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ba8b5c17 | 1 | /* |
2 | ** $Id: lcorolib.c,v 1.5 2013/02/21 13:44:53 roberto Exp $ | |
3 | ** Coroutine Library | |
4 | ** See Copyright Notice in lua.h | |
5 | */ | |
6 | ||
7 | ||
8 | #include <stdlib.h> | |
9 | ||
10 | ||
11 | #define lcorolib_c | |
12 | #define LUA_LIB | |
13 | ||
14 | #include "lua.h" | |
15 | ||
16 | #include "lauxlib.h" | |
17 | #include "lualib.h" | |
18 | ||
19 | ||
20 | static int auxresume (lua_State *L, lua_State *co, int narg) { | |
21 | int status; | |
22 | if (!lua_checkstack(co, narg)) { | |
23 | lua_pushliteral(L, "too many arguments to resume"); | |
24 | return -1; /* error flag */ | |
25 | } | |
26 | if (lua_status(co) == LUA_OK && lua_gettop(co) == 0) { | |
27 | lua_pushliteral(L, "cannot resume dead coroutine"); | |
28 | return -1; /* error flag */ | |
29 | } | |
30 | lua_xmove(L, co, narg); | |
31 | status = lua_resume(co, L, narg); | |
32 | if (status == LUA_OK || status == LUA_YIELD) { | |
33 | int nres = lua_gettop(co); | |
34 | if (!lua_checkstack(L, nres + 1)) { | |
35 | lua_pop(co, nres); /* remove results anyway */ | |
36 | lua_pushliteral(L, "too many results to resume"); | |
37 | return -1; /* error flag */ | |
38 | } | |
39 | lua_xmove(co, L, nres); /* move yielded values */ | |
40 | return nres; | |
41 | } | |
42 | else { | |
43 | lua_xmove(co, L, 1); /* move error message */ | |
44 | return -1; /* error flag */ | |
45 | } | |
46 | } | |
47 | ||
48 | ||
49 | static int luaB_coresume (lua_State *L) { | |
50 | lua_State *co = lua_tothread(L, 1); | |
51 | int r; | |
52 | luaL_argcheck(L, co, 1, "coroutine expected"); | |
53 | r = auxresume(L, co, lua_gettop(L) - 1); | |
54 | if (r < 0) { | |
55 | lua_pushboolean(L, 0); | |
56 | lua_insert(L, -2); | |
57 | return 2; /* return false + error message */ | |
58 | } | |
59 | else { | |
60 | lua_pushboolean(L, 1); | |
61 | lua_insert(L, -(r + 1)); | |
62 | return r + 1; /* return true + `resume' returns */ | |
63 | } | |
64 | } | |
65 | ||
66 | ||
67 | static int luaB_auxwrap (lua_State *L) { | |
68 | lua_State *co = lua_tothread(L, lua_upvalueindex(1)); | |
69 | int r = auxresume(L, co, lua_gettop(L)); | |
70 | if (r < 0) { | |
71 | if (lua_isstring(L, -1)) { /* error object is a string? */ | |
72 | luaL_where(L, 1); /* add extra info */ | |
73 | lua_insert(L, -2); | |
74 | lua_concat(L, 2); | |
75 | } | |
76 | return lua_error(L); /* propagate error */ | |
77 | } | |
78 | return r; | |
79 | } | |
80 | ||
81 | ||
82 | static int luaB_cocreate (lua_State *L) { | |
83 | lua_State *NL; | |
84 | luaL_checktype(L, 1, LUA_TFUNCTION); | |
85 | NL = lua_newthread(L); | |
86 | lua_pushvalue(L, 1); /* move function to top */ | |
87 | lua_xmove(L, NL, 1); /* move function from L to NL */ | |
88 | return 1; | |
89 | } | |
90 | ||
91 | ||
92 | static int luaB_cowrap (lua_State *L) { | |
93 | luaB_cocreate(L); | |
94 | lua_pushcclosure(L, luaB_auxwrap, 1); | |
95 | return 1; | |
96 | } | |
97 | ||
98 | ||
99 | static int luaB_yield (lua_State *L) { | |
100 | return lua_yield(L, lua_gettop(L)); | |
101 | } | |
102 | ||
103 | ||
104 | static int luaB_costatus (lua_State *L) { | |
105 | lua_State *co = lua_tothread(L, 1); | |
106 | luaL_argcheck(L, co, 1, "coroutine expected"); | |
107 | if (L == co) lua_pushliteral(L, "running"); | |
108 | else { | |
109 | switch (lua_status(co)) { | |
110 | case LUA_YIELD: | |
111 | lua_pushliteral(L, "suspended"); | |
112 | break; | |
113 | case LUA_OK: { | |
114 | lua_Debug ar; | |
115 | if (lua_getstack(co, 0, &ar) > 0) /* does it have frames? */ | |
116 | lua_pushliteral(L, "normal"); /* it is running */ | |
117 | else if (lua_gettop(co) == 0) | |
118 | lua_pushliteral(L, "dead"); | |
119 | else | |
120 | lua_pushliteral(L, "suspended"); /* initial state */ | |
121 | break; | |
122 | } | |
123 | default: /* some error occurred */ | |
124 | lua_pushliteral(L, "dead"); | |
125 | break; | |
126 | } | |
127 | } | |
128 | return 1; | |
129 | } | |
130 | ||
131 | ||
132 | static int luaB_corunning (lua_State *L) { | |
133 | int ismain = lua_pushthread(L); | |
134 | lua_pushboolean(L, ismain); | |
135 | return 2; | |
136 | } | |
137 | ||
138 | ||
139 | static const luaL_Reg co_funcs[] = { | |
140 | {"create", luaB_cocreate}, | |
141 | {"resume", luaB_coresume}, | |
142 | {"running", luaB_corunning}, | |
143 | {"status", luaB_costatus}, | |
144 | {"wrap", luaB_cowrap}, | |
145 | {"yield", luaB_yield}, | |
146 | {NULL, NULL} | |
147 | }; | |
148 | ||
149 | ||
150 | ||
151 | LUAMOD_API int luaopen_coroutine (lua_State *L) { | |
152 | luaL_newlib(L, co_funcs); | |
153 | return 1; | |
154 | } | |
155 |