| Index: third_party/lua/src/lgc.c
|
| diff --git a/third_party/lua/src/lgc.c b/third_party/lua/src/lgc.c
|
| new file mode 100644
|
| index 0000000000000000000000000000000000000000..535e988ae02a0070c7e2267dac103d460b5623a1
|
| --- /dev/null
|
| +++ b/third_party/lua/src/lgc.c
|
| @@ -0,0 +1,1213 @@
|
| +/*
|
| +** $Id: lgc.c,v 2.140 2013/03/16 21:10:18 roberto Exp $
|
| +** Garbage Collector
|
| +** See Copyright Notice in lua.h
|
| +*/
|
| +
|
| +#include <string.h>
|
| +
|
| +#define lgc_c
|
| +#define LUA_CORE
|
| +
|
| +#include "lua.h"
|
| +
|
| +#include "ldebug.h"
|
| +#include "ldo.h"
|
| +#include "lfunc.h"
|
| +#include "lgc.h"
|
| +#include "lmem.h"
|
| +#include "lobject.h"
|
| +#include "lstate.h"
|
| +#include "lstring.h"
|
| +#include "ltable.h"
|
| +#include "ltm.h"
|
| +
|
| +
|
| +
|
| +/*
|
| +** cost of sweeping one element (the size of a small object divided
|
| +** by some adjust for the sweep speed)
|
| +*/
|
| +#define GCSWEEPCOST ((sizeof(TString) + 4) / 4)
|
| +
|
| +/* maximum number of elements to sweep in each single step */
|
| +#define GCSWEEPMAX (cast_int((GCSTEPSIZE / GCSWEEPCOST) / 4))
|
| +
|
| +/* maximum number of finalizers to call in each GC step */
|
| +#define GCFINALIZENUM 4
|
| +
|
| +
|
| +/*
|
| +** macro to adjust 'stepmul': 'stepmul' is actually used like
|
| +** 'stepmul / STEPMULADJ' (value chosen by tests)
|
| +*/
|
| +#define STEPMULADJ 200
|
| +
|
| +
|
| +/*
|
| +** macro to adjust 'pause': 'pause' is actually used like
|
| +** 'pause / PAUSEADJ' (value chosen by tests)
|
| +*/
|
| +#define PAUSEADJ 100
|
| +
|
| +
|
| +/*
|
| +** 'makewhite' erases all color bits plus the old bit and then
|
| +** sets only the current white bit
|
| +*/
|
| +#define maskcolors (~(bit2mask(BLACKBIT, OLDBIT) | WHITEBITS))
|
| +#define makewhite(g,x) \
|
| + (gch(x)->marked = cast_byte((gch(x)->marked & maskcolors) | luaC_white(g)))
|
| +
|
| +#define white2gray(x) resetbits(gch(x)->marked, WHITEBITS)
|
| +#define black2gray(x) resetbit(gch(x)->marked, BLACKBIT)
|
| +
|
| +
|
| +#define isfinalized(x) testbit(gch(x)->marked, FINALIZEDBIT)
|
| +
|
| +#define checkdeadkey(n) lua_assert(!ttisdeadkey(gkey(n)) || ttisnil(gval(n)))
|
| +
|
| +
|
| +#define checkconsistency(obj) \
|
| + lua_longassert(!iscollectable(obj) || righttt(obj))
|
| +
|
| +
|
| +#define markvalue(g,o) { checkconsistency(o); \
|
| + if (valiswhite(o)) reallymarkobject(g,gcvalue(o)); }
|
| +
|
| +#define markobject(g,t) { if ((t) && iswhite(obj2gco(t))) \
|
| + reallymarkobject(g, obj2gco(t)); }
|
| +
|
| +static void reallymarkobject (global_State *g, GCObject *o);
|
| +
|
| +
|
| +/*
|
| +** {======================================================
|
| +** Generic functions
|
| +** =======================================================
|
| +*/
|
| +
|
| +
|
| +/*
|
| +** one after last element in a hash array
|
| +*/
|
| +#define gnodelast(h) gnode(h, cast(size_t, sizenode(h)))
|
| +
|
| +
|
| +/*
|
| +** link table 'h' into list pointed by 'p'
|
| +*/
|
| +#define linktable(h,p) ((h)->gclist = *(p), *(p) = obj2gco(h))
|
| +
|
| +
|
| +/*
|
| +** if key is not marked, mark its entry as dead (therefore removing it
|
| +** from the table)
|
| +*/
|
| +static void removeentry (Node *n) {
|
| + lua_assert(ttisnil(gval(n)));
|
| + if (valiswhite(gkey(n)))
|
| + setdeadvalue(gkey(n)); /* unused and unmarked key; remove it */
|
| +}
|
| +
|
| +
|
| +/*
|
| +** tells whether a key or value can be cleared from a weak
|
| +** table. Non-collectable objects are never removed from weak
|
| +** tables. Strings behave as `values', so are never removed too. for
|
| +** other objects: if really collected, cannot keep them; for objects
|
| +** being finalized, keep them in keys, but not in values
|
| +*/
|
| +static int iscleared (global_State *g, const TValue *o) {
|
| + if (!iscollectable(o)) return 0;
|
| + else if (ttisstring(o)) {
|
| + markobject(g, rawtsvalue(o)); /* strings are `values', so are never weak */
|
| + return 0;
|
| + }
|
| + else return iswhite(gcvalue(o));
|
| +}
|
| +
|
| +
|
| +/*
|
| +** barrier that moves collector forward, that is, mark the white object
|
| +** being pointed by a black object.
|
| +*/
|
| +void luaC_barrier_ (lua_State *L, GCObject *o, GCObject *v) {
|
| + 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 */
|
| + }
|
| +}
|
| +
|
| +
|
| +/*
|
| +** barrier that moves collector backward, that is, mark the black object
|
| +** pointing to a white object as gray again. (Current implementation
|
| +** only works for tables; access to 'gclist' is not uniform across
|
| +** different types.)
