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-rw-r--r--lua/lgc.c101
1 files changed, 58 insertions, 43 deletions
diff --git a/lua/lgc.c b/lua/lgc.c
index 06f972a..52460dc 100644
--- a/lua/lgc.c
+++ b/lua/lgc.c
@@ -1,5 +1,5 @@
/*
-** $Id: lgc.c,v 2.133 2012/05/31 21:28:59 roberto Exp $
+** $Id: lgc.c,v 2.140.1.2 2013/04/26 18:22:05 roberto Exp $
** Garbage Collector
** See Copyright Notice in lua.h
*/
@@ -43,21 +43,12 @@
*/
#define STEPMULADJ 200
+
/*
** macro to adjust 'pause': 'pause' is actually used like
** 'pause / PAUSEADJ' (value chosen by tests)
*/
-#define PAUSEADJ 200
-
-
-
-
-/*
-** standard negative debt for GC; a reasonable "time" to wait before
-** starting a new cycle
-*/
-#define stddebtest(g,e) (-cast(l_mem, (e)/PAUSEADJ) * g->gcpause)
-#define stddebt(g) stddebtest(g, gettotalbytes(g))
+#define PAUSEADJ 100
/*
@@ -144,9 +135,9 @@ static int iscleared (global_State *g, const TValue *o) {
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(g->gcstate != GCSpause);
lua_assert(gch(o)->tt != LUA_TTABLE);
- if (keepinvariant(g)) /* must keep invariant? */
+ if (keepinvariantout(g)) /* must keep invariant? */
reallymarkobject(g, v); /* restore invariant */
else { /* sweep phase */
lua_assert(issweepphase(g));
@@ -343,7 +334,7 @@ static void remarkupvals (global_State *g) {
** mark root set and reset all gray lists, to start a new
** incremental (or full) collection
*/
-static void markroot (global_State *g) {
+static void restartcollection (global_State *g) {
g->gray = g->grayagain = NULL;
g->weak = g->allweak = g->ephemeron = NULL;
markobject(g, g->mainthread);
@@ -459,7 +450,7 @@ static lu_mem traversetable (global_State *g, Table *h) {
else /* not weak */
traversestrongtable(g, h);
return sizeof(Table) + sizeof(TValue) * h->sizearray +
- sizeof(Node) * sizenode(h);
+ sizeof(Node) * cast(size_t, sizenode(h));
}
@@ -502,17 +493,24 @@ static lu_mem traverseLclosure (global_State *g, LClosure *cl) {
static lu_mem traversestack (global_State *g, lua_State *th) {
+ int n = 0;
StkId o = th->stack;
if (o == NULL)
return 1; /* stack not completely built yet */
- for (; o < th->top; o++)
+ for (; o < th->top; o++) /* mark live elements in the stack */
markvalue(g, o);
if (g->gcstate == GCSatomic) { /* final traversal? */
StkId lim = th->stack + th->stacksize; /* real end of stack */
for (; o < lim; o++) /* clear not-marked stack slice */
setnilvalue(o);
}
- return sizeof(lua_State) + sizeof(TValue) * th->stacksize;
+ else { /* count call infos to compute size */
+ CallInfo *ci;
+ for (ci = &th->base_ci; ci != th->ci; ci = ci->next)
+ n++;
+ }
+ return sizeof(lua_State) + sizeof(TValue) * th->stacksize +
+ sizeof(CallInfo) * n;
}
@@ -796,7 +794,7 @@ static GCObject *udata2finalize (global_State *g) {
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? */
+ if (!keepinvariantout(g)) /* not keeping invariant? */
makewhite(g, o); /* "sweep" object */
return o;
}
@@ -855,7 +853,7 @@ static void separatetobefnz (lua_State *L, int all) {
while ((curr = *p) != NULL) { /* traverse all finalizable objects */
lua_assert(!isfinalized(curr));
lua_assert(testbit(gch(curr)->marked, SEPARATED));
- if (!(all || iswhite(curr))) /* not being collected? */
+ if (!(iswhite(curr) || all)) /* not being collected? */
p = &gch(curr)->next; /* don't bother with it */
else {
l_setbit(gch(curr)->marked, FINALIZEDBIT); /* won't be finalized again */
@@ -891,7 +889,7 @@ void luaC_checkfinalizer (lua_State *L, GCObject *o, Table *mt) {
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? */
+ if (!keepinvariantout(g)) /* not keeping invariant? */
makewhite(g, o); /* "sweep" object */
else
resetoldbit(o); /* see MOVE OLD rule */
@@ -908,6 +906,21 @@ void luaC_checkfinalizer (lua_State *L, GCObject *o, Table *mt) {
*/
+/*
+** set a reasonable "time" to wait before starting a new GC cycle;
+** cycle will start when memory use hits threshold
+*/
+static void setpause (global_State *g, l_mem estimate) {
+ l_mem debt, threshold;
+ estimate = estimate / PAUSEADJ; /* adjust 'estimate' */
+ threshold = (g->gcpause < MAX_LMEM / estimate) /* overflow? */
+ ? estimate * g->gcpause /* no overflow */
+ : MAX_LMEM; /* overflow; truncate to maximum */
+ debt = -cast(l_mem, threshold - gettotalbytes(g));
+ luaE_setdebt(g, debt);
+}
+
+
#define sweepphases \
(bitmask(GCSsweepstring) | bitmask(GCSsweepudata) | bitmask(GCSsweep))
@@ -918,7 +931,7 @@ void luaC_checkfinalizer (lua_State *L, GCObject *o, Table *mt) {
** object inside the list (instead of to the header), so that the real
** sweep do not need to skip objects created between "now" and the start
** of the real sweep.
-** Returns how many objects it sweeped.
