static l_mem singlestep (lua_State *L) {
global_State *g = G(L);
switch (g->gcstate) {
case GCSpause: {
if (!isgenerational(g))
markroot(g); /* start a new collection */
/* in any case, root must be marked */
lua_assert(!iswhite(obj2gco(g->mainthread))
&& !iswhite(gcvalue(&g->l_registry)));
g->gcstate = GCSpropagate;
return GCROOTCOST;
}
case GCSpropagate: {
if (g->gray)
return propagatemark(g);
else { /* no more `gray' objects */
g->gcstate = GCSatomic; /* finish mark phase */
atomic(L);
return GCATOMICCOST;
}
}
case GCSsweepstring: {
if (g->sweepstrgc < g->strt.size) {
sweepwholelist(L, &g->strt.hash[g->sweepstrgc++]);
return GCSWEEPCOST;
}
else { /* no more strings to sweep */
g->sweepgc = &g->finobj; /* prepare to sweep finalizable objects */
g->gcstate = GCSsweepudata;
return 0;
}
}
case GCSsweepudata: {
if (*g->sweepgc) {
g->sweepgc = sweeplist(L, g->sweepgc, GCSWEEPMAX);
return GCSWEEPMAX*GCSWEEPCOST;
}
else {
g->sweepgc = &g->allgc; /* go to next phase */
g->gcstate = GCSsweep;
return GCSWEEPCOST;
}
}
case GCSsweep: {
if (*g->sweepgc) {
g->sweepgc = sweeplist(L, g->sweepgc, GCSWEEPMAX);
return GCSWEEPMAX*GCSWEEPCOST;
}
else {
/* sweep main thread */
GCObject *mt = obj2gco(g->mainthread);
sweeplist(L, &mt, 1);
checkSizes(L);
g->gcstate = GCSpause; /* finish collection */
return GCSWEEPCOST;
}
}
default: lua_assert(0); return 0;
}
}
/*
** performs a basic GC step even if the collector is stopped
*/
void luaC_forcestep (lua_State *L) {
global_State *g = G(L);
int i;
if (isgenerational(g)) generationalcollection(L);
else step(L);
for (i = 0; i < GCFINALIZENUM && g->tobefnz; i++)
GCTM(L, 1); /* Call a few pending finalizers */
}
/*
** performs a basic GC step
*/
void luaC_forcestep (lua_State *L) {
global_State *g = G(L);
int i;
if (isgenerational(g)) generationalcollection(L);
else incstep(L);
/* run a few finalizers (or all of them at the end of a collect cycle) */
for (i = 0; g->tobefnz && (i < GCFINALIZENUM || g->gcstate == GCSpause); i++)
GCTM(L, 1); /* call one finalizer */
}
/*
** 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 */
}
}
static lu_mem singlestep (lua_State *L) {
global_State *g = G(L);
switch (g->gcstate) {
case GCSpause: {
/* start to count memory traversed */
g->GCmemtrav = g->strt.size * sizeof(GCObject*);
lua_assert(!isgenerational(g));
restartcollection(g);
g->gcstate = GCSpropagate;
return g->GCmemtrav;
}
case GCSpropagate: {
if (g->gray) {
lu_mem oldtrav = g->GCmemtrav;
propagatemark(g);
return g->GCmemtrav - oldtrav; /* memory traversed in this step */
}
else { /* no more `gray' objects */
lu_mem work;
int sw;
g->gcstate = GCSatomic; /* finish mark phase */
g->GCestimate = g->GCmemtrav; /* save what was counted */;
work = atomic(L); /* add what was traversed by 'atomic' */
g->GCestimate += work; /* estimate of total memory traversed */
sw = entersweep(L);
return work + sw * GCSWEEPCOST;
}
}
case GCSsweepstring: {
int i;
for (i = 0; i < GCSWEEPMAX && g->sweepstrgc + i < g->strt.size; i++)
sweepwholelist(L, &g->strt.hash[g->sweepstrgc + i]);
g->sweepstrgc += i;
if (g->sweepstrgc >= g->strt.size) /* no more strings to sweep? */
g->gcstate = GCSsweepudata;
return i * GCSWEEPCOST;
}
case GCSsweepudata: {
if (g->sweepfin) {
g->sweepfin = sweeplist(L, g->sweepfin, GCSWEEPMAX);
return GCSWEEPMAX*GCSWEEPCOST;
}
else {
g->gcstate = GCSsweep;
return 0;
}
}
case GCSsweep: {
if (g->sweepgc) {
g->sweepgc = sweeplist(L, g->sweepgc, GCSWEEPMAX);
return GCSWEEPMAX*GCSWEEPCOST;
}
else {
/* sweep main thread */
GCObject *mt = obj2gco(g->mainthread);
sweeplist(L, &mt, 1);
checkSizes(L);
g->gcstate = GCSpause; /* finish collection */
return GCSWEEPCOST;
}
}
default: lua_assert(0); return 0;
}
}
