1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
|
/*
** $Id: lcorolib.c $
** Coroutine Library
** See Copyright Notice in lua.h
*/
#define lcorolib_c
#define LUA_LIB
#include "lprefix.h"
#include <stdlib.h>
#include "lua.h"
#include "lauxlib.h"
#include "lualib.h"
static lua_State *getco (lua_State *L) {
lua_State *co = lua_tothread(L, 1);
luaL_argexpected(L, co, 1, "thread");
return co;
}
/*
** Resumes a coroutine. Returns the number of results for non-error
** cases or -1 for errors.
*/
static int auxresume (lua_State *L, lua_State *co, int narg) {
int status, nres;
if (!lua_checkstack(co, narg)) {
lua_pushliteral(L, "too many arguments to resume");
return -1; /* error flag */
}
lua_xmove(L, co, narg);
status = lua_resume(co, L, narg, &nres);
if (status == LUA_OK || status == LUA_YIELD) {
if (!lua_checkstack(L, nres + 1)) {
lua_pop(co, nres); /* remove results anyway */
lua_pushliteral(L, "too many results to resume");
return -1; /* error flag */
}
lua_xmove(co, L, nres); /* move yielded values */
return nres;
}
else {
lua_xmove(co, L, 1); /* move error message */
return -1; /* error flag */
}
}
static int luaB_coresume (lua_State *L) {
lua_State *co = getco(L);
int r;
r = auxresume(L, co, lua_gettop(L) - 1);
if (r < 0) {
lua_pushboolean(L, 0);
lua_insert(L, -2);
return 2; /* return false + error message */
}
else {
lua_pushboolean(L, 1);
lua_insert(L, -(r + 1));
return r + 1; /* return true + 'resume' returns */
}
}
static int luaB_auxwrap (lua_State *L) {
lua_State *co = lua_tothread(L, lua_upvalueindex(1));
int r = auxresume(L, co, lua_gettop(L));
if (r < 0) { /* error? */
int stat = lua_status(co);
if (stat != LUA_OK && stat != LUA_YIELD) /* error in the coroutine? */
lua_resetthread(co); /* close its tbc variables */
if (stat != LUA_ERRMEM && /* not a memory error and ... */
lua_type(L, -1) == LUA_TSTRING) { /* ... error object is a string? */
luaL_where(L, 1); /* add extra info, if available */
lua_insert(L, -2);
lua_concat(L, 2);
}
return lua_error(L); /* propagate error */
}
return r;
}
static int luaB_cocreate (lua_State *L) {
lua_State *NL;
luaL_checktype(L, 1, LUA_TFUNCTION);
NL = lua_newthread(L);
lua_pushvalue(L, 1); /* move function to top */
lua_xmove(L, NL, 1); /* move function from L to NL */
return 1;
}
static int luaB_cowrap (lua_State *L) {
luaB_cocreate(L);
lua_pushcclosure(L, luaB_auxwrap, 1);
return 1;
}
static int luaB_yield (lua_State *L) {
return lua_yield(L, lua_gettop(L));
}
#define COS_RUN 0
#define COS_DEAD 1
#define COS_YIELD 2
#define COS_NORM 3
static const char *const statname[] =
{"running", "dead", "suspended", "normal"};
static int auxstatus (lua_State *L, lua_State *co) {
if (L == co) return COS_RUN;
else {
switch (lua_status(co)) {
case LUA_YIELD:
return COS_YIELD;
case LUA_OK: {
lua_Debug ar;
if (lua_getstack(co, 0, &ar)) /* does it have frames? */
return COS_NORM; /* it is running */
else if (lua_gettop(co) == 0)
return COS_DEAD;
else
return COS_YIELD; /* initial state */
}
default: /* some error occurred */
return COS_DEAD;
}
}
}
static int luaB_costatus (lua_State *L) {
lua_State *co = getco(L);
lua_pushstring(L, statname[auxstatus(L, co)]);
return 1;
}
static int luaB_yieldable (lua_State *L) {
lua_State *co = lua_isnone(L, 1) ? L : getco(L);
lua_pushboolean(L, lua_isyieldable(co));
return 1;
}
static int luaB_corunning (lua_State *L) {
int ismain = lua_pushthread(L);
lua_pushboolean(L, ismain);
return 2;
}
static int luaB_close (lua_State *L) {
lua_State *co = getco(L);
int status = auxstatus(L, co);
switch (status) {
case COS_DEAD: case COS_YIELD: {
status = lua_resetthread(co);
if (status == LUA_OK) {
lua_pushboolean(L, 1);
return 1;
}
else {
lua_pushboolean(L, 0);
lua_xmove(co, L, 1); /* copy error message */
return 2;
}
}
default: /* normal or running coroutine */
return luaL_error(L, "cannot close a %s coroutine", statname[status]);
}
}
static const luaL_Reg co_funcs[] = {
{"create", luaB_cocreate},
{"resume", luaB_coresume},
{"running", luaB_corunning},
{"status", luaB_costatus},
{"wrap", luaB_cowrap},
{"yield", luaB_yield},
{"isyieldable", luaB_yieldable},
{"close", luaB_close},
{NULL, NULL}
};
LUAMOD_API int luaopen_coroutine (lua_State *L) {
luaL_newlib(L, co_funcs);
return 1;
}
|
