1/*
2** $Id: lstate.c,v 2.36.1.2 2008/01/03 15:20:39 roberto Exp $
3** Global State
4** See Copyright Notice in lua.h
5*/
6
7
8#include <stddef.h>
9
10#define lstate_c
11#define LUA_CORE
12
13#include "lua.h"
14
15#include "ldebug.h"
16#include "ldo.h"
17#include "lfunc.h"
18#include "lgc.h"
19#include "llex.h"
20#include "lmem.h"
21#include "lstate.h"
22#include "lstring.h"
23#include "ltable.h"
24#include "ltm.h"
25
26
27#define state_size(x) (sizeof(x) + LUAI_EXTRASPACE)
28#define fromstate(l) (cast(lu_byte *, (l)) - LUAI_EXTRASPACE)
29#define tostate(l) (cast(lua_State *, cast(lu_byte *, l) + LUAI_EXTRASPACE))
30
31
32/*
33** Main thread combines a thread state and the global state
34*/
35typedef struct LG {
36 lua_State l;
37 global_State g;
38} LG;
39
40
41
42static void stack_init (lua_State *L1, lua_State *L) {
43 /* initialize CallInfo array */
44 L1->base_ci = luaM_newvector(L, BASIC_CI_SIZE, CallInfo);
45 L1->ci = L1->base_ci;
46 L1->size_ci = BASIC_CI_SIZE;
47 L1->end_ci = L1->base_ci + L1->size_ci - 1;
48 /* initialize stack array */
49 L1->stack = luaM_newvector(L, BASIC_STACK_SIZE + EXTRA_STACK, TValue);
50 L1->stacksize = BASIC_STACK_SIZE + EXTRA_STACK;
51 L1->top = L1->stack;
52 L1->stack_last = L1->stack+(L1->stacksize - EXTRA_STACK)-1;
53 /* initialize first ci */
54 L1->ci->func = L1->top;
55 setnilvalue(L1->top++); /* `function' entry for this `ci' */
56 L1->base = L1->ci->base = L1->top;
57 L1->ci->top = L1->top + LUA_MINSTACK;
58}
59
60
61static void freestack (lua_State *L, lua_State *L1) {
62 luaM_freearray(L, L1->base_ci, L1->size_ci, CallInfo);
63 luaM_freearray(L, L1->stack, L1->stacksize, TValue);
64}
65
66
67/*
68** open parts that may cause memory-allocation errors
69*/
70static void f_luaopen (lua_State *L, void *ud) {
71 global_State *g = G(L);
72 UNUSED(ud);
73 stack_init(L, L); /* init stack */
74 sethvalue(L, gt(L), luaH_new(L, 0, 2)); /* table of globals */
75 sethvalue(L, registry(L), luaH_new(L, 0, 2)); /* registry */
76 luaS_resize(L, MINSTRTABSIZE); /* initial size of string table */
77 luaT_init(L);
78 luaX_init(L);
79 luaS_fix(luaS_newliteral(L, MEMERRMSG));
80 g->GCthreshold = 4*g->totalbytes;
81}
82
83
84static void preinit_state (lua_State *L, global_State *g) {
85 G(L) = g;
86 L->stack = NULL;
87 L->stacksize = 0;
88 L->errorJmp = NULL;
89 L->hook = NULL;
90 L->hookmask = 0;
91 L->basehookcount = 0;
92 L->allowhook = 1;
93 resethookcount(L);
94 L->openupval = NULL;
95 L->size_ci = 0;
96 L->nCcalls = L->baseCcalls = 0;
97 L->status = 0;
98 L->base_ci = L->ci = NULL;
99 L->savedpc = NULL;
100 L->errfunc = 0;
101 setnilvalue(gt(L));
102}
103
104
105static void close_state (lua_State *L) {
106 global_State *g = G(L);
107 luaF_close(L, L->stack); /* close all upvalues for this thread */
108 luaC_freeall(L); /* collect all objects */
109 lua_assert(g->rootgc == obj2gco(L));
110 lua_assert(g->strt.nuse == 0);
111 luaM_freearray(L, G(L)->strt.hash, G(L)->strt.size, TString *);
112 luaZ_freebuffer(L, &g->buff);
113 freestack(L, L);
