/*

** $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);

}