From ae2779e504ca5ae11a87e047b4536a5f428cce4d Mon Sep 17 00:00:00 2001 From: pixel Date: Sat, 27 Nov 2004 21:46:02 +0000 Subject: Large dos2unix commit... --- lib/lua/src/lgc.c | 986 +++++++++++++++++++++++++++--------------------------- 1 file changed, 493 insertions(+), 493 deletions(-) (limited to 'lib/lua/src/lgc.c') diff --git a/lib/lua/src/lgc.c b/lib/lua/src/lgc.c index f565df6..15ddbb6 100644 --- a/lib/lua/src/lgc.c +++ b/lib/lua/src/lgc.c @@ -1,493 +1,493 @@ -/* -** $Id: lgc.c,v 1.3 2004-11-27 21:35:20 pixel Exp $ -** Garbage Collector -** See Copyright Notice in lua.h -*/ - -#include - -#define lgc_c - -#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" - - -typedef struct GCState { - GCObject *tmark; /* list of marked objects to be traversed */ - GCObject *wk; /* list of traversed key-weak tables (to be cleared) */ - GCObject *wv; /* list of traversed value-weak tables */ - GCObject *wkv; /* list of traversed key-value weak tables */ - global_State *g; -} GCState; - - -/* -** some userful bit tricks -*/ -#define setbit(x,b) ((x) |= (1<<(b))) -#define resetbit(x,b) ((x) &= cast(lu_byte, ~(1<<(b)))) -#define testbit(x,b) ((x) & (1<<(b))) - -#define unmark(x) resetbit((x)->gch.marked, 0) -#define ismarked(x) ((x)->gch.marked & ((1<<4)|1)) - -#define stringmark(s) setbit((s)->tsv.marked, 0) - - -#define isfinalized(u) (!testbit((u)->uv.marked, 1)) -#define markfinalized(u) resetbit((u)->uv.marked, 1) - - -#define KEYWEAKBIT 1 -#define VALUEWEAKBIT 2 -#define KEYWEAK (1<gch.marked, 0); /* mark object */ - switch (o->gch.tt) { - case LUA_TUSERDATA: { - markvalue(st, gcotou(o)->uv.metatable); - break; - } - case LUA_TFUNCTION: { - gcotocl(o)->c.gclist = st->tmark; - st->tmark = o; - break; - } - case LUA_TTABLE: { - gcotoh(o)->gclist = st->tmark; - st->tmark = o; - break; - } - case LUA_TTHREAD: { - gcototh(o)->gclist = st->tmark; - st->tmark = o; - break; - } - case LUA_TPROTO: { - gcotop(o)->gclist = st->tmark; - st->tmark = o; - break; - } - default: lua_assert(o->gch.tt == LUA_TSTRING); - } -} - - -static void marktmu (GCState *st) { - GCObject *u; - for (u = st->g->tmudata; u; u = u->gch.next) { - unmark(u); /* may be marked, if left from previous GC */ - reallymarkobject(st, u); - } -} - - -/* move `dead' udata that need finalization to list `tmudata' */ -void luaC_separateudata (lua_State *L) { - GCObject **p = &G(L)->rootudata; - GCObject *curr; - GCObject *collected = NULL; /* to collect udata with gc event */ - GCObject **lastcollected = &collected; - while ((curr = *p) != NULL) { - lua_assert(curr->gch.tt == LUA_TUSERDATA); - if (ismarked(curr) || isfinalized(gcotou(curr))) - p = &curr->gch.next; /* don't bother with them */ - - else if (fasttm(L, gcotou(curr)->uv.metatable, TM_GC) == NULL) { - markfinalized(gcotou(curr)); /* don't need finalization */ - p = &curr->gch.next; - } - else { /* must call its gc method */ - *p = curr->gch.next; - curr->gch.next = NULL; /* link `curr' at the end of `collected' list */ - *lastcollected = curr; - lastcollected = &curr->gch.next; - } - } - /* insert