/*=========================================================================*\
* Select implementation
* LuaSocket toolkit
\*=========================================================================*/
#include "luasocket.h"
#include "socket.h"
#include "timeout.h"
#include "select.h"
#include <string.h>
/*=========================================================================*\
* Internal function prototypes.
\*=========================================================================*/
static t_socket getfd(lua_State *L);
static int dirty(lua_State *L);
static void collect_fd(lua_State *L, int tab, int itab,
fd_set *set, t_socket *max_fd);
static int check_dirty(lua_State *L, int tab, int dtab, fd_set *set);
static void return_fd(lua_State *L, fd_set *set, t_socket max_fd,
int itab, int tab, int start);
static void make_assoc(lua_State *L, int tab);
static int global_select(lua_State *L);
/* functions in library namespace */
static luaL_Reg func[] = {
{"select", global_select},
{NULL, NULL}
};
/*-------------------------------------------------------------------------*\
* Initializes module
\*-------------------------------------------------------------------------*/
int select_open(lua_State *L) {
lua_pushstring(L, "_SETSIZE");
lua_pushinteger(L, FD_SETSIZE);
lua_rawset(L, -3);
lua_pushstring(L, "_SOCKETINVALID");
lua_pushinteger(L, SOCKET_INVALID);
lua_rawset(L, -3);
luaL_setfuncs(L, func, 0);
return 0;
}
/*=========================================================================*\
* Global Lua functions
\*=========================================================================*/
/*-------------------------------------------------------------------------*\
* Waits for a set of sockets until a condition is met or timeout.
\*-------------------------------------------------------------------------*/
static int global_select(lua_State *L) {
int rtab, wtab, itab, ret, ndirty;
t_socket max_fd = SOCKET_INVALID;
fd_set rset, wset;
t_timeout tm;
double t = luaL_optnumber(L, 3, -1);
FD_ZERO(&rset); FD_ZERO(&wset);
lua_settop(L, 3);
lua_newtable(L); itab = lua_gettop(L);
lua_newtable(L); rtab = lua_gettop(L);
lua_newtable(L); wtab = lua_gettop(L);
collect_fd(L, 1, itab, &rset, &max_fd);
collect_fd(L, 2, itab, &wset, &max_fd);
ndirty = check_dirty(L, 1, rtab, &rset);
t = ndirty > 0? 0.0: t;
timeout_init(&tm, t, -1);
timeout_markstart(&tm);
ret = socket_select(max_fd+1, &rset, &wset, NULL, &tm);
if (ret > 0 || ndirty > 0) {
return_fd(L, &rset, max_fd+1, itab, rtab, ndirty);
return_fd(L, &wset, max_fd+1, itab, wtab, 0);
make_assoc(L, rtab);
make_assoc(L, wtab);
return 2;
} else if (ret == 0) {
lua_pushstring(L, "timeout");
return 3;
} else {
luaL_error(L, "select failed");
return 3;
}
}
/*=========================================================================*\
* Internal functions
\*=========================================================================*/
static t_socket getfd(lua_State *L) {
t_socket fd = SOCKET_INVALID;
lua_pushstring(L, "getfd");
lua_gettable(L, -2);
if (!lua_isnil(L, -1)) {
lua_pushvalue(L, -2);
lua_call(L, 1, 1);
if (lua_isnumber(L, -1)) {
double numfd = lua_tonumber(L, -1);
fd = (numfd >= 0.0)? (t_socket) numfd: SOCKET_INVALID;
}
}
lua_pop(L, 1);
return fd;
}
static int dirty(lua_State *L) {
int is = 0;
lua_pushstring(L, "dirty");
lua_gettable(L, -2);
if (!lua_isnil(L, -1)) {
lua_pushvalue(L, -2);
lua_call(L, 1, 1);
is = lua_toboolean(L, -1);
}
lua_pop(L, 1);
return is;
}
static void collect_fd(lua_State *L, int tab, int itab,
fd_set *set, t_socket *max_fd) {
int i = 1, n = 0;
/* nil is the same as an empty table */
if (lua_isnil(L, tab)) return;
/* otherwise we need it to be a table */
luaL_checktype(L, tab, LUA_TTABLE);
for ( ;; ) {
t_socket fd;
lua_pushnumber(L, i);
lua_gettable(L, tab);
if (lua_isnil(L, -1)) {
lua_pop(L, 1);
break;
}
/* getfd figures out if this is a socket */
fd = getfd(L);
if (fd != SOCKET_INVALID) {
/* make sure we don't overflow the fd_set */
#ifdef _WIN32
if (n >= FD_SETSIZE)
luaL_argerror(L, tab, "too many sockets");
#else
if (fd >= FD_SETSIZE)
luaL_argerror(L, tab, "descriptor too large for set size");
#endif
FD_SET(fd, set);
n++;
/* keep track of the largest descriptor so far */
if (*max_fd == SOCKET_INVALID || *max_fd < fd)
*max_fd = fd;
/* make sure we can map back from descriptor to the object */
lua_pushnumber(L, (lua_Number) fd);
lua_pushvalue(L, -2);
lua_settable(L, itab);
}
lua_pop(L, 1);
i = i + 1;
}
}
static int check_dirty(lua_State *L, int tab, int dtab, fd_set *set) {
int ndirty = 0, i = 1;
if (lua_isnil(L, tab))
return 0;
for ( ;; ) {
t_socket fd;
lua_pushnumber(L, i);
lua_gettable(L, tab);
if (lua_isnil(L, -1)) {
lua_pop(L, 1);
break;
}
fd = getfd(L);
if (fd != SOCKET_INVALID && dirty(L)) {
lua_pushnumber(L, ++ndirty);
lua_pushvalue(L, -2);
lua_settable(L, dtab);
FD_CLR(fd, set);
}
lua_pop(L, 1);
i = i + 1;
}
return ndirty;
}
static void return_fd(lua_State *L, fd_set *set, t_socket max_fd,
int itab, int tab, int start) {
t_socket fd;
for (fd = 0; fd < max_fd; fd++) {
if (FD_ISSET(fd, set)) {
lua_pushnumber(L, ++start);
lua_pushnumber(L, (lua_Number) fd);
lua_gettable(L, itab);
lua_settable(L, tab);
}
}
}
static void make_assoc(lua_State *L, int tab) {
int i = 1, atab;
lua_newtable(L); atab = lua_gettop(L);
for ( ;; ) {
lua_pushnumber(L, i);
lua_gettable(L, tab);
if (!lua_isnil(L, -1)) {
lua_pushnumber(L, i);
lua_pushvalue(L, -2);
lua_settable(L, atab);
lua_pushnumber(L, i);
lua_settable(L, atab);
} else {
lua_pop(L, 1);
break;
}
i = i+1;
}
}