1 /* $NetBSD: lstate.h,v 1.4 2015/10/08 13:21:00 mbalmer Exp $ */ 2 3 /* 4 ** Id: lstate.h,v 2.122 2015/06/01 16:34:37 roberto Exp 5 ** Global State 6 ** See Copyright Notice in lua.h 7 */ 8 9 #ifndef lstate_h 10 #define lstate_h 11 12 #include "lua.h" 13 14 #include "lobject.h" 15 #include "ltm.h" 16 #include "lzio.h" 17 18 19 /* 20 21 ** Some notes about garbage-collected objects: All objects in Lua must 22 ** be kept somehow accessible until being freed, so all objects always 23 ** belong to one (and only one) of these lists, using field 'next' of 24 ** the 'CommonHeader' for the link: 25 ** 26 ** 'allgc': all objects not marked for finalization; 27 ** 'finobj': all objects marked for finalization; 28 ** 'tobefnz': all objects ready to be finalized; 29 ** 'fixedgc': all objects that are not to be collected (currently 30 ** only small strings, such as reserved words). 31 32 */ 33 34 35 struct lua_longjmp; /* defined in ldo.c */ 36 37 38 39 /* extra stack space to handle TM calls and some other extras */ 40 #define EXTRA_STACK 5 41 42 43 #define BASIC_STACK_SIZE (2*LUA_MINSTACK) 44 45 46 /* kinds of Garbage Collection */ 47 #define KGC_NORMAL 0 48 #define KGC_EMERGENCY 1 /* gc was forced by an allocation failure */ 49 50 51 typedef struct stringtable { 52 TString **hash; 53 int nuse; /* number of elements */ 54 int size; 55 } stringtable; 56 57 58 /* 59 ** Information about a call. 60 ** When a thread yields, 'func' is adjusted to pretend that the 61 ** top function has only the yielded values in its stack; in that 62 ** case, the actual 'func' value is saved in field 'extra'. 63 ** When a function calls another with a continuation, 'extra' keeps 64 ** the function index so that, in case of errors, the continuation 65 ** function can be called with the correct top. 66 */ 67 typedef struct CallInfo { 68 StkId func; /* function index in the stack */ 69 StkId top; /* top for this function */ 70 struct CallInfo *previous, *next; /* dynamic call link */ 71 union { 72 struct { /* only for Lua functions */ 73 StkId base; /* base for this function */ 74 const Instruction *savedpc; 75 } l; 76 struct { /* only for C functions */ 77 lua_KFunction k; /* continuation in case of yields */ 78 ptrdiff_t old_errfunc; 79 lua_KContext ctx; /* context info. in case of yields */ 80 } c; 81 } u; 82 ptrdiff_t extra; 83 short nresults; /* expected number of results from this function */ 84 lu_byte callstatus; 85 } CallInfo; 86 87 88 /* 89 ** Bits in CallInfo status 90 */ 91 #define CIST_OAH (1<<0) /* original value of 'allowhook' */ 92 #define CIST_LUA (1<<1) /* call is running a Lua function */ 93 #define CIST_HOOKED (1<<2) /* call is running a debug hook */ 94 #define CIST_REENTRY (1<<3) /* call is running on same invocation of 95 luaV_execute of previous call */ 96 #define CIST_YPCALL (1<<4) /* call is a yieldable protected call */ 97 #define CIST_TAIL (1<<5) /* call was tail called */ 98 #define CIST_HOOKYIELD (1<<6) /* last hook called yielded */ 99 #define CIST_LEQ (1<<7) /* using __lt for __le */ 100 101 #define isLua(ci) ((ci)->callstatus & CIST_LUA) 102 103 /* assume that CIST_OAH has offset 0 and that 'v' is strictly 0/1 */ 104 #define setoah(st,v) ((st) = ((st) & ~CIST_OAH) | (v)) 105 #define getoah(st) ((st) & CIST_OAH) 106 107 108 /* 109 ** 'global state', shared by all threads of this state 110 */ 111 typedef struct global_State { 112 lua_Alloc frealloc; /* function to reallocate memory */ 113 void *ud; /* auxiliary data to 'frealloc' */ 114 lu_mem totalbytes; /* number of bytes currently allocated - GCdebt */ 115 l_mem GCdebt; /* bytes allocated not yet compensated by the collector */ 116 lu_mem GCmemtrav; /* memory traversed by the GC */ 117 lu_mem GCestimate; /* an estimate of the non-garbage memory in use */ 118 stringtable strt; /* hash table for strings */ 119 TValue l_registry; 120 unsigned int seed; /* randomized seed for hashes */ 121 lu_byte currentwhite; 122 lu_byte gcstate; /* state of garbage collector */ 123 lu_byte gckind; /* kind of GC running */ 124 lu_byte gcrunning; /* true if