diff options
Diffstat (limited to '3rdparty/lua/src/lgc.c')
-rw-r--r-- | 3rdparty/lua/src/lgc.c | 873 |
1 files changed, 406 insertions, 467 deletions
diff --git a/3rdparty/lua/src/lgc.c b/3rdparty/lua/src/lgc.c index 52460dcdd5a..8b95fb67da0 100644 --- a/3rdparty/lua/src/lgc.c +++ b/3rdparty/lua/src/lgc.c @@ -1,14 +1,17 @@ /* -** $Id: lgc.c,v 2.140.1.2 2013/04/26 18:22:05 roberto Exp $ +** $Id: lgc.c,v 2.201 2014/12/20 13:58:15 roberto Exp $ ** Garbage Collector ** See Copyright Notice in lua.h */ -#include <string.h> - #define lgc_c #define LUA_CORE +#include "lprefix.h" + + +#include <string.h> + #include "lua.h" #include "ldebug.h" @@ -23,6 +26,11 @@ #include "ltm.h" +/* +** internal state for collector while inside the atomic phase. The +** collector should never be in this state while running regular code. +*/ +#define GCSinsideatomic (GCSpause + 1) /* ** cost of sweeping one element (the size of a small object divided @@ -33,8 +41,8 @@ /* 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 +/* cost of calling one finalizer */ +#define GCFINALIZECOST GCSWEEPCOST /* @@ -52,18 +60,18 @@ /* -** 'makewhite' erases all color bits plus the old bit and then -** sets only the current white bit +** 'makewhite' erases all color bits then sets only the current white +** bit */ -#define maskcolors (~(bit2mask(BLACKBIT, OLDBIT) | WHITEBITS)) +#define maskcolors (~(bitmask(BLACKBIT) | WHITEBITS)) #define makewhite(g,x) \ - (gch(x)->marked = cast_byte((gch(x)->marked & maskcolors) | luaC_white(g))) + (x->marked = cast_byte((x->marked & maskcolors) | luaC_white(g))) -#define white2gray(x) resetbits(gch(x)->marked, WHITEBITS) -#define black2gray(x) resetbit(gch(x)->marked, BLACKBIT) +#define white2gray(x) resetbits(x->marked, WHITEBITS) +#define black2gray(x) resetbit(x->marked, BLACKBIT) -#define isfinalized(x) testbit(gch(x)->marked, FINALIZEDBIT) +#define valiswhite(x) (iscollectable(x) && iswhite(gcvalue(x))) #define checkdeadkey(n) lua_assert(!ttisdeadkey(gkey(n)) || ttisnil(gval(n))) @@ -75,8 +83,8 @@ #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)); } +#define markobject(g,t) \ + { if ((t) && iswhite(t)) reallymarkobject(g, obj2gco(t)); } static void reallymarkobject (global_State *g, GCObject *o); @@ -95,9 +103,9 @@ static void reallymarkobject (global_State *g, GCObject *o); /* -** link table 'h' into list pointed by 'p' +** link collectable object 'o' into list pointed by 'p' */ -#define linktable(h,p) ((h)->gclist = *(p), *(p) = obj2gco(h)) +#define linkgclist(o,p) ((o)->gclist = (p), (p) = obj2gco(o)) /* @@ -107,21 +115,21 @@ static void reallymarkobject (global_State *g, GCObject *o); static void removeentry (Node *n) { lua_assert(ttisnil(gval(n))); if (valiswhite(gkey(n))) - setdeadvalue(gkey(n)); /* unused and unmarked key; remove it */ + setdeadvalue(wgkey(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 +** 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 */ + markobject(g, tsvalue(o)); /* strings are 'values', so are never weak */ return 0; } else return iswhite(gcvalue(o)); @@ -130,14 +138,14 @@ static int iscleared (global_State *g, const TValue *o) { /* ** barrier that moves collector forward, that is, mark the white object -** being pointed by a black object. +** being pointed by a black object. (If in sweep phase, clear the black +** object to white [sweep it] to avoid other barrier calls for this +** same 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? */ + if (keepinvariant(g)) /* must keep invariant? */ reallymarkobject(g, v); /* restore invariant */ else { /* sweep phase */ lua_assert(issweepphase(g)); @@ -148,78 +156,52 @@ void luaC_barrier_ (lua_State *L, GCObject *o, GCObject *v) { /* ** 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.) +** pointing to a white object as gray again. */ -void luaC_barrierback_ (lua_State *L, GCObject *o) { +void luaC_barrierback_ (lua_State *L, Table *t) { 