collected udata with gc event into `tmudata' list */ - *lastcollected = G(L)->tmudata; - G(L)->tmudata = collected; -} - - -static void removekey (Node *n) { - setnilvalue(gval(n)); /* remove corresponding value ... */ - if (iscollectable(gkey(n))) - setttype(gkey(n), LUA_TNONE); /* dead key; remove it */ -} - - -static void traversetable (GCState *st, Table *h) { - int i; - int weakkey = 0; - int weakvalue = 0; - const TObject *mode; - markvalue(st, h->metatable); - lua_assert(h->lsizenode || h->node == st->g->dummynode); - mode = gfasttm(st->g, h->metatable, TM_MODE); - if (mode && ttisstring(mode)) { /* is there a weak mode? */ - weakkey = (strchr(svalue(mode), 'k') != NULL); - weakvalue = (strchr(svalue(mode), 'v') != NULL); - if (weakkey || weakvalue) { /* is really weak? */ - GCObject **weaklist; - h->marked &= ~(KEYWEAK | VALUEWEAK); /* clear bits */ - h->marked |= cast(lu_byte, (weakkey << KEYWEAKBIT) | - (weakvalue << VALUEWEAKBIT)); - weaklist = (weakkey && weakvalue) ? &st->wkv : - (weakkey) ? &st->wk : - &st->wv; - h->gclist = *weaklist; /* must be cleared after GC, ... */ - *weaklist = valtogco(h); /* ... so put in the appropriate list */ - } - } - if (!weakvalue) { - i = h->sizearray; - while (i--) - markobject(st, &h->array[i]); - } - i = sizenode(h); - while (i--) { - Node *n = gnode(h, i); - if (!ttisnil(gval(n))) { - lua_assert(!ttisnil(gkey(n))); - condmarkobject(st, gkey(n), !weakkey); - condmarkobject(st, gval(n), !weakvalue); - } - } -} - - -static void traverseproto (GCState *st, Proto *f) { - int i; - stringmark(f->source); - for (i=0; isizek; i++) { /* mark literal strings */ - if (ttisstring(f->k+i)) - stringmark(tsvalue(f->k+i)); - } - for (i=0; isizeupvalues; i++) /* mark upvalue names */ - stringmark(f->upvalues[i]); - for (i=0; isizep; i++) /* mark nested protos */ - markvalue(st, f->p[i]); - for (i=0; isizelocvars; i++) /* mark local-variable names */ - stringmark(f->locvars[i].varname); - lua_assert(luaG_checkcode(f)); -} - - - -static void traverseclosure (GCState *st, Closure *cl) { - if (cl->c.isC) { - int i; - for (i=0; ic.nupvalues; i++) /* mark its upvalues */ - markobject(st, &cl->c.upvalue[i]); - } - else { - int i; - lua_assert(cl->l.nupvalues == cl->l.p->nups); - markvalue(st, hvalue(&cl->l.g)); - markvalue(st, cl->l.p); - for (i=0; il.nupvalues; i++) { /* mark its upvalues */ - UpVal *u = cl->l.upvals[i]; - if (!u->marked) { - markobject(st, &u->value); - u->marked = 1; - } - } - } -} - - -static void checkstacksizes (lua_State *L, StkId max) { - int used = L->ci - L->base_ci; /* number of `ci' in use */ - if (4*used < L->size_ci && 2*BASIC_CI_SIZE < L->size_ci) - luaD_reallocCI(L, L->size_ci/2); /* still big enough... */ - else condhardstacktests(luaD_reallocCI(L, L->size_ci)); - used = max - L->stack; /* part of stack in use */ - if (4*used < L->stacksize && 2*(BASIC_STACK_SIZE+EXTRA_STACK) < L->stacksize) - luaD_reallocstack(L, L->stacksize/2); /* still big enough... */ - else condhardstacktests(luaD_reallocstack(L, L->stacksize)); -} - - -static void traversestack (GCState *st, lua_State *L1) { - StkId o, lim; - CallInfo *ci; - markobject(st, gt(L1)); - lim = L1->top; - for (ci = L1->base_ci; ci <= L1->ci; ci++) { - lua_assert(ci->top <= L1->stack_last); - lua_assert(ci->state & (CI_C | CI_HASFRAME | CI_SAVEDPC)); - if (!