Upvalues collected like everything else (with mark-sweep) instead

of reference count (simpler and better for generational mode)
This commit is contained in:
Roberto Ierusalimschy 2017-04-11 15:41:09 -03:00
parent 9569ad6b0d
commit a3d36fe283
9 changed files with 97 additions and 127 deletions

25
lapi.c
View File

@ -1,5 +1,5 @@
/*
** $Id: lapi.c,v 2.260 2017/02/23 21:07:34 roberto Exp roberto $
** $Id: lapi.c,v 2.261 2017/04/06 13:08:56 roberto Exp roberto $
** Lua API
** See Copyright Notice in lua.h
*/
@ -1004,7 +1004,7 @@ LUA_API int lua_load (lua_State *L, lua_Reader reader, void *data,
const TValue *gt = luaH_getint(reg, LUA_RIDX_GLOBALS);
/* set global table as 1st upvalue of 'f' (may be LUA_ENV) */
setobj(L, f->upvals[0]->v, gt);
luaC_upvalbarrier(L, f->upvals[0], gt);
luaC_barrier(L, f->upvals[0], gt);
}
}
lua_unlock(L);
@ -1202,13 +1202,13 @@ LUA_API void *lua_newuserdata (lua_State *L, size_t size) {
static const char *aux_upvalue (StkId fi, int n, TValue **val,
CClosure **owner, UpVal **uv) {
GCObject **owner) {
switch (ttype(fi)) {
case LUA_TCCL: { /* C closure */
CClosure *f = clCvalue(fi);
if (!(1 <= n && n <= f->nupvalues)) return NULL;
*val = &f->upvalue[n-1];
if (owner) *owner = f;
if (owner) *owner = obj2gco(f);
return "";
}
case LUA_TLCL: { /* Lua closure */
@ -1217,7 +1217,7 @@ static const char *aux_upvalue (StkId fi, int n, TValue **val,
Proto *p = f->p;
if (!(1 <= n && n <= p->sizeupvalues)) return NULL;
*val = f->upvals[n-1]->v;
if (uv) *uv = f->upvals[n - 1];
if (owner) *owner = obj2gco(f->upvals[n - 1]);
name = p->upvalues[n-1].name;
return (name == NULL) ? "(*no name)" : getstr(name);
}
@ -1230,7 +1230,7 @@ LUA_API const char *lua_getupvalue (lua_State *L, int funcindex, int n) {
const char *name;
TValue *val = NULL; /* to avoid warnings */
lua_lock(L);
name = aux_upvalue(index2addr(L, funcindex), n, &val, NULL, NULL);
name = aux_upvalue(index2addr(L, funcindex), n, &val, NULL);
if (name) {
setobj2s(L, L->top, val);
api_incr_top(L);
@ -1243,18 +1243,16 @@ LUA_API const char *lua_getupvalue (lua_State *L, int funcindex, int n) {
LUA_API const char *lua_setupvalue (lua_State *L, int funcindex, int n) {
const char *name;
TValue *val = NULL; /* to avoid warnings */
CClosure *owner = NULL;
UpVal *uv = NULL;
GCObject *owner = NULL; /* to avoid warnings */
StkId fi;
lua_lock(L);
fi = index2addr(L, funcindex);
api_checknelems(L, 1);
name = aux_upvalue(fi, n, &val, &owner, &uv);
name = aux_upvalue(fi, n, &val, &owner);
if (name) {
L->top--;
setobj(L, val, L->top);
if (owner) { luaC_barrier(L, owner, val); }
else if (uv) { luaC_upvalbarrier(L, uv, val); }
luaC_barrier(L, owner, val);
}
lua_unlock(L);
return name;
@ -1296,11 +1294,8 @@ LUA_API void lua_upvaluejoin (lua_State *L, int fidx1, int n1,
LClosure *f1;
UpVal **up1 = getupvalref(L, fidx1, n1, &f1);
UpVal **up2 = getupvalref(L, fidx2, n2, NULL);
luaC_upvdeccount(L, *up1);
*up1 = *up2;
(*up1)->refcount++;
if (upisopen(*up1)) (*up1)->u.open.touched = 1;
luaC_upvalbarrier(L, *up1, (*up1)->v);
luaC_objbarrier(L, f1, *up1);
}

