/*

 ** $Id: lstate.c,v 2.36.1.2 2008/01/03 15:20:39 roberto Exp $

 ** Global State

 ** See Copyright Notice in lua.h

 */

 

 

 #include <stddef.h>

 

 #define lstate_c

 #define LUA_CORE

 

 #include "lua.h"

 

 #include "ldebug.h"

 #include "ldo.h"

 #include "lfunc.h"

 #include "lgc.h"

 #include "llex.h"

 #include "lmem.h"

 #include "lstate.h"

 #include "lstring.h"

 #include "ltable.h"

 #include "ltm.h"

 

 

 #define state_size(x)	(sizeof(x) + LUAI_EXTRASPACE)

 #define fromstate(l)	(cast(lu_byte *, (l)) - LUAI_EXTRASPACE)

 #define tostate(l)   (cast(lua_State *, cast(lu_byte *, l) + LUAI_EXTRASPACE))

 

 

 /*

 ** Main thread combines a thread state and the global state

 */

 typedef struct LG {

   lua_State l;

   global_State g;

 } LG;

   

 

 

 static void stack_init (lua_State *L1, lua_State *L) {

   /* initialize CallInfo array */

   L1->base_ci = luaM_newvector(L, BASIC_CI_SIZE, CallInfo);

   L1->ci = L1->base_ci;

   L1->size_ci = BASIC_CI_SIZE;

   L1->end_ci = L1->base_ci + L1->size_ci - 1;

   /* initialize stack array */

   L1->stack = luaM_newvector(L, BASIC_STACK_SIZE + EXTRA_STACK, TValue);

   L1->stacksize = BASIC_STACK_SIZE + EXTRA_STACK;

   L1->top = L1->stack;

   L1->stack_last = L1->stack+(L1->stacksize - EXTRA_STACK)-1;

   /* initialize first ci */

   L1->ci->func = L1->top;

   setnilvalue(L1->top++);  /* `function' entry for this `ci' */

   L1->base = L1->ci->base = L1->top;

   L1->ci->top = L1->top + LUA_MINSTACK;

 }

 

 

 static void freestack (lua_State *L, lua_State *L1) {

   luaM_freearray(L, L1->base_ci, L1->size_ci, CallInfo);

   luaM_freearray(L, L1->stack, L1->stacksize, TValue);

 }

 

 

 /*

 ** open parts that may cause memory-allocation errors

 */

 static void f_luaopen (lua_State *L, void *ud) {

   global_State *g = G(L);

   UNUSED(ud);

   stack_init(L, L);  /* init stack */

   sethvalue(L, gt(L), luaH_new(L, 0, 2));  /* table of globals */

   sethvalue(L, registry(L), luaH_new(L, 0, 2));  /* registry */

   luaS_resize(L, MINSTRTABSIZE);  /* initial size of string table */

   luaT_init(L);

   luaX_init(L);

   luaS_fix(luaS_newliteral(L, MEMERRMSG));

   g->GCthreshold = 4*g->totalbytes;

 }

 

 

 static void preinit_state (lua_State *L, global_State *g) {

   G(L) = g;

   L->stack = NULL;

   L->stacksize = 0;

   L->errorJmp = NULL;

   L->hook = NULL;

   L->hookmask = 0;

   L->basehookcount = 0;

   L->allowhook = 1;

   resethookcount(L);

   L->openupval = NULL;

   L->size_ci = 0;

   L->nCcalls = L->baseCcalls = 0;

   L->status = 0;

   L->base_ci = L->ci = NULL;

   L->savedpc = NULL;

   L->errfunc = 0;

   setnilvalue(gt(L));

 }

 

 

 static void close_state (lua_State *L) {

   global_State *g = G(L);

   luaF_close(L, L->stack);  /* close all upvalues for this thread */

   luaC_freeall(L);  /* collect all objects */

   lua_assert(g->rootgc == obj2gco(L));

   lua_assert(g->strt.nuse == 0);

   luaM_freearray(L, G(L)->strt.hash, G(L)->strt.size, TString *);

   luaZ_freebuffer(L, &g->buff);

   freestack(L, L);

   lua_assert(g->totalbytes == sizeof(LG));