|
| +*/
|
| +void luaC_barrierback_ (lua_State *L, GCObject *o) {
|
| + global_State *g = G(L);
|
| + lua_assert(isblack(o) && !isdead(g, o) && gch(o)->tt == LUA_TTABLE);
|
| + black2gray(o); /* make object gray (again) */
|
| + gco2t(o)->gclist = g->grayagain;
|
| + g->grayagain = o;
|
| +}
|
| +
|
| +
|
| +/*
|
| +** barrier for prototypes. When creating first closure (cache is
|
| +** NULL), use a forward barrier; this may be the only closure of the
|
| +** prototype (if it is a "regular" function, with a single instance)
|
| +** and the prototype may be big, so it is better to avoid traversing
|
| +** it again. Otherwise, use a backward barrier, to avoid marking all
|
| +** possible instances.
|
| +*/
|
| +LUAI_FUNC void luaC_barrierproto_ (lua_State *L, Proto *p, Closure *c) {
|
| + global_State *g = G(L);
|
| + lua_assert(isblack(obj2gco(p)));
|
| + if (p->cache == NULL) { /* first time? */
|
| + luaC_objbarrier(L, p, c);
|
| + }
|
| + else { /* use a backward barrier */
|
| + black2gray(obj2gco(p)); /* make prototype gray (again) */
|
| + p->gclist = g->grayagain;
|
| + g->grayagain = obj2gco(p);
|
| + }
|
| +}
|
| +
|
| +
|
| +/*
|
| +** 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)) {
|
| + resetoldbit(o); /* see MOVE OLD rule */
|
| + 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
|
| +** object itself (used only by states).
|
| +*/
|
| +GCObject *luaC_newobj (lua_State *L, int tt, size_t sz, GCObject **list,
|
| + int offset) {
|
| + global_State *g = G(L);
|
| + char *raw = cast(char *, luaM_newobject(L, novariant(tt), sz));
|
| + GCObject *o = obj2gco(raw + offset);
|
| + if (list == NULL)
|
| + list = &g->allgc; /* standard list for collectable objects */
|
| + gch(o)->marked = luaC_white(g);
|
| + gch(o)->tt = tt;
|
| + gch(o)->next = *list;
|
| + *list = o;
|
| + return o;
|
| +}
|
| +
|
| +/* }====================================================== */
|
| +
|
| +
|
| +
|
| +/*
|
| +** {======================================================
|
| +** Mark functions
|
| +** =======================================================
|
| +*/
|
| +
|
| +
|
| +/*
|
| +** 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.)
|
| +*/
|
| +static void reallymarkobject (global_State *g, GCObject *o) {
|
| + lu_mem size;
|
| + white2gray(o);
|
| + switch (gch(o)->tt) {
|
| + case LUA_TSHRSTR:
|
| + case LUA_TLNGSTR: {
|
| + size = sizestring(gco2ts(o));
|
| + break; /* nothing else to mark; make it black */
|
| + }
|
| + case LUA_TUSERDATA: {
|
| + Table *mt = gco2u(o)->metatable;
|
| + markobject(g, mt);
|
| + markobject(g, gco2u(o)->env);
|
| + size = sizeudata(gco2u(o));
|
| + break;
|
| + }
|
| + case LUA_TUPVAL: {
|
| + UpVal *uv = gco2uv(o);
|
| + markvalue(g, uv->v);
|
| + if (uv->v != &uv->u.value) /* open? */
|
| + return; /* open upvalues remain gray */
|
| + size = sizeof(UpVal);
|
| + break;
|
| + }
|
| + case LUA_TLCL: {
|
| + gco2lcl(o)->gclist = g->gray;
|
| + g->gray = o;
|
| + return;
|
| + }
|
| + case LUA_TCCL: {
|
| + gco2ccl(o)->gclist = g->gray;
|
| + g->gray = o;
|
| + return;
|
| + }
|
| + case LUA_TTABLE: {
|
| + linktable(gco2t(o), &g->gray);
|
| + return;
|
| + }
|
| + case LUA_TTHREAD: {
|
| + gco2th(o)->gclist = g->gray;
|
| + g->gray = o;
|
| + return;
|
| + }
|
| + case LUA_TPROTO: {
|
| + gco2p(o)->gclist = g->gray;
|
| + g->gray = o;
|
| + return;
|
| + }
|
| + default: lua_assert(0); return;
|
| + }
|
| + gray2black(o);
|
| + g->GCmemtrav += size;
|
| +}
|
| +
|
| +
|
| +/*
|
| +** mark metamethods for basic types
|
| +*/
|
| +static void markmt (global_State *g) {
|
| + int i;
|
| + for (i=0; i < LUA_NUMTAGS; i++)
|
| + markobject(g, g->mt[i]);
|
| +}
|
| +
|
| +
|
| +/*
|
| +** mark all objects in list of being-finalized
|
| +*/
|
| +static void markbeingfnz (global_State *g) {
|
| + GCObject *o;
|
| + for (o = g->tobefnz; o != NULL; o = gch(o)->next) {
|
| + makewhite(g, o);
|
| + reallymarkobject(g, o);
|
| + }
|
| +}
|
| +
|
| +
|
| +/*
|
| +** mark all values stored in marked open upvalues. (See comment in
|
| +** 'lstate.h'.)
