src/event_callback.c

   1 /* LuaEvent - Copyright (C) 2007 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         ret = lua_tointeger(L, -2);
  37         if(lua_isnumber(L, -1)) {
  38                 double newTimeout = lua_tonumber(L, -1);
  39                 if(newTimeout > 0) {
  40                         load_timeval(newTimeout, &new_tv);
  41                 }
  42         }
  43         lua_pop(L, 2);
  44         if(ret == -1) {
  45                 freeCallbackArgs(cb, L);
  46         } else {
  47                 struct event *ev = &cb->ev;
  48                 int newEvent = ret;
  49                 if( newEvent != event || (cb->timeout.tv_sec != new_tv.tv_sec || cb->timeout.tv_usec != new_tv.tv_usec) ) {
  50                         struct timeval *ptv = &cb->timeout;
  51                         cb->timeout = new_tv;
  52                         if(!cb->timeout.tv_sec && !cb->timeout.tv_usec)
  53                                 ptv = NULL;
  54                         event_del(ev);
  55                         event_set(ev, fd, EV_PERSIST | newEvent, luaevent_callback, cb);
  56                         /* Assume cannot set a new timeout.. */
  57                         event_add(ev, ptv);
  58                 }
  59         }
  60 }
  61
  62 static int luaevent_cb_gc(lua_State* L) {
  63         le_callback* arg = luaL_checkudata(L, 1, EVENT_CALLBACK_ARG_MT);
  64         freeCallbackArgs(arg, L);
  65         return 0;
  66 }
  67
  68 le_callback* event_callback_push(lua_State* L, int baseIdx, int callbackIdx) {
  69         le_callback* cb;
  70         le_base *base = event_base_get(L, baseIdx);
  71         luaL_checktype(L, callbackIdx, LUA_TFUNCTION);
  72         cb = lua_newuserdata(L, sizeof(*cb));
  73         luaL_getmetatable(L, EVENT_CALLBACK_ARG_MT);
  74         lua_setmetatable(L, -2);
  75
  76         lua_pushvalue(L, callbackIdx);
  77         cb->callbackRef = luaL_ref(L, LUA_REGISTRYINDEX);
  78         cb->base = base;
  79         memset(&cb->timeout, 0, sizeof(cb->timeout));
  80         return cb;
  81 }
  82
  83 void event_callback_register(lua_State* L) {
  84         luaL_newmetatable(L, EVENT_CALLBACK_ARG_MT);
  85         lua_pushcfunction(L, luaevent_cb_gc);
  86         lua_setfield(L, -2, "__gc");
  87         lua_newtable(L);
  88         lua_pushcfunction(L, luaevent_cb_gc);
  89         lua_setfield(L, -2, "close");
  90         lua_setfield(L, -2, "__index");
  91         lua_pop(L, 1);
  92 }