src/event_callback.c

   1 /* LuaEvent - Copyright (C) 2007 Thomas Harning <harningt@gmail.com>
   2  * Licensed as LGPL - See doc/COPYING for details */
   3 #include "event_callback.h"
   4 #include <assert.h>
   5 #include <lauxlib.h>
   6
   7 void freeCallbackArgs(le_callback* arg, lua_State* L) {
   8         if(arg->base) {
   9                 arg->base = NULL;
  10                 event_del(&arg->ev);
  11                 luaL_unref(L, LUA_REGISTRYINDEX, arg->callbackRef);
  12         }
  13 }
  14 /* le_callback is allocated at the beginning of the coroutine in which it
  15 is used, no need to manually de-allocate */
  16
  17 /* Index for coroutine is fd as integer for *nix, as lightuserdata for Win */
  18 void luaevent_callback(int fd, short event, void* p) {
  19         le_callback* arg = p;
  20         lua_State* L;
  21         int ret;
  22         assert(arg && arg->base && arg->base->loop_L);
  23         L = arg->base->loop_L;
  24         lua_rawgeti(L, LUA_REGISTRYINDEX, arg->callbackRef);
  25         lua_pushinteger(L, event);
  26         lua_call(L, 1, 1);
  27         ret = lua_tointeger(L, -1);
  28         lua_pop(L, 1);
  29         if(ret == -1) {
  30                 freeCallbackArgs(arg, L);
  31         } else {
  32                 struct event *ev = &arg->ev;
  33                 int newEvent = ret;
  34                 if(newEvent != event) { // Need to hook up new event...
  35                         event_del(ev);
  36                         event_set(ev, fd, EV_PERSIST | newEvent, luaevent_callback, arg);
  37                         event_add(ev, NULL);
  38                 }
  39         }
  40 }
  41
  42 static int luaevent_cb_gc(lua_State* L) {
  43         le_callback* arg = luaL_checkudata(L, 1, EVENT_CALLBACK_ARG_MT);
  44         freeCallbackArgs(arg, L);
  45         return 0;
  46 }
  47
  48 int event_callback_register(lua_State* L) {
  49         luaL_newmetatable(L, EVENT_CALLBACK_ARG_MT);
  50         lua_pushcfunction(L, luaevent_cb_gc);
  51         lua_setfield(L, -2, "__gc");
  52         lua_newtable(L);
  53         lua_pushcfunction(L, luaevent_cb_gc);
  54         lua_setfield(L, -2, "close");
  55         lua_setfield(L, -2, "__index");
  56         lua_pop(L, 1);
  57         return 0;
  58 }