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authorRoberto Ierusalimschy <roberto@inf.puc-rio.br>2010-06-10 18:30:26 -0300
committerRoberto Ierusalimschy <roberto@inf.puc-rio.br>2010-06-10 18:30:26 -0300
commitbd262d591f56a4c14be58c14c54aa929d0d3bf64 (patch)
tree753b3b57a04c2bdd2fcae53447e6b54bcb2ae23e /lcorolib.c
parent0d116c3adab7bf831ecb8adec0cedfe9a807476e (diff)
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'coroutine' library separated from 'baselib'
Diffstat (limited to 'lcorolib.c')
-rw-r--r--lcorolib.c154
1 files changed, 154 insertions, 0 deletions
diff --git a/lcorolib.c b/lcorolib.c
new file mode 100644
index 00000000..fdcbc6de
--- /dev/null
+++ b/lcorolib.c
@@ -0,0 +1,154 @@
1/*
2** $Id: lcorolib.c,v $
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
20static 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, 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 }
42 else {
43 lua_xmove(co, L, 1); /* move error message */
44 return -1; /* error flag */
45 }
46}
47
48
49static int luaB_coresume (lua_State *L) {
50 lua_State *co = lua_tothread(L, 1);
51 int r;
52 luaL_argcheck(L, co, 1, "coroutine expected");
53 r = auxresume(L, co, lua_gettop(L) - 1);
54 if (r < 0) {
55 lua_pushboolean(L, 0);
56 lua_insert(L, -2);
57 return 2; /* return false + error message */
58 }
59 else {
60 lua_pushboolean(L, 1);
61 lua_insert(L, -(r + 1));
62 return r + 1; /* return true + `resume' returns */
63 }
64}
65
66
67static int luaB_auxwrap (lua_State *L) {
68 lua_State *co = lua_tothread(L, lua_upvalueindex(1));
69 int r = auxresume(L, co, lua_gettop(L));
70 if (r < 0) {
71 if (lua_isstring(L, -1)) { /* error object is a string? */
72 luaL_where(L, 1); /* add extra info */
73 lua_insert(L, -2);
74 lua_concat(L, 2);
75 }
76 lua_error(L); /* propagate error */
77 }
78 return r;
79}
80
81
82static int luaB_cocreate (lua_State *L) {
83 lua_State *NL = lua_newthread(L);
84 luaL_checktype(L, 1, LUA_TFUNCTION);
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
91static int luaB_cowrap (lua_State *L) {
92 luaB_cocreate(L);
93 lua_pushcclosure(L, luaB_auxwrap, 1);
94 return 1;
95}
96
97
98static int luaB_yield (lua_State *L) {
99 return lua_yield(L, lua_gettop(L));
100}
101
102
103static 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
131static int luaB_corunning (lua_State *L) {
132 int ismain = lua_pushthread(L);
133 lua_pushboolean(L, ismain);
134 return 2;
135}
136
137
138static 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
150LUAMOD_API int luaopen_coroutine (lua_State *L) {
151 luaL_register(L, LUA_COLIBNAME, co_funcs);
152 return 1;
153}
154