lgc.h File Reference

#include "lobject.h"
#include "lstate.h"

Go to the source code of this file.

Macros
#define	GCSTEPSIZE   (cast_int(100 * sizeof(TString)))
#define	GCSpropagate   0
#define	GCSatomic   1
#define	GCSswpallgc   2
#define	GCSswpfinobj   3
#define	GCSswptobefnz   4
#define	GCSswpend   5
#define	GCScallfin   6
#define	GCSpause   7
#define	issweepphase(g)    (GCSswpallgc <= (g)->gcstate && (g)->gcstate <= GCSswpend)
#define	keepinvariant(g)   ((g)->gcstate <= GCSatomic)
#define	resetbits(x, m)   ((x) &= cast(lu_byte, ~(m)))
#define	setbits(x, m)   ((x) |= (m))
#define	testbits(x, m)   ((x) & (m))
#define	bitmask(b)   (1<<(b))
#define	bit2mask(b1, b2)   (bitmask(b1) | bitmask(b2))
#define	l_setbit(x, b)   setbits(x, bitmask(b))
#define	resetbit(x, b)   resetbits(x, bitmask(b))
#define	testbit(x, b)   testbits(x, bitmask(b))
#define	WHITE0BIT   0 /* object is white (type 0) */
#define	WHITE1BIT   1 /* object is white (type 1) */
#define	BLACKBIT   2 /* object is black */
#define	FINALIZEDBIT   3 /* object has been marked for finalization */
#define	WHITEBITS   bit2mask(WHITE0BIT, WHITE1BIT)
#define	iswhite(x)   testbits((x)->marked, WHITEBITS)
#define	isblack(x)   testbit((x)->marked, BLACKBIT)
#define	isgray(x)
#define	tofinalize(x)   testbit((x)->marked, FINALIZEDBIT)
#define	otherwhite(g)   ((g)->currentwhite ^ WHITEBITS)
#define	isdeadm(ow, m)   (!(((m) ^ WHITEBITS) & (ow)))
#define	isdead(g, v)   isdeadm(otherwhite(g), (v)->marked)
#define	changewhite(x)   ((x)->marked ^= WHITEBITS)
#define	gray2black(x)   l_setbit((x)->marked, BLACKBIT)
#define	luaC_white(g)   cast(lu_byte, (g)->currentwhite & WHITEBITS)
#define	luaC_condGC(L, pre, pos)
#define	luaC_checkGC(L)   luaC_condGC(L,(void)0,(void)0)
#define	luaC_barrier(L, p, v)
#define	luaC_barrierback(L, p, v)
#define	luaC_objbarrier(L, p, o)
#define	luaC_upvalbarrier(L, uv)

Functions
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)
LUAI_FUNC void	luaC_runtilstate (lua_State *L, int statesmask)
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, UpVal *uv)
LUAI_FUNC void	luaC_checkfinalizer (lua_State *L, GCObject *o, Table *mt)
LUAI_FUNC void	luaC_upvdeccount (lua_State *L, UpVal *uv)

Macro Definition Documentation

bit2mask

#define bit2mask	(		b1,
			b2 )   (bitmask(b1) | bitmask(b2))

Definition at line 71 of file lua-5.3.6/src/lgc.h.

bitmask

#define bitmask

(

b

)

(1<<(b))

Definition at line 70 of file lua-5.3.6/src/lgc.h.

BLACKBIT

#define BLACKBIT   2 /* object is black */

Definition at line 80 of file lua-5.3.6/src/lgc.h.

changewhite

#define changewhite

(

x

)

((x)->marked ^= WHITEBITS)

Definition at line 98 of file lua-5.3.6/src/lgc.h.

FINALIZEDBIT

#define FINALIZEDBIT   3 /* object has been marked for finalization */

Definition at line 81 of file lua-5.3.6/src/lgc.h.

GCSatomic

#define GCSatomic   1

Definition at line 40 of file lua-5.3.6/src/lgc.h.

GCScallfin

#define GCScallfin   6

Definition at line 45 of file lua-5.3.6/src/lgc.h.

Referenced by fullinc(), luaC_fullgc(), singlestep(), and singlestep().

