src/event_callback.c

   1 /* LuaEvent
   2    Copyright (C) 2007,2012,2013 Thomas Harning <harningt@gmail.com>
   3
   4    Permission is hereby granted, free of charge, to any person obtaining a copy
   5    of this software and associated documentation files (the "Software"), to deal
   6    in the Software without restriction, including without limitation the rights
   7    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   8    copies of the Software, and to permit persons to whom the Software is
   9    furnished to do so, subject to the following conditions:
  10
  11    The above copyright notice and this permission notice shall be included in
  12    all copies or substantial portions of the Software.
  13
  14    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  17    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  18    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  19    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  20    THE SOFTWARE.
  21    */
  22
  23 #include "event_callback.h"
  24 #include <assert.h>
  25 #include <lauxlib.h>
  26 #include <string.h>
  27
  28 #define EVENT_CALLBACK_ARG_MT "EVENT_CALLBACK_ARG_MT"
  29
  30 void freeCallbackArgs(le_callback* arg, lua_State* L) {
  31         if(arg->base) {
  32                 arg->base = NULL;
  33                 event_del(&arg->ev);
  34                 luaL_unref(L, LUA_REGISTRYINDEX, arg->callbackRef);
  35         }
  36 }
  37 /* le_callback is allocated at the beginning of the coroutine in which it
  38 is used, no need to manually de-allocate */
  39
  40 /* Index for coroutine is fd as integer for *nix, as lightuserdata for Win */
  41 void luaevent_callback(int fd, short event, void* p) {
  42         le_callback* cb = p;
  43         lua_State* L;
  44         int ret;
  45         struct timeval new_tv = { 0, 0 };
  46         assert(cb);
  47         if(!cb->base)
  48                 return; /* Event has already been collected + destroyed */
  49         assert(cb->base->loop_L);
  50         L = cb->base->loop_L;
  51         lua_rawgeti(L, LUA_REGISTRYINDEX, cb->callbackRef);
  52         lua_pushinteger(L, event);
  53         if(lua_pcall(L, 1, 2, 0))
  54         {
  55                 cb->base->errorMessage = luaL_ref(L, LUA_REGISTRYINDEX);
  56                 event_base_loopbreak(cb->base->base);
  57                 lua_pop(L, 1);
  58                 return;
  59         }
  60         if(!cb->base) {
  61                 lua_pop(L, 2);
  62                 return; /* event was destroyed during callback */
  63         }
  64         /* If nothing is returned, re-use the old event value */
  65         ret = luaL_optinteger(L, -2, event);
  66         /* Clone the old timeout value in case a new one wasn't set */
  67         memcpy(&new_tv, &cb->timeout, sizeof(new_tv));
  68         if(lua_isnumber(L, -1)) {
  69                 double newTimeout = lua_tonumber(L, -1);
  70                 if(newTimeout > 0) {
  71                         load_timeval(newTimeout, &new_tv);
  72                 }
  73         }
  74         lua_pop(L, 2);
  75         if(ret == -1) {
  76                 freeCallbackArgs(cb, L);
  77         } else {
  78                 struct event *ev = &cb->ev;
  79                 int newEvent = ret;
  80                 if( newEvent != event || (cb->timeout.tv_sec != new_tv.tv_sec || cb->timeout.tv_usec != new_tv.tv_usec) ) {
  81                         struct timeval *ptv = &cb->timeout;
  82                         cb->timeout = new_tv;
  83                         if(!cb->timeout.tv_sec && !cb->timeout.tv_usec)
  84                                 ptv = NULL;
  85                         event_del(ev);
  86                         event_set(ev, fd, EV_PERSIST | newEvent, luaevent_callback, cb);
  87                         /* Assume cannot set a new timeout.. */
  88                         event_add(ev, ptv);
  89                 }
  90         }
  91 }
  92
  93 static int luaevent_cb_gc(lua_State* L) {
  94         le_callback* arg = luaL_checkudata(L, 1, EVENT_CALLBACK_ARG_MT);
  95         freeCallbackArgs(arg, L);
  96         return 0;
  97 }
  98
  99 le_callback* event_callback_push(lua_State* L, int baseIdx, int callbackIdx) {
 100         le_callback* cb;
 101         le_base *base = event_base_get(L, baseIdx);
 102         luaL_checktype(L, callbackIdx, LUA_TFUNCTION);
 103         cb = lua_newuserdata(L, sizeof(*cb));
 104         luaL_getmetatable(L, EVENT_CALLBACK_ARG_MT);
 105         lua_setmetatable(L, -2);
 106
 107         lua_pushvalue(L, callbackIdx);
 108         cb->callbackRef = luaL_ref(L, LUA_REGISTRYINDEX);
 109         cb->base = base;
 110         memset(&cb->timeout, 0, sizeof(cb->timeout));
 111         return cb;
 112 }
 113
 114 void event_callback_register(lua_State* L) {
 115         luaL_newmetatable(L, EVENT_CALLBACK_ARG_MT);
 116         lua_pushcfunction(L, luaevent_cb_gc);
 117         lua_setfield(L, -2, "__gc");
 118         lua_newtable(L);
 119         lua_pushcfunction(L, luaevent_cb_gc);
 120         lua_setfield(L, -2, "close");
 121         lua_setfield(L, -2, "__index");
 122         lua_pop(L, 1);
 123 }