/* ** $Id: lcorolib.c,v 1.10.1.1 2017/04/19 17:20:42 roberto Exp $ ** Coroutine Library ** See Copyright Notice in lua.h */ #define lcorolib_c #define LUA_LIB #include "lprefix.h" #include #include "lua.h" #include "lauxlib.h" #include "lualib.h" static lua_State *getco (lua_State *L) { lua_State *co = lua_tothread(L, 1); luaL_argcheck(L, co, 1, "thread expected"); return co; } static int auxresume (lua_State *L, lua_State *co, int narg) { int status; if (!lua_checkstack(co, narg)) { lua_pushliteral(L, "too many arguments to resume"); return -1; /* error flag */ } if (lua_status(co) == LUA_OK && lua_gettop(co) == 0) { lua_pushliteral(L, "cannot resume dead coroutine"); return -1; /* error flag */ } lua_xmove(L, co, narg); status = lua_resume(co, L, narg); if (status == LUA_OK || status == LUA_YIELD) { int nres = lua_gettop(co); if (!lua_checkstack(L, nres + 1)) { lua_pop(co, nres); /* remove results anyway */ lua_pushliteral(L, "too many results to resume"); return -1; /* error flag */ } lua_xmove(co, L, nres); /* move yielded values */ return nres; } else { lua_xmove(co, L, 1); /* move error message */ return -1; /* error flag */ } } static int luaB_coresume (lua_State *L) { lua_State *co = getco(L); int r; r = auxresume(L, co, lua_gettop(L) - 1); if (r < 0) { lua_pushboolean(L, 0); lua_insert(L, -2); return 2; /* return false + error message */ } else { lua_pushboolean(L, 1); lua_insert(L, -(r + 1)); return r + 1; /* return true + 'resume' returns */ } } static int luaB_auxwrap (lua_State *L) { lua_State *co = lua_tothread(L, lua_upvalueindex(1)); int r = auxresume(L, co, lua_gettop(L)); if (r < 0) { if (lua_type(L, -1) == LUA_TSTRING) { /* error object is a string? */ luaL_where(L, 1); /* add extra info */ lua_insert(L, -2); lua_concat(L, 2); } return lua_error(L); /* propagate error */ } return r; } static int luaB_cocreate (lua_State *L) { lua_State *NL; luaL_checktype(L, 1, LUA_TFUNCTION); NL = lua_newthread(L); lua_pushvalue(L, 1); /* move function to top */ lua_xmove(L, NL, 1); /* move function from L to NL */ return 1; } static int luaB_cowrap (lua_State *L) { luaB_cocreate(L); lua_pushcclosure(L, luaB_auxwrap, 1); return 1; } static int luaB_yield (lua_State *L) { return lua_yield(L, lua_gettop(L)); } static int luaB_costatus (lua_State *L) { lua_State *co = getco(L); if (L == co) lua_pushliteral(L, "running"); else { switch (lua_status(co)) { case LUA_YIELD: lua_pushliteral(L, "suspended"); break; case LUA_OK: { lua_Debug ar; if (lua_getstack(co, 0, &ar) > 0) /* does it have frames? */ lua_pushliteral(L, "normal"); /* it is running */ else if (lua_gettop(co) == 0) lua_pushliteral(L, "dead"); else lua_pushliteral(L, "suspended"); /* initial state */ break; } default: /* some error occurred */ lua_pushliteral(L, "dead"); break; } } return 1; } static int luaB_yieldable (lua_State *L) { lua_pushboolean(L, lua_isyieldable(L)); return 1; } static int luaB_corunning (lua_State *L) { int ismain = lua_pushthread(L); lua_pushboolean(L, ismain); return 2; } static const luaL_Reg co_funcs[] = { {"create", luaB_cocreate}, {"resume", luaB_coresume}, {"running", luaB_corunning}, {"status", luaB_costatus}, {"wrap", luaB_cowrap}, {"yield", luaB_yield}, {"isyieldable", luaB_yieldable}, {NULL, NULL} }; LUAMOD_API int luaopen_coroutine (lua_State *L) { luaL_newlib(L, co_funcs); return 1; }