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         le_base* base;
  47         assert(cb);
  48         if(!cb->base)
  49                 return; /* Event has already been collected + destroyed */
  50         assert(cb->base->loop_L);
  51         L = cb->base->loop_L;
  52         lua_rawgeti(L, LUA_REGISTRYINDEX, cb->callbackRef);
  53         lua_pushinteger(L, event);
  54         /* cb->base may be NULL after the pcall, if the event is destroyed */
  55         base = cb->base;
  56         if(lua_pcall(L, 1, 2, 0))
  57         {
  58                 base->errorMessage = luaL_ref(L, LUA_REGISTRYINDEX);
  59                 event_base_loopbreak(base->base);
  60                 lua_pop(L, 1);
  61                 return;
  62         }
  63         if(!cb->base) {
  64                 lua_pop(L, 2);
  65                 return; /* event was destroyed during callback */
  66         }
  67         /* If nothing is returned, re-use the old event value */
  68         ret = luaL_optinteger(L, -2, event);
  69         /* Clone the old timeout value in case a new one wasn't set */
  70         memcpy(&new_tv, &cb->timeout, sizeof(new_tv));
  71         if(lua_isnumber(L, -1)) {
  72                 double newTimeout = lua_tonumber(L, -1);
  73                 if(newTimeout > 0) {
  74                         load_timeval(newTimeout, &new_tv);
  75                 }
  76         }
  77         lua_pop(L, 2);
  78         if(ret == -1) {
  79                 freeCallbackArgs(cb, L);
  80         } else {
  81                 struct event *ev = &cb->ev;
  82                 int newEvent = ret;
  83                 if( newEvent != event || (cb->timeout.tv_sec != new_tv.tv_sec || cb->timeout.tv_usec != new_tv.tv_usec) ) {
  84                         struct timeval *ptv = &cb->timeout;
  85                         cb->timeout = new_tv;
  86                         if(!cb->timeout.tv_sec && !cb->timeout.tv_usec)
  87                                 ptv = NULL;
  88                         event_del(ev);
  89                         event_set(ev, fd, EV_PERSIST | newEvent, luaevent_callback, cb);
  90                         /* Assume cannot set a new timeout.. */
  91                         event_add(ev, ptv);
  92                 }
  93         }
  94 }
  95
  96 static int luaevent_cb_gc(lua_State* L) {
  97         le_callback* arg = luaL_checkudata(L, 1, EVENT_CALLBACK_ARG_MT);
  98         freeCallbackArgs(arg, L);
  99         return 0;
 100 }
 101
 102 le_callback* event_callback_push(lua_State* L, int baseIdx, int callbackIdx) {
 103         le_callback* cb;
 104         le_base *base = event_base_get(L, baseIdx);
 105         luaL_checktype(L, callbackIdx, LUA_TFUNCTION);
 106         cb = lua_newuserdata(L, sizeof(*cb));
 107         luaL_getmetatable(L, EVENT_CALLBACK_ARG_MT);
 108         lua_setmetatable(L, -2);
 109
 110         lua_pushvalue(L, callbackIdx);
 111         cb->callbackRef = luaL_ref(L, LUA_REGISTRYINDEX);
 112         cb->base = base;
 113         memset(&cb->timeout, 0, sizeof(cb->timeout));
 114         return cb;
 115 }
 116
 117 void event_callback_register(lua_State* L) {
 118         luaL_newmetatable(L, EVENT_CALLBACK_ARG_MT);
 119         lua_pushcfunction(L, luaevent_cb_gc);
 120         lua_setfield(L, -2, "__gc");
 121         lua_newtable(L);
 122         lua_pushcfunction(L, luaevent_cb_gc);
 123         lua_setfield(L, -2, "close");
 124         lua_setfield(L, -2, "__index");
 125         lua_pop(L, 1);
 126 }