commit 0e961ad47acbe2d67b72c90cc1ba0040f3907b75
parent c06cc609466d4527848bbf87268ec714942d554a
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Mon, 29 Oct 2007 14:50:57 -0200
some changes toward ephemerons
Diffstat:
| M | lgc.c | | | 135 | ++++++++++++++++++++++++++++++++++++++++++++++++++++--------------------------- |
| M | lgc.h | | | 6 | +----- |
| M | lstate.c | | | 6 | ++++-- |
| M | lstate.h | | | 6 | ++++-- |
4 files changed, 98 insertions(+), 55 deletions(-)
diff --git a/lgc.c b/lgc.c
@@ -1,5 +1,5 @@
/*
-** $Id: lgc.c,v 2.39 2006/07/11 15:53:29 roberto Exp roberto $
+** $Id: lgc.c,v 2.40 2006/09/11 14:07:24 roberto Exp roberto $
** Garbage Collector
** See Copyright Notice in lua.h
*/
@@ -44,10 +44,6 @@
#define markfinalized(u) l_setbit((u)->marked, FINALIZEDBIT)
-#define KEYWEAK bitmask(KEYWEAKBIT)
-#define VALUEWEAK bitmask(VALUEWEAKBIT)
-
-
#define markvalue(g,o) { checkconsistency(o); \
if (iscollectable(o) && iswhite(gcvalue(o))) reallymarkobject(g,gcvalue(o)); }
@@ -59,6 +55,12 @@
#define setthreshold(g) (g->GCthreshold = (g->estimate/100) * g->gcpause)
+static void linktable (Table *h, GCObject **p) {
+ h->gclist = *p;
+ *p = obj2gco(h);
+}
+
+
static void removeentry (Node *n) {
lua_assert(ttisnil(gval(n)));
if (iscollectable(gkey(n)))
@@ -93,8 +95,7 @@ static void reallymarkobject (global_State *g, GCObject *o) {
break;
}
case LUA_TTABLE: {
- gco2h(o)->gclist = g->gray;
- g->gray = o;
+ linktable(gco2h(o), &g->gray);
break;
}
case LUA_TTHREAD: {
@@ -155,30 +156,48 @@ size_t luaC_separateudata (lua_State *L, int all) {
}
-static int traversetable (global_State *g, Table *h) {
+static void traverseweakvalue (global_State *g, Table *h) {
int i;
- int weakkey = 0;
- int weakvalue = 0;
- const TValue *mode;
- markobject(g, h->metatable);
- mode = gfasttm(g, h->metatable, TM_MODE);
- if (mode && ttisstring(mode)) { /* is there a weak mode? */
- weakkey = (strchr(svalue(mode), 'k') != NULL);
- weakvalue = (strchr(svalue(mode), 'v') != NULL);
- if (weakkey || weakvalue) { /* is really weak? */
- h->marked &= ~(KEYWEAK | VALUEWEAK); /* clear bits */
- h->marked |= cast_byte((weakkey << KEYWEAKBIT) |
- (weakvalue << VALUEWEAKBIT));
- h->gclist = g->weak; /* must be cleared after GC, ... */
- g->weak = obj2gco(h); /* ... so put in the appropriate list */
+ linktable(h, &g->weakvalue);
+ i = sizenode(h);
+ while (i--) {
+ Node *n = gnode(h, i);
+ lua_assert(ttype(gkey(n)) != LUA_TDEADKEY || ttisnil(gval(n)));
+ if (ttisnil(gval(n)))
+ removeentry(n); /* remove empty entries */
+ else {
+ lua_assert(!ttisnil(gkey(n)));
+ markvalue(g, gkey(n));
}
}
- if (weakkey && weakvalue) return 1;
- if (!weakvalue) {
- i = h->sizearray;
- while (i--)
- markvalue(g, &h->array[i]);
+}
+
+
+static void traverseephemeron (global_State *g, Table *h) {
+ int i;
+ linktable(h, &g->weakkey);
+ i = h->sizearray;
+ while (i--) /* mark array part (numeric keys are 'strong') */
+ markvalue(g, &h->array[i]);
+ i = sizenode(h);
+ while (i--) {
+ Node *n = gnode(h, i);
+ lua_assert(ttype(gkey(n)) != LUA_TDEADKEY || ttisnil(gval(n)));
