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