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 #define EVENT_CALLBACK_ARG_MT "EVENT_CALLBACK_ARG_MT"
   8
   9 void freeCallbackArgs(le_callback* arg, lua_State* L) {
  10         if(arg->base) {
  11                 arg->base = NULL;
  12                 event_del(&arg->ev);
  13                 luaL_unref(L, LUA_REGISTRYINDEX, arg->callbackRef);
  14         }
  15 }
  16 /* le_callback is allocated at the beginning of the coroutine in which it
  17 is used, no need to manually de-allocate */
  18
  19 /* Index for coroutine is fd as integer for *nix, as lightuserdata for Win */
  20 void luaevent_callback(int fd, short event, void* p) {
  21         le_callback* arg = p;
  22         lua_State* L;
  23         int ret;
  24         assert(arg && arg->base && arg->base->loop_L);
  25         L = arg->base->loop_L;
  26         lua_rawgeti(L, LUA_REGISTRYINDEX, arg->callbackRef);
  27         lua_pushinteger(L, event);
  28         lua_call(L, 1, 1);
  29         ret = lua_tointeger(L, -1);
  30         lua_pop(L, 1);
  31         if(ret == -1) {
  32                 freeCallbackArgs(arg, L);
  33         } else {
  34                 struct event *ev = &arg->ev;
  35                 int newEvent = ret;
  36                 if(newEvent != event) { // Need to hook up new event...
  37                         event_del(ev);
  38                         event_set(ev, fd, EV_PERSIST | newEvent, luaevent_callback, arg);
  39                         event_add(ev, NULL);
  40                 }
  41         }
  42 }
  43
  44 static int luaevent_cb_gc(lua_State* L) {
  45         le_callback* arg = luaL_checkudata(L, 1, EVENT_CALLBACK_ARG_MT);
  46         freeCallbackArgs(arg, L);
  47         return 0;
  48 }
  49
  50 le_callback* event_callback_push(lua_State* L, int baseIdx, int callbackIdx) {
  51         le_callback* cb;
  52         le_base *base = event_base_get(L, baseIdx);
  53         luaL_checktype(L, callbackIdx, LUA_TFUNCTION);
  54         cb = lua_newuserdata(L, sizeof(*cb));
  55         luaL_getmetatable(L, EVENT_CALLBACK_ARG_MT);
  56         lua_setmetatable(L, -2);
  57
  58         lua_pushvalue(L, callbackIdx);
  59         cb->callbackRef = luaL_ref(L, LUA_REGISTRYINDEX);
  60         cb->base = base;
  61         return cb;
  62 }
  63
  64 int event_callback_register(lua_State* L) {
  65         luaL_newmetatable(L, EVENT_CALLBACK_ARG_MT);
  66         lua_pushcfunction(L, luaevent_cb_gc);
  67         lua_setfield(L, -2, "__gc");
  68         lua_newtable(L);
  69         lua_pushcfunction(L, luaevent_cb_gc);
  70         lua_setfield(L, -2, "close");
  71         lua_setfield(L, -2, "__index");
  72         lua_pop(L, 1);
  73         return 0;
  74 }