summaryrefslogtreecommitdiff
path: root/lua/lstate.h
blob: de79fe8664cd8ecdf34e6800f162e3d3e43f1d0b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
/*
** $Id: lstate.h,v 1.2 2004/03/23 05:09:14 jbj Exp $
** Global State
** See Copyright Notice in lua.h
*/

#ifndef lstate_h
#define lstate_h

#include "lua.h"

#include "lobject.h"
#include "ltm.h"
#include "lzio.h"


/*
** macros for thread synchronization inside Lua core machine:
** all accesses to the global state and to global objects are synchronized.
** Because threads can read the stack of other threads
** (when running garbage collection),
** a thread must also synchronize any write-access to its own stack.
** Unsynchronized accesses are allowed only when reading its own stack,
** or when reading immutable fields from global objects
** (such as string values and udata values). 
*/
#ifndef lua_lock
#define lua_lock(L)	((void) 0)
#endif

#ifndef lua_unlock
#define lua_unlock(L)	((void) 0)
#endif


#ifndef lua_userstateopen
#define lua_userstateopen(l)
#endif



struct lua_longjmp;  /* defined in ldo.c */


/* default meta table (both for tables and udata) */
#define defaultmeta(L)	(&G(L)->_defaultmeta)

/* table of globals */
#define gt(L)	(&L->_gt)

/* registry */
#define registry(L)	(&G(L)->_registry)


/* extra stack space to handle TM calls and some other extras */
#define EXTRA_STACK   5


#define BASIC_CI_SIZE           8

#define BASIC_STACK_SIZE        (2*LUA_MINSTACK)



typedef struct stringtable {
/*@null@*/
  GCObject **hash;
  ls_nstr nuse;  /* number of elements */
  int size;
} stringtable;


/*
** informations about a call
*/
typedef struct CallInfo {
/*@dependent@*/ /*@relnull@*/
  StkId base;  /* base for called function */
/*@dependent@*/ /*@relnull@*/
  StkId	top;  /* top for this function */
  int state;  /* bit fields; see below */
  union {
    struct {  /* for Lua functions */
/*@observer@*/
      const Instruction *savedpc;
/*@observer@*/
      const Instruction **pc;  /* points to `pc' variable in `luaV_execute' */
      int tailcalls;  /* number of tail calls lost under this entry */
    } l;
    struct {  /* for C functions */
      int dummy;  /* just to avoid an empty struct */
    } c;
  } u;
} CallInfo;


/*
** bit fields for `CallInfo.state'
*/
#define CI_C		(1<<0)  /* 1 if function is a C function */
/* 1 if (Lua) function has an active `luaV_execute' running it */
#define CI_HASFRAME	(1<<1)
/* 1 if Lua function is calling another Lua function (and therefore its
   `pc' is being used by the other, and therefore CI_SAVEDPC is 1 too) */
#define CI_CALLING	(1<<2)
#define CI_SAVEDPC	(1<<3)  /* 1 if `savedpc' is updated */
#define CI_YIELD	(1<<4)  /* 1 if thread is suspended */


#define ci_func(ci)	(clvalue((ci)->base - 1))


/*
** `global state', shared by all threads of this state
*/
typedef struct global_State {
  stringtable strt;  /* hash table for strings */
/*@owned@*/
  GCObject *rootgc;  /* list of (almost) all collectable objects */
/*@dependent@*/ /*@null@*/
  GCObject *rootudata;   /* (separated) list of all userdata */
/*@dependent@*/ /*@null@*/
  GCObject *tmudata;  /* list of userdata to be GC */
  Mbuffer buff;  /* temporary buffer for string concatentation */
  lu_mem GCthreshold;
  lu_mem nblocks;  /* number of `bytes' currently allocated */
  lua_CFunction panic;  /* to be called in unprotected errors */
  TObject _registry;
  TObject _defaultmeta;
  struct lua_State *mainthread;
  Node dummynode[1];  /* common node array for all empty tables */
  TString *tmname[TM_N];  /* array with tag-method names */
} global_State;


/*
** `per thread' state
*/
struct lua_State {
  CommonHeader;
/*@dependent@*/ /*@relnull@*/
  StkId top;  /* first free slot in the stack */
/*@dependent@*/ /*@relnull@*/
  StkId base;  /* base of current function */
/*@relnull@*/
  global_State *l_G;
/*@dependent@*/ /*@relnull@*/
  CallInfo *ci;  /* call info for current function */
/*@dependent@*/
  StkId stack_last;  /* last free slot in the stack */
/*@owned@*/ /*@relnull@*/
  StkId stack;  /* stack base */
  int stacksize;
/*@dependent@*/ /*@relnull@*/
  CallInfo *end_ci;  /* points after end of ci array*/
/*@owned@*/ /*@relnull@*/
  CallInfo *base_ci;  /* array of CallInfo's */
  unsigned short size_ci;  /* size of array `base_ci' */
  unsigned short nCcalls;  /* number of nested C calls */
  lu_byte hookmask;
  lu_byte allowhook;
  lu_byte hookinit;
  int basehookcount;
  int hookcount;
/*@relnull@*/
  lua_Hook hook;
  TObject _gt;  /* table of globals */
/*@dependent@*/ /*@relnull@*/
  GCObject *openupval;  /* list of open upvalues in this stack */
/*@dependent@*/ /*@relnull@*/
  GCObject *gclist;
/*@relnull@*/
  struct lua_longjmp *errorJmp;  /* current error recover point */
  ptrdiff_t errfunc;  /* current error handling function (stack index) */
};


#define G(L)	(L->l_G)


/*
** Union of all collectable objects
*/
union GCObject {
  GCheader gch;
  union TString ts;
  union Udata u;
  union Closure cl;
  struct Table h;
  struct Proto p;
  struct UpVal uv;
  struct lua_State th;  /* thread */
};


/* macros to convert a GCObject into a specific value */
#define gcotots(o)	check_exp((o)->gch.tt == LUA_TSTRING, &((o)->ts))
#define gcotou(o)	check_exp((o)->gch.tt == LUA_TUSERDATA, &((o)->u))
#define gcotocl(o)	check_exp((o)->gch.tt == LUA_TFUNCTION, &((o)->cl))
#define gcotoh(o)	check_exp((o)->gch.tt == LUA_TTABLE, &((o)->h))
#define gcotop(o)	check_exp((o)->gch.tt == LUA_TPROTO, &((o)->p))
#define gcotouv(o)	check_exp((o)->gch.tt == LUA_TUPVAL, &((o)->uv))
#define ngcotouv(o) \
	check_exp((o) == NULL || (o)->gch.tt == LUA_TUPVAL, &((o)->uv))
#define gcototh(o)	check_exp((o)->gch.tt == LUA_TTHREAD, &((o)->th))

/* macro to convert any value into a GCObject */
#define valtogco(v)	(cast(GCObject *, (v)))


/*@null@*/
lua_State *luaE_newthread (lua_State *L)
	/*@modifies L @*/;
void luaE_freethread (lua_State *L, lua_State *L1)
	/*@modifies L, L1 @*/;

#endif