From e4f609d0ee1cbbd357bec00c43effc659971bc7a Mon Sep 17 00:00:00 2001
From: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Wed, 4 Jul 2012 12:52:38 -0300
Subject: collector in generational mode must be in 'propagate' state when not
running a collection
---
lgc.c | 30 +++++++++++++-----------------
lgc.h | 7 ++++---
ltests.c | 12 +++++++-----
3 files changed, 24 insertions(+), 25 deletions(-)
diff --git a/lgc.c b/lgc.c
index 7874f205..8b559cb6 100644
--- a/lgc.c
+++ b/lgc.c
@@ -1,5 +1,5 @@
/*
-** $Id: lgc.c,v 2.133 2012/05/31 21:28:59 roberto Exp roberto $
+** $Id: lgc.c,v 2.134 2012/07/02 13:40:05 roberto Exp roberto $
** Garbage Collector
** See Copyright Notice in lua.h
*/
@@ -144,7 +144,7 @@ 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? */
reallymarkobject(g, v); /* restore invariant */
@@ -343,7 +343,7 @@ static void remarkupvals (global_State *g) {
** mark root set and reset all gray lists, to start a new
** incremental (or full) collection
*/
-static void startcollection (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);
@@ -855,7 +855,7 @@ 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 */
@@ -1029,11 +1029,8 @@ static lu_mem singlestep (lua_State *L) {
switch (g->gcstate) {
case GCSpause: {
g->GCmemtrav = 0; /* start to count memory traversed */
- if (!isgenerational(g))
- startcollection(g);
- /* in any case, root must be marked at this point */
- lua_assert(!iswhite(obj2gco(g->mainthread))
- && !iswhite(gcvalue(&g->l_registry)));
+ lua_assert(!isgenerational(g));
+ restartcollection(g);
g->gcstate = GCSpropagate;
return g->GCmemtrav;
}
@@ -1105,14 +1102,15 @@ 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
@@ -1175,7 +1173,6 @@ 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;
@@ -1183,18 +1180,17 @@ 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;
diff --git a/lgc.h b/lgc.h
index 282336c7..569aefae 100644
--- a/lgc.h
+++ b/lgc.h
@@ -1,5 +1,5 @@
/*
-** $Id: lgc.h,v 2.55 2012/05/21 13:18:10 roberto Exp roberto $
+** $Id: lgc.h,v 2.56 2012/05/23 15:43:14 roberto Exp roberto $
** Garbage Collector
** See Copyright Notice in lua.h
*/
@@ -55,9 +55,10 @@
** phase may break the invariant, as objects turned white may point to
** still-black objects. The invariant is restored when sweep ends and
** all objects are white again. During a generational collection, the
-** invariant must be kept all times.
+** invariant must be kept all times. (The state in generational mode
+** is kept in 'propagate', so 'keepinvariant' is always true.)
*/
-#define keepinvariant(g) (isgenerational(g) || g->gcstate <= GCSatomic)
+#define keepinvariant(g) (g->gcstate <= GCSatomic)
/*
diff --git a/ltests.c b/ltests.c
index 0a8b526a..610af463 100644
--- a/ltests.c
+++ b/ltests.c
@@ -1,5 +1,5 @@
/*
-** $Id: ltests.c,v 2.130 2012/06/07 18:52:47 roberto Exp roberto $
+** $Id: ltests.c,v 2.131 2012/07/02 15:38:36 roberto Exp roberto $
** Internal Module for Debugging of the Lua Implementation
** See Copyright Notice in lua.h
*/
@@ -182,8 +182,8 @@ void *debug_realloc (void *ud, void *b, size_t oldsize, size_t size) {
static int testobjref1 (global_State *g, GCObject *f, GCObject *t) {
if (isdead(g,t)) return 0;
- if (isgenerational(g) || !issweepphase(g))
- return !isblack(f) || !iswhite(t);
+ if (!issweepphase(g))
+ return !(isblack(f) && iswhite(t));
else return 1;
}
@@ -329,7 +329,7 @@ static void checkobject (global_State *g, GCObject *o, int maybedead) {
if (isdead(g, o))
lua_assert(maybedead);
else {
- if (g->gcstate == GCSpause && !isgenerational(g))
+ if (g->gcstate == GCSpause)
lua_assert(iswhite(o));
switch (gch(o)->tt) {
case LUA_TUPVAL: {
@@ -432,6 +432,8 @@ int lua_checkmemory (lua_State *L) {
lua_assert(!iswhite(obj2gco(g->mainthread)));
lua_assert(!iswhite(gcvalue(&g->l_registry)));
}
+ else /* generational mode keeps collector in 'propagate' state */
+ lua_assert(!isgenerational(g));
lua_assert(!isdead(g, gcvalue(&g->l_registry)));
checkstack(g, g->mainthread);
resetbit(g->mainthread->marked, TESTGRAYBIT);
@@ -457,7 +459,7 @@ int lua_checkmemory (lua_State *L) {
/* check 'tobefnz' list */
checkold(g, g->tobefnz);
for (o = g->tobefnz; o != NULL; o = gch(o)->next) {
- lua_assert(!iswhite(o));
+ lua_assert(!iswhite(o) || g->gcstate == GCSpause);
lua_assert(!isdead(g, o) && testbit(o->gch.marked, SEPARATED));
lua_assert(gch(o)->tt == LUA_TUSERDATA ||
gch(o)->tt == LUA_TTABLE);
--
cgit v1.2.3-55-g6feb