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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 | |