ceph/src/civetweb/src/third_party/lua-5.3.3/src/lstate.h

   1 /*
   2 ** $Id: lstate.h,v 2.130 2015/12/16 16:39:38 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 ** Atomic type (relative to signals) to better ensure that 'lua_sethook'
  38 ** is thread safe
  39 */
  40 #if !defined(l_signalT)
  41 #include <signal.h>
  42 #define l_signalT       sig_atomic_t
  43 #endif
  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
  57
  58 typedef struct stringtable {
  59   TString **hash;
  60   int nuse;  /* number of elements */
  61   int size;
  62 } stringtable;
  63
  64
  65 /*
  66 ** Information about a call.
  67 ** When a thread yields, 'func' is adjusted to pretend that the
  68 ** top function has only the yielded values in its stack; in that
  69 ** case, the actual 'func' value is saved in field 'extra'.
  70 ** When a function calls another with a continuation, 'extra' keeps
  71 ** the function index so that, in case of errors, the continuation
  72 ** function can be called with the correct top.
  73 */
  74 typedef struct CallInfo {
  75   StkId func;  /* function index in the stack */
  76   StkId top;  /* top for this function */
  77   struct CallInfo *previous, *next;  /* dynamic call link */
  78   union {
  79     struct {  /* only for Lua functions */
  80       StkId base;  /* base for this function */
  81       const Instruction *savedpc;
  82     } l;
  83     struct {  /* only for C functions */
  84       lua_KFunction k;  /* continuation in case of yields */
  85       ptrdiff_t old_errfunc;
  86       lua_KContext ctx;  /* context info. in case of yields */
  87     } c;
  88   } u;
  89   ptrdiff_t extra;
  90   short nresults;  /* expected number of results from this function */
  91   lu_byte callstatus;
  92 } CallInfo;
  93
  94
  95 /*
  96 ** Bits in CallInfo status
  97 */
  98 #define CIST_OAH        (1<<0)  /* original value of 'allowhook' */
  99 #define CIST_LUA        (1<<1)  /* call is running a Lua function */
 100 #define CIST_HOOKED     (1<<2)  /* call is running a debug hook */
 101 #define CIST_FRESH      (1<<3)  /* call is running on a fresh invocation
 102                                    of luaV_execute */
 103 #define CIST_YPCALL     (1<<4)  /* call is a yieldable protected call */
 104 #define CIST_TAIL       (1<<5)  /* call was tail called */
 105 #define CIST_HOOKYIELD  (1<<6)  /* last hook called yielded */
 106 #define CIST_LEQ        (1<<7)  /* using __lt for __le */
 107
 108 #define isLua(ci)       ((ci)->callstatus & CIST_LUA)
 109
 110 /* assume that CIST_OAH has offset 0 and that 'v' is strictly 0/1 */
 111 #define setoah(st,v)    ((st) = ((st) & ~CIST_OAH) | (v))
 112 #define getoah(st)      ((st) & CIST_OAH)
 113
 114
 115 /*
 116 ** 'global state', shared by all threads of this state
 117 */
 118 typedef struct global_State {
 119   lua_Alloc frealloc;  /* function to reallocate memory */
 120   void *ud;         /* auxiliary data to 'frealloc' */
 121   l_mem totalbytes;  /* number of bytes currently allocated - GCdebt */
 122   l_mem GCdebt;  /* bytes allocated not yet compensated by the collector */
 123   lu_mem GCmemtrav;  /* memory traversed by the GC */
 124   lu_mem GCestimate;  /* an estimate of the non-garbage memory in use */
 125   stringtable strt;  /* hash table for strings */
 126   TValue l_registry;
 127   unsigned int seed;  /* randomized seed for hashes */
 128   lu_byte currentwhite;
 129   lu_byte gcstate;  /* state of garbage collector */
 130   lu_byte gckind;  /* kind of GC running */
 131   lu_byte gcrunning;  /* true if GC is running */
 132   GCObject *allgc;  /* list of all collectable objects */
 133   GCObject **sweepgc;  /* current position of sweep in list */
 134   GCObject *finobj;  /* list of collectable objects with finalizers */
 135   GCObject *gray;  /* list of gray objects */
 136   GCObject *grayagain;  /* list of objects to be traversed atomically */
 137   GCObject *weak;  /* list of tables with weak values */
