bug: incremental sweep was not cleaning old bits (as it stopped in the

first old object) + bug: moving udata to 'udgc' list might put old object in front a new one + some new macros + generational mode may be in 'pause' state (it just skips 'markroot')
author: Roberto Ierusalimschy <roberto@inf.puc-rio.br> 2010-05-07 15:19:36 -0300
committer: Roberto Ierusalimschy <roberto@inf.puc-rio.br> 2010-05-07 15:19:36 -0300
commit: 0fac33da9eba15464c186c8645d81920c245e944 (patch)
tree: 14e15105ff33d342a22f4c3eb723a58f5461bd98 /lgc.c
parent: 8e1bdda66a7eba39a39d27dffe6412e7d37ad09c (diff)
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lua-0fac33da9eba15464c186c8645d81920c245e944.zip
1 files changed, 28 insertions, 28 deletions
diff --git a/lgc.c b/lgc.c
index 422a49d7..1721220a 100644
--- a/lgc.c
+++ b/lgc.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lgc.c,v 2.89 2010/05/05 18:58:36 roberto Exp roberto $
+** $Id: lgc.c,v 2.90 2010/05/06 18:18:07 roberto Exp roberto $
 ** Garbage Collector
 ** See Copyright Notice in lua.h
 */
@@ -130,7 +130,7 @@ static int iscleared (const TValue *o, int iskey) {
 void luaC_barrierf (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(g->gckind == KGC_GEN || g->gcstate != GCSpause);
+  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 */
@@ -149,15 +149,9 @@ void luaC_barrierback (lua_State *L, Table *t) {
  global_State *g = G(L);
  GCObject *o = obj2gco(t);
  lua_assert(isblack(o) && !isdead(g, o));
-  if (keepinvariant(g)) {
+  black2gray(o);  /* make table gray (again) */
-    black2gray(o);  /* make table gray (again) */
+  t->gclist = g->grayagain;
-    t->gclist = g->grayagain;
+  g->grayagain = o;
-    g->grayagain = o;
-  }
-  else {  /* sweep phase */
-    lua_assert(issweepphase(g));
-    makewhite(g, o);  /* mark main obj. as white to avoid other barriers */
-  }
 }
@@ -612,31 +606,31 @@ static void sweepthread (lua_State *L, lua_State *L1) {
 */
 static GCObject **sweeplist (lua_State *L, GCObject **p, lu_mem count) {
  global_State *g = G(L);
-  int deadmask = otherwhite(g);
+  int ow = otherwhite(g);
  int toclear, toset;  /* bits to clear and to set in all live objects */
-  if (g->gckind == KGC_GEN) {  /* generational mode? */
+  int tostop;  /* stop sweep when this is true */
+  if (isgenerational(g)) {  /* generational mode? */
    toclear = ~0;  /* clear nothing */
-    toset = OLDBIT;  /* set the old bit of all surviving objects */
+    toset = bitmask(OLDBIT);  /* set the old bit of all surviving objects */
+    tostop = bitmask(OLDBIT);  /* do not sweep old generation */
  }
  else {  /* normal mode */
-    toclear = maskcolors;  /* clear all color bits */
+    toclear = maskcolors;  /* clear all color bits + old bit */
    toset = luaC_white(g);  /* make object white */
+    tostop = 0;  /* do not stop */
  }
  while (*p != NULL && count-- > 0) {
    GCObject *curr = *p;
    int marked = gch(curr)->marked;
-    if (!((marked ^ WHITEBITS) & deadmask)) {  /* is 'curr' dead? */
+    if (isdeadm(ow, marked)) {  /* is 'curr' dead? */
-      lua_assert(isdead(g, curr) || deadmask == 0);
      *p = gch(curr)->next;  /* remove 'curr' from list */
      freeobj(L, curr);  /* erase 'curr' */
    }
    else {
-      lua_assert(!isdead(g, curr) || testbit(marked, FIXEDBIT));
      if (gch(curr)->tt == LUA_TTHREAD)
        sweepthread(L, gco2th(curr));  /* sweep thread's upvalues */
-      if (testbit(marked, OLDBIT)) {  /* old generation? */
+      if (testbits(marked, tostop)) {
        static GCObject *nullp = NULL;
-        lua_assert(g->gckind == KGC_GEN); /* can happen only in gen. mode */
        return &nullp;  /* stop sweeping this list */
      }
      /* update marks */
@@ -671,7 +665,7 @@ static Udata *udata2finalize (global_State *g) {
  GCObject *o = g->tobefnz;  /* get first element */
  Udata *u = rawgco2u(o);
  lua_assert(isfinalized(&u->uv));
-  lua_assert(!testbit(u->uv.marked, OLDBIT));
+  lua_assert(!isold(o));
  g->tobefnz = u->uv.next;  /* remove it from 'tobefnz' list */
  u->uv.next = g->allgc;  /* return it to 'allgc' list */
  g->allgc = o;
