luaevent/src/luaevent.c

   1 /* LuaEvent - Copyright (C) 2007 Thomas Harning <harningt@gmail.com>
   2  * Licensed as LGPL - See doc/COPYING for details */
   3  #include "luaevent.h"
   4
   5 #include <lua.h>
   6 #include <lauxlib.h>
   7 #include <assert.h>
   8
   9 #define EVENT_BASE_MT "EVENT_BASE_MT"
  10 #define EVENT_CALLBACK_ARG_MT "EVENT_CALLBACK_ARG_MT"
  11 #define MAIN_THREAD_LOCATION 1
  12
  13 void setMainThread(lua_State* L) {
  14         lua_pushthread(L);
  15         lua_rawseti(L, LUA_ENVIRONINDEX, MAIN_THREAD_LOCATION);
  16 }
  17 lua_State* getMainThread(lua_State* L) {
  18         lua_State* g_L;
  19         lua_rawgeti(L, LUA_ENVIRONINDEX, MAIN_THREAD_LOCATION);
  20         g_L = lua_tothread(L, -1);
  21         lua_pop(L, 1);
  22         return g_L;
  23 }
  24
  25 int luaevent_newbase(lua_State* L) {
  26         le_base *base = (le_base*)lua_newuserdata(L, sizeof(le_base));
  27         base->loop_L = NULL; /* No running loop */
  28         base->base = event_init();
  29         luaL_getmetatable(L, EVENT_BASE_MT);
  30         lua_setmetatable(L, -2);
  31         return 1;
  32 }
  33
  34 void freeCallbackArgs(le_callback* arg, lua_State* L) {
  35         if(arg->base) {
  36                 arg->base = NULL;
  37                 event_del(&arg->ev);
  38                 luaL_unref(L, LUA_REGISTRYINDEX, arg->callbackRef);
  39         }
  40 }
  41 /* le_callback is allocated at the beginning of the coroutine in which it
  42 is used, no need to manually de-allocate */
  43
  44 /* Index for coroutine is fd as integer for *nix, as lightuserdata for Win */
  45 static void luaevent_callback(int fd, short event, void* p) {
  46         le_callback* arg = p;
  47         lua_State* L;
  48         int ret;
  49         assert(arg && arg->base && arg->base->loop_L);
  50         L = arg->base->loop_L;
  51         lua_rawgeti(L, LUA_REGISTRYINDEX, arg->callbackRef);
  52         lua_pushinteger(L, event);
  53         lua_call(L, 1, 1);
  54         ret = lua_tointeger(L, -1);
  55         lua_pop(L, 1);
  56         if(ret == -1) {
  57                 freeCallbackArgs(arg, L);
  58         } else {
  59                 struct event *ev = &arg->ev;
  60                 int newEvent = ret;
  61                 if(newEvent != event) { // Need to hook up new event...