 138   GCObject *ephemeron;  /* list of ephemeron tables (weak keys) */
 139   GCObject *allweak;  /* list of all-weak tables */
 140   GCObject *tobefnz;  /* list of userdata to be GC */
 141   GCObject *fixedgc;  /* list of objects not to be collected */
 142   struct lua_State *twups;  /* list of threads with open upvalues */
 143   unsigned int gcfinnum;  /* number of finalizers to call in each GC step */
 144   int gcpause;  /* size of pause between successive GCs */
 145   int gcstepmul;  /* GC 'granularity' */
 146   lua_CFunction panic;  /* to be called in unprotected errors */
 147   struct lua_State *mainthread;
 148   const lua_Number *version;  /* pointer to version number */
 149   TString *memerrmsg;  /* memory-error message */
 150   TString *tmname[TM_N];  /* array with tag-method names */
 151   struct Table *mt[LUA_NUMTAGS];  /* metatables for basic types */
 152   TString *strcache[STRCACHE_N][STRCACHE_M];  /* cache for strings in API */
 153 } global_State;
 154
 155
 156 /*
 157 ** 'per thread' state
 158 */
 159 struct lua_State {
 160   CommonHeader;
 161   unsigned short nci;  /* number of items in 'ci' list */
 162   lu_byte status;
 163   StkId top;  /* first free slot in the stack */
 164   global_State *l_G;
 165   CallInfo *ci;  /* call info for current function */
 166   const Instruction *oldpc;  /* last pc traced */
 167   StkId stack_last;  /* last free slot in the stack */
 168   StkId stack;  /* stack base */
 169   UpVal *openupval;  /* list of open upvalues in this stack */
 170   GCObject *gclist;
 171   struct lua_State *twups;  /* list of threads with open upvalues */
 172   struct lua_longjmp *errorJmp;  /* current error recover point */
 173   CallInfo base_ci;  /* CallInfo for first level (C calling Lua) */
 174   volatile lua_Hook hook;
 175   ptrdiff_t errfunc;  /* current error handling function (stack index) */
 176   int stacksize;
 177   int basehookcount;
 178   int hookcount;
 179   unsigned short nny;  /* number of non-yieldable calls in stack */
 180   unsigned short nCcalls;  /* number of nested C calls */
 181   l_signalT hookmask;
 182   lu_byte allowhook;
 183 };
 184
 185
 186 #define G(L)    (L->l_G)
 187
 188
 189 /*
 190 ** Union of all collectable objects (only for conversions)
 191 */
 192 union GCUnion {
 193   GCObject gc;  /* common header */
 194   struct TString ts;
 195   struct Udata u;
 196   union Closure cl;
 197   struct Table h;
 198   struct Proto p;
 199   struct lua_State th;  /* thread */
 200 };
 201
 202
 203 #define cast_u(o)       cast(union GCUnion *, (o))
 204
 205 /* macros to convert a GCObject into a specific value */
 206 #define gco2ts(o)  \
 207         check_exp(novariant((o)->tt) == LUA_TSTRING, &((cast_u(o))->ts))
 208 #define gco2u(o)  check_exp((o)->tt == LUA_TUSERDATA, &((cast_u(o))->u))
 209 #define gco2lcl(o)  check_exp((o)->tt == LUA_TLCL, &((cast_u(o))->cl.l))
 210 #define gco2ccl(o)  check_exp((o)->tt == LUA_TCCL, &((cast_u(o))->cl.c))
 211 #define gco2cl(o)  \
 212         check_exp(novariant((o)->tt) == LUA_TFUNCTION, &((cast_u(o))->cl))
 213 #define gco2t(o)  check_exp((o)->tt == LUA_TTABLE, &((cast_u(o))->h))
 214 #define gco2p(o)  check_exp((o)->tt == LUA_TPROTO, &((cast_u(o))->p))
 215 #define gco2th(o)  check_exp((o)->tt == LUA_TTHREAD, &((cast_u(o))->th))
 216
 217
 218 /* macro to convert a Lua object into a GCObject */
 219 #define obj2gco(v) \
 220         check_exp(novariant((v)->tt) < LUA_TDEADKEY, (&(cast_u(v)->gc)))
 221
 222
 223 /* actual number of total bytes allocated */
 224 #define gettotalbytes(g)        cast(lu_mem, (g)->totalbytes + (g)->GCdebt)
 225
 226 LUAI_FUNC void luaE_setdebt (global_State *g, l_mem debt);
 227 LUAI_FUNC void luaE_freethread (lua_State *L, lua_State *L1);
 228 LUAI_FUNC CallInfo *luaE_extendCI (lua_State *L);
 229 LUAI_FUNC void luaE_freeCI (lua_State *L);
 230 LUAI_FUNC void luaE_shrinkCI (lua_State *L);
 231
 232
 233 #endif
 234