GCSpause

#define GCSpause   7

Definition at line 46 of file lua-5.3.6/src/lgc.h.

GCSpropagate

#define GCSpropagate   0

Definition at line 39 of file lua-5.3.6/src/lgc.h.

GCSswpallgc

#define GCSswpallgc   2

Definition at line 41 of file lua-5.3.6/src/lgc.h.

Referenced by atomic2gen(), entersweep(), entersweep(), singlestep(), singlestep(), and youngcollection().

GCSswpend

#define GCSswpend   5

Definition at line 44 of file lua-5.3.6/src/lgc.h.

Referenced by singlestep(), and singlestep().

GCSswpfinobj

#define GCSswpfinobj   3

Definition at line 42 of file lua-5.3.6/src/lgc.h.

Referenced by singlestep(), and singlestep().

GCSswptobefnz

#define GCSswptobefnz   4

Definition at line 43 of file lua-5.3.6/src/lgc.h.

Referenced by singlestep(), and singlestep().

GCSTEPSIZE

#define GCSTEPSIZE   (cast_int(100 * sizeof(TString)))

Definition at line 32 of file lua-5.3.6/src/lgc.h.

gray2black

#define gray2black

(

x

)

l_setbit((x)->marked, BLACKBIT)

Definition at line 99 of file lua-5.3.6/src/lgc.h.

isblack

#define isblack

(

x

)

testbit((x)->marked, BLACKBIT)

Definition at line 88 of file lua-5.3.6/src/lgc.h.

isdead

#define isdead	(		g,
			v )   isdeadm(otherwhite(g), (v)->marked)

Definition at line 96 of file lua-5.3.6/src/lgc.h.

isdeadm

#define isdeadm	(		ow,
			m )   (!(((m) ^ WHITEBITS) & (ow)))

Definition at line 95 of file lua-5.3.6/src/lgc.h.

isgray

#define isgray

(

x

)

Value:

    /* neither white nor black */  \
    (!testbits((x)->marked, WHITEBITS | bitmask(BLACKBIT)))

Definition at line 89 of file lua-5.3.6/src/lgc.h.

#define isgray(x)  /* neither white nor black */  \
    (!testbits((x)->marked, WHITEBITS | bitmask(BLACKBIT)))

issweepphase

#define issweepphase

(

g

)

(GCSswpallgc <= (g)->gcstate && (g)->gcstate <= GCSswpend)

Definition at line 49 of file lua-5.3.6/src/lgc.h.

#define issweepphase(g)  \
    (GCSswpallgc <= (g)->gcstate && (g)->gcstate <= GCSswpend)

iswhite

#define iswhite

(

x

)

testbits((x)->marked, WHITEBITS)

Definition at line 87 of file lua-5.3.6/src/lgc.h.

keepinvariant

#define keepinvariant

(

g

)

((g)->gcstate <= GCSatomic)

Definition at line 61 of file lua-5.3.6/src/lgc.h.

l_setbit

#define l_setbit	(		x,
			b )   setbits(x, bitmask(b))

Definition at line 72 of file lua-5.3.6/src/lgc.h.

luaC_barrier

#define luaC_barrier	(		L,
			p,
			v )

Value:

    (  \
    (iscollectable(v) && isblack(p) && iswhite(gcvalue(v))) ?  \
    luaC_barrier_(L,obj2gco(p),gcvalue(v)) : cast_void(0))

Definition at line 118 of file lua-5.3.6/src/lgc.h.

#define luaC_barrier(L,p,v) (  \
    (iscollectable(v) && isblack(p) && iswhite(gcvalue(v))) ?  \
    luaC_barrier_(L,obj2gco(p),gcvalue(v)) : cast_void(0))

luaC_barrierback

#define luaC_barrierback	(		L,
			p,
			v )

Value:

    (  \
    (iscollectable(v) && isblack(p) && iswhite(gcvalue(v))) ? \
    luaC_barrierback_(L,p) : cast_void(0))

Definition at line 122 of file lua-5.3.6/src/lgc.h.

