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 getco(lua_State * L)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 auxresume(lua_State * L,lua_State * co,int narg)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 luaB_coresume(lua_State * L)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 luaB_auxwrap(lua_State * L)74 static int luaB_auxwrap (lua_State *L) { 75 lua_State *co = lua_tothread(L, lua_upvalueindex(1)); 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 luaB_cocreate(lua_State * L)89 static int luaB_cocreate (lua_State *L) { 90 lua_State *NL; 91 luaL_checktype(L, 1, LUA_TFUNCTION); 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 luaB_cowrap(lua_State * L)99 static int luaB_cowrap (lua_State *L) { 100 luaB_cocreate(L); 101 lua_pushcclosure(L, luaB_auxwrap, 1); 102 return 1; 103 } 104 105 luaB_yield(lua_State * L)106 static int luaB_yield (lua_State *L) { 107 return lua_yield(L, lua_gettop(L)); 108 } 109 110 luaB_costatus(lua_State * L)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 luaB_yieldable(lua_State * L)138 static int luaB_yieldable (lua_State *L) { 139 lua_pushboolean(L, lua_isyieldable(L)); 140 return 1; 141 } 142 143 luaB_corunning(lua_State * L)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 luaopen_coroutine(lua_State * L)164 LUAMOD_API int luaopen_coroutine (lua_State *L) { 165 luaL_newlib(L, co_funcs); 166 return 1; 167 } 168 169