client/deps/liblua/lcorolib.c

   1 /*
   2 ** $Id: lcorolib.c,v 1.5 2013/02/21 13:44:53 roberto Exp $
   3 ** Coroutine Library
   4 ** See Copyright Notice in lua.h
   5 */
   6
   7
   8 #include <stdlib.h>
   9
  10
  11 #define lcorolib_c
  12 #define LUA_LIB
  13
  14 #include "lua.h"
  15
  16 #include "lauxlib.h"
  17 #include "lualib.h"
  18
  19
  20 static int auxresume(lua_State *L, lua_State *co, int narg) {
  21     int status;
  22     if (!lua_checkstack(co, narg)) {
  23         lua_pushliteral(L, "too many arguments to resume");
  24         return -1;  /* error flag */
  25     }
  26     if (lua_status(co) == LUA_OK && lua_gettop(co) == 0) {
  27         lua_pushliteral(L, "cannot resume dead coroutine");
  28         return -1;  /* error flag */
  29     }
  30     lua_xmove(L, co, narg);
  31     status = lua_resume(co, L, narg);
  32     if (status == LUA_OK || status == LUA_YIELD) {
  33         int nres = lua_gettop(co);
  34         if (!lua_checkstack(L, nres + 1)) {
  35             lua_pop(co, nres);  /* remove results anyway */
  36             lua_pushliteral(L, "too many results to resume");
  37             return -1;  /* error flag */
  38         }
  39         lua_xmove(co, L, nres);  /* move yielded values */
  40         return nres;
  41     } else {
  42         lua_xmove(co, L, 1);  /* move error message */
  43         return -1;  /* error flag */
  44     }
  45 }
  46
  47
  48 static int luaB_coresume(lua_State *L) {
  49     lua_State *co = lua_tothread(L, 1);
  50     int r;
  51     luaL_argcheck(L, co, 1, "coroutine expected");
  52     r = auxresume(L, co, lua_gettop(L) - 1);
  53     if (r < 0) {
  54         lua_pushboolean(L, 0);
  55         lua_insert(L, -2);
  56         return 2;  /* return false + error message */
  57     } else {
  58         lua_pushboolean(L, 1);
  59         lua_insert(L, -(r + 1));
  60         return r + 1;  /* return true + `resume' returns */
  61     }
  62 }
  63
  64
  65 static int luaB_auxwrap(lua_State *L) {
  66     lua_State *co = lua_tothread(L, lua_upvalueindex(1));
  67     int r = auxresume(L, co, lua_gettop(L));
  68     if (r < 0) {
  69         if (lua_isstring(L, -1)) {  /* error object is a string? */
  70             luaL_where(L, 1);  /* add extra info */
  71             lua_insert(L, -2);
  72             lua_concat(L, 2);
  73         }
  74         return lua_error(L);  /* propagate error */
  75     }
  76     return r;
  77 }
  78
  79
  80 static int luaB_cocreate(lua_State *L) {
  81     lua_State *NL;
  82     luaL_checktype(L, 1, LUA_TFUNCTION);
  83     NL = lua_newthread(L);
  84     lua_pushvalue(L, 1);  /* move function to top */
  85     lua_xmove(L, NL, 1);  /* move function from L to NL */
  86     return 1;
  87 }
  88
  89
  90 static int luaB_cowrap(lua_State *L) {
  91     luaB_cocreate(L);
  92     lua_pushcclosure(L, luaB_auxwrap, 1);
  93     return 1;
  94 }
  95
  96
  97 static int luaB_yield(lua_State *L) {
  98     return lua_yield(L, lua_gettop(L));
  99 }
 100
 101
 102 static int luaB_costatus(lua_State *L) {
 103     lua_State *co = lua_tothread(L, 1);
 104     luaL_argcheck(L, co, 1, "coroutine expected");
 105     if (L == co) lua_pushliteral(L, "running");
 106     else {
 107         switch (lua_status(co)) {
 108             case LUA_YIELD:
 109                 lua_pushliteral(L, "suspended");
 110                 break;
 111             case LUA_OK: {
 112                 lua_Debug ar;
 113                 if (lua_getstack(co, 0, &ar) > 0)  /* does it have frames? */
 114                     lua_pushliteral(L, "normal");  /* it is running */
 115                 else if (lua_gettop(co) == 0)
 116                     lua_pushliteral(L, "dead");
 117                 else
 118                     lua_pushliteral(L, "suspended");  /* initial state */
 119                 break;
 120             }
 121             default:  /* some error occurred */
 122                 lua_pushliteral(L, "dead");
 123                 break;
 124         }
 125     }
 126     return 1;
 127 }
 128
 129
 130 static int luaB_corunning(lua_State *L) {
 131     int ismain = lua_pushthread(L);
 132     lua_pushboolean(L, ismain);
 133     return 2;
 134 }
 135
 136
 137 static const luaL_Reg co_funcs[] = {
 138     {"create", luaB_cocreate},
 139     {"resume", luaB_coresume},
 140     {"running", luaB_corunning},
 141     {"status", luaB_costatus},
 142     {"wrap", luaB_cowrap},
 143     {"yield", luaB_yield},
 144     {NULL, NULL}
 145 };
 146
 147
 148
 149 LUAMOD_API int luaopen_coroutine(lua_State *L) {
 150     luaL_newlib(L, co_funcs);
 151     return 1;
 152 }
 153