commit c6eac44a9420a26a2f8907dcd5266a6aecdb18ea
parent 8878554b854009066eeccfe7b17e6e019c69758a
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Wed, 3 Dec 2003 18:02:45 -0200
two different white flags (to distinguish dead elements from new ones)
Diffstat:
6 files changed, 63 insertions(+), 52 deletions(-)
diff --git a/lfunc.c b/lfunc.c
@@ -1,5 +1,5 @@
/*
-** $Id: lfunc.c,v 1.71 2003/11/19 19:41:30 roberto Exp roberto $
+** $Id: lfunc.c,v 1.72 2003/11/24 18:50:36 roberto Exp roberto $
** Auxiliary functions to manipulate prototypes and closures
** See Copyright Notice in lua.h
*/
@@ -71,7 +71,6 @@ void luaF_close (lua_State *L, StkId level) {
setobj(&uv->value, uv->v); /* save current value (write barrier) */
uv->v = &uv->value; /* now current value lives here */
L->openupval = uv->next; /* remove from `open' list */
- resetbit(uv->marked, FIXEDBIT); /* closed upvalues can be collected */
luaC_link(L, valtogco(uv), LUA_TUPVAL);
}
}
diff --git a/lgc.c b/lgc.c
@@ -1,5 +1,5 @@
/*
-** $Id: lgc.c,v 1.182 2003/12/01 18:22:56 roberto Exp roberto $
+** $Id: lgc.c,v 1.183 2003/12/03 12:30:41 roberto Exp roberto $
** Garbage Collector
** See Copyright Notice in lua.h
*/
@@ -25,26 +25,27 @@
#define GCSTEPSIZE (20*sizeof(TObject))
+#define otherwhite(g) (g->currentwhite ^ bit2mask(WHITE0BIT, WHITE1BIT))
#define isblack(x) testbit((x)->gch.marked, BLACKBIT)
-#define gray2black(x) ((x)->gch.marked++)
-#define white2black(x) setbit((x)->gch.marked, BLACKBIT)
+#define gray2black(x) setbit((x)->gch.marked, BLACKBIT)
-#define iswhite(x) (!test2bits((x)->gch.marked, GRAYBIT, BLACKBIT))
-#define makewhite(x) reset2bits((x)->gch.marked, GRAYBIT, BLACKBIT)
+#define iswhite(x) test2bits((x)->gch.marked, WHITE0BIT, WHITE1BIT)
+#define maskmarks \
+ cast(lu_byte, ~(bitmask(BLACKBIT)|bit2mask(WHITE0BIT, WHITE1BIT)))
+#define makewhite(g,x) \
+ ((x)->gch.marked = ((x)->gch.marked & maskmarks) | g->currentwhite)
-#define isgray(x) testbit((x)->gch.marked, GRAYBIT)
-#define white2gray(x) setbit((x)->gch.marked, GRAYBIT)
+#define isgray(x) (!isblack(x) && !iswhite(x))
+#define white2gray(x) reset2bits((x)->gch.marked, WHITE0BIT, WHITE1BIT)
-#define stringmark(s) setbit((s)->tsv.marked, BLACKBIT)
+#define stringmark(s) reset2bits((s)->tsv.marked, WHITE0BIT, WHITE1BIT)
#define isfinalized(u) testbit((u)->uv.marked, FINALIZEDBIT)
#define markfinalized(u) setbit((u)->uv.marked, FINALIZEDBIT)
-#define maskbf bit2mask(BLACKBIT, FIXEDBIT)
-
#define KEYWEAK bitmask(KEYWEAKBIT)
#define VALUEWEAK bitmask(VALUEWEAKBIT)
@@ -108,14 +109,14 @@ static size_t objsize (GCObject *o) {
static void reallymarkobject (global_State *g, GCObject *o) {
lua_assert(iswhite(o));
+ lua_assert(!(o->gch.marked & otherwhite(g)));
+ white2gray(o);
switch (o->gch.tt) {
case LUA_TSTRING: {
- white2black(o); /* strings do not go to gray list */
return;
}
case LUA_TUSERDATA: {
Table *mt = gcotou(o)->uv.metatable;
- white2black(o); /* userdata do not go to gray list */
if (mt) markobject(g, mt);
return;
}
@@ -142,14 +143,13 @@ static void reallymarkobject (global_State *g, GCObject *o) {
default: lua_assert(0);
}
g->gray = o; /* finish list linking */
- white2gray(o);
}
static void marktmu (global_State *g) {
GCObject *u;
for (u = g->tmudata; u; u = u->gch.next) {
- makewhite(u); /* may be marked, if left from previous GC */
+ makewhite(g, u); /* may be marked, if left from previous GC */
reallymarkobject(g, u);
}
}
@@ -164,9 +164,8 @@ size_t luaC_separateudata (lua_State *L) {
GCObject **lastcollected = &collected;