|
| +*/
|
| +static void remarkupvals (global_State *g) {
|
| + UpVal *uv;
|
| + for (uv = g->uvhead.u.l.next; uv != &g->uvhead; uv = uv->u.l.next) {
|
| + if (isgray(obj2gco(uv)))
|
| + markvalue(g, uv->v);
|
| + }
|
| +}
|
| +
|
| +
|
| +/*
|
| +** mark root set and reset all gray lists, to start a new
|
| +** incremental (or full) collection
|
| +*/
|
| +static void restartcollection (global_State *g) {
|
| + g->gray = g->grayagain = NULL;
|
| + g->weak = g->allweak = g->ephemeron = NULL;
|
| + markobject(g, g->mainthread);
|
| + markvalue(g, &g->l_registry);
|
| + markmt(g);
|
| + markbeingfnz(g); /* mark any finalizing object left from previous cycle */
|
| +}
|
| +
|
| +/* }====================================================== */
|
| +
|
| +
|
| +/*
|
| +** {======================================================
|
| +** Traverse functions
|
| +** =======================================================
|
| +*/
|
| +
|
| +static void traverseweakvalue (global_State *g, Table *h) {
|
| + Node *n, *limit = gnodelast(h);
|
| + /* if there is array part, assume it may have white values (do not
|
| + traverse it just to check) */
|
| + int hasclears = (h->sizearray > 0);
|
| + for (n = gnode(h, 0); n < limit; n++) {
|
| + checkdeadkey(n);
|
| + if (ttisnil(gval(n))) /* entry is empty? */
|
| + removeentry(n); /* remove it */
|
| + else {
|
| + lua_assert(!ttisnil(gkey(n)));
|
| + markvalue(g, gkey(n)); /* mark key */
|
| + if (!hasclears && iscleared(g, gval(n))) /* is there a white value? */
|
| + hasclears = 1; /* table will have to be cleared */
|
| + }
|
| + }
|
| + if (hasclears)
|
| + linktable(h, &g->weak); /* has to be cleared later */
|
| + else /* no white values */
|
| + linktable(h, &g->grayagain); /* no need to clean */
|
| +}
|
| +
|
| +
|
| +static int traverseephemeron (global_State *g, Table *h) {
|
| + int marked = 0; /* true if an object is marked in this traversal */
|
| + int hasclears = 0; /* true if table has white keys */
|
| + int prop = 0; /* true if table has entry "white-key -> white-value" */
|
| + Node *n, *limit = gnodelast(h);
|
| + int i;
|
| + /* traverse array part (numeric keys are 'strong') */
|
| + for (i = 0; i < h->sizearray; i++) {
|
| + if (valiswhite(&h->array[i])) {
|
| + marked = 1;
|
| + reallymarkobject(g, gcvalue(&h->array[i]));
|
| + }
|
| + }
|
| + /* traverse hash part */
|
| + for (n = gnode(h, 0); n < limit; n++) {
|
| + checkdeadkey(n);
|
| + if (ttisnil(gval(n))) /* entry is empty? */
|
| + removeentry(n); /* remove it */
|
| + else if (iscleared(g, gkey(n))) { /* key is not marked (yet)? */
|
| + hasclears = 1; /* table must be cleared */
|
| + if (valiswhite(gval(n))) /* value not marked yet? */
|
| + prop = 1; /* must propagate again */
|
| + }
|
| + else if (valiswhite(gval(n))) { /* value not marked yet? */
|
| + marked = 1;
|
| + reallymarkobject(g, gcvalue(gval(n))); /* mark it now */
|
| + }
|
| + }
|
| + if (prop)
|
| + linktable(h, &g->ephemeron); /* have to propagate again */
|
| + else if (hasclears) /* does table have white keys? */
|
| + linktable(h, &g->allweak); /* may have to clean white keys */
|
| + else /* no white keys */
|
| + linktable(h, &g->grayagain); /* no need to clean */
|
| + return marked;
|
| +}
|
| +
|
| +
|
| +static void traversestrongtable (global_State *g, Table *h) {
|
| + Node *n, *limit = gnodelast(h);
|
| + int i;
|
| + for (i = 0; i < h->sizearray; i++) /* traverse array part */
|
| + markvalue(g, &h->array[i]);
|
| + for (n = gnode(h, 0); n < limit; n++) { /* traverse hash part */
|
| + checkdeadkey(n);
|
| + if (ttisnil(gval(n))) /* entry is empty? */
|
| + removeentry(n); /* remove it */
|
| + else {
|
| + lua_assert(!ttisnil(gkey(n)));
|
| + markvalue(g, gkey(n)); /* mark key */
|
| + markvalue(g, gval(n)); /* mark value */
|
| + }
|
| + }
|
| +}
|
| +
|
| +
|
| +static lu_mem traversetable (global_State *g, Table *h) {
|
| + const char *weakkey, *weakvalue;
|
| + const TValue *mode = gfasttm(g, h->metatable, TM_MODE);
|
| + markobject(g, h->metatable);
|
| + if (mode && ttisstring(mode) && /* is there a weak mode? */
|
| + ((weakkey = strchr(svalue(mode), 'k')),
|
| + (weakvalue = strchr(svalue(mode), 'v')),
|
| + (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 /* all weak */
|
| + linktable(h, &g->allweak); /* nothing to traverse now */
|
| + }
|
| + else /* not weak */
|
| + traversestrongtable(g, h);
|
| + return sizeof(Table) + sizeof(TValue) * h->sizearray +
|
| + sizeof(Node) * cast(size_t, sizenode(h));
|
| +}
|
| +
|
| +
|
| +static int traverseproto (global_State *g, Proto *f) {
|
| + int i;
|
| + if (f->cache && iswhite(obj2gco(f->cache)))
|
| + f->cache = NULL; /* allow cache to be collected */
|
| + markobject(g, f->source);
|
| + for (i = 0; i < f->sizek; i++) /* mark literals */
|
| + markvalue(g, &f->k[i]);
|
| + for (i = 0; i < f->sizeupvalues; i++) /* mark upvalue names */
|
| + markobject(g, f->upvalues[i].name);
|
| + for (i = 0; i < f->sizep; i++) /* mark nested protos */
|
| + markobject(g, f->p[i]);
|
| + for (i = 0; i < f->sizelocvars; i++) /* mark local-variable names */
|
| + markobject(g, f->locvars[i].varname);
|
| + return sizeof(Proto) + sizeof(Instruction) * f->sizecode +
|
| + sizeof(Proto *) * f->sizep +
|
| + sizeof(TValue) * f->sizek +
|
| + sizeof(int) * f->sizelineinfo +
|
| + sizeof(LocVar) * f->sizelocvars +
|
| + sizeof(Upvaldesc) * f->sizeupvalues;
|
| +}
|
| +
|
| +
|
| +static lu_mem traverseCclosure (global_State *g, CClosure *cl) {
|
| + int i;
|
| + for (i = 0; i < cl->nupvalues; i++) /* mark its upvalues */
|
| + markvalue(g, &cl->upvalue[i]);
|
| + return sizeCclosure(cl->nupvalues);
|
| +}
|
| +
|
| +static lu_mem traverseLclosure (global_State *g, LClosure *cl) {
|
| + int i;
|
| + markobject(g, cl->p); /* mark its prototype */
|
| + for (i = 0; i < cl->nupvalues; i++) /* mark its upvalues */
|
| + markobject(g, cl->upvals[i]);
|
| + return sizeLclosure(cl->nupvalues);
|
| +}
|
| +
|
| +
|
| +static lu_mem traversestack (global_State *g, lua_State *th) {
|
| + StkId o = th->stack;
|
| + if (o == NULL)
|
| + return 1; /* stack not completely built yet */
|
| + for (; o < th->top; o++)
|
| + markvalue(g, o);
|
| + if (g->gcstate == GCSatomic) { /* final traversal? */
|
| + StkId lim = th->stack + th->stacksize; /* real end of stack */
|
| + for (; o < lim; o++) /* clear not-marked stack slice */
|
| + setnilvalue(o);
|
| + }
|
| + return sizeof(lua_State) + sizeof(TValue) * th->stacksize;
|
| +}
|
| +
|
| +
|
| +/*
|
| +** traverse one gray object, turning it to black (except for threads,
|
| +** which are always gray).