+ if (ttisnil(gval(n)))
+ removeentry(n); /* remove empty entries */
+ else {
+ lua_assert(!ttisnil(gkey(n)));
+ markvalue(g, gval(n));
+ }
}
+}
+
+
+static void traversestrongtable (global_State *g, Table *h) {
+ int i;
+ i = h->sizearray;
+ while (i--)
+ markvalue(g, &h->array[i]);
i = sizenode(h);
while (i--) {
Node *n = gnode(h, i);
@@ -187,11 +206,33 @@ static int traversetable (global_State *g, Table *h) {
removeentry(n); /* remove empty entries */
else {
lua_assert(!ttisnil(gkey(n)));
- if (!weakkey) markvalue(g, gkey(n));
- if (!weakvalue) markvalue(g, gval(n));
+ markvalue(g, gkey(n));
+ markvalue(g, gval(n));
}
}
- return weakkey || weakvalue;
+}
+
+
+static void traversetable (global_State *g, Table *h) {
+ const TValue *mode = gfasttm(g, h->metatable, TM_MODE);
+ markobject(g, h->metatable);
+ if (mode && ttisstring(mode)) { /* is there a weak mode? */
+ int weakkey = (strchr(svalue(mode), 'k') != NULL);
+ int weakvalue = (strchr(svalue(mode), 'v') != NULL);
+ if (weakkey || weakvalue) { /* is really weak? */
+ black2gray(obj2gco(h)); /* keep table gray */
+ if (!weakkey) /* strong keys? */
+ traverseweakvalue(g, h);
+ else if (!weakvalue) /* strong values? */
+ traverseephemeron(g, h);
+ else {
+ lua_assert(weakkey && weakvalue); /* nothing to traverse now */
+ linktable(h, &g->weakkeyvalue);
+ }
+ return;
+ } /* else go through */
+ }
+ traversestrongtable(g, h);
}
@@ -282,8 +323,7 @@ static l_mem propagatemark (global_State *g) {
case LUA_TTABLE: {
Table *h = gco2h(o);
g->gray = h->gclist;
- if (traversetable(g, h)) /* table is weak? */
- black2gray(o); /* keep it gray */
+ traversetable(g, h);
return sizeof(Table) + sizeof(TValue) * h->sizearray +
sizeof(Node) * sizenode(h);
}
@@ -352,14 +392,10 @@ static void cleartable (GCObject *l) {
while (l) {
Table *h = gco2h(l);
int i = h->sizearray;
- lua_assert(testbit(h->marked, VALUEWEAKBIT) ||
- testbit(h->marked, KEYWEAKBIT));
- if (testbit(h->marked, VALUEWEAKBIT)) {
- while (i--) {
- TValue *o = &h->array[i];
- if (iscleared(o, 0)) /* value was collected? */
- setnilvalue(o); /* remove value */
- }
+ while (i--) {
+ TValue *o = &h->array[i];
+ if (iscleared(o, 0)) /* value was collected? */
+ setnilvalue(o); /* remove value */
}
i = sizenode(h);
while (i--) {
@@ -516,7 +552,7 @@ static void markroot (lua_State *L) {
global_State *g = G(L);
g->gray = NULL;
g->grayagain = NULL;
- g->weak = NULL;
+ g->weakvalue = g->weakkey = g->weakkeyvalue = NULL;
markobject(g, g->mainthread);
/* make global table be traversed before main stack */
markvalue(g, gt(g->mainthread));
@@ -543,13 +579,17 @@ static void atomic (lua_State *L) {
remarkupvals(g);
/* traverse objects cautch by write barrier and by 'remarkupvals' */
propagateall(g);
- /* remark weak tables */
- g->gray = g->weak;
- g->weak = NULL;
+ /* remark value-weak tables */
+ g->gray = g->weakvalue;
+ g->weakvalue = NULL;
lua_assert(!iswhite(obj2gco(g->mainthread)));
markobject(g, L); /* mark running thread */
markmt(g); /* mark basic metatables (again) */
propagateall(g);
+ /* remark key-weak tables */
+ g->gray = g->weakkey;