47
lfunc.c
View File

@ -1,5 +1,5 @@
/*
** $Id: lfunc.c,v 2.45 2014/11/02 19:19:04 roberto Exp roberto $
** $Id: lfunc.c,v 2.46 2017/04/06 13:08:56 roberto Exp roberto $
** Auxiliary functions to manipulate prototypes and closures
** See Copyright Notice in lua.h
*/
@ -45,31 +45,35 @@ LClosure *luaF_newLclosure (lua_State *L, int n) {
void luaF_initupvals (lua_State *L, LClosure *cl) {
int i;
for (i = 0; i < cl->nupvalues; i++) {
UpVal *uv = luaM_new(L, UpVal);
uv->refcount = 1;
GCObject *o = luaC_newobj(L, LUA_TUPVAL, sizeof(UpVal));
UpVal *uv = gco2upv(o);
uv->v = &uv->u.value; /* make it closed */
setnilvalue(uv->v);
cl->upvals[i] = uv;
luaC_objbarrier(L, cl, o);
}
}
UpVal *luaF_findupval (lua_State *L, StkId level) {
UpVal **pp = &L->openupval;
GCObject *o;
UpVal *p;
UpVal *uv;
lua_assert(isintwups(L) || L->openupval == NULL);
while (*pp != NULL && (p = *pp)->v >= level) {
while ((p = *pp) != NULL && p->v >= level) {
lua_assert(upisopen(p));
if (p->v == level) /* found a corresponding upvalue? */
return p; /* return it */
pp = &p->u.open.next;
}
/* not found: create a new upvalue */
uv = luaM_new(L, UpVal);
uv->refcount = 0;
uv->u.open.next = *pp; /* link it to list of open upvalues */
uv->u.open.touched = 1;
/* not found: create a new upvalue between 'pp' and 'p' */
o = luaC_newobj(L, LUA_TUPVAL, sizeof(UpVal));
uv = gco2upv(o);
uv->u.open.next = p; /* link it to list of open upvalues */
uv->u.open.previous = pp;
if (p)
p->u.open.previous = &uv->u.open.next;
*pp = uv;
uv->v = level; /* current value lives in the stack */
if (!isintwups(L)) { /* thread not in list of threads with upvalues? */
@ -80,19 +84,24 @@ UpVal *luaF_findupval (lua_State *L, StkId level) {
}
void luaF_unlinkupval (UpVal *uv) {
lua_assert(upisopen(uv));
*uv->u.open.previous = uv->u.open.next;
if (uv->u.open.next)
uv->u.open.next->u.open.previous = uv->u.open.previous;
}
void luaF_close (lua_State *L, StkId level) {
UpVal *uv;
while (L->openupval != NULL && (uv = L->openupval)->v >= level) {
lua_assert(upisopen(uv));
L->openupval = uv->u.open.next; /* remove from 'open' list */
if (uv->refcount == 0) /* no references? */
luaM_free(L, uv); /* free upvalue */
else {
TValue *slot = &uv->u.value; /* new position for value */
setobj(L, slot, uv->v); /* move value to upvalue slot */
uv->v = slot; /* now current value lives here */
luaC_upvalbarrier(L, uv, slot);
}
TValue *slot = &uv->u.value; /* new position for value */
luaF_unlinkupval(uv);
setobj(L, slot, uv->v); /* move value to upvalue slot */
uv->v = slot; /* now current value lives here */
if (!iswhite(uv))
gray2black(uv); /* closed upvalues cannot be gray */
luaC_barrier(L, uv, slot);
}
}

18
lfunc.h
View File

@ -1,5 +1,5 @@
/*
** $Id: lfunc.h,v 2.14 2014/06/19 18:27:20 roberto Exp roberto $
** $Id: lfunc.h,v 2.15 2015/01/13 15:49:11 roberto Exp roberto $
** Auxiliary functions to manipulate prototypes and closures
** See Copyright Notice in lua.h
*/
@ -29,21 +29,6 @@
#define MAXUPVAL 255
/*
** Upvalues for Lua closures
*/
struct UpVal {
TValue *v; /* points to stack or to its own value */
lu_mem refcount; /* reference counter */
union {
struct { /* (when open) */
UpVal *next; /* linked list */
int touched; /* mark to avoid cycles with dead threads */
} open;
TValue value; /* the value (when closed) */
} u;
};
#define upisopen(up) ((up)->v != &(up)->u.value)
@ -53,6 +38,7 @@ LUAI_FUNC LClosure *luaF_newLclosure (lua_State *L, int nelems);
LUAI_FUNC void luaF_initupvals (lua_State *L, LClosure *cl);
LUAI_FUNC UpVal *luaF_findupval (lua_State *L, StkId level);
LUAI_FUNC void luaF_close (lua_State *L, StkId level);
LUAI_FUNC void luaF_unlinkupval (UpVal *uv);
LUAI_FUNC void luaF_freeproto (lua_State *L, Proto *f);
LUAI_FUNC const char *luaF_getlocalname (const Proto *func, int local_number,
int pc);