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; + lua_assert(isblack(t) && !isdead(g, t)); + black2gray(t); /* make table gray (again) */ + linkgclist(t, g->grayagain); } /* -** 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. +** 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. */ -LUAI_FUNC void luaC_barrierproto_ (lua_State *L, Proto *p, Closure *c) { +void luaC_upvalbarrier_ (lua_State *L, UpVal *uv) { 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); - } + GCObject *o = gcvalue(uv->v); + lua_assert(!upisopen(uv)); /* ensured by macro luaC_upvalbarrier */ + if (keepinvariant(g)) + markobject(g, o); } -/* -** 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); - } - } +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 */ + g->allgc = o->next; /* remove object from 'allgc' list */ + o->next = g->fixedgc; /* link it to 'fixedgc' list */ + g->fixedgc = 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). +** it to 'allgc' list. */ -GCObject *luaC_newobj (lua_State *L, int tt, size_t sz, GCObject **list, - int offset) { +GCObject *luaC_newobj (lua_State *L, int tt, size_t sz) { 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; + 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; } @@ -241,57 +223,49 @@ GCObject *luaC_newobj (lua_State *L, int tt, size_t sz, GCObject **list, ** upvalues are already linked in 'headuv' list.) */ static void reallymarkobject (global_State *g, GCObject *o) { - lu_mem size; + reentry: white2gray(o); - switch (gch(o)->tt) { + switch (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)); + gray2black(o); + g->GCmemtrav += sizestring(gco2ts(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); + case LUA_TUSERDATA: { + TValue uvalue; + markobject(g, gco2u(o)->metatable); /* mark its metatable */ + gray2black(o); + g->GCmemtrav += sizeudata(gco2u(o)); + getuservalue(g->mainthread, gco2u(o), &uvalue); + if (valiswhite(&uvalue)) { /* markvalue(g, &uvalue); */ + o = gcvalue(&uvalue); + goto reentry; + } break; } case LUA_TLCL: { - gco2lcl(o)->gclist = g->gray; - g->gray = o; - return; + linkgclist(gco2lcl(o), g->gray); + break; } case LUA_TCCL: { - gco2ccl(o)->gclist = g->gray; - g->gray = o; - return; + linkgclist(gco2ccl(o), g->gray); + break; } case LUA_TTABLE: { - linktable(gco2t(o), &g->gray); - return; + linkgclist(gco2t(o), g->gray); + break; } case LUA_TTHREAD: { - gco2th(o)->gclist = g->gray; - g->gray = o; - return; + linkgclist(gco2th(o), g->gray); + break; } case LUA_TPROTO: { - gco2p(o)->gclist = g->gray; - g->gray = o; - return; + linkgclist(gco2p(o), g->gray); + break; } - default: lua_assert(0); return; + default: lua_assert(0); break; } - gray2black(o); - g->GCmemtrav += size; } @@ -310,29 +284,41 @@ static void markmt (global_State *g) { */ static void markbeingfnz (global_State *g) { GCObject *o; - for (o = g->tobefnz; o != NULL; o = gch(o)->next) { - makewhite(g, o); - reallymarkobject(g, o); - } + for (o = g->tobefnz; o != NULL; o = o->next) + markobject(g, o); } /* -** mark all values stored in marked open upvalues. (See comment in -** 'lstate.h'.) +** Mark all values stored in marked open upvalues from non-marked threads. +** (Values from marked threads were already marked when traversing the +** thread.) Remove from the list threads that no longer have upvalues and +** not-marked threads. */ 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); + lua_State *thread; + lua_State **p = &g->twups; + while ((thread = *p) != NULL) { + lua_assert(!isblack(thread)); /* threads are never black */ + if (isgray(thread) && thread->openupval != NULL) + p = &thread->twups; /* keep marked thread with upvalues in the list */ + else { /* thread is not marked or without upvalues */ + UpVal *uv; + *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; + } + } + } } } /* -** mark root set and reset all gray lists, to start a new -** incremental (or full) collection +** mark root set and reset all gray lists, to start a