1 /*
2 ** $Id: lcorolib.c,v 1.5.1.1 2013/04/12 18:48:47 roberto Exp $
3 ** Coroutine Library
4 ** See Copyright Notice in lua.h
5 */
6
7
8 #define lcorolib_c
9 #define LUA_LIB
10
11 #include <sys/lua/lua.h>
12
13 #include <sys/lua/lauxlib.h>
14 #include <sys/lua/lualib.h>
15
16
auxresume(lua_State * L,lua_State * co,int narg)17 static int auxresume (lua_State *L, lua_State *co, int narg) {
18 int status;
19 if (!lua_checkstack(co, narg)) {
20 lua_pushliteral(L, "too many arguments to resume");
21 return -1; /* error flag */
22 }
23 if (lua_status(co) == LUA_OK && lua_gettop(co) == 0) {
24 lua_pushliteral(L, "cannot resume dead coroutine");
25 return -1; /* error flag */
26 }
27 lua_xmove(L, co, narg);
28 status = lua_resume(co, L, narg);
29 if (status == LUA_OK || status == LUA_YIELD) {
30 int nres = lua_gettop(co);
31 if (!lua_checkstack(L, nres + 1)) {
32 lua_pop(co, nres); /* remove results anyway */
33 lua_pushliteral(L, "too many results to resume");
34 return -1; /* error flag */
35 }
36 lua_xmove(co, L, nres); /* move yielded values */
37 return nres;
38 }
39 else {
40 lua_xmove(co, L, 1); /* move error message */
41 return -1; /* error flag */
42 }
43 }
44
45
luaB_coresume(lua_State * L)46 static int luaB_coresume (lua_State *L) {
47 lua_State *co = lua_tothread(L, 1);
48 int r;
49 luaL_argcheck(L, co, 1, "coroutine expected");
50 r = auxresume(L, co, lua_gettop(L) - 1);
51 if (r < 0) {
52 lua_pushboolean(L, 0);
53 lua_insert(L, -2);
54 return 2; /* return false + error message */
55 }
56 else {
57 lua_pushboolean(L, 1);
58 lua_insert(L, -(r + 1));
59 return r + 1; /* return true + 'resume' returns */
60 }
61 }
62
63
luaB_auxwrap(lua_State * L)64 static int luaB_auxwrap (lua_State *L) {
65 lua_State *co = lua_tothread(L, lua_upvalueindex(1));
66 int r = auxresume(L, co, lua_gettop(L));
67 if (r < 0) {
68 if (lua_isstring(L, -1)) { /* error object is a string? */
69 luaL_where(L, 1); /* add extra info */
70 lua_insert(L, -2);
71 lua_concat(L, 2);
72 }
73 return lua_error(L); /* propagate error */
74 }
75 return r;
76 }
77
78
luaB_cocreate(lua_State * L)79 static int luaB_cocreate (lua_State *L) {
80 lua_State *NL;
81 luaL_checktype(L, 1, LUA_TFUNCTION);
82 NL = lua_newthread(L);
83 lua_pushvalue(L, 1); /* move function to top */
84 lua_xmove(L, NL, 1); /* move function from L to NL */
85 return 1;
86 }
87
88
luaB_cowrap(lua_State * L)89 static int luaB_cowrap (lua_State *L) {
90 luaB_cocreate(L);
91 lua_pushcclosure(L, luaB_auxwrap, 1);
92 return 1;
93 }
94
95
luaB_yield(lua_State * L)96 static int luaB_yield (lua_State *L) {
97 return lua_yield(L, lua_gettop(L));
98 }
99
100
luaB_costatus(lua_State * L)101 static int luaB_costatus (lua_State *L) {
102 lua_State *co = lua_tothread(L, 1);
103 luaL_argcheck(L, co, 1, "coroutine expected");
104 if (L == co) lua_pushliteral(L, "running");
105 else {
106 switch (lua_status(co)) {
107 case LUA_YIELD:
108 lua_pushliteral(L, "suspended");
109 break;
110 case LUA_OK: {
111 lua_Debug ar;
112 if (lua_getstack(co, 0, &ar) > 0) /* does it have frames? */
113 lua_pushliteral(L, "normal"); /* it is running */
114 else if (lua_gettop(co) == 0)
115 lua_pushliteral(L, "dead");
116 else
117 lua_pushliteral(L, "suspended"); /* initial state */
118 break;
119 }
120 default: /* some error occurred */
121 lua_pushliteral(L, "dead");
122 break;
123 }
124 }
125 return 1;
126 }
127
128
luaB_corunning(lua_State * L)129 static int luaB_corunning (lua_State *L) {
130 int ismain = lua_pushthread(L);
131 lua_pushboolean(L, ismain);
132 return 2;
133 }
134
135
136 static const luaL_Reg co_funcs[] = {
137 {"create", luaB_cocreate},
138 {"resume", luaB_coresume},
139 {"running", luaB_corunning},
140 {"status", luaB_costatus},
141 {"wrap", luaB_cowrap},
142 {"yield", luaB_yield},
143 {NULL, NULL}
144 };
145
146
147
luaopen_coroutine(lua_State * L)148 LUAMOD_API int luaopen_coroutine (lua_State *L) {
149 luaL_newlib(L, co_funcs);
150 return 1;
151 }
152
153 #if defined(_KERNEL)
154
155 EXPORT_SYMBOL(luaopen_coroutine);
156
157 #endif
158