#define luaC_barrierback(L,p,v) (  \
    (iscollectable(v) && isblack(p) && iswhite(gcvalue(v))) ? \
    luaC_barrierback_(L,p) : cast_void(0))

luaC_checkGC

#define luaC_checkGC

(

L

)

luaC_condGC(L,(void)0,(void)0)

Definition at line 115 of file lua-5.3.6/src/lgc.h.

luaC_condGC

#define luaC_condGC	(		L,
			pre,
			pos )

Value:

    { if (G(L)->GCdebt > 0) { pre; luaC_step(L); pos;}; \
      condchangemem(L,pre,pos); }

Definition at line 110 of file lua-5.3.6/src/lgc.h.

#define luaC_condGC(L,pre,pos) \
    { if (G(L)->GCdebt > 0) { pre; luaC_step(L); pos;}; \
      condchangemem(L,pre,pos); }

luaC_objbarrier

#define luaC_objbarrier	(		L,
			p,
			o )

Value:

    (  \
    (isblack(p) && iswhite(o)) ? \
    luaC_barrier_(L,obj2gco(p),obj2gco(o)) : cast_void(0))

Definition at line 126 of file lua-5.3.6/src/lgc.h.

#define luaC_objbarrier(L,p,o) (  \
    (isblack(p) && iswhite(o)) ? \
    luaC_barrier_(L,obj2gco(p),obj2gco(o)) : cast_void(0))

luaC_upvalbarrier

#define luaC_upvalbarrier	(		L,
			uv )

Value:

    ( \
    (iscollectable((uv)->v) && !upisopen(uv)) ? \
         luaC_upvalbarrier_(L,uv) : cast_void(0))

Definition at line 130 of file lua-5.3.6/src/lgc.h.

#define luaC_upvalbarrier(L,uv) ( \
    (iscollectable((uv)->v) && !upisopen(uv)) ? \
         luaC_upvalbarrier_(L,uv) : cast_void(0))

Referenced by lua_load(), lua_setupvalue(), lua_upvaluejoin(), luaF_close(), and luaV_execute().

luaC_white

#define luaC_white

(

g

)

cast(lu_byte, (g)->currentwhite & WHITEBITS)

Definition at line 101 of file lua-5.3.6/src/lgc.h.

otherwhite

#define otherwhite

(

g

)

((g)->currentwhite ^ WHITEBITS)

Definition at line 94 of file lua-5.3.6/src/lgc.h.

resetbit

#define resetbit	(		x,
			b )   resetbits(x, bitmask(b))

Definition at line 73 of file lua-5.3.6/src/lgc.h.

resetbits

#define resetbits	(		x,
			m )   ((x) &= cast(lu_byte, ~(m)))

Definition at line 67 of file lua-5.3.6/src/lgc.h.

setbits

#define setbits	(		x,
			m )   ((x) |= (m))

Definition at line 68 of file lua-5.3.6/src/lgc.h.

testbit

#define testbit	(		x,
			b )   testbits(x, bitmask(b))

Definition at line 74 of file lua-5.3.6/src/lgc.h.

testbits

#define testbits	(		x,
			m )   ((x) & (m))

Definition at line 69 of file lua-5.3.6/src/lgc.h.

tofinalize

#define tofinalize

(

x

)

testbit((x)->marked, FINALIZEDBIT)

Definition at line 92 of file lua-5.3.6/src/lgc.h.

Referenced by luaC_checkfinalizer(), separatetobefnz(), separatetobefnz(), udata2finalize(), and udata2finalize().

WHITE0BIT

#define WHITE0BIT   0 /* object is white (type 0) */

Definition at line 78 of file lua-5.3.6/src/lgc.h.

WHITE1BIT

#define WHITE1BIT   1 /* object is white (type 1) */

Definition at line 79 of file lua-5.3.6/src/lgc.h.

WHITEBITS

#define WHITEBITS   bit2mask(WHITE0BIT, WHITE1BIT)

Definition at line 84 of file lua-5.3.6/src/lgc.h.

Function Documentation

luaC_barrier_()

LUAI_FUNC void luaC_barrier_	(	lua_State *	L,
		GCObject *	o,
		GCObject *	v )

Definition at line 135 of file lua-5.2.4/src/lgc.c.