new collection */ static void restartcollection (global_State *g) { g->gray = g->grayagain = NULL; @@ -352,12 +338,18 @@ static void restartcollection (global_State *g) { ** ======================================================= */ +/* +** Traverse a table with weak values and link it to proper list. During +** propagate phase, keep it in 'grayagain' list, to be revisited in the +** atomic phase. In the atomic phase, if table has any white value, +** put it in 'weak' list, to be cleared. +*/ 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) */ + /* if there is array part, assume it may have white values (it is not + worth traversing it now just to check) */ int hasclears = (h->sizearray > 0); - for (n = gnode(h, 0); n < limit; n++) { + for (n = gnode(h, 0); n < limit; n++) { /* traverse hash part */ checkdeadkey(n); if (ttisnil(gval(n))) /* entry is empty? */ removeentry(n); /* remove it */ @@ -368,20 +360,30 @@ static void traverseweakvalue (global_State *g, Table *h) { 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 */ + if (g->gcstate == GCSpropagate) + linkgclist(h, g->grayagain); /* must retraverse it in atomic phase */ + else if (hasclears) + linkgclist(h, g->weak); /* has to be cleared later */ } +/* +** Traverse an ephemeron table and link it to proper list. Returns true +** iff any object was marked during this traversal (which implies that +** convergence has to continue). During propagation phase, keep table +** in 'grayagain' list, to be visited again in the atomic phase. In +** the atomic phase, if table has any white->white entry, it has to +** be revisited during ephemeron convergence (as that key may turn +** black). Otherwise, if it has any white key, table has to be cleared +** (in the atomic phase). +*/ 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" */ + int hasww = 0; /* true if table has entry "white-key -> white-value" */ Node *n, *limit = gnodelast(h); - int i; - /* traverse array part (numeric keys are 'strong') */ + unsigned int i; + /* traverse array part */ for (i = 0; i < h->sizearray; i++) { if (valiswhite(&h->array[i])) { marked = 1; @@ -396,26 +398,27 @@ static int traverseephemeron (global_State *g, Table *h) { 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 */ + hasww = 1; /* white-white entry */ } 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 */ + /* link table into proper list */ + if (g->gcstate == GCSpropagate) + linkgclist(h, g->grayagain); /* must retraverse it in atomic phase */ + else if (hasww) /* table has white->white entries? */ + linkgclist(h, g->ephemeron); /* have to propagate again */ + else if (hasclears) /* table has white keys? */ + linkgclist(h, g->allweak); /* may have to clean white keys */ return marked; } static void traversestrongtable (global_State *g, Table *h) { Node *n, *limit = gnodelast(h); - int i; + unsigned 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 */ @@ -439,13 +442,13 @@ static lu_mem traversetable (global_State *g, Table *h) { ((weakkey = strchr(svalue(mode), 'k')), (weakvalue = strchr(svalue(mode), 'v')), (weakkey || weakvalue))) { /* is really weak? */ - black2gray(obj2gco(h)); /* keep table gray */ + black2gray(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 */ + linkgclist(h, g->allweak); /* nothing to traverse now */ } else /* not weak */ traversestrongtable(g, h); @@ -456,7 +459,7 @@ static lu_mem traversetable (global_State *g, Table *h) { static int traverseproto (global_State *g, Proto *f) { int i; - if (f->cache && iswhite(obj2gco(f->cache))) + if (f->cache && iswhite(f->cache)) f->cache = NULL; /* allow cache to be collected */ markobject(g, f->source); for (i = 0; i < f->sizek; i++) /* mark literals */ @@ -483,34 +486,49 @@ static lu_mem traverseCclosure (global_State *g, CClosure *cl) { return sizeCclosure(cl->nupvalues); } +/* +** 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) +*/ 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]); + for (i = 0; i < cl->nupvalues; i++) { /* mark its upvalues */ + UpVal *uv = cl->upvals[i]; + if (uv != NULL) { + if (upisopen(uv) && g->gcstate != GCSinsideatomic) + uv->u.open.touched = 1; /* can be marked in 'remarkupvals' */ + else + markvalue(g, uv->v); + } + } return sizeLclosure(cl->nupvalues); } -static lu_mem traversestack (global_State *g, lua_State *th) { - int n = 0; +static lu_mem traversethread (global_State *g, lua_State *th) { StkId o = th->stack; if (o == NULL) return 1; /* stack not completely built yet */ + lua_assert(g->gcstate == GCSinsideatomic || + th->openupval == NULL || isintwups(th)); for (; o < th->top; o++) /* mark live elements in the stack */ markvalue(g, o); - if (g->gcstate == GCSatomic) { /* final traversal? */ + if (g->gcstate == GCSinsideatomic) { /* final traversal? */ StkId lim = th->stack + th->stacksize; /* real end of stack */ for (; o < lim; o++) /* clear not-marked stack slice */ setnilvalue(o); + /* 'remarkupvals' may have removed thread from 'twups' list */ + if (!isintwups(th) && th->openupval != NULL) { + th->twups = g->twups; /* link it back to the list */ + g->twups = th; + } } - else { /* count call infos to compute size */ - CallInfo *ci; - for (ci = &th->base_ci; ci != th->ci; ci = ci->next) - n++; - } - return sizeof(lua_State) + sizeof(TValue) * th->stacksize + - sizeof(CallInfo) * n; + else if (g->gckind != KGC_EMERGENCY) + luaD_shrinkstack(th); /* do not change stack in emergency cycle */ + return (sizeof(lua_State) + sizeof(TValue) * th->stacksize); } @@ -523,7 +541,7 @@ static void propagatemark (global_State *g) { GCObject *o = g->gray; lua_assert(isgray(o)); gray2black(o); - switch (gch(o)->tt) { + switch (o->tt) { case LUA_TTABLE: { Table *h = gco2t(o); g->gray = h->gclist; /* remove from 'gray' list */ @@ -545,10 +563,9 @@ static void propagatemark (global_State *g) { 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 */ + linkgclist(th, g->grayagain); /* insert into 'grayagain' list */ black2gray(o); - size = traversestack(g, th); + size = traversethread(g, th); break; } case LUA_TPROTO: { @@ -568,35 +585,12 @@ static void propagateall (global_State *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 */ + g->ephemeron = NULL; /* tables may return to this list when traversed */ changed = 0; while ((w = next) != NULL) { next = gco2t(w)->gclist; @@ -644,7 +638,7 @@ 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; + unsigned int i; for (i = 0; i < h->sizearray; i++) { TValue *o = &h->array[i]; if (iscleared(g, o)) /* value was collected? */ @@ -660,23 +654,41 @@ static void clearvalues (global_State *g, GCObject *l, GCObject *f) { } +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 freeobj (lua_State *L, GCObject *o) { - switch (gch(o)->tt) { + switch (o->tt) { case LUA_TPROTO: luaF_freeproto(L, gco2p(o)); break; case LUA_TLCL: { - luaM_freemem(L, o, sizeLclosure(gco2lcl(o)->nupvalues)); + freeLclosure(L, gco2lcl(o)); 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--; + luaS_remove(L, gco2ts(o)); /* remove it from hash table */ /* go through */ case LUA_TLNGSTR: { luaM_freemem(L, o, sizestring(gco2ts(o))); @@ -692,60 +704,26 @@ 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. +** objects, where a dead object is one marked with the old (non current) +** white; change all non-dead objects back to white, preparing for next +** collection cycle. Return where to continue the traversal or NULL if +** list is finished. */ 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 */ - } + int white = luaC_white(g); /* current white */ while (*p != NULL && count-- > 0) { GCObject *curr = *p; - int marked = gch(curr)->marked; + int marked = curr->marked; if (isdeadm(ow, marked)) { /* is 'curr' dead? */ - *p = gch(curr)->next; /* remove 'curr' from list */ + *p = 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 */ + else { /* change mark to 'white' */ + curr->marked = cast_byte((marked & maskcolors) | white); + p = &curr->next; /* go to next element */ } } return (*p == NULL) ? NULL : p; @@ -756,7 +734,7 @@ static GCObject **sweeplist (lua_State *L, GCObject **p, lu_mem count) { ** sweep a list until a live object (or end of list) */ static GCObject **sweeptolive (lua_State *L, GCObject **p, int *n) { - GCObject ** old = p; + GCObject **old = p; int i = 0; do { i++; @@ -775,26 +753,28 @@ static GCObject **sweeptolive (lua_State *L, GCObject **p, int *n) { ** ======================================================= */ -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 */ +/* +** If possible, free concatenation buffer and shrink string table +*/ +static void checkSizes (lua_State *L, global_State *g) { + if (g->gckind != KGC_EMERGENCY) { + l_mem olddebt = g->GCdebt; luaZ_freebuffer(L, &g->buff); /* free concatenation buffer */ + if (g->strt.nuse < g->strt.size / 4) /* string table too big? */ + luaS_resize(L, g->strt.size / 2); /* shrink it a little */ + g->GCestimate += g->GCdebt - olddebt; /* update estimate */ } } 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 */ + lua_assert(tofinalize(o)); + g->tobefnz = o->next; /* remove it from 'tobefnz' list */ + 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? */ + resetbit(o->marked, FINALIZEDBIT); /* object is "normal" again */ + if (issweepphase(g)) makewhite(g, o); /* "sweep" object */ return o; } @@ -839,28 +819,57 @@ static void GCTM (lua_State *L, int propagateerrors) { /* +** call a few (up to 'g->gcfinnum') finalizers +*/ +static int runafewfinalizers (lua_State *L) { + global_State *g = G(L); + unsigned int i; + lua_assert(!g->tobefnz || g->gcfinnum > 0); + for (i = 0; g->tobefnz && i < g->gcfinnum; i++) + GCTM(L, 1); /* call one finalizer */ + g->gcfinnum = (!g->tobefnz) ? 0 /* nothing more to finalize? */ + : g->gcfinnum * 2; /* else call a few more next time */ + return i; +} + + +/* +** call all pending finalizers +*/ +static void callallpendingfinalizers (lua_State *L, int propagateerrors) { + global_State *g = G(L); + while (g->tobefnz) + GCTM(L, propagateerrors); +} + + +/* +** find last 'next' field in list 'p' list (to add elements in its end) +*/ +static GCObject **findlast (GCObject **p) { + while (*p != NULL) + p = &(*p)->next; + return p; +} + + +/* ** 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; +static void separatetobefnz (global_State *g, int all) { 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; + GCObject **p = &g->finobj; + GCObject **lastnext = findlast(&g->tobefnz); while ((curr = *p) != NULL) { /* traverse all finalizable objects */ - lua_assert(!isfinalized(curr)); - lua_assert(testbit(gch(curr)->marked, SEPARATED)); + lua_assert(tofinalize(curr)); if (!(iswhite(curr) || all)) /* not being collected? */ - p = &gch(curr)->next; /* don't bother with it */ + p = &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 */ + *p = curr->next; /* remove 'curr' from 'finobj' list */ + curr->next = *lastnext; /* link at the end of 'tobefnz' list */ *lastnext = curr; - lastnext = &gch(curr)->next; + lastnext = &curr->next; } } } @@ -872,33 +881,29 @@ static void separatetobefnz (lua_State *L, int all) { */ 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? */ + if (tofinalize(o) || /* obj. is already marked... */ + 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); + if (issweepphase(g)) { + makewhite(g, o); /* "sweep" object 'o' */ + if (g->sweepgc == &o->next) /* should not remove 'sweepgc' object */ + g->sweepgc = sweeptolive(L, g->sweepgc, NULL); /* change 'sweepgc' */ } /* 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' */ + for (p = &g->allgc; *p != o; p = &(*p)->next) { /* empty */ } + *p = o->next; /* remove 'o' from 'allgc' list */ + o->next = g->finobj; /* link it in 'finobj' list */ 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 */ + l_setbit(o->marked, FINALIZEDBIT); /* mark it as such */ } } /* }====================================================== */ + /* ** {====================================================== ** GC control @@ -907,127 +912,93 @@ void luaC_checkfinalizer (lua_State *L, GCObject *o, Table *mt) { /* -** set a reasonable "time" to wait before starting a new GC cycle; -** cycle will start when memory use hits threshold +** Set a reasonable "time" to wait before starting a new GC cycle; cycle +** will start when memory use hits threshold. (Division by 'estimate' +** should be OK: it cannot be zero (because Lua cannot even start with +** less than PAUSEADJ bytes). */ -static void setpause (global_State *g, l_mem estimate) { - l_mem debt, threshold; - estimate = estimate / PAUSEADJ; /* adjust 'estimate' */ +static void setpause (global_State *g) { + l_mem threshold, debt; + l_mem estimate = g->GCestimate / PAUSEADJ; /* adjust 'estimate' */ + lua_assert(estimate > 0); 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)); + debt = gettotalbytes(g) - threshold; 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. +** Enter first sweep phase. +** The call to 'sweeptolive' makes pointer 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->gcstate = GCSswpallgc; + lua_assert(g->sweepgc == NULL); 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 */ + separatetobefnz(g, 1); /* separate all objects with finalizers */ lua_assert(g->finobj == NULL); callallpendingfinalizers(L, 0); + lua_assert(g->tobefnz == NULL); 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->finobj); sweepwholelist(L, &g->allgc); - for (i = 0; i < g->strt.size; i++) /* free all string lists */ - sweepwholelist(L, &g->strt.hash[i]); + sweepwholelist(L, &g->fixedgc); /* collect fixed objects */ 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 */ + l_mem work; GCObject *origweak, *origall; - lua_assert(!iswhite(obj2gco(g->mainthread))); + GCObject *grayagain = g->grayagain; /* save original list */ + lua_assert(g->ephemeron == NULL && g->weak == NULL); + lua_assert(!iswhite(g->mainthread)); + g->gcstate = GCSinsideatomic; + g->GCmemtrav = 0; /* start counting work */ 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 */ + markmt(g); /* mark global 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 */ + work = g->GCmemtrav; /* stop counting (do not recount 'grayagain') */ + g->gray = grayagain; + propagateall(g); /* traverse 'grayagain' list */ + g->GCmemtrav = 0; /* restart counting */ convergeephemerons(g); /* at this point, all strongly accessible objects are marked. */ - /* clear values from weak tables, before checking finalizers */ + /* 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 */ + separatetobefnz(g, 0); /* separate objects to be finalized */ + g->gcfinnum = 1; /* there may be objects to be finalized */ markbeingfnz(g); /* mark objects that will be finalized */ - propagateall(g); /* remark, to propagate `preserveness' */ - work -= g->GCmemtrav; /* restart counting */ + propagateall(g); /* remark, to propagate 'resurrection' */ + g->GCmemtrav = 0; /* 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 */ + 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); @@ -1037,65 +1008,71 @@ static l_mem atomic (lua_State *L) { } +static lu_mem sweepstep (lua_State *L, global_State *g, + int nextstate, GCObject **nextlist) { + if (g->sweepgc) { + l_mem olddebt = g->GCdebt; + g->sweepgc = sweeplist(L, g->sweepgc, GCSWEEPMAX); + g->GCestimate += g->GCdebt - olddebt; /* update estimate */ + if (g->sweepgc) /* is there still something to sweep? */ + return (GCSWEEPMAX * GCSWEEPCOST); + } + /* else enter next state */ + g->gcstate = nextstate; + g->sweepgc = nextlist; + return 0; +} + + 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; - } + g->GCmemtrav = 0; + lua_assert(g->gray); + propagatemark(g); + if (g->gray == NULL) /* no more gray objects? */ + g->gcstate = GCSatomic; /* finish propagate phase */ + return g->GCmemtrav; /* memory traversed in this step */ } - 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 GCSatomic: { + lu_mem work; + int sw; + propagateall(g); /* make sure gray list is empty */ + work = atomic(L); /* work is what was traversed by 'atomic' */ + sw = entersweep(L); + g->GCestimate = gettotalbytes(g); /* first estimate */; + return work + sw * GCSWEEPCOST; } - case GCSsweepudata: { - if (g->sweepfin) { - g->sweepfin = sweeplist(L, g->sweepfin, GCSWEEPMAX); - return GCSWEEPMAX*GCSWEEPCOST; - } - else { - g->gcstate = GCSsweep; - return 0; - } + case GCSswpallgc: { /* sweep "regular" objects */ + return sweepstep(L, g, GCSswpfinobj, &g->finobj); + } + case GCSswpfinobj: { /* sweep objects with finalizers */ + return sweepstep(L, g, GCSswptobefnz, &g->tobefnz); + } + case GCSswptobefnz: { /* sweep objects to be finalized */ + return sweepstep(L, g, GCSswpend, NULL); } - case GCSsweep: { - if (g->sweepgc) { - g->sweepgc = sweeplist(L, g->sweepgc, GCSWEEPMAX); - return GCSWEEPMAX*GCSWEEPCOST; + case GCSswpend: { /* finish sweeps */ + makewhite(g, g->mainthread); /* sweep main thread */ + checkSizes(L, g); + g->gcstate = GCScallfin; + return 0; + } + case GCScallfin: { /* call remaining finalizers */ + if (g->tobefnz && g->gckind != KGC_EMERGENCY) { + int n = runafewfinalizers(L); + return (n * GCFINALIZECOST); } - else { - /* sweep main thread */ - GCObject *mt = obj2gco(g->mainthread); - sweeplist(L, &mt, 1); - checkSizes(L); + else { /* emergency mode or no more finalizers */ g->gcstate = GCSpause; /* finish collection */ - return GCSWEEPCOST; + return 0; } } default: lua_assert(0); return 0; @@ -1114,105 +1091,67 @@ void luaC_runtilstate (lua_State *L, int statesmask) { } -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); +/* +** get GC debt and convert it from Kb to 'work units' (avoid zero debt +** and overflows) +*/ +static l_mem getdebt (global_State *g) { 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); - } + return 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 +** performs a basic GC step when 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 */ + l_mem debt = getdebt(g); /* GC deficit (be paid now) */ + if (!g->gcrunning) { /* not running? */ + luaE_setdebt(g, -GCSTEPSIZE * 10); /* avoid being called too often */ + return; + } + do { /* repeat until pause or enough "credit" (negative debt) */ + lu_mem work = singlestep(L); /* perform one single step */ + debt -= work; + } while (debt > -GCSTEPSIZE && g->gcstate != GCSpause); + if (g->gcstate == GCSpause) + setpause(g); /* pause until next cycle */ + else { + debt = (debt / g->gcstepmul) * STEPMULADJ; /* convert 'work units' to Kb */ + luaE_setdebt(g, debt); + runafewfinalizers(L); + } } - /* -** performs a full GC cycle; if "isemergency", does not call -** finalizers (which could change stack positions) +** Performs a full GC cycle; if 'isemergency', set a flag to avoid +** some operations which could change the interpreter state in some +** unexpected ways (running finalizers and shrinking some structures). +** Before running the collection, check 'keepinvariant'; if it is true, +** there may be some objects marked as black, so the collector has +** to sweep all objects to turn them back to white (as white has not +** changed, nothing will be collected). */ 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); + lua_assert(g->gckind == KGC_NORMAL); + if (isemergency) g->gckind = KGC_EMERGENCY; /* set flag */ + if (keepinvariant(g)) { /* black objects? */ + entersweep(L); /* sweep everything to turn them back to white */ } /* 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_runtilstate(L, bitmask(GCScallfin)); /* run up to finalizers */ + /* estimate must be correct after a full GC cycle */ + lua_assert(g->GCestimate == gettotalbytes(g)); + luaC_runtilstate(L, bitmask(GCSpause)); /* finish collection */ + g->gckind = KGC_NORMAL; + setpause(g); } /* }====================================================== */ |