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
|
/* Copyright (C) 2001 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <ucontext.h>
static ucontext_t ctx[3];
static int was_in_f1;
static int was_in_f2;
static char st2[8192];
static void
f1 (long a0, long a1, long a2, long a3)
{
printf ("start f1(a0=%lx,a1=%lx,a2=%lx,a3=%lx)\n", a0, a1, a2, a3);
if (a0 != 1 || a1 != 2 || a2 != 3 || a3 != -4)
{
puts ("arg mismatch");
exit (-1);
}
if (swapcontext (&ctx[1], &ctx[2]) != 0)
{
printf ("%s: swapcontext: %m\n", __FUNCTION__);
exit (1);
}
puts ("finish f1");
was_in_f1 = 1;
}
static void
f2 (void)
{
char on_stack[1];
puts ("start f2");
printf ("&on_stack=%p\n", on_stack);
if (on_stack < st2 || on_stack >= st2 + sizeof (st2))
{
printf ("%s: memory stack is not where it belongs!", __FUNCTION__);
exit (1);
}
if (swapcontext (&ctx[2], &ctx[1]) != 0)
{
printf ("%s: swapcontext: %m\n", __FUNCTION__);
exit (1);
}
puts ("finish f2");
was_in_f2 = 1;
}
volatile int global;
int
main (void)
{
char st1[8192];
puts ("making contexts");
if (getcontext (&ctx[1]) != 0)
{
if (errno == ENOSYS)
exit (0);
printf ("%s: getcontext: %m\n", __FUNCTION__);
exit (1);
}
/* Play some tricks with this context. */
if (++global == 1)
if (setcontext (&ctx[1]) != 0)
{
printf ("%s: setcontext: %m\n", __FUNCTION__);
exit (1);
}
if (global != 2)
{
printf ("%s: 'global' not incremented twice\n", __FUNCTION__);
exit (1);
}
ctx[1].uc_stack.ss_sp = st1;
ctx[1].uc_stack.ss_size = sizeof st1;
ctx[1].uc_link = &ctx[0];
makecontext (&ctx[1], (void (*) (void)) f1, 4, 1, 2, 3, -4);
if (getcontext (&ctx[2]) != 0)
{
printf ("%s: second getcontext: %m\n", __FUNCTION__);
exit (1);
}
ctx[2].uc_stack.ss_sp = st2;
ctx[2].uc_stack.ss_size = sizeof st2;
ctx[2].uc_link = &ctx[1];
makecontext (&ctx[2], f2, 0);
puts ("swapping contexts");
if (swapcontext (&ctx[0], &ctx[2]) != 0)
{
printf ("%s: swapcontext: %m\n", __FUNCTION__);
exit (1);
}
puts ("back at main program");
if (was_in_f1 == 0)
{
puts ("didn't reach f1");
exit (1);
}
if (was_in_f2 == 0)
{
puts ("didn't reach f2");
exit (1);
}
puts ("test succeeded");
return 0;
}
|