114 lua_assert(g->totalbytes == sizeof(LG));
115 (*g->frealloc)(g->ud, fromstate(L), state_size(LG), 0);
116}
117
118
119lua_State *luaE_newthread (lua_State *L) {
120 lua_State *L1 = tostate(luaM_malloc(L, state_size(lua_State)));
121 luaC_link(L, obj2gco(L1), LUA_TTHREAD);
122 preinit_state(L1, G(L));
123 stack_init(L1, L); /* init stack */
124 setobj2n(L, gt(L1), gt(L)); /* share table of globals */
125 L1->hookmask = L->hookmask;
126 L1->basehookcount = L->basehookcount;
127 L1->hook = L->hook;
128 resethookcount(L1);
129 lua_assert(iswhite(obj2gco(L1)));
130 return L1;
131}
132
133
134void luaE_freethread (lua_State *L, lua_State *L1) {
135 luaF_close(L1, L1->stack); /* close all upvalues for this thread */
136 lua_assert(L1->openupval == NULL);
137 luai_userstatefree(L1);
138 freestack(L, L1);
139 luaM_freemem(L, fromstate(L1), state_size(lua_State));
140}
141
142
143LUA_API lua_State *lua_newstate (lua_Alloc f, void *ud) {
144 int i;
145 lua_State *L;
146 global_State *g;
147 void *l = (*f)(ud, NULL, 0, state_size(LG));
148 if (l == NULL) return NULL;
149 L = tostate(l);
150 g = &((LG *)L)->g;
151 L->next = NULL;
152 L->tt = LUA_TTHREAD;
153 g->currentwhite = bit2mask(WHITE0BIT, FIXEDBIT);
154 L->marked = luaC_white(g);
155 set2bits(L->marked, FIXEDBIT, SFIXEDBIT);
156 preinit_state(L, g);
157 g->frealloc = f;
158 g->ud = ud;
159 g->mainthread = L;
160 g->uvhead.u.l.prev = &g->uvhead;
161 g->uvhead.u.l.next = &g->uvhead;
162 g->GCthreshold = 0; /* mark it as unfinished state */
163 g->strt.size = 0;
164 g->strt.nuse = 0;
165 g->strt.hash = NULL;
166 setnilvalue(registry(L));
167 luaZ_initbuffer(L, &g->buff);
168 g->panic = NULL;
169 g->gcstate = GCSpause;
170 g->rootgc = obj2gco(L);
171 g->sweepstrgc = 0;
172 g->sweepgc = &g->rootgc;
173 g->gray = NULL;
174 g->grayagain = NULL;
175 g->weak = NULL;
176 g->tmudata = NULL;
177 g->totalbytes = sizeof(LG);
178 g->gcpause = LUAI_GCPAUSE;
179 g->gcstepmul = LUAI_GCMUL;
180 g->gcdept = 0;
181 for (i=0; i<NUM_TAGS; i++) g->mt[i] = NULL;
182 if (luaD_rawrunprotected(L, f_luaopen, NULL) != 0) {
183 /* memory allocation error: free partial state */
184 close_state(L);
185 L = NULL;
186 }
187 else
188 luai_userstateopen(L);
189 return L;
190}
191
192
193static void callallgcTM (lua_State *L, void *ud) {
194 UNUSED(ud);
195 luaC_callGCTM(L); /* call GC metamethods for all udata */
196}
197
198
199LUA_API void lua_close (lua_State *L) {
200 L = G(L)->mainthread; /* only the main thread can be closed */
201 lua_lock(L);
202 luaF_close(L, L->stack); /* close all upvalues for this thread */
203 luaC_separateudata(L, 1); /* separate udata that have GC metamethods */
204 L->errfunc = 0; /* no error function during GC metamethods */
205 do { /* repeat until no more errors */
206 L->ci = L->base_ci;
207 L->base = L->top = L->ci->base;
208 L->nCcalls = L->baseCcalls = 0;
209 } while (luaD_rawrunprotected(L, callallgcTM, NULL) != 0);
210 lua_assert(G(L)->tmudata == NULL);
211 luai_userstateclose(L);
212 close_state(L);
213}
214
215