lua/lstate.c
Roberto Ierusalimschy de6fc75d63 several configuration options that do not change often moved out of
luaconf.h and into more internal files
2009-12-17 10:26:09 -02:00

289 lines
6.8 KiB
C

/*
** $Id: lstate.c,v 2.66 2009/12/16 16:42:58 roberto Exp roberto $
** Global State
** See Copyright Notice in lua.h
*/
#include <stddef.h>
#define lstate_c
#define LUA_CORE
#include "lua.h"
#include "lapi.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"
#if !defined(LUAI_GCPAUSE)
#define LUAI_GCPAUSE 162 /* 162% (wait memory to double before next GC) */
#endif
#if !defined(LUAI_GCMUL)
#define LUAI_GCMUL 200 /* GC runs 'twice the speed' of memory allocation */
#endif
/*
** thread state + extra space
*/
typedef struct LX {
#if defined(LUAI_EXTRASPACE)
char buff[LUAI_EXTRASPACE];
#endif
lua_State l;
} LX;
/*
** Main thread combines a thread state and the global state
*/
typedef struct LG {
LX l;
global_State g;
} LG;
#define fromstate(L) (cast(LX *, cast(lu_byte *, (L)) - offsetof(LX, l)))
/*
** maximum number of nested calls made by error-handling function
*/
#define LUAI_EXTRACALLS 10
CallInfo *luaE_extendCI (lua_State *L) {
CallInfo *ci = luaM_new(L, CallInfo);
lua_assert(L->ci->next == NULL);
L->ci->next = ci;
ci->previous = L->ci;
ci->next = NULL;
return ci;
}
void luaE_freeCI (lua_State *L) {
CallInfo *ci = L->ci;
CallInfo *next = ci->next;
ci->next = NULL;
while ((ci = next) != NULL) {
next = ci->next;
luaM_free(L, ci);
}
}
static void stack_init (lua_State *L1, lua_State *L) {
int i;
/* initialize stack array */
L1->stack = luaM_newvector(L, BASIC_STACK_SIZE, TValue);
L1->stacksize = BASIC_STACK_SIZE;
for (i = 0; i < BASIC_STACK_SIZE; i++)
setnilvalue(L1->stack + i); /* erase new stack */
L1->top = L1->stack;
L1->stack_last = L1->stack + L1->stacksize - EXTRA_STACK;
/* initialize first ci */
L1->ci->func = L1->top;
setnilvalue(L1->top++); /* 'function' entry for this 'ci' */
L1->ci->top = L1->top + LUA_MINSTACK;
L1->ci->callstatus = 0;
}
static void freestack (lua_State *L) {
L->ci = &L->base_ci; /* reset 'ci' list */
luaE_freeCI(L);
luaM_freearray(L, L->stack, L->stacksize);
}
/*
** Calls the function in variable pointed to by userdata in first argument
** (Userdata cannot point directly to the function because pointer to
** function is not compatible with void*.)
*/
static int cpcall (lua_State *L) {
lua_CFunction f = *(lua_CFunction *)lua_touserdata(L, 1);
lua_remove(L, 1); /* remove f from stack */
/* restore original environment for 'cpcall' */
lua_copy(L, LUA_GLOBALSINDEX, LUA_ENVIRONINDEX);
return f(L);
}
/*
** Create registry table and its predefined values
*/
static void init_registry (lua_State *L, global_State *g) {
Closure *cp;
TValue mt;
/* create registry */
Table *registry = luaH_new(L);
sethvalue(L, &g->l_registry, registry);
luaH_resize(L, registry, LUA_RIDX_LAST, 0);
/* registry[LUA_RIDX_MAINTHREAD] = L */
setthvalue(L, &mt, L);
setobj2t(L, luaH_setint(L, registry, LUA_RIDX_MAINTHREAD), &mt);
/* registry[LUA_RIDX_CPCALL] = cpcall */
cp = luaF_newCclosure(L, 0, hvalue(&g->l_gt));
cp->c.f = cpcall;
setclvalue(L, &mt, cp);
setobj2t(L, luaH_setint(L, registry, LUA_RIDX_CPCALL), &mt);
}
/*
** open parts of the state 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, &g->l_gt, luaH_new(L)); /* table of globals */
init_registry(L, g);
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;
}
/*
** preinitialize a state with consistent values without allocating
** any memory (to avoid errors)
*/
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->nny = 1;
L->status = LUA_OK;
L->base_ci.next = L->base_ci.previous = NULL;
L->ci = &L->base_ci;
L->errfunc = 0;
}
static void close_state (lua_State *L) {
global_State *g = G(L);
luaF_close(L, L->stack); /* close all upvalues for this thread */
luaC_freeallobjects(L); /* collect all objects */
luaM_freearray(L, G(L)->strt.hash, G(L)->strt.size);
luaZ_freebuffer(L, &g->buff);
freestack(L);
lua_assert(g->totalbytes == sizeof(LG));
(*g->frealloc)(g->ud, fromstate(L), sizeof(LG), 0);
}
LUA_API lua_State *lua_newthread (lua_State *L) {
lua_State *L1;
lua_lock(L);
luaC_checkGC(L);
L1 = &luaC_newobj(L, LUA_TTHREAD, sizeof(LX), NULL, offsetof(LX, l))->th;
setthvalue(L, L->top, L1);
api_incr_top(L);
preinit_state(L1, G(L));
stack_init(L1, L); /* init stack */
L1->hookmask = L->hookmask;
L1->basehookcount = L->basehookcount;
L1->hook = L->hook;
resethookcount(L1);
lua_assert(iswhite(obj2gco(L1)));
lua_unlock(L);
luai_userstatethread(L, L1);
return L1;
}
void luaE_freethread (lua_State *L, lua_State *L1) {
LX *l = fromstate(L1);
luaF_close(L1, L1->stack); /* close all upvalues for this thread */
lua_assert(L1->openupval == NULL);
luai_userstatefree(L1);
freestack(L1);
luaM_free(L, l);
}
LUA_API lua_State *lua_newstate (lua_Alloc f, void *ud) {
int i;
lua_State *L;
global_State *g;
LG *l = cast(LG *, (*f)(ud, NULL, 0, sizeof(LG)));
if (l == NULL) return NULL;
L = &l->l.l;
g = &l->g;
L->next = NULL;
L->tt = LUA_TTHREAD;
g->currentwhite = bit2mask(WHITE0BIT, FIXEDBIT);
L->marked = luaC_white(g);
g->gckind = KGC_NORMAL;
g->nCcalls = 0;
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 = MAX_LUMEM; /* no GC while building state */
g->strt.size = 0;
g->strt.nuse = 0;
g->strt.hash = NULL;
setnilvalue(&g->l_registry);
setnilvalue(&g->l_gt);
luaZ_initbuffer(L, &g->buff);
g->panic = NULL;
g->version = lua_version(NULL);
g->gcstate = GCSpause;
g->rootgc = obj2gco(L);
g->tobefnz = NULL;
g->totalbytes = sizeof(LG);
g->gcpause = LUAI_GCPAUSE;
g->gcstepmul = LUAI_GCMUL;
for (i=0; i<NUM_TAGS; i++) g->mt[i] = NULL;
if (luaD_rawrunprotected(L, f_luaopen, NULL) != LUA_OK) {
/* memory allocation error: free partial state */
close_state(L);
L = NULL;
}
else
luai_userstateopen(L);
return L;
}
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 all udata with GC metamethods */
lua_assert(L->next == NULL);
luai_userstateclose(L);
close_state(L);
}