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 } 155 156
