source/texk/web2c/luatexdir/luasocket/src/select.c

   1 /*=========================================================================*\
   2 * Select implementation
   3 * LuaSocket toolkit
   4 \*=========================================================================*/
   5 #include <string.h>
   6
   7 #include "lua.h"
   8 #include "lauxlib.h"
   9
  10 #include "socket.h"
  11 #include "timeout.h"
  12 #include "select.h"
  13
  14 /*=========================================================================*\
  15 * Internal function prototypes.
  16 \*=========================================================================*/
  17 static t_socket getfd(lua_State *L);
  18 static int dirty(lua_State *L);
  19 static void collect_fd(lua_State *L, int tab, int itab,
  20         fd_set *set, t_socket *max_fd);
  21 static int check_dirty(lua_State *L, int tab, int dtab, fd_set *set);
  22 static void return_fd(lua_State *L, fd_set *set, t_socket max_fd,
  23         int itab, int tab, int start);
  24 static void make_assoc(lua_State *L, int tab);
  25 static int global_select(lua_State *L);
  26
  27 /* functions in library namespace */
  28 static luaL_Reg func[] = {
  29     {"select", global_select},
  30     {NULL,     NULL}
  31 };
  32
  33 /*=========================================================================*\
  34 * Exported functions
  35 \*=========================================================================*/
  36 /*-------------------------------------------------------------------------*\
  37 * Initializes module
  38 \*-------------------------------------------------------------------------*/
  39 int select_open(lua_State *L) {
  40     lua_pushstring(L, "_SETSIZE");
  41     lua_pushnumber(L, FD_SETSIZE);
  42     lua_rawset(L, -3);
  43     luaL_openlib(L, NULL, func, 0);
  44     return 0;
  45 }
  46
  47 /*=========================================================================*\
  48 * Global Lua functions
  49 \*=========================================================================*/
  50 /*-------------------------------------------------------------------------*\
  51 * Waits for a set of sockets until a condition is met or timeout.
  52 \*-------------------------------------------------------------------------*/
  53 static int global_select(lua_State *L) {
  54     int rtab, wtab, itab, ret, ndirty;
  55     t_socket max_fd = SOCKET_INVALID;
  56     fd_set rset, wset;
  57     t_timeout tm;
  58     double t = luaL_optnumber(L, 3, -1);
  59     FD_ZERO(&rset); FD_ZERO(&wset);
  60     lua_settop(L, 3);
  61     lua_newtable(L); itab = lua_gettop(L);
  62     lua_newtable(L); rtab = lua_gettop(L);
  63     lua_newtable(L); wtab = lua_gettop(L);
  64     collect_fd(L, 1, itab, &rset, &max_fd);
  65     collect_fd(L, 2, itab, &wset, &max_fd);
  66     ndirty = check_dirty(L, 1, rtab, &rset);
  67     t = ndirty > 0? 0.0: t;
  68     timeout_init(&tm, t, -1);
  69     timeout_markstart(&tm);
  70     ret = socket_select(max_fd+1, &rset, &wset, NULL, &tm);
  71     if (ret > 0 || ndirty > 0) {
  72         return_fd(L, &rset, max_fd+1, itab, rtab, ndirty);
  73         return_fd(L, &wset, max_fd+1, itab, wtab, 0);
  74         make_assoc(L, rtab);
  75         make_assoc(L, wtab);
  76         return 2;
  77     } else if (ret == 0) {
  78         lua_pushstring(L, "timeout");
  79         return 3;
  80     } else {
  81         luaL_error(L, "select failed");
  82         return 3;
  83     }
  84 }
  85
  86 /*=========================================================================*\
  87 * Internal functions
  88 \*=========================================================================*/
  89 static t_socket getfd(lua_State *L) {
  90     t_socket fd = SOCKET_INVALID;
  91     lua_pushstring(L, "getfd");
  92     lua_gettable(L, -2);
  93     if (!lua_isnil(L, -1)) {
  94         lua_pushvalue(L, -2);
