The Battle for Wesnoth  1.15.2+dev
lcorolib.cpp
Go to the documentation of this file.
1 /*
2 ** $Id: lcorolib.c,v 1.10.1.1 2017/04/19 17:20:42 roberto Exp $
3 ** Coroutine Library
4 ** See Copyright Notice in lua.h
5 */
6 
7 #define lcorolib_c
8 #define LUA_LIB
9 
10 #include "lprefix.h"
11 
12 
13 #include <stdlib.h>
14 
15 #include "lua.h"
16 
17 #include "lauxlib.h"
18 #include "lualib.h"
19 
20 
21 static lua_State *getco (lua_State *L) {
22  lua_State *co = lua_tothread(L, 1);
23  luaL_argcheck(L, co, 1, "thread expected");
24  return co;
25 }
26 
27 
28 static int auxresume (lua_State *L, lua_State *co, int narg) {
29  int status;
30  if (!lua_checkstack(co, narg)) {
31  lua_pushliteral(L, "too many arguments to resume");
32  return -1; /* error flag */
33  }
34  if (lua_status(co) == LUA_OK && lua_gettop(co) == 0) {
35  lua_pushliteral(L, "cannot resume dead coroutine");
36  return -1; /* error flag */
37  }
38  lua_xmove(L, co, narg);
39  status = lua_resume(co, L, narg);
40  if (status == LUA_OK || status == LUA_YIELD) {
41  int nres = lua_gettop(co);
42  if (!lua_checkstack(L, nres + 1)) {
43  lua_pop(co, nres); /* remove results anyway */
44  lua_pushliteral(L, "too many results to resume");
45  return -1; /* error flag */
46  }
47  lua_xmove(co, L, nres); /* move yielded values */
48  return nres;
49  }
50  else {
51  lua_xmove(co, L, 1); /* move error message */
52  return -1; /* error flag */
53  }
54 }
55 
56 
57 static int luaB_coresume (lua_State *L) {
58  lua_State *co = getco(L);
59  int r;
60  r = auxresume(L, co, lua_gettop(L) - 1);
61  if (r < 0) {
62  lua_pushboolean(L, 0);
63  lua_insert(L, -2);
64  return 2; /* return false + error message */
65  }
66  else {
67  lua_pushboolean(L, 1);
68  lua_insert(L, -(r + 1));
69  return r + 1; /* return true + 'resume' returns */
70  }
71 }
72 
73 
74 static int luaB_auxwrap (lua_State *L) {
76  int r = auxresume(L, co, lua_gettop(L));
77  if (r < 0) {
78  if (lua_type(L, -1) == LUA_TSTRING) { /* error object is a string? */
79  luaL_where(L, 1); /* add extra info */
80  lua_insert(L, -2);
81  lua_concat(L, 2);
82  }
83  return lua_error(L); /* propagate error */
84  }
85  return r;
86 }
87 
88 
89 static int luaB_cocreate (lua_State *L) {
90  lua_State *NL;
92  NL = lua_newthread(L);
93  lua_pushvalue(L, 1); /* move function to top */
94  lua_xmove(L, NL, 1); /* move function from L to NL */
95  return 1;
96 }
97 
98 
99 static int luaB_cowrap (lua_State *L) {
100  luaB_cocreate(L);
102  return 1;
103 }
104 
105 
106 static int luaB_yield (lua_State *L) {
107  return lua_yield(L, lua_gettop(L));
108 }
109 
110 
111 static int luaB_costatus (lua_State *L) {
112  lua_State *co = getco(L);
113  if (L == co) lua_pushliteral(L, "running");
114  else {
115  switch (lua_status(co)) {
116  case LUA_YIELD:
117  lua_pushliteral(L, "suspended");
118  break;
119  case LUA_OK: {
120  lua_Debug ar;
121  if (lua_getstack(co, 0, &ar) > 0) /* does it have frames? */
122  lua_pushliteral(L, "normal"); /* it is running */
123  else if (lua_gettop(co) == 0)
124  lua_pushliteral(L, "dead");
125  else
126  lua_pushliteral(L, "suspended"); /* initial state */
127  break;
128  }
129  default: /* some error occurred */
130  lua_pushliteral(L, "dead");
131  break;
132  }
133  }
134  return 1;
135 }
136 
137 
138 static int luaB_yieldable (lua_State *L) {
