diff options
author | Manoj Srivastava <srivasta@debian.org> | 2020-05-22 19:57:41 -0700 |
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committer | Manoj Srivastava <srivasta@debian.org> | 2020-05-22 20:02:19 -0700 |
commit | c3d2579ad8d7eb33059aa8fdbaf5b564411a57f2 (patch) | |
tree | 1570cda0676fdcf4171a69a7fe313c1b89a52b0c /src/lua/lgc.c | |
parent | 986b7742bf244b4073ecca0723615f70be8a1ab6 (diff) | |
parent | 4e9b9c402ed95bf9a17fd6d795bc49bb4128a6fa (diff) |
Merge branch 'upstream' into debian-cmake-fixes
Diffstat (limited to 'src/lua/lgc.c')
-rw-r--r-- | src/lua/lgc.c | 353 |
1 files changed, 0 insertions, 353 deletions
diff --git a/src/lua/lgc.c b/src/lua/lgc.c deleted file mode 100644 index 4e8b234d..00000000 --- a/src/lua/lgc.c +++ /dev/null @@ -1,353 +0,0 @@ -/* -** $Id: lgc.c,v 1.3 2001/11/26 23:00:24 darkgod Exp $ -** Garbage Collector -** See Copyright Notice in lua.h -*/ - -#include "lua.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 { - Hash *tmark; /* list of marked tables to be visited */ - Closure *cmark; /* list of marked closures to be visited */ -} GCState; - - - -static void markobject (GCState *st, TObject *o); - - -/* mark a string; marks larger than 1 cannot be changed */ -#define strmark(s) {if ((s)->marked == 0) (s)->marked = 1;} - - - -static void protomark (Proto *f) { - if (!f->marked) { - int i; - f->marked = 1; - strmark(f->source); - for (i=0; i<f->nkstr; i++) - strmark(f->kstr[i]); - for (i=0; i<f->nkproto; i++) - protomark(f->kproto[i]); - for (i=0; i<f->nlocvars; i++) /* mark local-variable names */ - strmark(f->locvars[i].varname); - } -} - - -static void markstack (lua_State *L, GCState *st) { - StkId o; - for (o=L->stack; o<L->top; o++) - markobject(st, o); -} - - -static void marklock (lua_State *L, GCState *st) { - int i; - for (i=0; i<L->refSize; i++) { - if (L->refArray[i].st == LOCK) - markobject(st, &L->refArray[i].o); - } -} - - -static void markclosure (GCState *st, Closure *cl) { - if (!ismarked(cl)) { - if (!cl->isC) - protomark(cl->f.l); - cl->mark = st->cmark; /* chain it for later traversal */ - st->cmark = cl; - } -} - - -static void marktagmethods (lua_State *L, GCState *st) { - int e; - for (e=0; e<TM_N; e++) { - int t; - for (t=0; t<=L->last_tag; t++) { - Closure *cl = luaT_gettm(L, t, e); - if (cl) markclosure(st, cl); - } - } -} - - -static void markobject (GCState *st, TObject *o) { - switch (ttype(o)) { - case LUA_TUSERDATA: case LUA_TSTRING: - strmark(tsvalue(o)); - break; - case LUA_TMARK: - markclosure(st, infovalue(o)->func); - break; - case LUA_TFUNCTION: - markclosure(st, clvalue(o)); - break; - case LUA_TTABLE: { - if (!ismarked(hvalue(o))) { - hvalue(o)->mark = st->tmark; /* chain it in list of marked */ - st->tmark = hvalue(o); - } - break; - } - default: break; /* numbers, etc */ - } -} - - -static void markall (lua_State *L) { - GCState st; - st.cmark = NULL; - st.tmark = L->gt; /* put table of globals in mark list */ - L->gt->mark = NULL; - marktagmethods(L, &st); /* mark tag methods */ - markstack(L, &st); /* mark stack objects */ - marklock(L, &st); /* mark locked objects */ - for (;;) { /* mark tables and closures */ - if (st.cmark) { - int i; - Closure *f = st.cmark; /* get first closure from list */ - st.cmark = f->mark; /* remove it from list */ - for (i=0; i<f->nupvalues; i++) /* mark its upvalues */ - markobject(&st, &f->upvalue[i]); - } - else if (st.tmark) { - int i; - Hash *h = st.tmark; /* get first table from list */ - st.tmark = h->mark; /* remove it from list */ - for (i=0; i<h->size; i++) { - Node *n = node(h, i); - if (ttype(key(n)) != LUA_TNIL) { - if (ttype(val(n)) == LUA_TNIL) - luaH_remove(h, key(n)); /* dead element; try to remove it */ - markobject(&st, &n->key); - markobject(&st, &n->val); - } - } - } - else break; /* nothing else to mark */ - } -} - - -static int hasmark (const TObject *o) { - /* valid only for locked objects */ - switch (o->ttype) { - case LUA_TSTRING: case LUA_TUSERDATA: - return tsvalue(o)->marked; - case LUA_TTABLE: - return ismarked(hvalue(o)); - case LUA_TFUNCTION: - return ismarked(clvalue(o)); - default: /* number */ - return 1; - } -} - - -/* macro for internal debugging; check if a link of free refs is valid */ -#define VALIDLINK(L, st,n) (NONEXT <= (st) && (st) < (n)) - -static void invalidaterefs (lua_State *L) { - int