ba8b5c17 |
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 | |