(ci->state & CI_C) && lim < ci->top) - lim = ci->top; - } - for (o = L1->stack; o < L1->top; o++) - markobject(st, o); - for (; o <= lim; o++) - setnilvalue(o); - checkstacksizes(L1, lim); -} - - -static void propagatemarks (GCState *st) { - while (st->tmark) { /* traverse marked objects */ - switch (st->tmark->gch.tt) { - case LUA_TTABLE: { - Table *h = gcotoh(st->tmark); - st->tmark = h->gclist; - traversetable(st, h); - break; - } - case LUA_TFUNCTION: { - Closure *cl = gcotocl(st->tmark); - st->tmark = cl->c.gclist; - traverseclosure(st, cl); - break; - } - case LUA_TTHREAD: { - lua_State *th = gcototh(st->tmark); - st->tmark = th->gclist; - traversestack(st, th); - break; - } - case LUA_TPROTO: { - Proto *p = gcotop(st->tmark); - st->tmark = p->gclist; - traverseproto(st, p); - break; - } - default: lua_assert(0); - } - } -} - - -static int valismarked (const TObject *o) { - if (ttisstring(o)) - stringmark(tsvalue(o)); /* strings are `values', so are never weak */ - return !iscollectable(o) || testbit(o->value.gc->gch.marked, 0); -} - - -/* -** clear collected keys from weaktables -*/ -static void cleartablekeys (GCObject *l) { - while (l) { - Table *h = gcotoh(l); - int i = sizenode(h); - lua_assert(h->marked & KEYWEAK); - while (i--) { - Node *n = gnode(h, i); - if (!valismarked(gkey(n))) /* key was collected? */ - removekey(n); /* remove entry from table */ - } - l = h->gclist; - } -} - - -/* -** clear collected values from weaktables -*/ -static void cleartablevalues (GCObject *l) { - while (l) { - Table *h = gcotoh(l); - int i = h->sizearray; - lua_assert(h->marked & VALUEWEAK); - while (i--) { - TObject *o = &h->array[i]; - if (!valismarked(o)) /* value was collected? */ - setnilvalue(o); /* remove value */ - } - i = sizenode(h); - while (i--) { - Node *n = gnode(h, i); - if (!valismarked(gval(n))) /* value was collected? */ - removekey(n); /* remove entry from table */ - } - l = h->gclist; - } -} - - -static void freeobj (lua_State *L, GCObject *o) { - switch (o->gch.tt) { - case LUA_TPROTO: luaF_freeproto(L, gcotop(o)); break; - case LUA_TFUNCTION: luaF_freeclosure(L, gcotocl(o)); break; - case LUA_TUPVAL: luaM_freelem(L, gcotouv(o)); break; - case LUA_TTABLE: luaH_free(L, gcotoh(o)); break; - case LUA_TTHREAD: { - lua_assert(gcototh(o) != L && gcototh(o) != G(L)->mainthread); - luaE_freethread(L, gcototh(o)); - break; - } - case LUA_TSTRING: { - luaM_free(L, o, sizestring(gcotots(o)->tsv.len)); - break; - } - case LUA_TUSERDATA: { - luaM_free(L, o, sizeudata(gcotou(o)->uv.len)); - break; - } - default: lua_assert(0); - } -} - - -static int sweeplist (lua_State *L, GCObject **p, int limit) { - GCObject *curr; - int count = 0; /* number of collected items */ - while ((curr = *p) != NULL) { - if (curr->gch.marked > limit) { - unmark(curr); - p = &curr->gch.next; - } - else { - count++; - *p = curr->gch.next; - freeobj(L, curr); - } - } - return count; -} - - -static void sweepstrings (lua_State *L, int all) { - int i; - for (i=0; istrt.size; i++) { /* for each list */ - G(L)->strt.nuse -= sweeplist(L, &G(L)->strt.hash[i], all); - } -} - - -static void checkSizes (lua_State *L) { - /* check size of string hash */ - if (G(L)->strt.nuse < cast(ls_nstr, G(L)->strt.size/4) && - G(L)->strt.size > MINSTRTABSIZE*2) - luaS_resize(L, G(L)->strt.size/2); /* table is too big */ - /* check size of buffer */ - if (luaZ_sizebuffer(&G(L)->buff) > LUA_MINBUFFER*2) { /* buffer too big? */ - size_t newsize = luaZ_sizebuffer(&G(L)->buff) / 2; - luaZ_resizebuffer(L, &G(L)->buff, newsize); - } - G(L)->GCthreshold = 2*G(L)->nblocks; /* new threshold */ -} - - -static void do1gcTM (lua_State *L, Udata *udata) { - const TObject *tm = fasttm(L, udata->uv.metatable, TM_GC); - if (tm != NULL) { - setobj2s(L->top, tm); - setuvalue(L->top+1, udata); - L->top += 2; - luaD_call(L, L->top - 2, 0); - } -} - - -void luaC_callGCTM (lua_State *L) { - lu_byte oldah = L->allowhook; - L->allowhook = 0; /* stop debug hooks during GC tag methods */ - L->top++; /* reserve space to keep udata while runs its gc method */ - while (G(L)->tmudata != NULL) { - GCObject *o = G(L)->tmudata; - Udata *udata = gcotou(o); - G(L)->tmudata = udata->uv.next; /* remove udata from `tmudata' */ - udata->uv.next = G(L)->rootudata; /* return it to `root' list */ - G(L)->rootudata = o; - setuvalue(L->top - 1, udata); /* keep a reference to it */ - unmark(o); - markfinalized(udata); - do1gcTM(L, udata); - } - L->top--; - L->allowhook = oldah; /* restore hooks */ -} - - -void luaC_sweep (lua_State *L, int all) { - if (all) all = 256; /* larger than any mark */ - sweeplist(L, &G(L)->rootudata, all); - sweepstrings(L, all); - sweeplist(L, &G(L)->rootgc, all); -} - - -/* mark root set */ -static void markroot (GCState *st, lua_State *L) { - global_State *g = st->g; - markobject(st, defaultmeta(L)); - markobject(st, registry(L)); - traversestack(st, g->mainthread); - if (L != g->mainthread) /* another thread is running? */ - markvalue(st, L); /* cannot collect it */ -} - - -static void mark (lua_State *L) { - GCState st; - GCObject *wkv; - st.g = G(L); - st.tmark = NULL; - st.wkv = st.wk = st.wv = NULL; - markroot(&st, L); - propagatemarks(&st); /* mark all reachable objects */ - cleartablevalues(st.wkv); - cleartablevalues(st.wv); - wkv = st.wkv; /* keys must be cleared after preserving udata */ - st.wkv = NULL; - st.wv = NULL; - luaC_separateudata(L); /* separate userdata to be preserved */ - marktmu(&st); /* mark `preserved' userdata */ - propagatemarks(&st); /* remark, to propagate `preserveness' */ - cleartablekeys(wkv); - /* `propagatemarks' may resuscitate some weak tables; clear them too */ - cleartablekeys(st.wk); - cleartablevalues(st.wv); - cleartablekeys(st.wkv); - cleartablevalues(st.wkv); -} - - -void luaC_collectgarbage (lua_State *L) { - mark(L); - luaC_sweep(L, 0); - checkSizes(L); - luaC_callGCTM(L); -} - - -void luaC_link (lua_State *L, GCObject *o, lu_byte tt) { - o->gch.next = G(L)->rootgc; - G(L)->rootgc = o; - o->gch.marked = 0; - o->gch.tt = tt; -} - +/* +** $Id: lgc.c,v 1.4 2004-11-27 21:46:07 pixel Exp $ +** Garbage Collector +** See Copyright Notice in lua.h +*/ + +#include + +#define lgc_c + +#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" + + +typedef struct GCState { + GCObject *tmark; /* list of marked objects to be traversed */ + GCObject *wk; /* list of traversed key-weak tables (to be cleared) */ + GCObject *wv; /* list of traversed value-weak tables */ + GCObject *wkv; /* list of traversed key-value weak tables */ + global_State *g; +} GCState; + + +/* +** some userful bit tricks +*/ +#define setbit(x,b) ((x) |= (1<<(b))) +#define resetbit(x,b) ((x) &= cast(lu_byte, ~(1<<(b)))) +#define testbit(x,b) ((x) & (1<<(b))) + +#define unmark(x) resetbit((x)->gch.marked, 0) +#define ismarked(x) ((x)->gch.marked & ((1<<4)|1)) + +#define stringmark(s) setbit((s)->tsv.marked, 0) + + +#define isfinalized(u) (!testbit((u)->uv.marked, 1)) +#define markfinalized(u) resetbit((u)->uv.marked, 1) + + +#define KEYWEAKBIT 1 +#define VALUEWEAKBIT 2 +#define KEYWEAK (1<gch.marked, 0); /* mark object */ + switch (o->gch.tt) { + case LUA_TUSERDATA: { + markvalue(st, gcotou(o)->uv.metatable); + break; + } + case LUA_TFUNCTION: { + gcotocl(o)->c.gclist = st->tmark; + st->tmark = o; + break; + } + case LUA_TTABLE: { + gcotoh(o)->gclist = st->tmark; + st->tmark = o; + break; + } + case LUA_TTHREAD: { + gcototh(o)->gclist = st->tmark; + st->tmark = o; + break; + } + case LUA_TPROTO: { + gcotop(o)->gclist = st->tmark; + st->tmark = o; + break; + } + default: lua_assert(o->gch.tt == LUA_TSTRING); + } +} + + +static void marktmu (GCState *st) { + GCObject *u; + for (u = st->g->tmudata; u; u = u->gch.next) { + unmark(u); /* may be marked, if left from previous GC */ + reallymarkobject(st, u); + } +} + + +/* move `dead' udata that need finalization to list `tmudata' */ +void luaC_separateudata (lua_State *L) { + GCObject **p = &G(L)->rootudata; + GCObject *curr; + GCObject *collected = NULL; /* to collect udata with gc event */ + GCObject **lastcollected = &collected; + while ((curr = *p) != NULL) { + lua_assert(curr->gch.tt == LUA_TUSERDATA); + if (ismarked(curr) || isfinalized(gcotou(curr))) + p = &curr->gch.next; /* don't bother with them */ + + else if (fasttm(L, gcotou(curr)->uv.metatable, TM_GC) == NULL) { + markfinalized(gcotou(curr)); /* don't need finalization */ + p = &curr->gch.next; + } + else { /* must call its gc method */ + *p = curr->gch.next; + curr->gch.next = NULL; /* link `curr' at the end of `collected' list */ + *lastcollected = curr; + lastcollected = &curr->gch.next; + } + } + /* insert collected udata with gc event into `tmudata' list */ + *lastcollected = G(L)->tmudata; + G(L)->tmudata = collected; +} + + +static void removekey (Node *n) { + setnilvalue(gval(n)); /* remove corresponding value ... */ + if (iscollectable(gkey(n))) + setttype(gkey(n), LUA_TNONE); /* dead key; remove it */ +} + + +static void traversetable (GCState *st, Table *h) { + int i; + int weakkey = 0; + int weakvalue = 0; + const TObject *mode; + markvalue(st, h->metatable); + lua_assert(h->lsizenode || h->node == st->g->dummynode); + mode = gfasttm(st->g, h->metatable, TM_MODE); + if (mode && ttisstring(mode)) { /* is there a weak mode? */ + weakkey = (strchr(svalue(mode), 'k') != NULL); + weakvalue = (strchr(svalue(mode), 'v') != NULL); + if (weakkey || weakvalue) { /* is really weak? */ + GCObject **weaklist; + h->marked &= ~(KEYWEAK | VALUEWEAK); /* clear bits */ + h->marked |= cast(lu_byte, (weakkey << KEYWEAKBIT) | + (weakvalue << VALUEWEAKBIT)); + weaklist = (weakkey && weakvalue) ? &st->wkv : + (weakkey) ? &st->wk : + &st->wv; + h->gclist = *weaklist; /* must be cleared after GC, ... */ + *weaklist = valtogco(h); /* ... so put in the appropriate list */ + } + } + if (!weakvalue) { + i = h->sizearray; + while (i--) + markobject(st, &h->array[i]); + } + i = sizenode(h); + while (i--) { + Node *n = gnode(h, i); + if (!ttisnil(gval(n))) { + lua_assert(!ttisnil(gkey(n))); + condmarkobject(st, gkey(n), !weakkey); + condmarkobject(st, gval(n), !weakvalue); + } + } +} + + +static void traverseproto (GCState *st, Proto *f) { + int i; + stringmark(f->source); + for (i=0; isizek; i++) { /* mark literal strings */ + if (ttisstring(f->k+i)) + stringmark(tsvalue(f->k+i)); + } + for (i=0; isizeupvalues; i++) /* mark upvalue names */ + stringmark(f->upvalues[i]); + for (i=0; isizep; i++) /* mark nested protos */ + markvalue(st, f->p[i]); + for (i=0; isizelocvars; i++) /* mark local-variable names */ + stringmark(f->locvars[i].varname); + lua_assert(luaG_checkcode(f)); +} + + + +static void traverseclosure (GCState *st, Closure *cl) { + if (cl->c.isC) { + int i; + for (i=0; ic.nupvalues; i++) /* mark its upvalues */ + markobject(st, &cl->c.upvalue[i]); + } + else { + int i; + lua_assert(cl->l.nupvalues == cl->l.p->nups); + markvalue(st, hvalue(&cl->l.g)); + markvalue(st, cl->l.p); + for (i=0; il.nupvalues; i++) { /* mark its upvalues */ + UpVal *u = cl->l.upvals[i]; + if (!u->marked) { + markobject(st, &u->value); + u->marked = 1; + } + } + } +} + + +static void checkstacksizes (lua_State *L, StkId max) { + int used = L->ci - L->base_ci; /* number of `ci' in use */ + if (4*used < L->size_ci && 2*BASIC_CI_SIZE < L->size_ci) + luaD_reallocCI(L, L->size_ci/2); /* still big enough... */ + else condhardstacktests(luaD_reallocCI(L, L->size_ci)); + used = max - L->stack; /* part of stack in use */ + if (4*used < L->stacksize && 2*(BASIC_STACK_SIZE+EXTRA_STACK) < L->stacksize) + luaD_reallocstack(L, L->stacksize/2); /* still big enough... */ + else condhardstacktests(luaD_reallocstack(L, L->stacksize)); +} + + +static void traversestack (GCState *st, lua_State *L1) { + StkId o, lim; + CallInfo *ci; + markobject(st, gt(L1)); + lim = L1->top; + for (ci = L1->base_ci; ci <= L1->ci; ci++) { + lua_assert(ci->top <= L1->stack_last); + lua_assert(ci->state & (CI_C | CI_HASFRAME | CI_SAVEDPC)); + if (!