@@ -725,7 +719,7 @@ void luaC_separateudata (lua_State *L, int all) {
  GCObject **p = &g->udgc;
  GCObject *curr;
  GCObject **lastnext = &g->tobefnz;
-  /* find last 'next' field in 'tobefnz' list (to insert elements in its end) */
+  /* find last 'next' field in 'tobefnz' list (to add elements in its end) */
  while (*lastnext != NULL)
    lastnext = &gch(*lastnext)->next;
  while ((curr = *p) != NULL) {  /* traverse all finalizable objects */
@@ -735,6 +729,7 @@ void luaC_separateudata (lua_State *L, int all) {
      p = &gch(curr)->next;  /* don't bother with it */
    else {
      l_setbit(gch(curr)->marked, FINALIZEDBIT); /* won't be finalized again */
+      resetbit(gch(curr)->marked, OLDBIT); /* may be old when 'all' */
      *p = gch(curr)->next;  /* remove 'curr' from 'udgc' list */
      gch(curr)->next = *lastnext;  /* link at the end of 'tobefnz' list */
      *lastnext = curr;
@@ -761,6 +756,7 @@ void luaC_checkfinalizer (lua_State *L, Udata *u) {
    u->uv.next = g->udgc;  /* link it in list 'udgc' */
    g->udgc = obj2gco(u);
    l_setbit(u->uv.marked, SEPARATED);  /* mark it as such */
+    resetbit(u->uv.marked, OLDBIT);
  }
 }
@@ -814,6 +810,7 @@ void luaC_freeallobjects (lua_State *L) {
  callallpendingfinalizers(L, 0);
  /* following "white" makes all objects look dead */
  g->currentwhite = WHITEBITS;
+  g->gckind = KGC_NORMAL;
  sweepwholelist(L, &g->udgc);
  lua_assert(g->udgc == NULL);
  sweepwholelist(L, &g->allgc);
@@ -851,6 +848,7 @@ static void atomic (lua_State *L) {
  g->sweepstrgc = 0;  /* prepare to sweep strings */
  g->gcstate = GCSsweepstring;
  g->currentwhite = cast_byte(otherwhite(g));  /* flip current white */
+  /*lua_checkmemory(L);*/
 }
@@ -859,7 +857,11 @@ static l_mem singlestep (lua_State *L) {
  /*lua_checkmemory(L);*/
  switch (g->gcstate) {
    case GCSpause: {
-      markroot(L);  /* start a new collection */
+      if (!isgenerational(g))
+        markroot(L);  /* start a new collection */
+      else  /* root still marked */
+        lua_assert(!iswhite(obj2gco(g->mainthread))
+                && !iswhite(gcvalue(&g->l_registry)));
      g->gcstate = GCSpropagate;
      return GCROOTCOST;
    }
@@ -925,14 +927,12 @@ 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->lastmajormem == 0) {  /* signal for another major collection? */
    luaC_fullgc(L, 0);  /* perform a full regular collection */
    g->lastmajormem = g->totalbytes;  /* update control */
  }
  else {
-    luaC_runtilstate(L, bitmask(GCSpause));
+    luaC_runtilstate(L, bitmask(GCSpause));  /* run collection */
-    g->gcstate = GCSpropagate;  /* do not run 'markroot' */
    if (g->totalbytes > g->lastmajormem/100 * g->gcpause)
      g->lastmajormem = 0;  /* signal for a major collection */
  }
@@ -955,7 +955,7 @@ static void step (lua_State *L) {
 void luaC_step (lua_State *L) {
  int i;
-  if (G(L)->gckind == KGC_GEN) generationalcollection(L);
+  if (isgenerational(G(L))) generationalcollection(L);
  else step(L);
  for (i = 0; i < GCFINALIZENUM && G(L)->tobefnz; i++)
    GCTM(L, 1);  /* Call a few pending finalizers */
@@ -984,11 +984,11 @@ void luaC_fullgc (lua_State *L, int isemergency) {
  /* run entire collector */
  luaC_runtilstate(L, ~bitmask(GCSpause));
  luaC_runtilstate(L, bitmask(GCSpause));
-  g->gckind = origkind;
  if (origkind == KGC_GEN) {  /* generational mode? */
    /* generational mode must always start in propagate phase */
    luaC_runtilstate(L, bitmask(GCSpropagate));
  }
+  g->gckind = origkind;
  g->GCdebt = stddebt(g);
  if (!isemergency)   /* do not run finalizers during emergency GC */
    callallpendingfinalizers(L, 1);
author	Roberto Ierusalimschy <roberto@inf.puc-rio.br>	2010-05-07 15:19:36 -0300
committer	Roberto Ierusalimschy <roberto@inf.puc-rio.br>	2010-05-07 15:19:36 -0300
commit	0fac33da9eba15464c186c8645d81920c245e944 (patch)
tree	14e15105ff33d342a22f4c3eb723a58f5461bd98 /lgc.c
parent	8e1bdda66a7eba39a39d27dffe6412e7d37ad09c (diff)
download	lua-0fac33da9eba15464c186c8645d81920c245e944.tar.gz lua-0fac33da9eba15464c186c8645d81920c245e944.tar.bz2 lua-0fac33da9eba15464c186c8645d81920c245e944.zip