1 /*
2 ** $Id: lcorolib.c,v 1.5.1.1 2013/04/12 18:48:47 roberto Exp $
3 ** Coroutine Library
4 ** See Copyright Notice in lua.h
5 */
6
7
8 #include <sys/zfs_context.h>
9
10 #define lcorolib_c
11 #define LUA_LIB
12
13 #include "lua.h"
14
15 #include "lauxlib.h"
16 #include "lualib.h"
17
18
auxresume(lua_State * L,lua_State * co,int narg)19 static int auxresume (lua_State *L, lua_State *co, int narg) {
20 int status;
21 if (!lua_checkstack(co, narg)) {
22 lua_pushliteral(L, "too many arguments to resume");
23 return -1; /* error flag */
24 }
25 if (lua_status(co) == LUA_OK && lua_gettop(co) == 0) {
26 lua_pushliteral(L, "cannot resume dead coroutine");
27 return -1; /* error flag */
28 }
29 lua_xmove(L, co, narg);
30 status = lua_resume(co, L, narg);
31 if (status == LUA_OK || status == LUA_YIELD) {
32 int nres = lua_gettop(co);
33 if (!lua_checkstack(L, nres + 1)) {
34 lua_pop(co, nres); /* remove results anyway */
35 lua_pushliteral(L, "too many results to resume");
36 return -1; /* error flag */
37 }
38 lua_xmove(co, L, nres); /* move yielded values */
39 return nres;
40 }
41 else {
42 lua_xmove(co, L, 1); /* move error message */
43 return -1; /* error flag */
44 }
45 }
46
47
luaB_coresume(lua_State * L)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 }
58 else {
59 lua_pushboolean(L, 1);
60 lua_insert(L, -(r + 1));
61 return r + 1; /* return true + `resume' returns */
62 }
63 }
64
65
luaB_auxwrap(lua_State * L)66 static int luaB_auxwrap (lua_State *L) {
67 lua_State *co = lua_tothread(L, lua_upvalueindex(1));
68 int r = auxresume(L, co, lua_gettop(L));
69 if (r < 0) {
70 if (lua_isstring(L, -1)) { /* error object is a string? */
71 luaL_where(L, 1); /* add extra info */
72 lua_insert(L, -2);
73 lua_concat(L, 2);
74 }
75 return lua_error(L); /* propagate error */
76 }
77 return r;
78 }
79
80
luaB_cocreate(lua_State * L)81 static int luaB_cocreate (lua_State *L) {
82 lua_State *NL;
83 luaL_checktype(L, 1, LUA_TFUNCTION);
84 NL = lua_newthread(L);
85 lua_pushvalue(L, 1); /* move function to top */
86 lua_xmove(L, NL, 1); /* move function from L to NL */
87 return 1;
88 }
89
90
luaB_cowrap(lua_State * L)91 static int luaB_cowrap (lua_State *L) {
92 luaB_cocreate(L);
93 lua_pushcclosure(L, luaB_auxwrap, 1);
94 return 1;
95 }
96
97
luaB_yield(lua_State * L)98 static int luaB_yield (lua_State *L) {
99 return lua_yield(L, lua_gettop(L));
100 }
101
102
luaB_costatus(lua_State * L)103 static int luaB_costatus (lua_State *L) {
104 lua_State *co = lua_tothread(L, 1);
105 luaL_argcheck(L, co, 1, "coroutine expected");
106 if (L == co) lua_pushliteral(L, "running");
107 else {
108 switch (lua_status(co)) {
109 case LUA_YIELD:
110 lua_pushliteral(L, "suspended");
111 break;
112 case LUA_OK: {
113 lua_Debug ar;
114 if (lua_getstack(co, 0, &ar) > 0) /* does it have frames? */
115 lua_pushliteral(L, "normal"); /* it is running */
116 else if (lua_gettop(co) == 0)
117 lua_pushliteral(L, "dead");
118 else
119 lua_pushliteral(L, "suspended"); /* initial state */
120 break;
121 }
122 default: /* some error occurred */
123 lua_pushliteral(L, "dead");
124 break;
125 }
126 }
127 return 1;
128 }
129
130
luaB_corunning(lua_State * L)131 static int luaB_corunning (lua_State *L) {
132 int ismain = lua_pushthread(L);
133 lua_pushboolean(L, ismain);
134 return 2;
135 }
136
137
138 static const luaL_Reg co_funcs[] = {
139 {"create", luaB_cocreate},
140 {"resume", luaB_coresume},
141 {"running", luaB_corunning},
142 {"status", luaB_costatus},
143 {"wrap", luaB_cowrap},
144 {"yield", luaB_yield},
145 {NULL, NULL}
146 };
147
148
149
luaopen_coroutine(lua_State * L)150 LUAMOD_API int luaopen_coroutine (lua_State *L) {
151 luaL_newlib(L, co_funcs);
152 return 1;
153 }
154
155