89
lgc.c
View File

@ -1,5 +1,5 @@
/*
** $Id: lgc.c,v 2.218 2017/04/06 13:08:56 roberto Exp roberto $
** $Id: lgc.c,v 2.219 2017/04/10 13:33:04 roberto Exp roberto $
** Garbage Collector
** See Copyright Notice in lua.h
*/
@ -179,25 +179,11 @@ void luaC_barrierback_ (lua_State *L, Table *t) {
}
/*
** barrier for assignments to closed upvalues. Because upvalues are
** shared among closures, it is impossible to know the color of all
** closures pointing to it. So, we assume that the object being assigned
** must be marked.
*/
void luaC_upvalbarrier_ (lua_State *L, GCObject *o) {
global_State *g = G(L);
if (keepinvariant(g) && !isold(o)) {
markobject(g, o);
setage(o, G_OLD0);
}
}
void luaC_fix (lua_State *L, GCObject *o) {
global_State *g = G(L);
lua_assert(g->allgc == o); /* object must be 1st in 'allgc' list! */
white2gray(o); /* they will be gray forever */
setage(o, G_OLD); /* and old forever */
g->allgc = o->next; /* remove object from 'allgc' list */
o->next = g->fixedgc; /* link it to 'fixedgc' list */
g->fixedgc = o;
@ -230,10 +216,11 @@ GCObject *luaC_newobj (lua_State *L, int tt, size_t sz) {
/*
** mark an object. Userdata, strings, and closed upvalues are visited
** Mark an object. Userdata, strings, and closed upvalues are visited
** and turned black here. Other objects are marked gray and added
** to appropriate list to be visited (and turned black) later. (Open
** upvalues are already linked in 'headuv' list.)
** upvalues are already linked in 'headuv' list. They are kept gray
** to avoid barriers, as their values will be revisited by the thread.)
*/
static void reallymarkobject (global_State *g, GCObject *o) {
reentry:
@ -261,6 +248,14 @@ static void reallymarkobject (global_State *g, GCObject *o) {
}
break;
}
case LUA_TUPVAL: {
UpVal *uv = gco2upv(o);
g->GCmemtrav += sizeof(UpVal);
if (!upisopen(uv)) /* open upvalues are kept gray */
gray2black(o);
markvalue(g, uv->v); /* mark its content */
break;
}
case LUA_TLCL: {
linkgclist(gco2lcl(o), g->gray);
break;
@ -324,10 +319,8 @@ static void remarkupvals (global_State *g) {
*p = thread->twups; /* remove thread from the list */
thread->twups = thread; /* mark that it is out of list */
for (uv = thread->openupval; uv != NULL; uv = uv->u.open.next) {
if (uv->u.open.touched) {
markvalue(g, uv->v); /* remark upvalue's value */
uv->u.open.touched = 0;
}
if (!iswhite(uv)) /* upvalue already visited? */
markvalue(g, uv->v); /* mark its value */
}
}
}
@ -516,22 +509,15 @@ static lu_mem traverseCclosure (global_State *g, CClosure *cl) {
}
/*
** open upvalues point to values in a thread, so those values should
** be marked when the thread is traversed except in the atomic phase
** (because then the value cannot be changed by the thread and the
** thread may not be traversed again)
** Traverse a Lua closure, marking its prototype and its upvalues.
** (Both can be NULL while closure is being created.)
*/
static lu_mem traverseLclosure (global_State *g, LClosure *cl) {
int i;
markobjectN(g, cl->p); /* mark its prototype */
for (i = 0; i < cl->nupvalues; i++) { /* visit its upvalues */
UpVal *uv = cl->upvals[i];
if (uv != NULL) { /* can be NULL while closure is being built */
if (upisopen(uv) && g->gcstate != GCSatomic)
uv->u.open.touched = 1; /* can be marked in 'remarkupvals' */
else
markvalue(g, uv->v);
}
markobjectN(g, uv); /* mark upvalue */
}
return sizeLclosure(cl->nupvalues);
}
@ -569,7 +555,6 @@ static lu_mem traversethread (global_State *g, lua_State *th) {
static void propagatemark (global_State *g) {
lu_mem size;
GCObject *o = g->gray;
lua_assert(ongraylist(o));
gray2black(o);
switch (o->tt) {
case LUA_TTABLE: {
@ -683,26 +668,10 @@ static void clearvalues (global_State *g, GCObject *l, GCObject *f) {
}
/*
** Decrement the reference count of an upvalue. If it goes to zero and
** upvalue is closed, delete it.
*/
void luaC_upvdeccount (lua_State *L, UpVal *uv) {
lua_assert(uv->refcount > 0);
uv->refcount--;
if (uv->refcount == 0 && !upisopen(uv))
luaM_free(L, uv);
}
static void freeLclosure (lua_State *L, LClosure *cl) {
int i;
for (i = 0; i < cl->nupvalues; i++) {
UpVal *uv = cl->upvals[i];
if (uv)
luaC_upvdeccount(L, uv);
}
luaM_freemem(L, cl, sizeLclosure(cl->nupvalues));
static void freeupval (lua_State *L, UpVal *uv) {
if (upisopen(uv))
luaF_unlinkupval(uv);
luaM_free(L, uv);
}
@ -711,8 +680,11 @@ static void freeobj (lua_State *L, GCObject *o) {
case LUA_TPROTO:
luaF_freeproto(L, gco2p(o));
break;
case LUA_TUPVAL:
freeupval(L, gco2upv(o));
break;
case LUA_TLCL:
freeLclosure(L, gco2lcl(o));
luaM_freemem(L, o, sizeLclosure(gco2lcl(o)->nupvalues));
break;
case LUA_TCCL:
luaM_freemem(L, o, sizeCclosure(gco2ccl(o)->nupvalues));
@ -1144,14 +1116,14 @@ static void correctgraylists (global_State *g) {
/*
** Mark 'old1' objects when starting a new young collection. ('old1'
** tables are always black, threads are always gray.)
** Mark 'old1' objects when starting a new young collection. (Threads
** and open upvalues are always gray, and do not need to be marked.
** All other old objects are black.)
*/
static void markold (global_State *g, GCObject *from, GCObject *to) {
GCObject *p;
for (p = from; p != to; p = p->next) {
if (getage(p) == G_OLD1) {
lua_assert((p->tt == LUA_TTHREAD) ? isgray(p) : isblack(p));
if (isblack(p)) {
black2gray(p); /* should be '2white', but gray works too */
reallymarkobject(g, p);
@ -1228,6 +1200,8 @@ static void entergen (lua_State *L, global_State *g) {
sweep2old(L, &g->tobefnz);
setage(g->mainthread, G_OLD);
finishgencycle(L, g);
g->gckind = KGC_GEN;
}
@ -1282,6 +1256,7 @@ static void genstep (lua_State *L, global_State *g) {
youngcollection(L, g);
mem = gettotalbytes(g);
luaE_setdebt(g, -((mem / 100) * 20));
lua_checkmemory(L);
}

