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1 | /* | |
2 | ** $Id: lstate.h,v 2.82 2012/07/02 13:37:04 roberto Exp $ | |
3 | ** Global State | |
4 | ** See Copyright Notice in lua.h | |
5 | */ | |
6 | ||
7 | #ifndef lstate_h | |
8 | #define lstate_h | |
9 | ||
10 | #include "lua.h" | |
11 | ||
12 | #include "lobject.h" | |
13 | #include "ltm.h" | |
14 | #include "lzio.h" | |
15 | ||
16 | ||
17 | /* | |
18 | ||
19 | ** Some notes about garbage-collected objects: All objects in Lua must | |
20 | ** be kept somehow accessible until being freed. | |
21 | ** | |
22 | ** Lua keeps most objects linked in list g->allgc. The link uses field | |
23 | ** 'next' of the CommonHeader. | |
24 | ** | |
25 | ** Strings are kept in several lists headed by the array g->strt.hash. | |
26 | ** | |
27 | ** Open upvalues are not subject to independent garbage collection. They | |
28 | ** are collected together with their respective threads. Lua keeps a | |
29 | ** double-linked list with all open upvalues (g->uvhead) so that it can | |
30 | ** mark objects referred by them. (They are always gray, so they must | |
31 | ** be remarked in the atomic step. Usually their contents would be marked | |
32 | ** when traversing the respective threads, but the thread may already be | |
33 | ** dead, while the upvalue is still accessible through closures.) | |
34 | ** | |
35 | ** Objects with finalizers are kept in the list g->finobj. | |
36 | ** | |
37 | ** The list g->tobefnz links all objects being finalized. | |
38 | ||
39 | */ | |
40 | ||
41 | ||
42 | struct lua_longjmp; /* defined in ldo.c */ | |
43 | ||
44 | ||
45 | ||
46 | /* extra stack space to handle TM calls and some other extras */ | |
47 | #define EXTRA_STACK 5 | |
48 | ||
49 | ||
50 | #define BASIC_STACK_SIZE (2*LUA_MINSTACK) | |
51 | ||
52 | ||
53 | /* kinds of Garbage Collection */ | |
54 | #define KGC_NORMAL 0 | |
55 | #define KGC_EMERGENCY 1 /* gc was forced by an allocation failure */ | |
56 | #define KGC_GEN 2 /* generational collection */ | |
57 | ||
58 | ||
59 | typedef struct stringtable { | |
60 | GCObject **hash; | |
61 | lu_int32 nuse; /* number of elements */ | |
62 | int size; | |
63 | } stringtable; | |
64 | ||
65 | ||
66 | /* | |
67 | ** information about a call | |
68 | */ | |
69 | typedef struct CallInfo { | |
70 | StkId func; /* function index in the stack */ | |
71 | StkId top; /* top for this function */ | |
72 | struct CallInfo *previous, *next; /* dynamic call link */ | |
73 | short nresults; /* expected number of results from this function */ | |
74 | lu_byte callstatus; | |
75 | ptrdiff_t extra; | |
76 | union { | |
77 | struct { /* only for Lua functions */ | |
78 | StkId base; /* base for this function */ | |
79 | const Instruction *savedpc; | |
80 | } l; | |
81 | struct { /* only for C functions */ | |
82 | int ctx; /* context info. in case of yields */ | |
83 | lua_CFunction k; /* continuation in case of yields */ | |
84 | ptrdiff_t old_errfunc; | |
85 | lu_byte old_allowhook; | |
86 | lu_byte status; | |
87 | } c; | |
88 | } u; | |
89 | } CallInfo; | |
90 | ||
91 | ||
92 | /* | |
93 | ** Bits in CallInfo status | |
94 | */ | |
95 | #define CIST_LUA (1<<0) /* call is running a Lua function */ | |
96 | #define CIST_HOOKED (1<<1) /* call is running a debug hook */ | |
97 | #define CIST_REENTRY (1<<2) /* call is running on same invocation of | |
98 | luaV_execute of previous call */ | |
99 | #define CIST_YIELDED (1<<3) /* call reentered after suspension */ | |
100 | #define CIST_YPCALL (1<<4) /* call is a yieldable protected call */ | |
101 | #define CIST_STAT (1<<5) /* call has an error status (pcall) */ | |
102 | #define CIST_TAIL (1<<6) /* call was tail called */ | |
103 | #define CIST_HOOKYIELD (1<<7) /* last hook called yielded */ | |
104 | ||
105 | ||
106 | #define isLua(ci) ((ci)->callstatus & CIST_LUA) | |
107 | ||
108 | ||
109 | /* | |
110 | ** `global state', shared by all threads of this state | |
111 | */ | |
112 | typedef struct global_State { | |
113 | lua_Alloc frealloc; /* function to reallocate memory */ | |
114 | void *ud; /* auxiliary data to `frealloc' */ | |
115 | lu_mem totalbytes; /* number of bytes currently allocated - GCdebt */ | |
116 | l_mem GCdebt; /* bytes allocated not yet compensated by the collector */ | |
117 | lu_mem GCmemtrav; /* memory traversed by the GC */ | |
118 | lu_mem GCestimate; /* an estimate of the non-garbage memory in use */ | |
119 | stringtable strt; /* hash table for strings */ | |
120 | TValue l_registry; | |
121 | unsigned int seed; /* randomized seed for hashes */ | |
122 | lu_byte currentwhite; | |
123 | lu_byte gcstate; /* state of garbage collector */ | |