   (*g->frealloc)(g->ud, fromstate(L), state_size(LG), 0);

 }

 

 

 lua_State *luaE_newthread (lua_State *L) {

   lua_State *L1 = tostate(luaM_malloc(L, state_size(lua_State)));

   luaC_link(L, obj2gco(L1), LUA_TTHREAD);

   preinit_state(L1, G(L));

   stack_init(L1, L);  /* init stack */

   setobj2n(L, gt(L1), gt(L));  /* share table of globals */

   L1->hookmask = L->hookmask;

   L1->basehookcount = L->basehookcount;

   L1->hook = L->hook;

   resethookcount(L1);

   lua_assert(iswhite(obj2gco(L1)));

   return L1;

 }

 

 

 void luaE_freethread (lua_State *L, lua_State *L1) {

   luaF_close(L1, L1->stack);  /* close all upvalues for this thread */

   lua_assert(L1->openupval == NULL);

   luai_userstatefree(L1);

   freestack(L, L1);

   luaM_freemem(L, fromstate(L1), state_size(lua_State));

 }

 

 

 LUA_API lua_State *lua_newstate (lua_Alloc f, void *ud) {

   int i;

   lua_State *L;

   global_State *g;

   void *l = (*f)(ud, NULL, 0, state_size(LG));

   if (l == NULL) return NULL;

   L = tostate(l);

   g = &((LG *)L)->g;

   L->next = NULL;

   L->tt = LUA_TTHREAD;

   g->currentwhite = bit2mask(WHITE0BIT, FIXEDBIT);

   L->marked = luaC_white(g);

   set2bits(L->marked, FIXEDBIT, SFIXEDBIT);

   preinit_state(L, g);

   g->frealloc = f;

   g->ud = ud;

   g->mainthread = L;

   g->uvhead.u.l.prev = &g->uvhead;

   g->uvhead.u.l.next = &g->uvhead;

   g->GCthreshold = 0;  /* mark it as unfinished state */

   g->strt.size = 0;

   g->strt.nuse = 0;

   g->strt.hash = NULL;

   setnilvalue(registry(L));

   luaZ_initbuffer(L, &g->buff);

   g->panic = NULL;

   g->gcstate = GCSpause;

   g->rootgc = obj2gco(L);

   g->sweepstrgc = 0;

   g->sweepgc = &g->rootgc;

   g->gray = NULL;

   g->grayagain = NULL;

   g->weak = NULL;

   g->tmudata = NULL;

   g->totalbytes = sizeof(LG);

   g->gcpause = LUAI_GCPAUSE;

   g->gcstepmul = LUAI_GCMUL;

   g->gcdept = 0;

   for (i=0; i<NUM_TAGS; i++) g->mt[i] = NULL;

   if (luaD_rawrunprotected(L, f_luaopen, NULL) != 0) {

     /* memory allocation error: free partial state */

     close_state(L);

     L = NULL;

   }

   else

     luai_userstateopen(L);

   return L;

 }

 

 

 static void callallgcTM (lua_State *L, void *ud) {

   UNUSED(ud);

   luaC_callGCTM(L);  /* call GC metamethods for all udata */

 }

 

 

 LUA_API void lua_close (lua_State *L) {

   L = G(L)->mainthread;  /* only the main thread can be closed */

   lua_lock(L);

   luaF_close(L, L->stack);  /* close all upvalues for this thread */

   luaC_separateudata(L, 1);  /* separate udata that have GC metamethods */

   L->errfunc = 0;  /* no error function during GC metamethods */

   do {  /* repeat until no more errors */

     L->ci = L->base_ci;

     L->base = L->top = L->ci->base;

     L->nCcalls = L->baseCcalls = 0;

   } while (luaD_rawrunprotected(L, callallgcTM, NULL) != 0);

   lua_assert(G(L)->tmudata == NULL);

   luai_userstateclose(L);

   close_state(L);

 }