/*
** performs a full GC cycle; if "isemergency", does not call
** finalizers (which could change stack positions)
*/
void luaC_fullgc (lua_State *L, int isemergency) {
global_State *g = G(L);
int origkind = g->gckind;
lua_assert(origkind != KGC_EMERGENCY);
if (isemergency) /* do not run finalizers during emergency GC */
g->gckind = KGC_EMERGENCY;
else {
g->gckind = KGC_NORMAL;
callallpendingfinalizers(L, 1);
}
if (keepinvariant(g)) { /* may there be some black objects? */
/* must sweep all objects to turn them back to white
(as white has not changed, nothing will be collected) */
entersweep(L);
}
/* finish any pending sweep phase to start a new cycle */
luaC_runtilstate(L, bitmask(GCSpause));
luaC_runtilstate(L, ~bitmask(GCSpause)); /* start new collection */
luaC_runtilstate(L, bitmask(GCSpause)); /* run entire collection */
if (origkind == KGC_GEN) { /* generational mode? */
/* generational mode must be kept in propagate phase */
luaC_runtilstate(L, bitmask(GCSpropagate));
}
g->gckind = origkind;
setpause(g, gettotalbytes(g));
if (!isemergency) /* do not run finalizers during emergency GC */
callallpendingfinalizers(L, 1);
}
/*
** barrier for assignments to closed upvalues. Because upvalues are
** shared among closures, it is impossible to know the color of all
** closures pointing to it. So, we assume that the object being assigned
** must be marked.
*/
void luaC_upvalbarrier_ (lua_State *L, UpVal *uv) {
global_State *g = G(L);
GCObject *o = gcvalue(uv->v);
lua_assert(!upisopen(uv)); /* ensured by macro luaC_upvalbarrier */
if (keepinvariant(g))
markobject(g, o);
}
/*
** performs a full GC cycle; if "isemergency", does not call
** finalizers (which could change stack positions)
*/
void luaC_fullgc (lua_State *L, int isemergency) {
global_State *g = G(L);
int origkind = g->gckind;
lua_assert(origkind != KGC_EMERGENCY);
if (!isemergency) /* do not run finalizers during emergency GC */
callallpendingfinalizers(L, 1);
if (keepinvariant(g)) { /* marking phase? */
/* must sweep all objects to turn them back to white
(as white has not changed, nothing will be collected) */
g->sweepstrgc = 0;
g->gcstate = GCSsweepstring;
}
g->gckind = isemergency ? KGC_EMERGENCY : KGC_NORMAL;
/* finish any pending sweep phase to start a new cycle */
luaC_runtilstate(L, bitmask(GCSpause));
/* run entire collector */
luaC_runtilstate(L, ~bitmask(GCSpause));
luaC_runtilstate(L, bitmask(GCSpause));
if (origkind == KGC_GEN) { /* generational mode? */
/* generational mode must always start in propagate phase */
luaC_runtilstate(L, bitmask(GCSpropagate));
}
g->gckind = origkind;
luaE_setdebt(g, stddebt(g));
if (!isemergency) /* do not run finalizers during emergency GC */
callallpendingfinalizers(L, 1);
}
/*
** if object 'o' has a finalizer, remove it from 'allgc' list (must
** search the list to find it) and link it in 'finobj' list.
*/
void luaC_checkfinalizer (lua_State *L, GCObject *o, Table *mt) {
global_State *g = G(L);
if (testbit(gch(o)->marked, SEPARATED) || /* obj. is already separated... */
isfinalized(o) || /* ... or is finalized... */
gfasttm(g, mt, TM_GC) == NULL) /* or has no finalizer? */
return; /* nothing to be done */
else { /* move 'o' to 'finobj' list */
GCObject **p;
GCheader *ho = gch(o);
if (g->sweepgc == &ho->next) { /* avoid removing current sweep object */
lua_assert(issweepphase(g));
g->sweepgc = sweeptolive(L, g->sweepgc, NULL);
}
/* search for pointer pointing to 'o' */
for (p = &g->allgc; *p != o; p = &gch(*p)->next) { /* empty */ }
*p = ho->next; /* remove 'o' from root list */
ho->next = g->finobj; /* link it in list 'finobj' */
g->finobj = o;
l_setbit(ho->marked, SEPARATED); /* mark it as such */
if (!keepinvariant(g)) /* not keeping invariant? */
makewhite(g, o); /* "sweep" object */
else
resetoldbit(o); /* see MOVE OLD rule */
}
}
/*
** 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 GCObject *udata2finalize (global_State *g) {
GCObject *o = g->tobefnz; /* get first element */
lua_assert(isfinalized(o));
g->tobefnz = gch(o)->next; /* remove it from 'tobefnz' list */
gch(o)->next = g->allgc; /* return it to 'allgc' list */
g->allgc = o;
resetbit(gch(o)->marked, SEPARATED); /* mark that it is not in 'tobefnz' */
lua_assert(!isold(o)); /* see MOVE OLD rule */
if (!keepinvariant(g)) /* not keeping invariant? */
makewhite(g, o); /* "sweep" object */
return o;
}
/*
** 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 */
}
}
/*
** check color (and invariants) for an upvalue that was closed,
** i.e., moved into the 'allgc' list
*/
void luaC_checkupvalcolor (global_State *g, UpVal *uv) {
GCObject *o = obj2gco(uv);
lua_assert(!isblack(o)); /* open upvalues are never black */
if (isgray(o)) {
if (keepinvariant(g)) {
resetoldbit(o); /* see MOVE OLD rule */
gray2black(o); /* it is being visited now */
markvalue(g, uv->v);
}
else {
lua_assert(issweepphase(g));
makewhite(g, o);
}
}
}
/*
** Performs a full GC cycle; if 'isemergency', set a flag to avoid
** some operations which could change the interpreter state in some
** unexpected ways (running finalizers and shrinking some structures).
** Before running the collection, check 'keepinvariant'; if it is true,
** there may be some objects marked as black, so the collector has
** to sweep all objects to turn them back to white (as white has not
** changed, nothing will be collected).
*/
void luaC_fullgc (lua_State *L, int isemergency) {
global_State *g = G(L);
lua_assert(g->gckind == KGC_NORMAL);
if (isemergency) g->gckind = KGC_EMERGENCY; /* set flag */
if (keepinvariant(g)) { /* black objects? */
entersweep(L); /* sweep everything to turn them back to white */
}
/* finish any pending sweep phase to start a new cycle */
luaC_runtilstate(L, bitmask(GCSpause));
luaC_runtilstate(L, ~bitmask(GCSpause)); /* start new collection */
luaC_runtilstate(L, bitmask(GCScallfin)); /* run up to finalizers */
/* estimate must be correct after a full GC cycle */
lua_assert(g->GCestimate == gettotalbytes(g));
luaC_runtilstate(L, bitmask(GCSpause)); /* finish collection */
g->gckind = KGC_NORMAL;
setpause(g);
}
