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, errfunc;
  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
  53         errfunc = 0;
  54
  55         lua_getglobal(L, "debug");
  56
  57         if(lua_istable(L, -1)) {
  58                 lua_getfield(L, -1, "traceback");
  59
  60                 if(lua_isfunction(L, -1)) {
  61                         lua_remove(L, -2);
  62                         errfunc = lua_gettop(L);
  63                 } else {
  64                         lua_pop(L, 2);
  65                 }
  66         } else {
  67                 lua_pop(L, 1);
  68         }
  69
  70         lua_rawgeti(L, LUA_REGISTRYINDEX, cb->callbackRef);
  71         lua_pushinteger(L, event);
  72         /* cb->base may be NULL after the pcall, if the event is destroyed */
  73         base = cb->base;
  74
  75         ret = lua_pcall(L, 1, 2, errfunc);
  76         if(errfunc) {
  77                 lua_remove(L, errfunc);
  78         }
  79         if(ret)
  80         {
  81                 base->errorMessage = luaL_ref(L, LUA_REGISTRYINDEX);
  82                 event_base_loopbreak(base->base);
  83                 lua_pop(L, 1);
  84                 return;
  85         }
  86         if(!cb->base) {
  87                 lua_pop(L, 2);
  88                 return; /* event was destroyed during callback */
  89         }
  90         /* If nothing is returned, re-use the old event value */
  91         ret = luaL_optinteger(L, -2, event);
  92         /* Clone the old timeout value in case a new one wasn't set */
  93         memcpy(&new_tv, &cb->timeout, sizeof(new_tv));
  94         if(lua_isnumber(L, -1)) {
  95                 double newTimeout = lua_tonumber(L, -1);
  96                 if(newTimeout >= 0) {
  97                         load_timeval(newTimeout, &new_tv);
  98                 }
  99         }
 100         lua_pop(L, 2);
 101         if(ret == -1) {
 102                 freeCallbackArgs(cb, L);
 103         } else {
 104                 struct event *ev = &cb->ev;
 105                 int newEvent = ret;
 106                 if( newEvent != event || (cb->timeout.tv_sec != new_tv.tv_sec || cb->timeout.tv_usec != new_tv.tv_usec) ) {
 107                         struct timeval *ptv = &cb->timeout;
 108                         cb->timeout = new_tv;
 109                         event_del(ev);
 110                         event_set(ev, fd, EV_PERSIST | newEvent, luaevent_callback, cb);
 111                         /* Assume cannot set a new timeout.. */
 112                         event_add(ev, ptv);
 113                 }
 114         }
 115 }
 116
 117 static int luaevent_cb_gc(lua_State* L) {
 118         le_callback* arg = luaL_checkudata(L, 1, EVENT_CALLBACK_ARG_MT);
 119         freeCallbackArgs(arg, L);
 120         return 0;
 121 }
 122
 123 le_callback* event_callback_push(lua_State* L, int baseIdx, int callbackIdx) {
 124         le_callback* cb;
 125         le_base *base = event_base_get(L, baseIdx);
 126         luaL_checktype(L, callbackIdx, LUA_TFUNCTION);
 127         cb = lua_newuserdata(L, sizeof(*cb));
 128         luaL_getmetatable(L, EVENT_CALLBACK_ARG_MT);
 129         lua_setmetatable(L, -2);
 130
 131         lua_pushvalue(L, callbackIdx);
 132         cb->callbackRef = luaL_ref(L, LUA_REGISTRYINDEX);
 133         cb->base = base;
 134         memset(&cb->timeout, 0, sizeof(cb->timeout));
 135         return cb;
 136 }
 137
 138 void event_callback_register(lua_State* L) {
 139         luaL_newmetatable(L, EVENT_CALLBACK_ARG_MT);
 140         lua_pushcfunction(L, luaevent_cb_gc);
 141         lua_setfield(L, -2, "__gc");
 142         lua_newtable(L);
 143         lua_pushcfunction(L, luaevent_cb_gc);
 144         lua_setfield(L, -2, "close");
 145         lua_setfield(L, -2, "__index");
 146         lua_pop(L, 1);
 147 }