|
| +*/
|
| +static void propagatemark (global_State *g) {
|
| + lu_mem size;
|
| + GCObject *o = g->gray;
|
| + lua_assert(isgray(o));
|
| + gray2black(o);
|
| + switch (gch(o)->tt) {
|
| + case LUA_TTABLE: {
|
| + Table *h = gco2t(o);
|
| + g->gray = h->gclist; /* remove from 'gray' list */
|
| + size = traversetable(g, h);
|
| + break;
|
| + }
|
| + case LUA_TLCL: {
|
| + LClosure *cl = gco2lcl(o);
|
| + g->gray = cl->gclist; /* remove from 'gray' list */
|
| + size = traverseLclosure(g, cl);
|
| + break;
|
| + }
|
| + case LUA_TCCL: {
|
| + CClosure *cl = gco2ccl(o);
|
| + g->gray = cl->gclist; /* remove from 'gray' list */
|
| + size = traverseCclosure(g, cl);
|
| + break;
|
| + }
|
| + case LUA_TTHREAD: {
|
| + lua_State *th = gco2th(o);
|
| + g->gray = th->gclist; /* remove from 'gray' list */
|
| + th->gclist = g->grayagain;
|
| + g->grayagain = o; /* insert into 'grayagain' list */
|
| + black2gray(o);
|
| + size = traversestack(g, th);
|
| + break;
|
| + }
|
| + case LUA_TPROTO: {
|
| + Proto *p = gco2p(o);
|
| + g->gray = p->gclist; /* remove from 'gray' list */
|
| + size = traverseproto(g, p);
|
| + break;
|
| + }
|
| + default: lua_assert(0); return;
|
| + }
|
| + g->GCmemtrav += size;
|
| +}
|
| +
|
| +
|
| +static void propagateall (global_State *g) {
|
| + while (g->gray) propagatemark(g);
|
| +}
|
| +
|
| +
|
| +static void propagatelist (global_State *g, GCObject *l) {
|
| + lua_assert(g->gray == NULL); /* no grays left */
|
| + g->gray = l;
|
| + propagateall(g); /* traverse all elements from 'l' */
|
| +}
|
| +
|
| +/*
|
| +** retraverse all gray lists. Because tables may be reinserted in other
|
| +** lists when traversed, traverse the original lists to avoid traversing
|
| +** twice the same table (which is not wrong, but inefficient)
|
| +*/
|
| +static void retraversegrays (global_State *g) {
|
| + GCObject *weak = g->weak; /* save original lists */
|
| + GCObject *grayagain = g->grayagain;
|
| + GCObject *ephemeron = g->ephemeron;
|
| + g->weak = g->grayagain = g->ephemeron = NULL;
|
| + propagateall(g); /* traverse main gray list */
|
| + propagatelist(g, grayagain);
|
| + propagatelist(g, weak);
|
| + propagatelist(g, ephemeron);
|
| +}
|
| +
|
| +
|
| +static void convergeephemerons (global_State *g) {
|
| + int changed;
|
| + do {
|
| + GCObject *w;
|
| + GCObject *next = g->ephemeron; /* get ephemeron list */
|
| + g->ephemeron = NULL; /* tables will return to this list when traversed */
|
| + changed = 0;
|
| + while ((w = next) != NULL) {
|
| + next = gco2t(w)->gclist;
|
| + if (traverseephemeron(g, gco2t(w))) { /* traverse marked some value? */
|
| + propagateall(g); /* propagate changes */
|
| + changed = 1; /* will have to revisit all ephemeron tables */
|
| + }
|
| + }
|
| + } while (changed);
|
| +}
|
| +
|
| +/* }====================================================== */
|
| +
|
| +
|
| +/*
|
| +** {======================================================
|
| +** Sweep Functions
|
| +** =======================================================
|
| +*/
|
| +
|
| +
|
| +/*
|
| +** clear entries with unmarked keys from all weaktables in list 'l' up
|
| +** to element 'f'
|
| +*/
|
| +static void clearkeys (global_State *g, GCObject *l, GCObject *f) {
|
| + for (; l != f; l = gco2t(l)->gclist) {
|
| + Table *h = gco2t(l);
|
| + Node *n, *limit = gnodelast(h);
|
| + for (n = gnode(h, 0); n < limit; n++) {
|
| + if (!ttisnil(gval(n)) && (iscleared(g, gkey(n)))) {
|
| + setnilvalue(gval(n)); /* remove value ... */
|
| + removeentry(n); /* and remove entry from table */
|
| + }
|
| + }
|
| + }
|
| +}
|
| +
|
| +
|
| +/*
|
| +** clear entries with unmarked values from all weaktables in list 'l' up
|
| +** to element 'f'
|
| +*/
|
| +static void clearvalues (global_State *g, GCObject *l, GCObject *f) {
|
| + for (; l != f; l = gco2t(l)->gclist) {
|
| + Table *h = gco2t(l);
|
| + Node *n, *limit = gnodelast(h);
|
| + int i;
|
| + for (i = 0; i < h->sizearray; i++) {
|
| + TValue *o = &h->array[i];
|
| + if (iscleared(g, o)) /* value was collected? */