+ g->weakkey = NULL;
+ propagateall(g);
/* remark gray again */
g->gray = g->grayagain;
g->grayagain = NULL;
@@ -557,7 +597,10 @@ static void atomic (lua_State *L) {
udsize = luaC_separateudata(L, 0); /* separate userdata to be finalized */
marktmu(g); /* mark `preserved' userdata */
udsize += propagateall(g); /* remark, to propagate `preserveness' */
- cleartable(g->weak); /* remove collected objects from weak tables */
+ /* remove collected objects from weak tables */
+ cleartable(g->weakvalue);
+ cleartable(g->weakkey);
+ cleartable(g->weakkeyvalue);
/* flip current white */
g->currentwhite = cast_byte(otherwhite(g));
g->sweepstrgc = 0;
@@ -656,7 +699,7 @@ void luaC_fullgc (lua_State *L, int isemergency) {
/* reset other collector lists */
g->gray = NULL;
g->grayagain = NULL;
- g->weak = NULL;
+ g->weakvalue = g->weakkey = g->weakkeyvalue = NULL;
g->gcstate = GCSsweepstring;
}
lua_assert(g->gcstate != GCSpause && g->gcstate != GCSpropagate);
diff --git a/lgc.h b/lgc.h
@@ -1,5 +1,5 @@
/*
-** $Id: lgc.h,v 2.15 2005/08/24 16:15:49 roberto Exp roberto $
+** $Id: lgc.h,v 2.16 2006/07/11 15:53:29 roberto Exp roberto $
** Garbage Collector
** See Copyright Notice in lua.h
*/
@@ -44,8 +44,6 @@
** bit 1 - object is white (type 1)
** bit 2 - object is black
** bit 3 - for userdata: has been finalized
-** bit 3 - for tables: has weak keys
-** bit 4 - for tables: has weak values
** bit 5 - object is fixed (should not be collected)
** bit 6 - object is "super" fixed (only the main thread)
*/
@@ -55,8 +53,6 @@
#define WHITE1BIT 1
#define BLACKBIT 2
#define FINALIZEDBIT 3
-#define KEYWEAKBIT 3
-#define VALUEWEAKBIT 4
#define FIXEDBIT 5
#define SFIXEDBIT 6
#define WHITEBITS bit2mask(WHITE0BIT, WHITE1BIT)
diff --git a/lstate.c b/lstate.c
@@ -1,5 +1,5 @@
/*
-** $Id: lstate.c,v 2.39 2006/09/11 14:07:24 roberto Exp roberto $
+** $Id: lstate.c,v 2.40 2006/10/10 17:40:17 roberto Exp roberto $
** Global State
** See Copyright Notice in lua.h
*/
@@ -182,7 +182,9 @@ LUA_API lua_State *lua_newstate (lua_Alloc f, void *ud) {
g->sweepgc = &g->rootgc;
g->gray = NULL;
g->grayagain = NULL;
- g->weak = NULL;
+ g->weakvalue = NULL;
+ g->weakkey = NULL;
+ g->weakkeyvalue = NULL;
g->tmudata = NULL;
g->totalbytes = sizeof(LG);
g->gcpause = LUAI_GCPAUSE;
diff --git a/lstate.h b/lstate.h
@@ -1,5 +1,5 @@
/*
-** $Id: lstate.h,v 2.27 2006/09/19 13:57:50 roberto Exp roberto $
+** $Id: lstate.h,v 2.28 2007/02/07 17:48:52 roberto Exp roberto $
** Global State
** See Copyright Notice in lua.h
*/
@@ -78,7 +78,9 @@ typedef struct global_State {
GCObject **sweepgc; /* position of sweep in `rootgc' */
GCObject *gray; /* list of gray objects */
GCObject *grayagain; /* list of objects to be traversed atomically */
- GCObject *weak; /* list of weak tables (to be cleared) */
+ GCObject *weakvalue; /* list of value-weak tables */
+ GCObject *weakkey; /* list of key-weak tables */
+ GCObject *weakkeyvalue; /* list of all-weak tables */
GCObject *tmudata; /* last element of list of userdata to be GC */
Mbuffer buff; /* temporary buffer for string concatentation */
lu_mem GCthreshold;