10
lgc.h
View File

@ -1,5 +1,5 @@
/*
** $Id: lgc.h,v 2.94 2017/04/06 13:08:56 roberto Exp roberto $
** $Id: lgc.h,v 2.95 2017/04/10 13:33:04 roberto Exp roberto $
** Garbage Collector
** See Copyright Notice in lua.h
*/
@ -124,8 +124,6 @@
#define changeage(o,f,t) \
check_exp(getage(o) == (f), (o)->marked ^= ((f)^(t)))
#define ongraylist(o) (isgray(o) || getage(o) == G_TOUCHED2)
/*
** Does one step of collection when debt becomes positive. 'pre'/'pos'
@ -153,10 +151,6 @@
(isblack(p) && iswhite(o)) ? \
luaC_barrier_(L,obj2gco(p),obj2gco(o)) : cast_void(0))
#define luaC_upvalbarrier(L,uv,x) ( \
(iscollectable(x) && !upisopen(uv)) ? \
luaC_upvalbarrier_(L,gcvalue(x)) : cast_void(0))
LUAI_FUNC void luaC_fix (lua_State *L, GCObject *o);
LUAI_FUNC void luaC_freeallobjects (lua_State *L);
LUAI_FUNC void luaC_step (lua_State *L);
@ -165,9 +159,7 @@ LUAI_FUNC void luaC_fullgc (lua_State *L, int isemergency);
LUAI_FUNC GCObject *luaC_newobj (lua_State *L, int tt, size_t sz);
LUAI_FUNC void luaC_barrier_ (lua_State *L, GCObject *o, GCObject *v);
LUAI_FUNC void luaC_barrierback_ (lua_State *L, Table *o);
LUAI_FUNC void luaC_upvalbarrier_ (lua_State *L, GCObject *o);
LUAI_FUNC void luaC_checkfinalizer (lua_State *L, GCObject *o, Table *mt);
LUAI_FUNC void luaC_upvdeccount (lua_State *L, UpVal *uv);
LUAI_FUNC void luaC_changemode (lua_State *L, int newmode);

