src/event_callback.c

   1 /* LuaEvent - Copyright (C) 2007,2012 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         struct timeval new_tv = { 0, 0 };
  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         /* If nothing is returned, re-use the old event value */
  37         ret = luaL_optinteger(L, -2, event);
  38         /* Clone the old timeout value in case a new one wasn't set */
  39         memcpy(&new_tv, &cb->timeout, sizeof(new_tv));
  40         if(lua_isnumber(L, -1)) {
  41                 double newTimeout = lua_tonumber(L, -1);
  42                 if(newTimeout > 0) {
  43                         load_timeval(newTimeout, &new_tv);
  44                 }
  45         }
  46         lua_pop(L, 2);
  47         if(ret == -1) {
  48                 freeCallbackArgs(cb, L);
  49         } else {
  50                 struct event *ev = &cb->ev;
  51                 int newEvent = ret;
  52                 if( newEvent != event || (cb->timeout.tv_sec != new_tv.tv_sec || cb->timeout.tv_usec != new_tv.tv_usec) ) {
  53                         struct timeval *ptv = &cb->timeout;
  54                         cb->timeout = new_tv;
  55                         if(!cb->timeout.tv_sec && !cb->timeout.tv_usec)
  56                                 ptv = NULL;
  57                         event_del(ev);
  58                         event_set(ev, fd, EV_PERSIST | newEvent, luaevent_callback, cb);
  59                         /* Assume cannot set a new timeout.. */
  60                         event_add(ev, ptv);
  61                 }
  62         }
  63 }
  64
  65 static int luaevent_cb_gc(lua_State* L) {
  66         le_callback* arg = luaL_checkudata(L, 1, EVENT_CALLBACK_ARG_MT);
  67         freeCallbackArgs(arg, L);
  68         return 0;
  69 }
  70
  71 le_callback* event_callback_push(lua_State* L, int baseIdx, int callbackIdx) {
  72         le_callback* cb;
  73         le_base *base = event_base_get(L, baseIdx);
  74         luaL_checktype(L, callbackIdx, LUA_TFUNCTION);
  75         cb = lua_newuserdata(L, sizeof(*cb));
  76         luaL_getmetatable(L, EVENT_CALLBACK_ARG_MT);
  77         lua_setmetatable(L, -2);
  78
  79         lua_pushvalue(L, callbackIdx);
  80         cb->callbackRef = luaL_ref(L, LUA_REGISTRYINDEX);
  81         cb->base = base;
  82         memset(&cb->timeout, 0, sizeof(cb->timeout));
  83         return cb;
  84 }
  85
  86 void event_callback_register(lua_State* L) {
  87         luaL_newmetatable(L, EVENT_CALLBACK_ARG_MT);
  88         lua_pushcfunction(L, luaevent_cb_gc);
  89         lua_setfield(L, -2, "__gc");
  90         lua_newtable(L);
  91         lua_pushcfunction(L, luaevent_cb_gc);
  92         lua_setfield(L, -2, "close");
  93         lua_setfield(L, -2, "__index");
  94         lua_pop(L, 1);
  95 }