}
static void freeobj (lua_State *L, GCObject *o) {
switch (o->tt) {
case LUA_TPROTO: luaF_freeproto(L, gco2p(o)); break;
case LUA_TLCL: {
freeLclosure(L, gco2lcl(o));
break;
}
case LUA_TCCL: {
luaM_freemem(L, o, sizeCclosure(gco2ccl(o)->nupvalues));
break;
}
case LUA_TTABLE: luaH_free(L, gco2t(o)); break;
case LUA_TTHREAD: luaE_freethread(L, gco2th(o)); break;
case LUA_TUSERDATA: luaM_freemem(L, o, sizeudata(gco2u(o))); break;
case LUA_TSHRSTR:
luaS_remove(L, gco2ts(o)); /* remove it from hash table */
luaM_freemem(L, o, sizelstring(gco2ts(o)->shrlen));
break;
case LUA_TLNGSTR: {
luaM_freemem(L, o, sizelstring(gco2ts(o)->u.lnglen));
break;
}
default: lua_assert(0);
}
}
static void freeobj (lua_State *L, GCObject *o) {
switch (gch(o)->tt) {
case LUA_TPROTO: luaF_freeproto(L, gco2p(o)); break;
case LUA_TLCL: {
luaM_freemem(L, o, sizeLclosure(gco2lcl(o)->nupvalues));
break;
}
case LUA_TCCL: {
luaM_freemem(L, o, sizeCclosure(gco2ccl(o)->nupvalues));
break;
}
case LUA_TUPVAL: luaF_freeupval(L, gco2uv(o)); break;
case LUA_TTABLE: luaH_free(L, gco2t(o)); break;
case LUA_TTHREAD: luaE_freethread(L, gco2th(o)); break;
case LUA_TUSERDATA: luaM_freemem(L, o, sizeudata(gco2u(o))); break;
case LUA_TSHRSTR:
G(L)->strt.nuse--;
/* go through */
case LUA_TLNGSTR: {
luaM_freemem(L, o, sizestring(gco2ts(o)));
break;
}
default: lua_assert(0);
}
}
static void convergeephemerons (global_State *g) {
int changed;
do {
GCObject *w;
GCObject *next = g->ephemeron; /* get ephemeron list */
g->ephemeron = NULL; /* tables may return to this list when traversed */
changed = 0;
while ((w = next) != NULL) {
next = gco2t(w)->gclist;
if (traverseephemeron(g, gco2t(w))) { /* traverse marked some value? */
propagateall(g); /* propagate changes */
changed = 1; /* will have to revisit all ephemeron tables */
}
}
} while (changed);
}
/*
** barrier that moves collector backward, that is, mark the black object
** pointing to a white object as gray again. (Current implementation
** only works for tables; access to 'gclist' is not uniform across
** different types.)
*/
void luaC_barrierback_ (lua_State *L, GCObject *o) {
global_State *g = G(L);
lua_assert(isblack(o) && !isdead(g, o) && gch(o)->tt == LUA_TTABLE);
black2gray(o); /* make object gray (again) */
gco2t(o)->gclist = g->grayagain;
g->grayagain = o;