GC is running */ 125 GCObject *allgc; /* list of all collectable objects */ 126 GCObject **sweepgc; /* current position of sweep in list */ 127 GCObject *finobj; /* list of collectable objects with finalizers */ 128 GCObject *gray; /* list of gray objects */ 129 GCObject *grayagain; /* list of objects to be traversed atomically */ 130 GCObject *weak; /* list of tables with weak values */ 131 GCObject *ephemeron; /* list of ephemeron tables (weak keys) */ 132 GCObject *allweak; /* list of all-weak tables */ 133 GCObject *tobefnz; /* list of userdata to be GC */ 134 GCObject *fixedgc; /* list of objects not to be collected */ 135 struct lua_State *twups; /* list of threads with open upvalues */ 136 Mbuffer buff; /* temporary buffer for string concatenation */ 137 unsigned int gcfinnum; /* number of finalizers to call in each GC step */ 138 int gcpause; /* size of pause between successive GCs */ 139 int gcstepmul; /* GC 'granularity' */ 140 lua_CFunction panic; /* to be called in unprotected errors */ 141 struct lua_State *mainthread; 142 const lua_Number *version; /* pointer to version number */ 143 TString *memerrmsg; /* memory-error message */ 144 TString *tmname[TM_N]; /* array with tag-method names */ 145 struct Table *mt[LUA_NUMTAGS]; /* metatables for basic types */ 146 TString *strcache[STRCACHE_SIZE][1]; /* cache for strings in API */ 147 } global_State; 148 149 150 /* 151 ** 'per thread' state 152 */ 153 struct lua_State { 154 CommonHeader; 155 lu_byte status; 156 StkId top; /* first free slot in the stack */ 157 global_State *l_G; 158 CallInfo *ci; /* call info for current function */ 159 const Instruction *oldpc; /* last pc traced */ 160 StkId stack_last; /* last free slot in the stack */ 161 StkId stack; /* stack base */ 162 UpVal *openupval; /* list of open upvalues in this stack */ 163 GCObject *gclist; 164 struct lua_State *twups; /* list of threads with open upvalues */ 165 struct lua_longjmp *errorJmp; /* current error recover point */ 166 CallInfo base_ci; /* CallInfo for first level (C calling Lua) */ 167 lua_Hook hook; 168 ptrdiff_t errfunc; /* current error handling function (stack index) */ 169 int stacksize; 170 int basehookcount; 171 int hookcount; 172 unsigned short nny; /* number of non-yieldable calls in stack */ 173 unsigned short nCcalls; /* number of nested C calls */ 174 lu_byte hookmask; 175 lu_byte allowhook; 176 }; 177 178 179 #define G(L) (L->l_G) 180 181 182 /* 183 ** Union of all collectable objects (only for conversions) 184 */ 185 union GCUnion { 186 GCObject gc; /* common header */ 187 struct TString ts; 188 struct Udata u; 189 union Closure cl; 190 struct Table h; 191 struct Proto p; 192 struct lua_State th; /* thread */ 193 }; 194 195 196 #define cast_u(o) cast(union GCUnion *, (o)) 197 198 /* macros to convert a GCObject into a specific value */ 199 #define gco2ts(o) \ 200 check_exp(novariant((o)->tt) == LUA_TSTRING, &((cast_u(o))->ts)) 201 #define gco2u(o) check_exp((o)->tt == LUA_TUSERDATA, &((cast_u(o))->u)) 202 #define gco2lcl(o) check_exp((o)->tt == LUA_TLCL, &((cast_u(o))->cl.l)) 203 #define gco2ccl(o) check_exp((o)->tt == LUA_TCCL, &((cast_u(o))->cl.c)) 204 #define gco2cl(o) \ 205 check_exp(novariant((o)->tt) == LUA_TFUNCTION, &((cast_u(o))->cl)) 206 #define gco2t(o) check_exp((o)->tt == LUA_TTABLE, &((cast_u(o))->h)) 207 #define gco2p(o) check_exp((o)->tt == LUA_TPROTO, &((cast_u(o))->p)) 208 #define gco2th(o) check_exp((o)->tt == LUA_TTHREAD, &((cast_u(o))->th)) 209 210 211 /* macro to convert a Lua object into a GCObject */ 212 #define obj2gco(v) \ 213 check_exp(novariant((v)->tt) < LUA_TDEADKEY, (&(cast_u(v)->gc))) 214 215 216 /* actual number of total bytes allocated */ 217 #define gettotalbytes(g) ((g)->totalbytes + (g)->GCdebt) 218 219 LUAI_FUNC void luaE_setdebt (global_State *g, l_mem debt); 220 LUAI_FUNC void luaE_freethread (lua_State *L, lua_State *L1); 221 LUAI_FUNC CallInfo *luaE_extendCI (lua_State *L); 222 LUAI_FUNC void luaE_freeCI (lua_State *L); 223 LUAI_FUNC void luaE_shrinkCI (lua_State *L); 224 225 226 #endif 227 228