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         /* cb->base may be NULL after the pcall, if the event is destroyed */
  34         le_base* base = cb->base;
  35         if(lua_pcall(L, 1, 2, 0))
  36         {
  37                 base->errorMessage = luaL_ref(L, LUA_REGISTRYINDEX);
  38                 event_base_loopbreak(base->base);
  39                 lua_pop(L, 1);
  40                 return;
  41         }
  42         if(!cb->base) {
  43                 lua_pop(L, 2);
  44                 return; /* event was destroyed during callback */
  45         }
  46         /* If nothing is returned, re-use the old event value */
  47         ret = luaL_optinteger(L, -2, event);
  48         /* Clone the old timeout value in case a new one wasn't set */
  49         memcpy(&new_tv, &cb->timeout, sizeof(new_tv));
  50         if(lua_isnumber(L, -1)) {
  51                 double newTimeout = lua_tonumber(L, -1);
  52                 if(newTimeout > 0) {
  53                         load_timeval(newTimeout, &new_tv);
  54                 }
  55         }
  56         lua_pop(L, 2);
  57         if(ret == -1) {
  58                 freeCallbackArgs(cb, L);
  59         } else {
  60                 struct event *ev = &cb->ev;
  61                 int newEvent = ret;
  62                 if( newEvent != event || (cb->timeout.tv_sec != new_tv.tv_sec || cb->timeout.tv_usec != new_tv.tv_usec) ) {
  63                         struct timeval *ptv = &cb->timeout;
  64                         cb->timeout = new_tv;
  65                         if(!cb->timeout.tv_sec && !cb->timeout.tv_usec)
  66                                 ptv = NULL;
  67                         event_del(ev);
  68                         event_set(ev, fd, EV_PERSIST | newEvent, luaevent_callback, cb);
  69                         /* Assume cannot set a new timeout.. */
  70                         event_add(ev, ptv);
  71                 }
  72         }
  73 }
  74
  75 static int luaevent_cb_gc(lua_State* L) {
  76         le_callback* arg = luaL_checkudata(L, 1, EVENT_CALLBACK_ARG_MT);
  77         freeCallbackArgs(arg, L);
  78         return 0;
  79 }
  80
  81 le_callback* event_callback_push(lua_State* L, int baseIdx, int callbackIdx) {
  82         le_callback* cb;
  83         le_base *base = event_base_get(L, baseIdx);
  84         luaL_checktype(L, callbackIdx, LUA_TFUNCTION);
  85         cb = lua_newuserdata(L, sizeof(*cb));
  86         luaL_getmetatable(L, EVENT_CALLBACK_ARG_MT);
  87         lua_setmetatable(L, -2);
  88
  89         lua_pushvalue(L, callbackIdx);
  90         cb->callbackRef = luaL_ref(L, LUA_REGISTRYINDEX);
  91         cb->base = base;
  92         memset(&cb->timeout, 0, sizeof(cb->timeout));
  93         return cb;
  94 }
  95
  96 void event_callback_register(lua_State* L) {
  97         luaL_newmetatable(L, EVENT_CALLBACK_ARG_MT);
  98         lua_pushcfunction(L, luaevent_cb_gc);
  99         lua_setfield(L, -2, "__gc");
 100         lua_newtable(L);
 101         lua_pushcfunction(L, luaevent_cb_gc);
 102         lua_setfield(L, -2, "close");
 103         lua_setfield(L, -2, "__index");
 104         lua_pop(L, 1);
 105 }