|
| + setnilvalue(o); /* remove value */
|
| + }
|
| + for (n = gnode(h, 0); n < limit; n++) {
|
| + if (!ttisnil(gval(n)) && iscleared(g, gval(n))) {
|
| + setnilvalue(gval(n)); /* remove value ... */
|
| + removeentry(n); /* and remove entry from table */
|
| + }
|
| + }
|
| + }
|
| +}
|
| +
|
| +
|
| +static void freeobj (lua_State *L, GCObject *o) {
|
| + switch (gch(o)->tt) {
|
| + case LUA_TPROTO: luaF_freeproto(L, gco2p(o)); break;
|
| + case LUA_TLCL: {
|
| + luaM_freemem(L, o, sizeLclosure(gco2lcl(o)->nupvalues));
|
| + break;
|
| + }
|
| + case LUA_TCCL: {
|
| + luaM_freemem(L, o, sizeCclosure(gco2ccl(o)->nupvalues));
|
| + break;
|
| + }
|
| + case LUA_TUPVAL: luaF_freeupval(L, gco2uv(o)); break;
|
| + case LUA_TTABLE: luaH_free(L, gco2t(o)); break;
|
| + case LUA_TTHREAD: luaE_freethread(L, gco2th(o)); break;
|
| + case LUA_TUSERDATA: luaM_freemem(L, o, sizeudata(gco2u(o))); break;
|
| + case LUA_TSHRSTR:
|
| + G(L)->strt.nuse--;
|
| + /* go through */
|
| + case LUA_TLNGSTR: {
|
| + luaM_freemem(L, o, sizestring(gco2ts(o)));
|
| + break;
|
| + }
|
| + default: lua_assert(0);
|
| + }
|
| +}
|
| +
|
| +
|
| +#define sweepwholelist(L,p) sweeplist(L,p,MAX_LUMEM)
|
| +static GCObject **sweeplist (lua_State *L, GCObject **p, lu_mem count);
|
| +
|
| +
|
| +/*
|
| +** sweep the (open) upvalues of a thread and resize its stack and
|
| +** list of call-info structures.
|
| +*/
|
| +static void sweepthread (lua_State *L, lua_State *L1) {
|
| + if (L1->stack == NULL) return; /* stack not completely built yet */
|
| + sweepwholelist(L, &L1->openupval); /* sweep open upvalues */
|
| + luaE_freeCI(L1); /* free extra CallInfo slots */
|
| + /* should not change the stack during an emergency gc cycle */
|
| + if (G(L)->gckind != KGC_EMERGENCY)
|
| + luaD_shrinkstack(L1);
|
| +}
|
| +
|
| +
|
| +/*
|
| +** sweep at most 'count' elements from a list of GCObjects erasing dead
|
| +** objects, where a dead (not alive) object is one marked with the "old"
|
| +** (non current) white and not fixed.
|
| +** In non-generational mode, change all non-dead objects back to white,
|
| +** preparing for next collection cycle.
|
| +** In generational mode, keep black objects black, and also mark them as
|
| +** old; stop when hitting an old object, as all objects after that
|
| +** one will be old too.
|
| +** When object is a thread, sweep its list of open upvalues too.
|
| +*/
|
| +static GCObject **sweeplist (lua_State *L, GCObject **p, lu_mem count) {
|
| + global_State *g = G(L);
|
| + int ow = otherwhite(g);
|
| + int toclear, toset; /* bits to clear and to set in all live objects */
|
| + int tostop; /* stop sweep when this is true */
|
| + if (isgenerational(g)) { /* generational mode? */
|
| + toclear = ~0; /* clear nothing */
|
| + toset = bitmask(OLDBIT); /* set the old bit of all surviving objects */
|
| + tostop = bitmask(OLDBIT); /* do not sweep old generation */
|
| + }
|
| + else { /* normal mode */
|
| + toclear = maskcolors; /* clear all color bits + old bit */
|
| + toset = luaC_white(g); /* make object white */
|
| + tostop = 0; /* do not stop */
|
| + }
|
| + while (*p != NULL && count-- > 0) {
|
| + GCObject *curr = *p;
|
| + int marked = gch(curr)->marked;
|
| + if (isdeadm(ow, marked)) { /* is 'curr' dead? */
|
| + *p = gch(curr)->next; /* remove 'curr' from list */
|
| + freeobj(L, curr); /* erase 'curr' */
|
| + }
|
| + else {
|
| + if (testbits(marked, tostop))
|
| + return NULL; /* stop sweeping this list */
|
| + if (gch(curr)->tt == LUA_TTHREAD)
|
| + sweepthread(L, gco2th(curr)); /* sweep thread's upvalues */
|
| + /* update marks */
|
| + gch(curr)->marked = cast_byte((marked & toclear) | toset);
|
| + p = &gch(curr)->next; /* go to next element */
|
| + }
|
| + }
|
| + return (*p == NULL) ? NULL : p;
|
| +}
|
| +
|
| +
|
| +/*
|
| +** sweep a list until a live object (or end of list)
|
| +*/
|
| +static GCObject **sweeptolive (lua_State *L, GCObject **p, int *n) {
|
| + GCObject ** old = p;
|
| + int i = 0;
|
| + do {
|
| + i++;
|
| + p = sweeplist(L, p, 1);