                                                            {
  global_State *g = G(L);
  lua_assert(isblack(o) && iswhite(v) && !isdead(g, v) && !isdead(g, o));
  lua_assert(g->gcstate != GCSpause);
  lua_assert(gch(o)->tt != LUA_TTABLE);
  if (keepinvariantout(g))  /* must keep invariant? */
    reallymarkobject(g, v);  /* restore invariant */
  else {  /* sweep phase */
    lua_assert(issweepphase(g));
    makewhite(g, o);  /* mark main obj. as white to avoid other barriers */
  }
}

luaC_barrierback_()

LUAI_FUNC void luaC_barrierback_	(	lua_State *	L,
		Table *	o )

Definition at line 171 of file lua-5.3.6/src/lgc.c.

                                                {
  global_State *g = G(L);
  lua_assert(isblack(t) && !isdead(g, t));
  black2gray(t);  /* make table gray (again) */
  linkgclist(t, g->grayagain);
}

References black2gray, G, global_State::grayagain, isblack, isdead, linkgclist, and lua_assert.

luaC_checkfinalizer()

LUAI_FUNC void luaC_checkfinalizer	(	lua_State *	L,
		GCObject *	o,
		Table *	mt )

Definition at line 873 of file lua-5.2.4/src/lgc.c.

                                                                {
  global_State *g = G(L);
  if (testbit(gch(o)->marked, SEPARATED) || /* obj. is already separated... */
      isfinalized(o) ||                           /* ... or is finalized... */
      gfasttm(g, mt, TM_GC) == NULL)                /* or has no finalizer? */
    return;  /* nothing to be done */
  else {  /* move 'o' to 'finobj' list */
    GCObject **p;
    GCheader *ho = gch(o);
    if (g->sweepgc == &ho->next) {  /* avoid removing current sweep object */
      lua_assert(issweepphase(g));
      g->sweepgc = sweeptolive(L, g->sweepgc, NULL);
    }
    /* search for pointer pointing to 'o' */
    for (p = &g->allgc; *p != o; p = &gch(*p)->next) { /* empty */ }
    *p = ho->next;  /* remove 'o' from root list */
    ho->next = g->finobj;  /* link it in list 'finobj' */
    g->finobj = o;
    l_setbit(ho->marked, SEPARATED);  /* mark it as such */
    if (!keepinvariantout(g))  /* not keeping invariant? */
      makewhite(g, o);  /* "sweep" object */
    else
      resetoldbit(o);  /* see MOVE OLD rule */
  }
}

luaC_fix()

LUAI_FUNC void luaC_fix	(	lua_State *	L,
		GCObject *	o )

Definition at line 194 of file lua-5.3.6/src/lgc.c.

                                          {
  global_State *g = G(L);
  lua_assert(g->allgc == o);  /* object must be 1st in 'allgc' list! */
  white2gray(o);  /* they will be gray forever */
  g->allgc = o->next;  /* remove object from 'allgc' list */
  o->next = g->fixedgc;  /* link it to 'fixedgc' list */
  g->fixedgc = o;
}

luaC_freeallobjects()

LUAI_FUNC void luaC_freeallobjects

(

lua_State *

L

)

Definition at line 983 of file lua-5.2.4/src/lgc.c.

                                        {
  global_State *g = G(L);
  int i;
  separatetobefnz(L, 1);  /* separate all objects with finalizers */
  lua_assert(g->finobj == NULL);
  callallpendingfinalizers(L, 0);
  g->currentwhite = WHITEBITS; /* this "white" makes all objects look dead */
  g->gckind = KGC_NORMAL;
  sweepwholelist(L, &g->finobj);  /* finalizers can create objs. in 'finobj' */
  sweepwholelist(L, &g->allgc);
  for (i = 0; i < g->strt.size; i++)  /* free all string lists */
    sweepwholelist(L, &g->strt.hash[i]);
  lua_assert(g->strt.nuse == 0);
}

luaC_fullgc()

LUAI_FUNC void luaC_fullgc	(	lua_State *	L,
		int	isemergency )

Definition at line 1189 of file lua-5.2.4/src/lgc.c.