while ((curr = *p) != NULL) {
lua_assert(curr->gch.tt == LUA_TUSERDATA);
- if (isblack(curr) || isfinalized(gcotou(curr)))
+ if (!iswhite(curr) || isfinalized(gcotou(curr)))
p = &curr->gch.next; /* don't bother with them */
-
else if (fasttm(L, gcotou(curr)->uv.metatable, TM_GC) == NULL) {
markfinalized(gcotou(curr)); /* don't need finalization */
p = &curr->gch.next;
@@ -362,7 +361,7 @@ static int iscleared (const TObject *o, int iskey) {
stringmark(tsvalue(o)); /* strings are `values', so are never weak */
return 0;
}
- return !isblack(gcvalue(o)) ||
+ return iswhite(gcvalue(o)) ||
(ttisuserdata(o) && (!iskey && isfinalized(uvalue(o))));
}
@@ -426,16 +425,19 @@ static void freeobj (lua_State *L, GCObject *o) {
}
-static GCObject **sweeplist (lua_State *L, GCObject **p, int mask,
+static GCObject **sweeplist (lua_State *L, GCObject **p, int all,
l_mem *plim) {
GCObject *curr;
+ global_State *g = G(L);
l_mem lim = *plim;
+ int white = otherwhite(g);
while ((curr = *p) != NULL) {
- lua_assert(!isgray(curr));
- if (curr->gch.marked & mask) {
- lim -= objsize(curr);
- makewhite(curr);
+ int mark = curr->gch.marked;
+ lua_assert(all || !(mark & g->currentwhite));
+ if (!all && (!(mark & white) || testbit(mark, FIXEDBIT))) {
+ makewhite(g, curr);
p = &curr->gch.next;
+ lim -= objsize(curr);
}
else {
*p = curr->gch.next;
@@ -448,16 +450,18 @@ static GCObject **sweeplist (lua_State *L, GCObject **p, int mask,
}
-static void sweepstrings (lua_State *L, int mask) {
+static void sweepstrings (lua_State *L, int all) {
int i;
global_State *g = G(L);
+ int white = otherwhite(g);
for (i = 0; i < g->strt.size; i++) { /* for each list */
GCObject *curr;
GCObject **p = &G(L)->strt.hash[i];
while ((curr = *p) != NULL) {
- lua_assert(!isgray(curr) && curr->gch.tt == LUA_TSTRING);
- if (curr->gch.marked & mask) {
- makewhite(curr);
+ int mark = curr->gch.marked;
+ lua_assert(all || !(mark & g->currentwhite));
+ if (!all && (!(mark & white) || testbit(mark, FIXEDBIT))) {
+ makewhite(g, curr);
p = &curr->gch.next;
}
else {
@@ -497,7 +501,7 @@ static void GCTM (lua_State *L) {
g->tmudata = udata->uv.next; /* remove udata from `tmudata' */
udata->uv.next = g->firstudata->uv.next; /* return it to `root' list */
g->firstudata->uv.next = o;
- makewhite(o);
+ makewhite(g, o);
tm = fasttm(L, udata->uv.metatable, TM_GC);
if (tm != NULL) {
lu_byte oldah = L->allowhook;
@@ -523,8 +527,8 @@ void luaC_callGCTM (lua_State *L) {
void luaC_sweepall (lua_State *L) {
l_mem dummy = MAXLMEM;
- sweepstrings(L, 0);
- sweeplist(L, &G(L)->rootgc, 0, &dummy);
+ sweepstrings(L, 1);
+ sweeplist(L, &G(L)->rootgc, 1, &dummy);
}
@@ -533,7 +537,7 @@ static void markroot (lua_State *L) {
global_State *g = G(L);
lua_assert(g->gray == NULL);
g->weak = NULL;
- makewhite(valtogco(g->mainthread));
+ makewhite(g, valtogco(g->mainthread));
markobject(g, g->mainthread);
markvalue(g, registry(L));
markobject(g, g->firstudata);
@@ -548,11 +552,13 @@ static void atomic (lua_State *L) {
marktmu(g); /* mark `preserved' userdata */
propagatemarks(g, MAXLMEM); /* remark, to propagate `preserveness' */
cleartable(g->weak); /* remove collected objects from weak tables */
+ /* echange current white */
+ g->currentwhite = otherwhite(g);
/* first element of root list will be used as temporary head for sweep
phase, so it won't be seeped */
- makewhite(g->rootgc);
+ makewhite(g, g->rootgc);
g->sweepgc = &g->rootgc->gch.next;
- sweepstrings(L, maskbf);
+ sweepstrings(L, 0);
g->gcstate = GCSsweep;
}
@@ -560,7 +566,7 @@ static void atomic (lua_State *L) {