View File

@ -1,5 +1,5 @@
/*
** $Id: lobject.h,v 2.116 2015/11/03 18:33:10 roberto Exp roberto $
** $Id: lobject.h,v 2.117 2016/08/01 19:51:24 roberto Exp roberto $
** Type definitions for Lua objects
** See Copyright Notice in lua.h
*/
@ -19,8 +19,9 @@
/*
** Extra tags for non-values
*/
#define LUA_TPROTO LUA_NUMTAGS /* function prototypes */
#define LUA_TDEADKEY (LUA_NUMTAGS+1) /* removed keys in tables */
#define LUA_TUPVAL LUA_NUMTAGS /* upvalues */
#define LUA_TPROTO (LUA_NUMTAGS+1) /* function prototypes */
#define LUA_TDEADKEY (LUA_NUMTAGS+2) /* removed keys in tables */
/*
** number of all possible tags (including LUA_TNONE but excluding DEADKEY)
@ -431,9 +432,20 @@ typedef struct Proto {
/*
** Lua Upvalues
** Upvalues for Lua closures
*/
typedef struct UpVal UpVal;
typedef struct UpVal {
CommonHeader;
TValue *v; /* points to stack or to its own value */
union {
struct { /* (when open) */
struct UpVal *next; /* linked list */
struct UpVal **previous;
} open;
TValue value; /* the value (when closed) */
} u;
} UpVal;
/*

View File

@ -1,5 +1,5 @@
/*
** $Id: lstate.h,v 2.135 2017/02/23 21:07:34 roberto Exp $
** $Id: lstate.h,v 2.136 2017/04/05 16:50:51 roberto Exp roberto $
** Global State
** See Copyright Notice in lua.h
*/
@ -224,6 +224,7 @@ union GCUnion {
struct Table h;
struct Proto p;
struct lua_State th; /* thread */
struct UpVal upv;
};
@ -240,6 +241,7 @@ union GCUnion {
#define gco2t(o) check_exp((o)->tt == LUA_TTABLE, &((cast_u(o))->h))
#define gco2p(o) check_exp((o)->tt == LUA_TPROTO, &((cast_u(o))->p))
#define gco2th(o) check_exp((o)->tt == LUA_TTHREAD, &((cast_u(o))->th))
#define gco2upv(o) check_exp((o)->tt == LUA_TUPVAL, &((cast_u(o))->upv))
/* macro to convert a Lua object into a GCObject */

4
ltm.c
View File

@ -1,5 +1,5 @@
/*
** $Id: ltm.c,v 2.37 2016/02/26 19:20:15 roberto Exp roberto $
** $Id: ltm.c,v 2.38 2016/12/22 13:08:50 roberto Exp roberto $
** Tag methods
** See Copyright Notice in lua.h
*/
@ -30,7 +30,7 @@ LUAI_DDEF const char *const luaT_typenames_[LUA_TOTALTAGS] = {
"no value",
"nil", "boolean", udatatypename, "number",
"string", "table", "function", udatatypename, "thread",
"proto" /* this last case is used for tests only */
"upvalue", "proto" /* these last cases are used for tests only */
};

5
lvm.c
View File

@ -1,5 +1,5 @@
/*
** $Id: lvm.c,v 2.268 2016/02/05 19:59:14 roberto Exp roberto $
** $Id: lvm.c,v 2.269 2017/04/06 13:08:56 roberto Exp roberto $
** Lua virtual machine
** See Copyright Notice in lua.h
*/
@ -642,7 +642,6 @@ static void pushclosure (lua_State *L, Proto *p, UpVal **encup, StkId base,
ncl->upvals[i] = luaF_findupval(L, base + uv[i].idx);
else /* get upvalue from enclosing function */
ncl->upvals[i] = encup[uv[i].idx];
ncl->upvals[i]->refcount++;
/* new closure is white, so we do not need a barrier here */
}
if (!isblack(p)) /* cache will not break GC invariant? */
@ -855,7 +854,7 @@ void luaV_execute (lua_State *L) {
vmcase(OP_SETUPVAL) {
UpVal *uv = cl->upvals[GETARG_B(i)];
setobj(L, uv->v, ra);
luaC_upvalbarrier(L, uv, ra);
luaC_barrier(L, uv, ra);
vmbreak;
}
vmcase(OP_SETTABLE) {