                                                 {
  global_State *g = G(L);
  int origkind = g->gckind;
  lua_assert(origkind != KGC_EMERGENCY);
  if (isemergency)  /* do not run finalizers during emergency GC */
    g->gckind = KGC_EMERGENCY;
  else {
    g->gckind = KGC_NORMAL;
    callallpendingfinalizers(L, 1);
  }
  if (keepinvariant(g)) {  /* may there be some black objects? */
    /* must sweep all objects to turn them back to white
       (as white has not changed, nothing will be collected) */
    entersweep(L);
  }
  /* finish any pending sweep phase to start a new cycle */
  luaC_runtilstate(L, bitmask(GCSpause));
  luaC_runtilstate(L, ~bitmask(GCSpause));  /* start new collection */
  luaC_runtilstate(L, bitmask(GCSpause));  /* run entire collection */
  if (origkind == KGC_GEN) {  /* generational mode? */
    /* generational mode must be kept in propagate phase */
    luaC_runtilstate(L, bitmask(GCSpropagate));
  }
  g->gckind = origkind;
  setpause(g, gettotalbytes(g));
  if (!isemergency)   /* do not run finalizers during emergency GC */
    callallpendingfinalizers(L, 1);
}

luaC_newobj()

LUAI_FUNC GCObject * luaC_newobj	(	lua_State *	L,
		int	tt,
		size_t	sz )

Definition at line 208 of file lua-5.3.6/src/lgc.c.

                                                        {
  global_State *g = G(L);
  GCObject *o = cast(GCObject *, luaM_newobject(L, novariant(tt), sz));
  o->marked = luaC_white(g);
  o->tt = tt;
  o->next = g->allgc;
  g->allgc = o;
  return o;
}

luaC_runtilstate()

LUAI_FUNC void luaC_runtilstate	(	lua_State *	L,
		int	statesmask )

Definition at line 1110 of file lua-5.2.4/src/lgc.c.

                                                     {
  global_State *g = G(L);
  while (!testbit(statesmask, g->gcstate))
    singlestep(L);
}

luaC_step()

LUAI_FUNC void luaC_step

(

lua_State *

L

)

Definition at line 610 of file lua-5.1.5/src/lgc.c.

                              {
  global_State *g = G(L);
  l_mem lim = (GCSTEPSIZE/100) * g->gcstepmul;
  if (lim == 0)
    lim = (MAX_LUMEM-1)/2;  /* no limit */
  g->gcdept += g->totalbytes - g->GCthreshold;
  do {
    lim -= singlestep(L);
    if (g->gcstate == GCSpause)
      break;
  } while (lim > 0);
  if (g->gcstate != GCSpause) {
    if (g->gcdept < GCSTEPSIZE)
      g->GCthreshold = g->totalbytes + GCSTEPSIZE;  /* - lim/g->gcstepmul;*/
    else {
      g->gcdept -= GCSTEPSIZE;
      g->GCthreshold = g->totalbytes;
    }
  }
  else {
    setthreshold(g);
  }
}

luaC_upvalbarrier_()

LUAI_FUNC void luaC_upvalbarrier_	(	lua_State *	L,
		UpVal *	uv )

Definition at line 185 of file lua-5.3.6/src/lgc.c.

                                                  {
  global_State *g = G(L);
  GCObject *o = gcvalue(uv->v);
  lua_assert(!upisopen(uv));  /* ensured by macro luaC_upvalbarrier */
  if (keepinvariant(g))
    markobject(g, o);
}

References G, gcvalue, keepinvariant, lua_assert, markobject, upisopen, and UpVal::v.

luaC_upvdeccount()

LUAI_FUNC void luaC_upvdeccount	(	lua_State *	L,
		UpVal *	uv )

Definition at line 678 of file lua-5.3.6/src/lgc.c.

                                                {
  lua_assert(uv->refcount > 0);
  uv->refcount--;
  if (uv->refcount == 0 && !upisopen(uv))
    luaM_free(L, uv);
}

References lua_assert, luaM_free, UpVal::refcount, and upisopen.

Referenced by freeLclosure(), and lua_upvaluejoin().