|
| + } while (p == old);
|
| + if (n) *n += i;
|
| + return p;
|
| +}
|
| +
|
| +/* }====================================================== */
|
| +
|
| +
|
| +/*
|
| +** {======================================================
|
| +** Finalization
|
| +** =======================================================
|
| +*/
|
| +
|
| +static void checkSizes (lua_State *L) {
|
| + global_State *g = G(L);
|
| + if (g->gckind != KGC_EMERGENCY) { /* do not change sizes in emergency */
|
| + int hs = g->strt.size / 2; /* half the size of the string table */
|
| + if (g->strt.nuse < cast(lu_int32, hs)) /* using less than that half? */
|
| + luaS_resize(L, hs); /* halve its size */
|
| + luaZ_freebuffer(L, &g->buff); /* free concatenation buffer */
|
| + }
|
| +}
|
| +
|
| +
|
| +static GCObject *udata2finalize (global_State *g) {
|
| + GCObject *o = g->tobefnz; /* get first element */
|
| + lua_assert(isfinalized(o));
|
| + g->tobefnz = gch(o)->next; /* remove it from 'tobefnz' list */
|
| + gch(o)->next = g->allgc; /* return it to 'allgc' list */
|
| + g->allgc = o;
|
| + resetbit(gch(o)->marked, SEPARATED); /* mark that it is not in 'tobefnz' */
|
| + lua_assert(!isold(o)); /* see MOVE OLD rule */
|
| + if (!keepinvariantout(g)) /* not keeping invariant? */
|
| + makewhite(g, o); /* "sweep" object */
|
| + return o;
|
| +}
|
| +
|
| +
|
| +static void dothecall (lua_State *L, void *ud) {
|
| + UNUSED(ud);
|
| + luaD_call(L, L->top - 2, 0, 0);
|
| +}
|
| +
|
| +
|
| +static void GCTM (lua_State *L, int propagateerrors) {
|
| + global_State *g = G(L);
|
| + const TValue *tm;
|
| + TValue v;
|
| + setgcovalue(L, &v, udata2finalize(g));
|
| + tm = luaT_gettmbyobj(L, &v, TM_GC);
|
| + if (tm != NULL && ttisfunction(tm)) { /* is there a finalizer? */
|
| + int status;
|
| + lu_byte oldah = L->allowhook;
|
| + int running = g->gcrunning;
|
| + L->allowhook = 0; /* stop debug hooks during GC metamethod */
|
| + g->gcrunning = 0; /* avoid GC steps */
|
| + setobj2s(L, L->top, tm); /* push finalizer... */
|
| + setobj2s(L, L->top + 1, &v); /* ... and its argument */
|
| + L->top += 2; /* and (next line) call the finalizer */
|
| + status = luaD_pcall(L, dothecall, NULL, savestack(L, L->top - 2), 0);
|
| + L->allowhook = oldah; /* restore hooks */
|
| + g->gcrunning = running; /* restore state */
|
| + if (status != LUA_OK && propagateerrors) { /* error while running __gc? */
|
| + if (status == LUA_ERRRUN) { /* is there an error object? */
|
| + const char *msg = (ttisstring(L->top - 1))
|
| + ? svalue(L->top - 1)
|
| + : "no message";
|
| + luaO_pushfstring(L, "error in __gc metamethod (%s)", msg);
|
| + status = LUA_ERRGCMM; /* error in __gc metamethod */
|
| + }
|
| + luaD_throw(L, status); /* re-throw error */
|
| + }
|
| + }
|
| +}
|
| +
|
| +
|
| +/*
|
| +** move all unreachable objects (or 'all' objects) that need
|
| +** finalization from list 'finobj' to list 'tobefnz' (to be finalized)
|
| +*/
|
| +static void separatetobefnz (lua_State *L, int all) {
|
| + global_State *g = G(L);
|
| + GCObject **p = &g->finobj;
|
| + GCObject *curr;
|
| + GCObject **lastnext = &g->tobefnz;
|
| + /* find last 'next' field in 'tobefnz' list (to add elements in its end) */
|
| + while (*lastnext != NULL)
|
| + lastnext = &gch(*lastnext)->next;
|
| + while ((curr = *p) != NULL) { /* traverse all finalizable objects */
|
| + lua_assert(!isfinalized(curr));
|
| + lua_assert(testbit(gch(curr)->marked, SEPARATED));
|
| + if (!(iswhite(curr) || all)) /* not being collected? */
|
| + p = &gch(curr)->next; /* don't bother with it */
|
| + else {
|
| + l_setbit(gch(curr)->marked, FINALIZEDBIT); /* won't be finalized again */
|
| + *p = gch(curr)->next; /* remove 'curr' from 'finobj' list */
|
| + gch(curr)->next = *lastnext; /* link at the end of 'tobefnz' list */
|
| + *lastnext = curr;
|
| + lastnext = &gch(curr)->next;
|
| + }
|
| + }
|
| +}
|
| +
|
| +
|
| +/*
|
| +** if object 'o' has a finalizer, remove it from 'allgc' list (must
|
| +** search the list to find it) and link it in 'finobj' list.