140  return 1;
141 }
142 
143 
144 static int luaB_corunning (lua_State *L) {
145  int ismain = lua_pushthread(L);
146  lua_pushboolean(L, ismain);
147  return 2;
148 }
149 
150 
151 static const luaL_Reg co_funcs[] = {
152  {"create", luaB_cocreate},
153  {"resume", luaB_coresume},
154  {"running", luaB_corunning},
155  {"status", luaB_costatus},
156  {"wrap", luaB_cowrap},
157  {"yield", luaB_yield},
158  {"isyieldable", luaB_yieldable},
159  {NULL, NULL}
160 };
161 
162 
163 
165  luaL_newlib(L, co_funcs);
166  return 1;
167 }
168 
Definition: lua.h:441
LUA_API int lua_type(lua_State *L, int idx)
Definition: lapi.cpp:251
LUA_API void lua_pushboolean(lua_State *L, int b)
Definition: lapi.cpp:557
LUA_API int lua_gettop(lua_State *L)
Definition: lapi.cpp:167
static int auxresume(lua_State *L, lua_State *co, int narg)
Definition: lcorolib.cpp:28
LUA_API int lua_checkstack(lua_State *L, int n)
Definition: lapi.cpp:97
#define LUA_TFUNCTION
Definition: lua.h:70
static int luaB_cocreate(lua_State *L)
Definition: lcorolib.cpp:89
LUA_API void lua_pushcclosure(lua_State *L, lua_CFunction fn, int n)
Definition: lapi.cpp:532
LUA_API int lua_getstack(lua_State *L, int level, lua_Debug *ar)
Definition: ldebug.cpp:110
#define lua_pop(L, n)
Definition: lua.h:344
#define lua_upvalueindex(i)
Definition: lua.h:43
#define LUA_TSTRING
Definition: lua.h:68
LUAMOD_API int luaopen_coroutine(lua_State *L)
Definition: lcorolib.cpp:164
#define LUA_YIELD
Definition: lua.h:48
static int luaB_yield(lua_State *L)
Definition: lcorolib.cpp:106
LUA_API lua_State * lua_tothread(lua_State *L, int idx)
Definition: lapi.cpp:423
LUALIB_API void luaL_where(lua_State *L, int level)
Definition: lauxlib.cpp:205
static int luaB_auxwrap(lua_State *L)
Definition: lcorolib.cpp:74
static int luaB_cowrap(lua_State *L)
Definition: lcorolib.cpp:99
LUA_API int lua_status(lua_State *L)
Definition: lapi.cpp:1031
static int luaB_costatus(lua_State *L)
Definition: lcorolib.cpp:111
#define lua_pushliteral(L, s)
Definition: lua.h:361
LUA_API int lua_pushthread(lua_State *L)
Definition: lapi.cpp:573
LUALIB_API void luaL_checktype(lua_State *L, int arg, int t)
Definition: lauxlib.cpp:378
LUA_API void lua_xmove(lua_State *from, lua_State *to, int n)
Definition: lapi.cpp:118
#define LUAMOD_API
Definition: luaconf.h:261
#define lua_yield(L, n)
Definition: lua.h:295
static int luaB_coresume(lua_State *L)
Definition: lcorolib.cpp:57
LUA_API void lua_pushvalue(lua_State *L, int idx)
Definition: lapi.cpp:237
static const luaL_Reg co_funcs[]
Definition: lcorolib.cpp:151
LUA_API int lua_resume(lua_State *L, lua_State *from, int nargs)
Definition: ldo.cpp:648
#define luaL_newlib(L, l)
Definition: lauxlib.h:119
#define luaL_argcheck(L, cond, arg, extramsg)
Definition: lauxlib.h:122
LUA_API int lua_isyieldable(lua_State *L)
Definition: ldo.cpp:687
static int luaB_corunning(lua_State *L)
Definition: lcorolib.cpp:144
LUA_API int lua_error(lua_State *L)
Definition: lapi.cpp:1114
#define LUA_OK
Definition: lua.h:47
LUA_API void lua_concat(lua_State *L, int n)
Definition: lapi.cpp:1140
#define lua_insert(L, idx)
Definition: lua.h:369
LUA_API lua_State * lua_newthread(lua_State *L)
Definition: lstate.cpp:255
static int luaB_yieldable(lua_State *L)
Definition: lcorolib.cpp:138
static lua_State * getco(lua_State *L)
Definition: lcorolib.cpp:21