(ci->state & CI_C) && lim < ci->top) + lim = ci->top; + } + for (o = L1->stack; o < L1->top; o++) + markobject(st, o); + for (; o <= lim; o++) + setnilvalue(o); + checkstacksizes(L1, lim); +} + + +static void propagatemarks (GCState *st) { + while (st->tmark) { /* traverse marked objects */ + switch (st->tmark->gch.tt) { + case LUA_TTABLE: { + Table *h = gcotoh(st->tmark); + st->tmark = h->gclist; + traversetable(st, h); + break; + } + case LUA_TFUNCTION: { + Closure *cl = gcotocl(st->tmark); + st->tmark = cl->c.gclist; + traverseclosure(st, cl); + break; + } + case LUA_TTHREAD: { + lua_State *th = gcototh(st->tmark); + st->tmark = th->gclist; + traversestack(st, th); + break; + } + case LUA_TPROTO: { + Proto *p = gcotop(st->tmark); + st->tmark = p->gclist; + traverseproto(st, p); + break; + } + default: lua_assert(0); + } + } +} + + +static int valismarked (const TObject *o) { + if (ttisstring(o)) + stringmark(tsvalue(o)); /* strings are `values', so are never weak */ + return !iscollectable(o) || testbit(o->value.gc->gch.marked, 0); +} + + +/* +** clear collected keys from weaktables +*/ +static void cleartablekeys (GCObject *l) { + while (l) { + Table *h = gcotoh(l); + int i = sizenode(h); + lua_assert(h->marked & KEYWEAK); + while (i--) { + Node *n = gnode(h, i); + if (!valismarked(gkey(n))) /* key was collected? */ + removekey(n); /* remove entry from table */ + } + l = h->gclist; + } +} + + +/* +** clear collected values from weaktables +*/ +static void cleartablevalues (GCObject *l) { + while (l) { + Table *h = gcotoh(l); + int i = h->sizearray; + lua_assert(h->marked & VALUEWEAK); + while (i--) { + TObject *o = &h->array[i]; + if (!valismarked(o)) /* value was collected? */ + setnilvalue(o); /* remove value */ + } + i = sizenode(h); + while (i--) { + Node *n = gnode(h, i); + if (!valismarked(gval(n))) /* value was collected? */ + removekey(n); /* remove entry from table */ + } + l = h->gclist; + } +} + + +static void freeobj (lua_State *L, GCObject *o) { + switch (o->gch.tt) { + case LUA_TPROTO: luaF_freeproto(L, gcotop(o)); break; + case LUA_TFUNCTION: luaF_freeclosure(L, gcotocl(o)); break; + case LUA_TUPVAL: luaM_freelem(L, gcotouv(o)); break; + case LUA_TTABLE: luaH_free(L, gcotoh(o)); break; + case LUA_TTHREAD: { + lua_assert(gcototh(o) != L && gcototh(o) != G(L)->mainthread); + luaE_freethread(L, gcototh(o)); + break; + } + case LUA_TSTRING: { + luaM_free(L, o, sizestring(gcotots(o)->tsv.len)); + break; + } + case LUA_TUSERDATA: { + luaM_free(L, o, sizeudata(gcotou(o)->uv.len)); + break; + } + default: lua_assert(0); + } +} + + +static int sweeplist (lua_State *L, GCObject **p, int limit) { + GCObject *curr; + int count = 0; /* number of collected items */ + while ((curr = *p) != NULL) { + if (curr->gch.marked > limit) { + unmark(curr); + p = &curr->gch.next; + } + else { + count++; + *p = curr->gch.next; + freeobj(L, curr); + } + } + return count; +} + + +static void sweepstrings (lua_State *L, int all) { + int i; + for (i=0; istrt.size; i++) { /* for each list */ + G(L)->strt.nuse -= sweeplist(L, &G(L)->strt.hash[i], all); + } +} + + +static void checkSizes (lua_State *L) { + /* check size of string hash */ + if (G(L)->strt.nuse < cast(ls_nstr, G(L)->strt.size/4) && + G(L)->strt.size > MINSTRTABSIZE*2) + luaS_resize(L, G(L)->strt.size/2); /* table is too big */ + /* check size of buffer */ + if (luaZ_sizebuffer(&G(L)->buff) > LUA_MINBUFFER*2) { /* buffer too big? */ + size_t newsize = luaZ_sizebuffer(&G(L)->buff) / 2; + luaZ_resizebuffer(L, &G(L)->buff, newsize); + } + G(L)->GCthreshold = 2*G(L)->nblocks; /* new threshold */ +} + + +static void do1gcTM (lua_State *L, Udata *udata) { + const TObject *tm = fasttm(L, udata->uv.metatable, TM_GC); + if (tm != NULL) { + setobj2s(L->top, tm); + setuvalue(L->top+1, udata); + L->top += 2; + luaD_call(L, L->top - 2, 0); + } +} + + +void luaC_callGCTM (lua_State *L) { + lu_byte oldah = L->allowhook; + L->allowhook = 0; /* stop debug hooks during GC tag methods */ + L->top++; /* reserve space to keep udata while runs its gc method */ + while (G(L)->tmudata != NULL) { + GCObject *o = G(L)->tmudata; + Udata *udata = gcotou(o); + G(L)->tmudata = udata->uv.next; /* remove udata from `tmudata' */ + udata->uv.next = G(L)->rootudata; /* return it to `root' list */ + G(L)->rootudata = o; + setuvalue(L->top - 1, udata); /* keep a reference to it */ + unmark(o); + markfinalized(udata); + do1gcTM(L, udata); + } + L->top--; + L->allowhook = oldah; /* restore hooks */ +} + + +void luaC_sweep (lua_State *L, int all) { + if (all) all = 256; /* larger than any mark */ + sweeplist(L, &G(L)->rootudata, all); + sweepstrings(L, all); + sweeplist(L, &G(L)->rootgc, all); +} + + +/* mark root set */ +static void markroot (GCState *st, lua_State *L) { + global_State *g = st->g; + markobject(st, defaultmeta(L)); + markobject(st, registry(L)); + traversestack(st, g->mainthread); + if (L != g->mainthread) /* another thread is running? */ + markvalue(st, L); /* cannot collect it */ +} + + +static void mark (lua_State *L) { + GCState st; + GCObject *wkv; + st.g = G(L); + st.tmark = NULL; + st.wkv = st.wk = st.wv = NULL; + markroot(&st, L); + propagatemarks(&st); /* mark all reachable objects */ + cleartablevalues(st.wkv); + cleartablevalues(st.wv); + wkv = st.wkv; /* keys must be cleared after preserving udata */ + st.wkv = NULL; + st.wv = NULL; + luaC_separateudata(L); /* separate userdata to be preserved */ + marktmu(&st); /* mark `preserved' userdata */ + propagatemarks(&st); /* remark, to propagate `preserveness' */ + cleartablekeys(wkv); + /* `propagatemarks' may resuscitate some weak tables; clear them too */ + cleartablekeys(st.wk); + cleartablevalues(st.wv); + cleartablekeys(st.wkv); + cleartablevalues(st.wkv); +} + + +void luaC_collectgarbage (lua_State *L) { + mark(L); + luaC_sweep(L, 0); + checkSizes(L); + luaC_callGCTM(L); +} + + +void luaC_link (lua_State *L, GCObject *o, lu_byte tt) { + o->gch.next = G(L)->rootgc; + G(L)->rootgc = o; + o->gch.marked = 0; + o->gch.tt = tt; +} + -- cgit v1.2.3