1 /* 2 ** $Id: lstate.h,v 2.122 2015/06/01 16:34:37 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, so all objects always 21 ** belong to one (and only one) of these lists, using field 'next' of 22 ** the 'CommonHeader' for the link: 23 ** 24 ** 'allgc': all objects not marked for finalization; 25 ** 'finobj': all objects marked for finalization; 26 ** 'tobefnz': all objects ready to be finalized; 27 ** 'fixedgc': all objects that are not to be collected (currently 28 ** only small strings, such as reserved words). 29 30 */ 31 32 33 struct lua_longjmp; /* defined in ldo.c */ 34 35 36 37 /* extra stack space to handle TM calls and some other extras */ 38 #define EXTRA_STACK 5 39 40 41 #define BASIC_STACK_SIZE (2*LUA_MINSTACK) 42 43 44 /* kinds of Garbage Collection */ 45 #define KGC_NORMAL 0 46 #define KGC_EMERGENCY 1 /* gc was forced by an allocation failure */ 47 48 49 typedef struct stringtable { 50 TString **hash; 51 int nuse; /* number of elements */ 52 int size; 53 } stringtable; 54 55 56 /* 57 ** Information about a call. 58 ** When a thread yields, 'func' is adjusted to pretend that the 59 ** top function has only the yielded values in its stack; in that 60 ** case, the actual 'func' value is saved in field 'extra'. 61 ** When a function calls another with a continuation, 'extra' keeps 62 ** the function index so that, in case of errors, the continuation 63 ** function can be called with the correct top. 64 */ 65 typedef struct CallInfo { 66 StkId func; /* function index in the stack */ 67 StkId top; /* top for this function */ 68 struct CallInfo *previous, *next; /* dynamic call link */ 69 union { 70 struct { /* only for Lua functions */ 71 StkId base; /* base for this function */ 72 const Instruction *savedpc; 73 } l; 74 struct { /* only for C functions */ 75 lua_KFunction k; /* continuation in case of yields */ 76 ptrdiff_t old_errfunc; 77 lua_KContext ctx; /* context info. in case of yields */ 78 } c; 79 } u; 80 ptrdiff_t extra; 81 short nresults; /* expected number of results from this function */ 82 lu_byte callstatus; 83 } CallInfo; 84 85 86 /* 87 ** Bits in CallInfo status 88 */ 89 #define CIST_OAH (1<<0) /* original value of 'allowhook' */ 90 #define CIST_LUA (1<<1) /* call is running a Lua function */ 91 #define CIST_HOOKED (1<<2) /* call is running a debug hook */ 92 #define CIST_REENTRY (1<<3) /* call is running on same invocation of 93 luaV_execute of previous call */ 94 #define CIST_YPCALL (1<<4) /* call is a yieldable protected call */ 95 #define CIST_TAIL (1<<5) /* call was tail called */ 96 #define CIST_HOOKYIELD (1<<6) /* last hook called yielded */ 97 #define CIST_LEQ (1<<7) /* using __lt for __le */ 98 99 #define isLua(ci) ((ci)->callstatus & CIST_LUA) 100 101 /* assume that CIST_OAH has offset 0 and that 'v' is strictly 0/1 */ 102 #define setoah(st,v) ((st) = ((st) & ~CIST_OAH) | (v)) 103 #define getoah(st) ((st) & CIST_OAH) 104 105 106 /* 107 ** 'global state', shared by all threads of this state 108 */ 109 typedef struct global_State { 110 lua_Alloc frealloc; /* function to reallocate memory */ 111 void *ud; /* auxiliary data to 'frealloc' */ 112 lu_mem totalbytes; /* number of bytes currently allocated - GCdebt */ 113 l_mem GCdebt; /* bytes allocated not yet compensated by the collector */ 114 lu_mem GCmemtrav; /* memory traversed by the GC */ 115 lu_mem GCestimate; /* an estimate of the non-garbage memory in use */ 116 stringtable strt; /* hash table for strings */ 117 TValue l_registry; 118 unsigned int seed; /* randomized seed for hashes */ 119 lu_byte currentwhite; 120 lu_byte gcstate; /* state of garbage collector */ 121 lu_byte gckind; /* kind of GC running */ 122 lu_byte gcrunning; /* true if GC is running */ 123 GCObject *allgc; /* list of all collectable objects */ 124 GCObject **sweepgc; /* current position of sweep in list */ 125 GCObject *finobj; /* list of