+** Returns how many objects it swept.
*/
static int entersweep (lua_State *L) {
global_State *g = G(L);
@@ -985,7 +998,7 @@ void luaC_freeallobjects (lua_State *L) {
static l_mem atomic (lua_State *L) {
global_State *g = G(L);
- l_mem work = -g->GCmemtrav; /* start counting work */
+ l_mem work = -cast(l_mem, g->GCmemtrav); /* start counting work */
GCObject *origweak, *origall;
lua_assert(!iswhite(obj2gco(g->mainthread)));
markobject(g, L); /* mark running thread */
@@ -1028,12 +1041,10 @@ static lu_mem singlestep (lua_State *L) {
global_State *g = G(L);
switch (g->gcstate) {
case GCSpause: {
- g->GCmemtrav = 0; /* start to count memory traversed */
- if (!isgenerational(g))
- markroot(g); /* start a new collection */
- /* in any case, root must be marked at this point */
- lua_assert(!iswhite(obj2gco(g->mainthread))
- && !iswhite(gcvalue(&g->l_registry)));
+ /* start to count memory traversed */
+ g->GCmemtrav = g->strt.size * sizeof(GCObject*);
+ lua_assert(!isgenerational(g));
+ restartcollection(g);
g->gcstate = GCSpropagate;
return g->GCmemtrav;
}
@@ -1105,18 +1116,23 @@ void luaC_runtilstate (lua_State *L, int statesmask) {
static void generationalcollection (lua_State *L) {
global_State *g = G(L);
+ lua_assert(g->gcstate == GCSpropagate);
if (g->GCestimate == 0) { /* signal for another major collection? */
luaC_fullgc(L, 0); /* perform a full regular collection */
g->GCestimate = gettotalbytes(g); /* update control */
}
else {
lu_mem estimate = g->GCestimate;
- luaC_runtilstate(L, ~bitmask(GCSpause)); /* run complete cycle */
- luaC_runtilstate(L, bitmask(GCSpause));
+ luaC_runtilstate(L, bitmask(GCSpause)); /* run complete (minor) cycle */
+ g->gcstate = GCSpropagate; /* skip restart */
if (gettotalbytes(g) > (estimate / 100) * g->gcmajorinc)
g->GCestimate = 0; /* signal for a major collection */
+ else
+ g->GCestimate = estimate; /* keep estimate from last major coll. */
+
}
- luaE_setdebt(g, stddebt(g));
+ setpause(g, gettotalbytes(g));
+ lua_assert(g->gcstate == GCSpropagate);
}
@@ -1124,7 +1140,7 @@ static void incstep (lua_State *L) {
global_State *g = G(L);
l_mem debt = g->GCdebt;
int stepmul = g->gcstepmul;
- if (stepmul < 40) stepmul = 40; /* avoid ridiculous low values */
+ if (stepmul < 40) stepmul = 40; /* avoid ridiculous low values (and 0) */
/* convert debt from Kb to 'work units' (avoid zero debt and overflows) */
debt = (debt / STEPMULADJ) + 1;
debt = (debt < MAX_LMEM / stepmul) ? debt * stepmul : MAX_LMEM;
@@ -1133,10 +1149,11 @@ static void incstep (lua_State *L) {
debt -= work;
} while (debt > -GCSTEPSIZE && g->gcstate != GCSpause);
if (g->gcstate == GCSpause)
- debt = stddebtest(g, g->GCestimate); /* pause until next cycle */
- else
+ setpause(g, g->GCestimate); /* pause until next cycle */
+ else {
debt = (debt / stepmul) * STEPMULADJ; /* convert 'work units' to Kb */
- luaE_setdebt(g, debt);
+ luaE_setdebt(g, debt);
+ }
}
@@ -1172,7 +1189,6 @@ void luaC_step (lua_State *L) {
void luaC_fullgc (lua_State *L, int isemergency) {
global_State *g = G(L);
int origkind = g->gckind;
- int someblack = keepinvariant(g);
lua_assert(origkind != KGC_EMERGENCY);
if (isemergency) /* do not run finalizers during emergency GC */
g->gckind = KGC_EMERGENCY;
@@ -1180,22 +1196,21 @@ void luaC_fullgc (lua_State *L, int isemergency) {
g->gckind = KGC_NORMAL;
callallpendingfinalizers(L, 1);
}
- if (someblack) { /* may there be some black objects? */
+ 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));
- /* run entire collector */
- luaC_runtilstate(L, ~bitmask(GCSpause));
- 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 always start in propagate phase */
+ /* generational mode must be kept in propagate phase */
luaC_runtilstate(L, bitmask(GCSpropagate));
}
g->gckind = origkind;
- luaE_setdebt(g, stddebt(g));
+ setpause(g, gettotalbytes(g));
if (!isemergency) /* do not run finalizers during emergency GC */
callallpendingfinalizers(L, 1);
}
generated by cgit v1.2.1 (git 2.18.0) at 2024-05-13 21:15:00 +0000