n = L->refSize; - int i; - for (i=0; i<n; i++) { - struct Ref *r = &L->refArray[i]; - if (r->st == HOLD && !hasmark(&r->o)) - r->st = COLLECTED; - LUA_ASSERT((r->st == LOCK && hasmark(&r->o)) || - (r->st == HOLD && hasmark(&r->o)) || - r->st == COLLECTED || - r->st == NONEXT || - (r->st < n && VALIDLINK(L, L->refArray[r->st].st, n)), - "inconsistent ref table"); - } - LUA_ASSERT(VALIDLINK(L, L->refFree, n), "inconsistent ref table"); -} - - - -static void collectproto (lua_State *L) { - Proto **p = &L->rootproto; - Proto *next; - while ((next = *p) != NULL) { - if (next->marked) { - next->marked = 0; - p = &next->next; - } - else { - *p = next->next; - luaF_freeproto(L, next); - } - } -} - - -static void collectclosure (lua_State *L) { - Closure **p = &L->rootcl; - Closure *next; - while ((next = *p) != NULL) { - if (ismarked(next)) { - next->mark = next; /* unmark */ - p = &next->next; - } - else { - *p = next->next; - luaF_freeclosure(L, next); - } - } -} - - -static void collecttable (lua_State *L) { - Hash **p = &L->roottable; - Hash *next; - while ((next = *p) != NULL) { - if (ismarked(next)) { - next->mark = next; /* unmark */ - p = &next->next; - } - else { - *p = next->next; - luaH_free(L, next); - } - } -} - - -static void checktab (lua_State *L, stringtable *tb) { - if (tb->nuse < (lint32)(tb->size/4) && tb->size > 10) - luaS_resize(L, tb, tb->size/2); /* table is too big */ -} - - -static void collectstrings (lua_State *L, int all) { - int i; - for (i=0; i<L->strt.size; i++) { /* for each list */ - TString **p = &L->strt.hash[i]; - TString *next; - while ((next = *p) != NULL) { - if (next->marked && !all) { /* preserve? */ - if (next->marked < FIXMARK) /* does not change FIXMARKs */ - next->marked = 0; - p = &next->nexthash; - } - else { /* collect */ - *p = next->nexthash; - L->strt.nuse--; - L->nblocks -= sizestring(next->len); - luaM_free(L, next); - } - } - } - checktab(L, &L->strt); -} - - -static void collectudata (lua_State *L, int all) { - int i; - for (i=0; i<L->udt.size; i++) { /* for each list */ - TString **p = &L->udt.hash[i]; - TString *next; - while ((next = *p) != NULL) { - LUA_ASSERT(next->marked <= 1, "udata cannot be fixed"); - if (next->marked && !all) { /* preserve? */ - next->marked = 0; - p = &next->nexthash; - } - else { /* collect */ - int tag = next->u.d.tag; - *p = next->nexthash; - next->nexthash = L->TMtable[tag].collected; /* chain udata */ - L->TMtable[tag].collected = next; - L->nblocks -= sizestring(next->len); - L->udt.nuse--; - } - } - } - checktab(L, &L->udt); -} - - -#define MINBUFFER 256 -static void checkMbuffer (lua_State *L) { - if (L->Mbuffsize > MINBUFFER*2) { /* is buffer too big? */ - size_t newsize = L->Mbuffsize/2; /* still larger than MINBUFFER */ - L->nblocks += (newsize - L->Mbuffsize)*sizeof(char); - L->Mbuffsize = newsize; - luaM_reallocvector(L, L->Mbuffer, newsize, char); - } -} - - -static void callgcTM (lua_State *L, const TObject *o) { - Closure *tm = luaT_gettmbyObj(L, o, TM_GC); - if (tm != NULL) { - int oldah = L->allowhooks; - L->allowhooks = 0; /* stop debug hooks during GC tag methods */ - luaD_checkstack(L, 2); - clvalue(L->top) = tm; - ttype(L->top) = LUA_TFUNCTION; - *(L->top+1) = *o; - L->top += 2; - luaD_call(L, L->top-2, 0); - L->allowhooks = oldah; /* restore hooks */ - } -} - - -static void callgcTMudata (lua_State *L) { - int tag; - TObject o; - ttype(&o) = LUA_TUSERDATA; - L->GCthreshold = 2*L->nblocks; /* avoid GC during tag methods */ - for (tag=L->last_tag; tag>=0; tag--) { /* for each tag (in reverse order) */ - TString *udata; - while ((udata = L->TMtable[tag].collected) != NULL) { - L->TMtable[tag].collected = udata->nexthash; /* remove it from list */ - tsvalue(&o) = udata; - callgcTM(L, &o); - luaM_free(L, udata); - } - } -} - - -void luaC_collect (lua_State *L, int all) { - collectudata(L, all); - callgcTMudata(L); - collectstrings(L, all); - collecttable(L); - collectproto(L); - collectclosure(L); -} - - -static void luaC_collectgarbage (lua_State *L) { - markall(L); - invalidaterefs(L); /* check unlocked references */ - luaC_collect(L, 0); - checkMbuffer(L); - L->GCthreshold = 2*L->nblocks; /* set new threshold */ - callgcTM(L, &luaO_nilobject); -} - - -void luaC_checkGC (lua_State *L) { - if (L->nblocks >= L->GCthreshold) - luaC_collectgarbage(L); -} - |