}
/*
** traverse one gray object, turning it to black (except for threads,
** which are always gray).
** Returns number of values traversed.
*/
static int propagatemark (global_State *g) {
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;
return traversetable(g, h);
}
case LUA_TFUNCTION: {
Closure *cl = gco2cl(o);
g->gray = cl->c.gclist;
return traverseclosure(g, cl);
}
case LUA_TTHREAD: {
lua_State *th = gco2th(o);
g->gray = th->gclist;
th->gclist = g->grayagain;
g->grayagain = o;
black2gray(o);
return traversestack(g, th);
}
case LUA_TPROTO: {
Proto *p = gco2p(o);
g->gray = p->gclist;
return traverseproto(g, p);
}
default: lua_assert(0); return 0;
}
}
/*
** clear entries with unmarked values from all weaktables in list 'l' up
** to element 'f'
*/
static void clearvalues (global_State *g, GCObject *l, GCObject *f) {
for (; l != f; l = gco2t(l)->gclist) {
Table *h = gco2t(l);
Node *n, *limit = gnodelast(h);
unsigned int i;
for (i = 0; i < h->sizearray; i++) {
TValue *o = &h->array[i];
if (iscleared(g, o)) /* value was collected? */
setnilvalue(o); /* remove value */
}
for (n = gnode(h, 0); n < limit; n++) {
if (!ttisnil(gval(n)) && iscleared(g, gval(n))) {
setnilvalue(gval(n)); /* remove value ... */
removeentry(n); /* and remove entry from table */
}
}
}
}
/*
** 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) {
lu_mem size;
white2gray(o);
switch (gch(o)->tt) {
case LUA_TSHRSTR:
case LUA_TLNGSTR: {
size = sizestring(gco2ts(o));
break; /* nothing else to mark; make it black */
}
case LUA_TUSERDATA: {
Table *mt = gco2u(o)->metatable;
markobject(g, mt);
markobject(g, gco2u(o)->env);
size = sizeudata(gco2u(o));
break;
}
case LUA_TUPVAL: {
UpVal *uv = gco2uv(o);
markvalue(g, uv->v);
if (uv->v != &uv->u.value) /* open? */
return; /* open upvalues remain gray */
size = sizeof(UpVal);
break;
}
case LUA_TLCL: {
gco2lcl(o)->gclist = g->gray;
g->gray = o;
return;
}
case LUA_TCCL: {
gco2ccl(o)->gclist = g->gray;
g->gray = o;
return;
}
case LUA_TTABLE: {
linktable(gco2t(o), &g->gray);
return;
}
case LUA_TTHREAD: {
gco2th(o)->gclist = g->gray;
g->gray = o;
return;
}
case LUA_TPROTO: {
gco2p(o)->gclist = g->gray;
g->gray = o;
return;
}
default: lua_assert(0); return;
}
gray2black(o);
g->GCmemtrav += size;
}
/*
** 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 (o->tt) {
case LUA_TSHRSTR: {
gray2black(o);
g->GCmemtrav += sizelstring(gco2ts(o)->shrlen);
break;
}
case LUA_TLNGSTR: {
gray2black(o);
g->GCmemtrav += sizelstring(gco2ts(o)->u.lnglen);
break;
}
case LUA_TUSERDATA: {
TValue uvalue;
markobjectN(g, gco2u(o)->metatable); /* mark its metatable */
gray2black(o);
g->GCmemtrav += sizeudata(gco2u(o));
getuservalue(g->mainthread, gco2u(o), &uvalue);
if (valiswhite(&uvalue)) { /* markvalue(g, &uvalue); */
o = gcvalue(&uvalue);
goto reentry;
}
break;
}
case LUA_TLCL: {
linkgclist(gco2lcl(o), g->gray);
break;
}
case LUA_TCCL: {
linkgclist(gco2ccl(o), g->gray);
break;
}
case LUA_TTABLE: {
linkgclist(gco2t(o), g->gray);
break;
}
case LUA_TTHREAD: {
linkgclist(gco2th(o), g->gray);
break;
}
case LUA_TPROTO: {
linkgclist(gco2p(o), g->gray);
break;
}
default:
lua_assert(0);
break;
}
}
static void freeobj (lua_State *L, GCObject *o) {
switch (gch(o)->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, gco2t(o)); break;
case LUA_TTHREAD: luaE_freethread(L, gco2th(o)); break;
case LUA_TUSERDATA: luaM_freemem(L, o, sizeudata(gco2u(o))); break;
case LUA_TSTRING: {
G(L)->strt.nuse--;
luaM_freemem(L, o, sizestring(gco2ts(o)));
break;
}
default: lua_assert(0);
}
}
/*
** 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 (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 */
linkgclist(th, g->grayagain); /* insert into 'grayagain' list */
black2gray(o);
size = traversethread(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;
}
/*
** mark an object. Userdata and closed upvalues are visited and turned
** black here. Strings remain gray (it is the same as making them
** black). 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) {
lua_assert(iswhite(o) && !isdead(g, o));
white2gray(o);
switch (gch(o)->tt) {
case LUA_TSTRING: {
return; /* for strings, gray is as good as black */
}
case LUA_TUSERDATA: {
Table *mt = gco2u(o)->metatable;
markobject(g, mt);
markobject(g, gco2u(o)->env);
gray2black(o); /* all pointers marked */
return;
}
case LUA_TUPVAL: {
UpVal *uv = gco2uv(o);
markvalue(g, uv->v);
if (uv->v == &uv->u.value) /* closed? (open upvalues remain gray) */
gray2black(o); /* make it black */
return;
}
case LUA_TFUNCTION: {
gco2cl(o)->c.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);
}
}
