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 #include <string.h>
   7
   8 #define EVENT_CALLBACK_ARG_MT "EVENT_CALLBACK_ARG_MT"
   9
  10 void freeCallbackArgs(le_callback* arg, lua_State* L) {
  11         if(arg->base) {
  12                 arg->base = NULL;
  13                 event_del(&arg->ev);
  14                 luaL_unref(L, LUA_REGISTRYINDEX, arg->callbackRef);
  15         }
  16 }
  17 /* le_callback is allocated at the beginning of the coroutine in which it
  18 is used, no need to manually de-allocate */
  19
  20 /* Index for coroutine is fd as integer for *nix, as lightuserdata for Win */
  21 void luaevent_callback(int fd, short event, void* p) {
  22         le_callback* cb = p;
  23         lua_State* L;
  24         int ret;
  25         double newTimeout = -1;
  26         assert(cb);
  27         if(!cb->base)
  28                 return; /* Event has already been collected + destroyed */
  29         assert(cb->base->loop_L);
  30         L = cb->base->loop_L;
  31         lua_rawgeti(L, LUA_REGISTRYINDEX, cb->callbackRef);
  32         lua_pushinteger(L, event);
  33         lua_call(L, 1, 2);
  34         if(!cb->base)
  35                 return; /* event was destroyed during callback */
  36         ret = lua_tointeger(L, -2);
  37         if(lua_isnumber(L, -1)) {
  38                 newTimeout = lua_tonumber(L, -1);
  39                 if(newTimeout <= 0) {
  40                         memset(&cb->timeout, 0, sizeof(cb->timeout));
  41                 } else {
  42                         load_timeval(newTimeout, &cb->timeout);
  43                 }
  44         }
  45         lua_pop(L, 2);
  46         if(ret == -1) {
  47                 freeCallbackArgs(cb, L);
  48         } else {
  49                 struct event *ev = &cb->ev;
  50                 int newEvent = ret;
  51                 /* NOTE: Currently, even if new timeout is the same as the old, a new event is setup regardless... */
  52                 if(newEvent != event || newTimeout != -1) { // Need to hook up new event...
  53                         struct timeval *ptv = &cb->timeout;
  54                         if(!cb->timeout.tv_sec && !cb->timeout.tv_usec)
  55                                 ptv = NULL;
  56                         event_del(ev);
  57                         event_set(ev, fd, EV_PERSIST | newEvent, luaevent_callback, cb);
  58                         /* Assume cannot set a new timeout.. */
  59                         event_add(ev, ptv);
  60                 }
  61         }
  62 }
  63
  64 static int luaevent_cb_gc(lua_State* L) {
  65         le_callback* arg = luaL_checkudata(L, 1, EVENT_CALLBACK_ARG_MT);
  66         freeCallbackArgs(arg, L);
  67         return 0;
  68 }
  69
  70 le_callback* event_callback_push(lua_State* L, int baseIdx, int callbackIdx) {
  71         le_callback* cb;
  72         le_base *base = event_base_get(L, baseIdx);
  73         luaL_checktype(L, callbackIdx, LUA_TFUNCTION);
  74         cb = lua_newuserdata(L, sizeof(*cb));
  75         luaL_getmetatable(L, EVENT_CALLBACK_ARG_MT);
  76         lua_setmetatable(L, -2);
  77
  78         lua_pushvalue(L, callbackIdx);
  79         cb->callbackRef = luaL_ref(L, LUA_REGISTRYINDEX);
  80         cb->base = base;
  81         memset(&cb->timeout, 0, sizeof(cb->timeout));
  82         return cb;
  83 }
  84
  85 int event_callback_register(lua_State* L) {
  86         luaL_newmetatable(L, EVENT_CALLBACK_ARG_MT);
  87         lua_pushcfunction(L, luaevent_cb_gc);
  88         lua_setfield(L, -2, "__gc");
  89         lua_newtable(L);
  90         lua_pushcfunction(L, luaevent_cb_gc);
  91         lua_setfield(L, -2, "close");
  92         lua_setfield(L, -2, "__index");
  93         lua_pop(L, 1);
  94         return 0;
  95 }