collectable objects with finalizers */ 126 GCObject *gray; /* list of gray objects */ 127 GCObject *grayagain; /* list of objects to be traversed atomically */ 128 GCObject *weak; /* list of tables with weak values */ 129 GCObject *ephemeron; /* list of ephemeron tables (weak keys) */ 130 GCObject *allweak; /* list of all-weak tables */ 131 GCObject *tobefnz; /* list of userdata to be GC */ 132 GCObject *fixedgc; /* list of objects not to be collected */ 133 struct lua_State *twups; /* list of threads with open upvalues */ 134 Mbuffer buff; /* temporary buffer for string concatenation */ 135 unsigned int gcfinnum; /* number of finalizers to call in each GC step */ 136 int gcpause; /* size of pause between successive GCs */ 137 int gcstepmul; /* GC 'granularity' */ 138 lua_CFunction panic; /* to be called in unprotected errors */ 139 struct lua_State *mainthread; 140 const lua_Number *version; /* pointer to version number */ 141 TString *memerrmsg; /* memory-error message */ 142 TString *tmname[TM_N]; /* array with tag-method names */ 143 struct Table *mt[LUA_NUMTAGS]; /* metatables for basic types */ 144 TString *strcache[STRCACHE_SIZE][1]; /* cache for strings in API */ 145 } global_State; 146 147 148 /* 149 ** 'per thread' state 150 */ 151 struct lua_State { 152 CommonHeader; 153 lu_byte status; 154 StkId top; /* first free slot in the stack */ 155 global_State *l_G; 156 CallInfo *ci; /* call info for current function */ 157 const Instruction *oldpc; /* last pc traced */ 158 StkId stack_last; /* last free slot in the stack */ 159 StkId stack; /* stack base */ 160 UpVal *openupval; /* list of open upvalues in this stack */ 161 GCObject *gclist; 162 struct lua_State *twups; /* list of threads with open upvalues */ 163 struct lua_longjmp *errorJmp; /* current error recover point */ 164 CallInfo base_ci; /* CallInfo for first level (C calling Lua) */ 165 lua_Hook hook; 166 ptrdiff_t errfunc; /* current error handling function (stack index) */ 167 int stacksize; 168 int basehookcount; 169 int hookcount; 170 unsigned short nny; /* number of non-yieldable calls in stack */ 171 unsigned short nCcalls; /* number of nested C calls */ 172 lu_byte hookmask; 173 lu_byte allowhook; 174 }; 175 176 177 #define G(L) (L->l_G) 178 179 180 /* 181 ** Union of all collectable objects (only for conversions) 182 */ 183 union GCUnion { 184 GCObject gc; /* common header */ 185 struct TString ts; 186 struct Udata u; 187 union Closure cl; 188 struct Table h; 189 struct Proto p; 190 struct lua_State th; /* thread */ 191 }; 192 193 194 #define cast_u(o) cast(union GCUnion *, (o)) 195 196 /* macros to convert a GCObject into a specific value */ 197 #define gco2ts(o) \ 198 check_exp(novariant((o)->tt) == LUA_TSTRING, &((cast_u(o))->ts)) 199 #define gco2u(o) check_exp((o)->tt == LUA_TUSERDATA, &((cast_u(o))->u)) 200 #define gco2lcl(o) check_exp((o)->tt == LUA_TLCL, &((cast_u(o))->cl.l)) 201 #define gco2ccl(o) check_exp((o)->tt == LUA_TCCL, &((cast_u(o))->cl.c)) 202 #define gco2cl(o) \ 203 check_exp(novariant((o)->tt) == LUA_TFUNCTION, &((cast_u(o))->cl)) 204 #define gco2t(o) check_exp((o)->tt == LUA_TTABLE, &((cast_u(o))->h)) 205 #define gco2p(o) check_exp((o)->tt == LUA_TPROTO, &((cast_u(o))->p)) 206 #define gco2th(o) check_exp((o)->tt == LUA_TTHREAD, &((cast_u(o))->th)) 207 208 209 /* macro to convert a Lua object into a GCObject */ 210 #define obj2gco(v) \ 211 check_exp(novariant((v)->tt) < LUA_TDEADKEY, (&(cast_u(v)->gc))) 212 213 214 /* actual number of total bytes allocated */ 215 #define gettotalbytes(g) ((g)->totalbytes + (g)->GCdebt) 216 217 LUAI_FUNC void luaE_setdebt (global_State *g, l_mem debt); 218 LUAI_FUNC void luaE_freethread (lua_State *L, lua_State *L1); 219 LUAI_FUNC CallInfo *luaE_extendCI (lua_State *L); 220 LUAI_FUNC void luaE_freeCI (lua_State *L); 221 LUAI_FUNC void luaE_shrinkCI (lua_State *L); 222 223 224 #endif 225 226