  95         lua_call(L, 1, 1);
  96         if (lua_isnumber(L, -1)) {
  97             double numfd = lua_tonumber(L, -1);
  98             fd = (numfd >= 0.0)? (t_socket) numfd: SOCKET_INVALID;
  99         }
 100     }
 101     lua_pop(L, 1);
 102     return fd;
 103 }
 104
 105 static int dirty(lua_State *L) {
 106     int is = 0;
 107     lua_pushstring(L, "dirty");
 108     lua_gettable(L, -2);
 109     if (!lua_isnil(L, -1)) {
 110         lua_pushvalue(L, -2);
 111         lua_call(L, 1, 1);
 112         is = lua_toboolean(L, -1);
 113     }
 114     lua_pop(L, 1);
 115     return is;
 116 }
 117
 118 static void collect_fd(lua_State *L, int tab, int itab,
 119         fd_set *set, t_socket *max_fd) {
 120     int i = 1, n = 0;
 121     /* nil is the same as an empty table */
 122     if (lua_isnil(L, tab)) return;
 123     /* otherwise we need it to be a table */
 124     luaL_checktype(L, tab, LUA_TTABLE);
 125     for ( ;; ) {
 126         t_socket fd;
 127         lua_pushnumber(L, i);
 128         lua_gettable(L, tab);
 129         if (lua_isnil(L, -1)) {
 130             lua_pop(L, 1);
 131             break;
 132         }
 133         /* getfd figures out if this is a socket */
 134         fd = getfd(L);
 135         if (fd != SOCKET_INVALID) {
 136             /* make sure we don't overflow the fd_set */
 137 #ifdef _WIN32
 138             if (n >= FD_SETSIZE)
 139                 luaL_argerror(L, tab, "too many sockets");
 140 #else
 141             if (fd >= FD_SETSIZE)
 142                 luaL_argerror(L, tab, "descriptor too large for set size");
 143 #endif
 144             FD_SET(fd, set);
 145             n++;
 146             /* keep track of the largest descriptor so far */
 147             if (*max_fd == SOCKET_INVALID || *max_fd < fd)
 148                 *max_fd = fd;
 149             /* make sure we can map back from descriptor to the object */
 150             lua_pushnumber(L, (lua_Number) fd);
 151             lua_pushvalue(L, -2);
 152             lua_settable(L, itab);
 153         }
 154         lua_pop(L, 1);
 155         i = i + 1;
 156     }
 157 }
 158
 159 static int check_dirty(lua_State *L, int tab, int dtab, fd_set *set) {
 160     int ndirty = 0, i = 1;
 161     if (lua_isnil(L, tab))
 162         return 0;
 163     for ( ;; ) {
 164         t_socket fd;
 165         lua_pushnumber(L, i);
 166         lua_gettable(L, tab);
 167         if (lua_isnil(L, -1)) {
 168             lua_pop(L, 1);
 169             break;
 170         }
 171         fd = getfd(L);
 172         if (fd != SOCKET_INVALID && dirty(L)) {
 173             lua_pushnumber(L, ++ndirty);
 174             lua_pushvalue(L, -2);
 175             lua_settable(L, dtab);
 176             FD_CLR(fd, set);
 177         }
 178         lua_pop(L, 1);
 179         i = i + 1;
 180     }
 181     return ndirty;
 182 }
 183
 184 static void return_fd(lua_State *L, fd_set *set, t_socket max_fd,
 185         int itab, int tab, int start) {
 186     t_socket fd;
 187     for (fd = 0; fd < max_fd; fd++) {
 188         if (FD_ISSET(fd, set)) {
 189             lua_pushnumber(L, ++start);
 190             lua_pushnumber(L, (lua_Number) fd);
 191             lua_gettable(L, itab);
 192             lua_settable(L, tab);
 193         }
 194     }
 195 }
 196
 197 static void make_assoc(lua_State *L, int tab) {
 198     int i = 1, atab;
 199     lua_newtable(L); atab = lua_gettop(L);
 200     for ( ;; ) {
 201         lua_pushnumber(L, i);
 202         lua_gettable(L, tab);
 203         if (!lua_isnil(L, -1)) {
 204             lua_pushnumber(L, i);
 205             lua_pushvalue(L, -2);
 206             lua_settable(L, atab);
 207             lua_pushnumber(L, i);
 208             lua_settable(L, atab);
 209         } else {
 210             lua_pop(L, 1);
 211             break;
 212         }
 213         i = i+1;
 214     }
 215 }
 216