|
| +*/
|
| +void luaC_checkfinalizer (lua_State *L, GCObject *o, Table *mt) {
|
| + 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 */
|
| + }
|
| +}
|
| +
|
| +/* }====================================================== */
|
| +
|
| +
|
| +/*
|
| +** {======================================================
|
| +** GC control
|
| +** =======================================================
|
| +*/
|
| +
|
| +
|
| +/*
|
| +** set a reasonable "time" to wait before starting a new GC cycle;
|
| +** cycle will start when memory use hits threshold
|
| +*/
|
| +static void setpause (global_State *g, l_mem estimate) {
|
| + l_mem debt, threshold;
|
| + estimate = estimate / PAUSEADJ; /* adjust 'estimate' */
|
| + threshold = (g->gcpause < MAX_LMEM / estimate) /* overflow? */
|
| + ? estimate * g->gcpause /* no overflow */
|
| + : MAX_LMEM; /* overflow; truncate to maximum */
|
| + debt = -cast(l_mem, threshold - gettotalbytes(g));
|
| + luaE_setdebt(g, debt);
|
| +}
|
| +
|
| +
|
| +#define sweepphases \
|
| + (bitmask(GCSsweepstring) | bitmask(GCSsweepudata) | bitmask(GCSsweep))
|
| +
|
| +
|
| +/*
|
| +** enter first sweep phase (strings) and prepare pointers for other
|
| +** sweep phases. The calls to 'sweeptolive' make pointers point to an
|
| +** object inside the list (instead of to the header), so that the real
|
| +** sweep do not need to skip objects created between "now" and the start
|
| +** of the real sweep.
|
| +** Returns how many objects it swept.
|
| +*/
|
| +static int entersweep (lua_State *L) {
|
| + global_State *g = G(L);
|
| + int n = 0;
|
| + g->gcstate = GCSsweepstring;
|
| + lua_assert(g->sweepgc == NULL && g->sweepfin == NULL);
|
| + /* prepare to sweep strings, finalizable objects, and regular objects */
|
| + g->sweepstrgc = 0;
|
| + g->sweepfin = sweeptolive(L, &g->finobj, &n);
|
| + g->sweepgc = sweeptolive(L, &g->allgc, &n);
|
| + return n;
|
| +}
|
| +
|
| +
|
| +/*
|
| +** change GC mode
|
| +*/
|
| +void luaC_changemode (lua_State *L, int mode) {
|
| + global_State *g = G(L);
|
| + if (mode == g->gckind) return; /* nothing to change */
|
| + if (mode == KGC_GEN) { /* change to generational mode */
|
| + /* make sure gray lists are consistent */
|
| + luaC_runtilstate(L, bitmask(GCSpropagate));
|
| + g->GCestimate = gettotalbytes(g);
|
| + g->gckind = KGC_GEN;
|
| + }
|
| + else { /* change to incremental mode */
|
| + /* sweep all objects to turn them back to white
|
| + (as white has not changed, nothing extra will be collected) */
|
| + g->gckind = KGC_NORMAL;
|
| + entersweep(L);
|
| + luaC_runtilstate(L, ~sweepphases);
|
| + }
|
| +}
|
| +
|
| +
|
| +/*
|
| +** call all pending finalizers
|
| +*/
|
| +static void callallpendingfinalizers (lua_State *L, int propagateerrors) {
|
| + global_State *g = G(L);
|
| + while (g->tobefnz) {
|
| + resetoldbit(g->tobefnz);
|
| + GCTM(L, propagateerrors);
|
| + }
|
| +}
|
| +
|
| +
|
| +void luaC_freeallobjects (lua_State *L) {
|
| + 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);
|
| +}
|
| +
|
| +
|
| +static l_mem atomic (lua_State *L) {
|
| + global_State *g = G(L);
|
| + l_mem work = -cast(l_mem, g->GCmemtrav); /* start counting work */
|
| + GCObject *origweak, *origall;
|
| + lua_assert(!iswhite(obj2gco(g->mainthread)));
|
| + markobject(g, L); /* mark running thread */
|
| + /* registry and global metatables may be changed by API */
|
| + markvalue(g, &g->l_registry);
|
| + markmt(g); /* mark basic metatables */
|
| + /* remark occasional upvalues of (maybe) dead threads */
|
| + remarkupvals(g);
|
| + propagateall(g); /* propagate changes */
|
| + work += g->GCmemtrav; /* stop counting (do not (re)count grays) */
|
| + /* traverse objects caught by write barrier and by 'remarkupvals' */
|
| + retraversegrays(g);
|
| + work -= g->GCmemtrav; /* restart counting */
|
| + convergeephemerons(g);
|
| + /* at this point, all strongly accessible objects are marked. */
|
| + /* clear values from weak tables, before checking finalizers */
|
| + clearvalues(g, g->weak, NULL);
|
| + clearvalues(g, g->allweak, NULL);
|
| + origweak = g->weak; origall = g->allweak;
|
| + work += g->GCmemtrav; /* stop counting (objects being finalized) */
|
| + separatetobefnz(L, 0); /* separate objects to be finalized */
|
| + markbeingfnz(g); /* mark objects that will be finalized */
|
| + propagateall(g); /* remark, to propagate `preserveness' */
|
| + work -= g->GCmemtrav; /* restart counting */
|
| + convergeephemerons(g);
|
| + /* at this point, all resurrected objects are marked. */
|
| + /* remove dead objects from weak tables */
|
| + clearkeys(g, g->ephemeron, NULL); /* clear keys from all ephemeron tables */
|
| + clearkeys(g, g->allweak, NULL); /* clear keys from all allweak tables */
|
| + /* clear values from resurrected weak tables */
|
| + clearvalues(g, g->weak, origweak);
|
| + clearvalues(g, g->allweak, origall);
|
| + g->currentwhite = cast_byte(otherwhite(g)); /* flip current white */
|
| + work += g->GCmemtrav; /* complete counting */
|
| + return work; /* estimate of memory marked by 'atomic' */
|
| +}
|
| +
|
| +
|
