1/* BEGIN CSTYLED */
2/*
3** $Id: lcorolib.c,v 1.5.1.1 2013/04/12 18:48:47 roberto Exp $
4** Coroutine Library
5** See Copyright Notice in lua.h
6*/
7
8
9#define lcorolib_c
10#define LUA_LIB
11
12#include <sys/lua/lua.h>
13
14#include <sys/lua/lauxlib.h>
15#include <sys/lua/lualib.h>
16
17
18static int auxresume (lua_State *L, lua_State *co, int narg) {
19  int status;
20  if (!lua_checkstack(co, narg)) {
21    lua_pushliteral(L, "too many arguments to resume");
22    return -1;  /* error flag */
23  }
24  if (lua_status(co) == LUA_OK && lua_gettop(co) == 0) {
25    lua_pushliteral(L, "cannot resume dead coroutine");
26    return -1;  /* error flag */
27  }
28  lua_xmove(L, co, narg);
29  status = lua_resume(co, L, narg);
30  if (status == LUA_OK || status == LUA_YIELD) {
31    int nres = lua_gettop(co);
32    if (!lua_checkstack(L, nres + 1)) {
33      lua_pop(co, nres);  /* remove results anyway */
34      lua_pushliteral(L, "too many results to resume");
35      return -1;  /* error flag */
36    }
37    lua_xmove(co, L, nres);  /* move yielded values */
38    return nres;
39  }
40  else {
41    lua_xmove(co, L, 1);  /* move error message */
42    return -1;  /* error flag */
43  }
44}
45
46
47static int luaB_coresume (lua_State *L) {
48  lua_State *co = lua_tothread(L, 1);
49  int r;
50  luaL_argcheck(L, co, 1, "coroutine expected");
51  r = auxresume(L, co, lua_gettop(L) - 1);
52  if (r < 0) {
53    lua_pushboolean(L, 0);
54    lua_insert(L, -2);
55    return 2;  /* return false + error message */
56  }
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
65static 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
80static 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
90static int luaB_cowrap (lua_State *L) {
91  luaB_cocreate(L);
92  lua_pushcclosure(L, luaB_auxwrap, 1);
93  return 1;
94}
95
96
97static int luaB_yield (lua_State *L) {
98  return lua_yield(L, lua_gettop(L));
99}
100
101
102static 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
130static int luaB_corunning (lua_State *L) {
131  int ismain = lua_pushthread(L);
132  lua_pushboolean(L, ismain);
133  return 2;
134}
135
136
137static 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
149LUAMOD_API int luaopen_coroutine (lua_State *L) {
150  luaL_newlib(L, co_funcs);
151  return 1;
152}
153
154#if defined(_KERNEL)
155
156EXPORT_SYMBOL(luaopen_coroutine);
157
158#endif
159/* END CSTYLED */
160