From cd2b60b101a398cb9356d746364e70eaed1860f1 Mon Sep 17 00:00:00 2001 From: Li Jin Date: Mon, 22 Jun 2020 16:50:40 +0800 Subject: add support for local variable declared with attribute 'close' and 'const' for Lua 5.4. --- src/lua/lcorolib.c | 206 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 206 insertions(+) create mode 100644 src/lua/lcorolib.c (limited to 'src/lua/lcorolib.c') diff --git a/src/lua/lcorolib.c b/src/lua/lcorolib.c new file mode 100644 index 0000000..7d6e585 --- /dev/null +++ b/src/lua/lcorolib.c @@ -0,0 +1,206 @@ +/* +** $Id: lcorolib.c $ +** 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_argexpected(L, co, 1, "thread"); + return co; +} + + +/* +** Resumes a coroutine. Returns the number of results for non-error +** cases or -1 for errors. +*/ +static int auxresume (lua_State *L, lua_State *co, int narg) { + int status, nres; + if (!lua_checkstack(co, narg)) { + lua_pushliteral(L, "too many arguments to resume"); + return -1; /* error flag */ + } + lua_xmove(L, co, narg); + status = lua_resume(co, L, narg, &nres); + if (status == LUA_OK || status == LUA_YIELD) { + 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) { + int stat = lua_status(co); + if (stat != LUA_OK && stat != LUA_YIELD) + lua_resetthread(co); /* close variables in case of errors */ + if (lua_type(L, -1) == LUA_TSTRING) { /* error object is a string? */ + luaL_where(L, 1); /* add extra info, if available */ + 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)); +} + + +#define COS_RUN 0 +#define COS_DEAD 1 +#define COS_YIELD 2 +#define COS_NORM 3 + + +static const char *const statname[] = + {"running", "dead", "suspended", "normal"}; + + +static int auxstatus (lua_State *L, lua_State *co) { + if (L == co) return COS_RUN; + else { + switch (lua_status(co)) { + case LUA_YIELD: + return COS_YIELD; + case LUA_OK: { + lua_Debug ar; + if (lua_getstack(co, 0, &ar)) /* does it have frames? */ + return COS_NORM; /* it is running */ + else if (lua_gettop(co) == 0) + return COS_DEAD; + else + return COS_YIELD; /* initial state */ + } + default: /* some error occurred */ + return COS_DEAD; + } + } +} + + +static int luaB_costatus (lua_State *L) { + lua_State *co = getco(L); + lua_pushstring(L, statname[auxstatus(L, co)]); + return 1; +} + + +static int luaB_yieldable (lua_State *L) { + lua_State *co = lua_isnone(L, 1) ? L : getco(L); + lua_pushboolean(L, lua_isyieldable(co)); + return 1; +} + + +static int luaB_corunning (lua_State *L) { + int ismain = lua_pushthread(L); + lua_pushboolean(L, ismain); + return 2; +} + + +static int luaB_close (lua_State *L) { + lua_State *co = getco(L); + int status = auxstatus(L, co); + switch (status) { + case COS_DEAD: case COS_YIELD: { + status = lua_resetthread(co); + if (status == LUA_OK) { + lua_pushboolean(L, 1); + return 1; + } + else { + lua_pushboolean(L, 0); + lua_xmove(co, L, 1); /* copy error message */ + return 2; + } + } + default: /* normal or running coroutine */ + return luaL_error(L, "cannot close a %s coroutine", statname[status]); + } +} + + +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}, + {"close", luaB_close}, + {NULL, NULL} +}; + + + +LUAMOD_API int luaopen_coroutine (lua_State *L) { + luaL_newlib(L, co_funcs); + return 1; +} + -- cgit v1.2.3-55-g6feb