nasty GC bug: upvalue must be turned white when not keeping invariant,

but barrier was not being called when uv->v were already white.
This commit is contained in:
Roberto Ierusalimschy 2010-04-29 18:43:36 -03:00
parent 5d79c6684b
commit 23001d8607
3 changed files with 26 additions and 9 deletions

View File

@ -1,5 +1,5 @@
/*
** $Id: lfunc.c,v 2.21 2010/03/26 20:58:11 roberto Exp roberto $
** $Id: lfunc.c,v 2.22 2010/04/29 17:34:35 roberto Exp roberto $
** Auxiliary functions to manipulate prototypes and closures
** See Copyright Notice in lua.h
*/
@ -101,11 +101,7 @@ void luaF_close (lua_State *L, StkId level) {
uv->v = &uv->u.value; /* now current value lives here */
gch(o)->next = g->allgc; /* link upvalue into 'allgc' list */
g->allgc = o;
lua_assert(!isblack(o)); /* open upvalues are never black */
if (isgray(o)) { /* is it marked? */
gray2black(o); /* could not be black; now it can */
luaC_barrier(L, uv, uv->v);
}
luaC_checkupvalcolor(g, uv);
}
}
}

22
lgc.c
View File

@ -1,5 +1,5 @@
/*
** $Id: lgc.c,v 2.80 2010/04/26 17:58:00 roberto Exp roberto $
** $Id: lgc.c,v 2.81 2010/04/29 17:32:40 roberto Exp roberto $
** Garbage Collector
** See Copyright Notice in lua.h
*/
@ -146,6 +146,26 @@ void luaC_barrierback (lua_State *L, Table *t) {
}
/*
** check color (and invariants) for an upvalue that was closed,
** i.e., moved into the 'allgc' list
*/
void luaC_checkupvalcolor (global_State *g, UpVal *uv) {
GCObject *o = obj2gco(uv);
lua_assert(!isblack(o)); /* open upvalues are never black */
if (isgray(o)) {
if (keepinvariant(g)) {
gray2black(o); /* it is being visited now */
markvalue(g, uv->v);
}
else {
lua_assert(issweepphase(g));
makewhite(g, o);
}
}
}
/*
** create a new collectable object (with given type and size) and link
** it to '*list'. 'offset' tells how many bytes to allocate before the

5
lgc.h
View File

@ -1,5 +1,5 @@
/*
** $Id: lgc.h,v 2.30 2010/03/25 13:06:36 roberto Exp roberto $
** $Id: lgc.h,v 2.31 2010/04/29 17:32:40 roberto Exp roberto $
** Garbage Collector
** See Copyright Notice in lua.h
*/
@ -9,6 +9,7 @@
#include "lobject.h"
#include "lstate.h"
/*
@ -120,6 +121,6 @@ LUAI_FUNC GCObject *luaC_newobj (lua_State *L, int tt, size_t sz,
LUAI_FUNC void luaC_barrierf (lua_State *L, GCObject *o, GCObject *v);
LUAI_FUNC void luaC_barrierback (lua_State *L, Table *t);
LUAI_FUNC void luaC_checkfinalizer (lua_State *L, Udata *u);
LUAI_FUNC void luaC_checkupvalcolor (global_State *g, UpVal *uv);
#endif