static void sweepstep (lua_State *L) {
global_State *g = G(L);
l_mem lim = GCSTEPSIZE;
- g->sweepgc = sweeplist(L, g->sweepgc, maskbf, &lim);
+ g->sweepgc = sweeplist(L, g->sweepgc, 0, &lim);
if (lim == GCSTEPSIZE) { /* nothing more to sweep? */
g->gcstate = GCSfinalize; /* end sweep phase */
}
@@ -587,9 +593,10 @@ void luaC_collectgarbage (lua_State *L) {
void luaC_link (lua_State *L, GCObject *o, lu_byte tt) {
- o->gch.next = G(L)->rootgc;
- G(L)->rootgc = o;
- o->gch.marked = 0;
+ global_State *g = G(L);
+ o->gch.next = g->rootgc;
+ g->rootgc = o;
+ o->gch.marked = luaC_white(g);
o->gch.tt = tt;
}
diff --git a/lgc.h b/lgc.h
@@ -1,5 +1,5 @@
/*
-** $Id: lgc.h,v 1.24 2003/11/19 19:41:57 roberto Exp roberto $
+** $Id: lgc.h,v 1.25 2003/12/01 16:33:30 roberto Exp roberto $
** Garbage Collector
** See Copyright Notice in lua.h
*/
@@ -22,8 +22,8 @@
/*
- * ** some userful bit tricks
- * */
+** some userful bit tricks
+*/
#define resetbits(x,m) ((x) &= cast(lu_byte, ~(m)))
#define setbits(x,m) ((x) |= (m))
#define testbits(x,m) ((x) & (m))
@@ -48,13 +48,16 @@
** bit 4 - object is fixed (should not be collected)
*/
-#define GRAYBIT 0
-#define BLACKBIT 1
-#define FINALIZEDBIT 2
-#define KEYWEAKBIT 2
-#define VALUEWEAKBIT 3
-#define FIXEDBIT 4
+#define WHITE0BIT 0
+#define WHITE1BIT 1
+#define BLACKBIT 2
+#define FINALIZEDBIT 3
+#define KEYWEAKBIT 3
+#define VALUEWEAKBIT 4
+#define FIXEDBIT 5
+
+#define luaC_white(g) cast(lu_byte, (g)->currentwhite)
#define luaC_checkGC(L) { if (G(L)->nblocks >= G(L)->GCthreshold) \
diff --git a/lstate.c b/lstate.c
@@ -1,5 +1,5 @@
/*
-** $Id: lstate.c,v 1.130 2003/12/01 18:22:56 roberto Exp roberto $
+** $Id: lstate.c,v 1.131 2003/12/03 12:30:41 roberto Exp roberto $
** Global State
** See Copyright Notice in lua.h
*/
@@ -167,6 +167,7 @@ LUA_API lua_State *lua_newstate (lua_Alloc f, void *ud) {
g->panic = NULL;
g->gcstate = 0;
g->rootgc = NULL;
+ g->currentwhite = bitmask(WHITE0BIT);
g->firstudata = NULL;
g->gray = NULL;
g->weak = NULL;
diff --git a/lstate.h b/lstate.h
@@ -1,5 +1,5 @@
/*
-** $Id: lstate.h,v 1.115 2003/12/01 18:22:56 roberto Exp roberto $
+** $Id: lstate.h,v 1.116 2003/12/03 12:30:41 roberto Exp roberto $
** Global State
** See Copyright Notice in lua.h
*/
@@ -97,6 +97,7 @@ typedef struct global_State {
stringtable strt; /* hash table for strings */
lua_Alloc realloc; /* function to reallocate memory */
void *ud; /* auxiliary data to `realloc' */
+ int currentwhite;
GCObject *rootgc; /* list of all collectable objects */
GCObject *firstudata; /* udata go to the end of `rootgc' */
GCObject **sweepgc; /* position of sweep in `rootgc' */
diff --git a/lstring.c b/lstring.c
@@ -1,5 +1,5 @@
/*
-** $Id: lstring.c,v 1.81 2003/12/01 18:22:56 roberto Exp roberto $
+** $Id: lstring.c,v 1.82 2003/12/03 12:30:41 roberto Exp roberto $
** String table (keeps all strings handled by Lua)
** See Copyright Notice in lua.h
*/
@@ -54,7 +54,7 @@ static TString *newlstr (lua_State *L, const char *str, size_t l,
stringtable *tb;
ts->tsv.len = l;
ts->tsv.hash = h;
- ts->tsv.marked = 0;
+ ts->tsv.marked = luaC_white(G(L));
ts->tsv.tt = LUA_TSTRING;
ts->tsv.reserved = 0;
memcpy(ts+1, str, l*sizeof(char));
@@ -91,7 +91,7 @@ TString *luaS_newlstr (lua_State *L, const char *str, size_t l) {
Udata *luaS_newudata (lua_State *L, size_t s) {
Udata *u;
u = cast(Udata *, luaM_malloc(L, sizeudata(s)));
- u->uv.marked = 0; /* is not finalized */
+ u->uv.marked = luaC_white(G(L)); /* is not finalized */
u->uv.tt = LUA_TUSERDATA;
u->uv.len = s;
u->uv.metatable = NULL;