124 | lu_byte gckind; /* kind of GC running */ | |
125 | lu_byte gcrunning; /* true if GC is running */ | |
126 | int sweepstrgc; /* position of sweep in `strt' */ | |
127 | GCObject *allgc; /* list of all collectable objects */ | |
128 | GCObject *finobj; /* list of collectable objects with finalizers */ | |
129 | GCObject **sweepgc; /* current position of sweep in list 'allgc' */ | |
130 | GCObject **sweepfin; /* current position of sweep in list 'finobj' */ | |
131 | GCObject *gray; /* list of gray objects */ | |
132 | GCObject *grayagain; /* list of objects to be traversed atomically */ | |
133 | GCObject *weak; /* list of tables with weak values */ | |
134 | GCObject *ephemeron; /* list of ephemeron tables (weak keys) */ | |
135 | GCObject *allweak; /* list of all-weak tables */ | |
136 | GCObject *tobefnz; /* list of userdata to be GC */ | |
137 | UpVal uvhead; /* head of double-linked list of all open upvalues */ | |
138 | Mbuffer buff; /* temporary buffer for string concatenation */ | |
139 | int gcpause; /* size of pause between successive GCs */ | |
140 | int gcmajorinc; /* pause between major collections (only in gen. mode) */ | |
141 | int gcstepmul; /* GC `granularity' */ | |
142 | lua_CFunction panic; /* to be called in unprotected errors */ | |
143 | struct lua_State *mainthread; | |
144 | const lua_Number *version; /* pointer to version number */ | |
145 | TString *memerrmsg; /* memory-error message */ | |
146 | TString *tmname[TM_N]; /* array with tag-method names */ | |
147 | struct Table *mt[LUA_NUMTAGS]; /* metatables for basic types */ | |
148 | } global_State; | |
149 | ||
150 | ||
151 | /* | |
152 | ** `per thread' state | |
153 | */ | |
154 | struct lua_State { | |
155 | CommonHeader; | |
156 | lu_byte status; | |
157 | StkId top; /* first free slot in the stack */ | |
158 | global_State *l_G; | |
159 | CallInfo *ci; /* call info for current function */ | |
160 | const Instruction *oldpc; /* last pc traced */ | |
161 | StkId stack_last; /* last free slot in the stack */ | |
162 | StkId stack; /* stack base */ | |
163 | int stacksize; | |
164 | unsigned short nny; /* number of non-yieldable calls in stack */ | |
165 | unsigned short nCcalls; /* number of nested C calls */ | |
166 | lu_byte hookmask; | |
167 | lu_byte allowhook; | |
168 | int basehookcount; | |
169 | int hookcount; | |
170 | lua_Hook hook; | |
171 | GCObject *openupval; /* list of open upvalues in this stack */ | |
172 | GCObject *gclist; | |
173 | struct lua_longjmp *errorJmp; /* current error recover point */ | |
174 | ptrdiff_t errfunc; /* current error handling function (stack index) */ | |
175 | CallInfo base_ci; /* CallInfo for first level (C calling Lua) */ | |
176 | }; | |
177 | ||
178 | ||
179 | #define G(L) (L->l_G) | |
180 | ||
181 | ||
182 | /* | |
183 | ** Union of all collectable objects | |
184 | */ | |
185 | union GCObject { | |
186 | GCheader gch; /* common header */ | |
187 | union TString ts; | |
188 | union Udata u; | |
189 | union Closure cl; | |
190 | struct Table h; | |
191 | struct Proto p; | |
192 | struct UpVal uv; | |
193 | struct lua_State th; /* thread */ | |
194 | }; | |
195 | ||
196 | ||
197 | #define gch(o) (&(o)->gch) | |
198 | ||
199 | /* macros to convert a GCObject into a specific value */ | |
200 | #define rawgco2ts(o) \ | |
201 | check_exp(novariant((o)->gch.tt) == LUA_TSTRING, &((o)->ts)) | |
202 | #define gco2ts(o) (&rawgco2ts(o)->tsv) | |
203 | #define rawgco2u(o) check_exp((o)->gch.tt == LUA_TUSERDATA, &((o)->u)) | |
204 | #define gco2u(o) (&rawgco2u(o)->uv) | |
205 | #define gco2lcl(o) check_exp((o)->gch.tt == LUA_TLCL, &((o)->cl.l)) | |
206 | #define gco2ccl(o) check_exp((o)->gch.tt == LUA_TCCL, &((o)->cl.c)) | |
207 | #define gco2cl(o) \ | |
208 | check_exp(novariant((o)->gch.tt) == LUA_TFUNCTION, &((o)->cl)) | |
209 | #define gco2t(o) check_exp((o)->gch.tt == LUA_TTABLE, &((o)->h)) | |
210 | #define gco2p(o) check_exp((o)->gch.tt == LUA_TPROTO, &((o)->p)) | |
211 | #define gco2uv(o) check_exp((o)->gch.tt == LUA_TUPVAL, &((o)->uv)) | |
212 | #define gco2th(o) check_exp((o)->gch.tt == LUA_TTHREAD, &((o)->th)) | |
213 | ||
214 | /* macro to convert any Lua object into a GCObject */ | |
215 | #define obj2gco(v) (cast(GCObject *, (v))) | |
216 | ||
217 | ||
218 | /* actual number of total bytes allocated */ | |
219 | #define gettotalbytes(g) ((g)->totalbytes + (g)->GCdebt) | |
220 | ||
221 | LUAI_FUNC void luaE_setdebt (global_State *g, l_mem debt); | |
222 | LUAI_FUNC void luaE_freethread (lua_State *L, lua_State *L1); | |
223 | LUAI_FUNC CallInfo *luaE_extendCI (lua_State *L); | |
224 | LUAI_FUNC void luaE_freeCI (lua_State *L); | |
225 | ||
226 | ||
227 | #endif | |
228 |