| +static lu_mem singlestep (lua_State *L) {
|
| + global_State *g = G(L);
|
| + switch (g->gcstate) {
|
| + case GCSpause: {
|
| + /* start to count memory traversed */
|
| + g->GCmemtrav = g->strt.size * sizeof(GCObject*);
|
| + lua_assert(!isgenerational(g));
|
| + restartcollection(g);
|
| + g->gcstate = GCSpropagate;
|
| + return g->GCmemtrav;
|
| + }
|
| + case GCSpropagate: {
|
| + if (g->gray) {
|
| + lu_mem oldtrav = g->GCmemtrav;
|
| + propagatemark(g);
|
| + return g->GCmemtrav - oldtrav; /* memory traversed in this step */
|
| + }
|
| + else { /* no more `gray' objects */
|
| + lu_mem work;
|
| + int sw;
|
| + g->gcstate = GCSatomic; /* finish mark phase */
|
| + g->GCestimate = g->GCmemtrav; /* save what was counted */;
|
| + work = atomic(L); /* add what was traversed by 'atomic' */
|
| + g->GCestimate += work; /* estimate of total memory traversed */
|
| + sw = entersweep(L);
|
| + return work + sw * GCSWEEPCOST;
|
| + }
|
| + }
|
| + case GCSsweepstring: {
|
| + int i;
|
| + for (i = 0; i < GCSWEEPMAX && g->sweepstrgc + i < g->strt.size; i++)
|
| + sweepwholelist(L, &g->strt.hash[g->sweepstrgc + i]);
|
| + g->sweepstrgc += i;
|
| + if (g->sweepstrgc >= g->strt.size) /* no more strings to sweep? */
|
| + g->gcstate = GCSsweepudata;
|
| + return i * GCSWEEPCOST;
|
| + }
|
| + case GCSsweepudata: {
|
| + if (g->sweepfin) {
|
| + g->sweepfin = sweeplist(L, g->sweepfin, GCSWEEPMAX);
|
| + return GCSWEEPMAX*GCSWEEPCOST;
|
| + }
|
| + else {
|
| + g->gcstate = GCSsweep;
|
| + return 0;
|
| + }
|
| + }
|
| + case GCSsweep: {
|
| + if (g->sweepgc) {
|
| + g->sweepgc = sweeplist(L, g->sweepgc, GCSWEEPMAX);
|
| + return GCSWEEPMAX*GCSWEEPCOST;
|
| + }
|
| + else {
|
| + /* sweep main thread */
|
| + GCObject *mt = obj2gco(g->mainthread);
|
| + sweeplist(L, &mt, 1);
|
| + checkSizes(L);
|
| + g->gcstate = GCSpause; /* finish collection */
|
| + return GCSWEEPCOST;
|
| + }
|
| + }
|
| + default: lua_assert(0); return 0;
|
| + }
|
| +}
|
| +
|
| +
|
| +/*
|
| +** advances the garbage collector until it reaches a state allowed
|
| +** by 'statemask'
|
| +*/
|
| +void luaC_runtilstate (lua_State *L, int statesmask) {
|
| + global_State *g = G(L);
|
| + while (!testbit(statesmask, g->gcstate))
|
| + singlestep(L);
|
| +}
|
| +
|
| +
|
| +static void generationalcollection (lua_State *L) {
|
| + global_State *g = G(L);
|
| + lua_assert(g->gcstate == GCSpropagate);
|
| + if (g->GCestimate == 0) { /* signal for another major collection? */
|
| + luaC_fullgc(L, 0); /* perform a full regular collection */
|
| + g->GCestimate = gettotalbytes(g); /* update control */
|
| + }
|
| + else {
|
| + lu_mem estimate = g->GCestimate;
|
| + luaC_runtilstate(L, bitmask(GCSpause)); /* run complete (minor) cycle */
|
| + g->gcstate = GCSpropagate; /* skip restart */
|
| + if (gettotalbytes(g) > (estimate / 100) * g->gcmajorinc)
|
| + g->GCestimate = 0; /* signal for a major collection */
|
| + else
|
| + g->GCestimate = estimate; /* keep estimate from last major coll. */
|
| +
|
| + }
|
| + setpause(g, gettotalbytes(g));
|
| + lua_assert(g->gcstate == GCSpropagate);
|
| +}
|
| +
|
| +
|
| +static void incstep (lua_State *L) {
|
| + global_State *g = G(L);
|
| + l_mem debt = g->GCdebt;
|
| + int stepmul = g->gcstepmul;
|
| + if (stepmul < 40) stepmul = 40; /* avoid ridiculous low values (and 0) */
|
| + /* convert debt from Kb to 'work units' (avoid zero debt and overflows) */
|
| + debt = (debt / STEPMULADJ) + 1;
|
| + debt = (debt < MAX_LMEM / stepmul) ? debt * stepmul : MAX_LMEM;
|
| + do { /* always perform at least one single step */
|
| + lu_mem work = singlestep(L); /* do some work */
|
| + debt -= work;
|
| + } while (debt > -GCSTEPSIZE && g->gcstate != GCSpause);
|
| + if (g->gcstate == GCSpause)
|
| + setpause(g, g->GCestimate); /* pause until next cycle */
|
| + else {
|
| + debt = (debt / stepmul) * STEPMULADJ; /* convert 'work units' to Kb */
|
| + luaE_setdebt(g, debt);
|
| + }
|
| +}
|
| +
|
| +
|
| +/*
|
| +** performs a basic GC step
|
| +*/
|
| +void luaC_forcestep (lua_State *L) {
|
| + global_State *g = G(L);
|
| + int i;
|
| + if (isgenerational(g)) generationalcollection(L);
|
| + else incstep(L);
|
| + /* run a few finalizers (or all of them at the end of a collect cycle) */
|
| + for (i = 0; g->tobefnz && (i < GCFINALIZENUM || g->gcstate == GCSpause); i++)
|
| + GCTM(L, 1); /* call one finalizer */
|
| +}
|
| +
|
| +
|
| +/*
|
| +** performs a basic GC step only if collector is running
|
| +*/
|
| +void luaC_step (lua_State *L) {
|
| + global_State *g = G(L);
|
| + if (g->gcrunning) luaC_forcestep(L);
|
| + else luaE_setdebt(g, -GCSTEPSIZE); /* avoid being called too often */
|
| +}
|
| +
|
| +
|
| +
|
| +/*
|
| +** performs a full GC cycle; if "isemergency", does not call
|
| +** finalizers (which could change stack positions)
|
| +*/
|
| +void luaC_fullgc (lua_State *L, int isemergency) {
|
| + 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);
|
| +}
|
| +
|
| +/* }====================================================== */
|
| +
|
| +
|
|
|
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