  62                         event_del(ev);
  63                         event_set(ev, fd, EV_PERSIST | newEvent, luaevent_callback, arg);
  64                         event_add(ev, NULL);
  65                 }
  66         }
  67 }
  68
  69 static int luaevent_base_gc(lua_State* L) {
  70         le_base *base = luaL_checkudata(L, 1, EVENT_BASE_MT);
  71         if(base->base) {
  72                 event_base_free(base->base);
  73                 base->base = NULL;
  74         }
  75         return 0;
  76 }
  77
  78 static int luaevent_cb_gc(lua_State* L) {
  79         le_callback* arg = luaL_checkudata(L, 1, EVENT_CALLBACK_ARG_MT);
  80         freeCallbackArgs(arg, L);
  81         return 0;
  82 }
  83
  84 int getSocketFd(lua_State* L, int idx) {
  85         int fd;
  86         luaL_checktype(L, idx, LUA_TUSERDATA);
  87         lua_getfield(L, idx, "getfd");
  88         if(lua_isnil(L, -1))
  89                 return luaL_error(L, "Socket type missing 'getfd' method");
  90         lua_pushvalue(L, idx);
  91         lua_call(L, 1, 1);
  92         fd = lua_tointeger(L, -1);
  93         lua_pop(L, 1);
  94         return fd;
  95 }
  96
  97 /* sock, event, callback */
  98 static int luaevent_addevent(lua_State* L) {
  99         int fd, event, callbackRef;
 100         le_callback* arg;
 101         le_base *base = luaL_checkudata(L, 1, EVENT_BASE_MT);
 102         fd = getSocketFd(L, 2);
 103         event = luaL_checkinteger(L, 3);
 104         luaL_checktype(L, 4, LUA_TFUNCTION);
 105         lua_pushvalue(L, 4);
 106         callbackRef = luaL_ref(L, LUA_REGISTRYINDEX);
 107         arg = lua_newuserdata(L, sizeof(*arg));
 108         luaL_getmetatable(L, EVENT_CALLBACK_ARG_MT);
 109         lua_setmetatable(L, -2);
 110
 111         arg->base = base;
 112         arg->callbackRef = callbackRef;
 113         /* Setup event... */
 114         event_set(&arg->ev, fd, event | EV_PERSIST, luaevent_callback, arg);
 115         event_base_set(base->base, &arg->ev);
 116         event_add(&arg->ev, NULL);
 117         return 1;
 118 }
 119
 120 static int luaevent_loop(lua_State* L) {
 121         le_base *base = luaL_checkudata(L, 1, EVENT_BASE_MT);
 122         base->loop_L = L;
 123         int ret = event_base_loop(base->base, 0);
 124         lua_pushinteger(L, ret);
 125         return 1;
 126 }
 127
 128 static luaL_Reg base_funcs[] = {
 129         { "addevent", luaevent_addevent },
 130         { "loop", luaevent_loop },
 131         { NULL, NULL }
 132 };
 133
 134 static luaL_Reg funcs[] = {
 135         { "new", luaevent_newbase },
 136         { NULL, NULL }
 137 };
 138
 139 typedef struct {
 140         const char* name;
 141         int value;
 142 } namedInteger;
 143
 144 static namedInteger consts[] = {
 145         {"LEAVE", -1},
 146         {"EV_READ", EV_READ},
 147         {"EV_WRITE", EV_WRITE},
 148         {NULL, 0}
 149 };
 150
 151 void setNamedIntegers(lua_State* L, namedInteger* p) {
 152         while(p->name) {
 153                 lua_pushinteger(L, p->value);
 154                 lua_setfield(L, -2, p->name);
 155                 p++;
 156         }
 157 }
 158
 159 /* Verified ok */
 160 int luaopen_luaevent_core(lua_State* L) {
 161         /* Setup environ table */
 162         lua_createtable(L, 1, 0);
 163         lua_replace(L, LUA_ENVIRONINDEX);
 164         /* Setup metatable */
 165         luaL_newmetatable(L, EVENT_BASE_MT);
 166         lua_newtable(L);
 167         luaL_register(L, NULL, base_funcs);
 168         lua_setfield(L, -2, "__index");
 169         lua_pushcfunction(L, luaevent_base_gc);
 170         lua_setfield(L, -2, "__gc");
 171         lua_pop(L, 1);
 172         luaL_newmetatable(L, EVENT_CALLBACK_ARG_MT);
 173         lua_pushcfunction(L, luaevent_cb_gc);
 174         lua_setfield(L, -2, "__gc");
 175         lua_newtable(L);
 176         lua_pushcfunction(L, luaevent_cb_gc);
 177         lua_setfield(L, -2, "close");
 178         lua_setfield(L, -2, "__index");
 179         lua_pop(L, 1);
 180
 181         luaL_register(L, "luaevent.core", funcs);
 182         setNamedIntegers(L, consts);
 183         return 1;
 184 }