diff options
Diffstat (limited to 'src/lua/src/lstate.c')
| -rw-r--r-- | src/lua/src/lstate.c | 347 |
1 files changed, 347 insertions, 0 deletions
diff --git a/src/lua/src/lstate.c b/src/lua/src/lstate.c new file mode 100644 index 00000000..9194ac34 --- /dev/null +++ b/src/lua/src/lstate.c @@ -0,0 +1,347 @@ +/* +** $Id: lstate.c,v 2.133 2015/11/13 12:16:51 roberto Exp $ +** Global State +** See Copyright Notice in lua.h +*/ + +#define lstate_c +#define LUA_CORE + +#include "lprefix.h" + + +#include <stddef.h> +#include <string.h> + +#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 200 /* 200% */ +#endif + +#if !defined(LUAI_GCMUL) +#define LUAI_GCMUL 200 /* GC runs 'twice the speed' of memory allocation */ +#endif + + +/* +** a macro to help the creation of a unique random seed when a state is +** created; the seed is used to randomize hashes. +*/ +#if !defined(luai_makeseed) +#include <time.h> +#define luai_makeseed() cast(unsigned int, time(NULL)) +#endif + + + +/* +** thread state + extra space +*/ +typedef struct LX { + lu_byte extra_[LUA_EXTRASPACE]; + 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))) + + +/* +** Compute an initial seed as random as possible. Rely on Address Space +** Layout Randomization (if present) to increase randomness.. +*/ +#define addbuff(b,p,e) \ + { size_t t = cast(size_t, e); \ + memcpy(b + p, &t, sizeof(t)); p += sizeof(t); } + +static unsigned int makeseed (lua_State *L) { + char buff[4 * sizeof(size_t)]; + unsigned int h = luai_makeseed(); + int p = 0; + addbuff(buff, p, L); /* heap variable */ + addbuff(buff, p, &h); /* local variable */ + addbuff(buff, p, luaO_nilobject); /* global variable */ + addbuff(buff, p, &lua_newstate); /* public function */ + lua_assert(p == sizeof(buff)); + return luaS_hash(buff, p, h); +} + + +/* +** set GCdebt to a new value keeping the value (totalbytes + GCdebt) +** invariant (and avoiding underflows in 'totalbytes') +*/ +void luaE_setdebt (global_State *g, l_mem debt) { + l_mem tb = gettotalbytes(g); + lua_assert(tb > 0); + if (debt < tb - MAX_LMEM) + debt = tb - MAX_LMEM; /* will make 'totalbytes == MAX_LMEM' */ + g->totalbytes = tb - debt; + g->GCdebt = debt; +} + + +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; + L->nci++; + return ci; +} + + +/* +** free all CallInfo structures not in use by a thread +*/ +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); + L->nci--; + } +} + + +/* +** free half of the CallInfo structures not in use by a thread +*/ +void luaE_shrinkCI (lua_State *L) { + CallInfo *ci = L->ci; + CallInfo *next2; /* next's next */ + /* while there are two nexts */ + while (ci->next != NULL && (next2 = ci->next->next) != NULL) { + luaM_free(L, ci->next); /* free next */ + L->nci--; + ci->next = next2; /* remove 'next' from the list */ + next2->previous = ci; + ci = next2; /* keep next's next */ + } +} + + +static void stack_init (lua_State *L1, lua_State *L) { + int i; CallInfo *ci; + /* 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 */ + ci = &L1->base_ci; + ci->next = ci->previous = NULL; + ci->callstatus = 0; + ci->func = L1->top; + setnilvalue(L1->top++); /* 'function' entry for this 'ci' */ + ci->top = L1->top + LUA_MINSTACK; + L1->ci = ci; +} + + +static void freestack (lua_State *L) { + if (L->stack == NULL) + return; /* stack not completely built yet */ + L->ci = &L->base_ci; /* free the entire 'ci' list */ + luaE_freeCI(L); + lua_assert(L->nci == 0); + luaM_freearray(L, L->stack, L->stacksize); /* free stack array */ +} + + +/* +** Create registry table and its predefined values +*/ +static void init_registry (lua_State *L, global_State *g) { + TValue temp; + /* 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, &temp, L); /* temp = L */ + luaH_setint(L, registry, LUA_RIDX_MAINTHREAD, &temp); + /* registry[LUA_RIDX_GLOBALS] = table of globals */ + sethvalue(L, &temp, luaH_new(L)); /* temp = new table (global table) */ + luaH_setint(L, registry, LUA_RIDX_GLOBALS, &temp); +} + + +/* +** open parts of the state that may cause memory-allocation errors. +** ('g->version' != NULL flags that the state was completely build) +*/ +static void f_luaopen (lua_State *L, void *ud) { + global_State *g = G(L); + UNUSED(ud); + stack_init(L, L); /* init stack */ + init_registry(L, g); + luaS_init(L); + luaT_init(L); + luaX_init(L); + g->gcrunning = 1; /* allow gc */ + g->version = lua_version(NULL); + luai_userstateopen(L); +} + + +/* +** preinitialize a thread with consistent values without allocating +** any memory (to avoid errors) +*/ +static void preinit_thread (lua_State *L, global_State *g) { + G(L) = g; + L->stack = NULL; + L->ci = NULL; + L->nci = 0; + L->stacksize = 0; + L->twups = L; /* thread has no upvalues */ + L->errorJmp = NULL; + L->nCcalls = 0; + 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->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 */ + if (g->version) /* closing a fully built state? */ + luai_userstateclose(L); + luaM_freearray(L, G(L)->strt.hash, G(L)->strt.size); + freestack(L); + lua_assert(gettotalbytes(g) == sizeof(LG)); + (*g->frealloc)(g->ud, fromstate(L), sizeof(LG), 0); /* free main block */ +} + + +LUA_API lua_State *lua_newthread (lua_State *L) { + global_State *g = G(L); + lua_State *L1; + lua_lock(L); + luaC_checkGC(L); + /* create new thread */ + L1 = &cast(LX *, luaM_newobject(L, LUA_TTHREAD, sizeof(LX)))->l; + L1->marked = luaC_white(g); + L1->tt = LUA_TTHREAD; + /* link it on list 'allgc' */ + L1->next = g->allgc; + g->allgc = obj2gco(L1); + /* anchor it on L stack */ + setthvalue(L, L->top, L1); + api_incr_top(L); + preinit_thread(L1, g); + L1->hookmask = L->hookmask; + L1->basehookcount = L->basehookcount; + L1->hook = L->hook; + resethookcount(L1); + /* initialize L1 extra space */ + memcpy(lua_getextraspace(L1), lua_getextraspace(g->mainthread), + LUA_EXTRASPACE); + luai_userstatethread(L, L1); + stack_init(L1, L); /* init stack */ + lua_unlock(L); + 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(L, 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, LUA_TTHREAD, sizeof(LG))); + if (l == NULL) return NULL; + L = &l->l.l; + g = &l->g; + L->next = NULL; + L->tt = LUA_TTHREAD; + g->currentwhite = bitmask(WHITE0BIT); + L->marked = luaC_white(g); + preinit_thread(L, g); + g->frealloc = f; + g->ud = ud; + g->mainthread = L; + g->seed = makeseed(L); + g->gcrunning = 0; /* no GC while building state */ + g->GCestimate = 0; + g->strt.size = g->strt.nuse = 0; + g->strt.hash = NULL; + setnilvalue(&g->l_registry); + g->panic = NULL; + g->version = NULL; + g->gcstate = GCSpause; + g->gckind = KGC_NORMAL; + g->allgc = g->finobj = g->tobefnz = g->fixedgc = NULL; + g->sweepgc = NULL; + g->gray = g->grayagain = NULL; + g->weak = g->ephemeron = g->allweak = NULL; + g->twups = NULL; + g->totalbytes = sizeof(LG); + g->GCdebt = 0; + g->gcfinnum = 0; + g->gcpause = LUAI_GCPAUSE; + g->gcstepmul = LUAI_GCMUL; + for (i=0; i < LUA_NUMTAGS; 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; + } + return L; +} + + +LUA_API void lua_close (lua_State *L) { + L = G(L)->mainthread; /* only the main thread can be closed */ + lua_lock(L); + close_state(L); +} + + |