scoutos / prex-0.9.0 / usr / test / deadlock / deadlock.c @ 03e9c04a
History | View | Annotate | Download (4.03 KB)
1 |
/*-
|
---|---|
2 |
* Copyright (c) 2005, Kohsuke Ohtani
|
3 |
* All rights reserved.
|
4 |
*
|
5 |
* Redistribution and use in source and binary forms, with or without
|
6 |
* modification, are permitted provided that the following conditions
|
7 |
* are met:
|
8 |
* 1. Redistributions of source code must retain the above copyright
|
9 |
* notice, this list of conditions and the following disclaimer.
|
10 |
* 2. Redistributions in binary form must reproduce the above copyright
|
11 |
* notice, this list of conditions and the following disclaimer in the
|
12 |
* documentation and/or other materials provided with the distribution.
|
13 |
* 3. Neither the name of the author nor the names of any co-contributors
|
14 |
* may be used to endorse or promote products derived from this software
|
15 |
* without specific prior written permission.
|
16 |
*
|
17 |
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
18 |
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
19 |
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
20 |
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
21 |
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
22 |
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
23 |
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
24 |
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
25 |
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
26 |
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
27 |
* SUCH DAMAGE.
|
28 |
*/
|
29 |
|
30 |
/*
|
31 |
* deadlock.c - test program for a kernel deadlock detection.
|
32 |
*/
|
33 |
|
34 |
/*
|
35 |
* Prex kernel has the feature of deadlock detection. The following
|
36 |
* senario is tested with this program.
|
37 |
*
|
38 |
* 1) Thread-2 locks mutex-A.
|
39 |
* 2) Thread-1 locks mutex-B.
|
40 |
* 3) Thread-1 locks mutex-A.
|
41 |
* 4) Thread-2 locks mutex-B.
|
42 |
*
|
43 |
* The deadlock occurs at 4) because mutex-B has been already locked by
|
44 |
* thread-1 and thread-1 is waiting for thread-2 (mutex-A).
|
45 |
* The kernel will detect this condition, and the mutex_lock() system
|
46 |
* call will return EDEADLK error code.
|
47 |
*/
|
48 |
|
49 |
#include <sys/prex.h> |
50 |
#include <stdio.h> |
51 |
#include <errno.h> |
52 |
|
53 |
static char stack[2][1024]; |
54 |
static thread_t th_1, th_2;
|
55 |
static mutex_t mtx_A, mtx_B;
|
56 |
|
57 |
thread_t |
58 |
thread_run(void (*start)(void), void *stack) |
59 |
{ |
60 |
thread_t t; |
61 |
int error;
|
62 |
|
63 |
error = thread_create(task_self(), &t); |
64 |
if (error)
|
65 |
panic("thread_create is failed");
|
66 |
|
67 |
error = thread_load(t, start, stack); |
68 |
if (error)
|
69 |
panic("thread_load is failed");
|
70 |
|
71 |
return t;
|
72 |
} |
73 |
|
74 |
/*
|
75 |
* Thread 1 - Priority = 100
|
76 |
*/
|
77 |
static void |
78 |
thread_1(void)
|
79 |
{ |
80 |
int error;
|
81 |
|
82 |
printf("thread_1: starting\n");
|
83 |
|
84 |
/*
|
85 |
* 2) Lock mutex B
|
86 |
*/
|
87 |
printf("thread_1: 2) lock B\n");
|
88 |
error = mutex_lock(&mtx_B); |
89 |
if (error) printf("error=%d\n", error); |
90 |
|
91 |
/*
|
92 |
* 3) Lock mutex A
|
93 |
*
|
94 |
* Switch to thread 1.
|
95 |
*/
|
96 |
printf("thread_1: 3) lock A\n");
|
97 |
error = mutex_lock(&mtx_A); |
98 |
if (error) printf("error=%d\n", error); |
99 |
|
100 |
printf("thread_1: exit\n");
|
101 |
thread_terminate(th_1); |
102 |
} |
103 |
|
104 |
/*
|
105 |
* Thread 2 - Priority = 101
|
106 |
*/
|
107 |
static void |
108 |
thread_2(void)
|
109 |
{ |
110 |
int error;
|
111 |
|
112 |
printf("thread_2: starting\n");
|
113 |
|
114 |
/*
|
115 |
* 1) Lock mutex A
|
116 |
*/
|
117 |
printf("thread_2: 1) lock A\n");
|
118 |
error = mutex_lock(&mtx_A); |
119 |
if (error) printf("error=%d\n", error); |
120 |
|
121 |
/*
|
122 |
* Switch to thread 1
|
123 |
*/
|
124 |
thread_resume(th_1); |
125 |
|
126 |
printf("thread_2: running\n");
|
127 |
/*
|
128 |
* 4) Lock mutex B
|
129 |
*
|
130 |
* Deadlock occurs here!
|
131 |
*/
|
132 |
printf("thread_2: 4) lock B\n");
|
133 |
error = mutex_lock(&mtx_B); |
134 |
if (error) printf("error=%d\n", error); |
135 |
if (error == EDEADLK)
|
136 |
printf("**** DEADLOCK!! ****\n");
|
137 |
|
138 |
printf("thread_2: exit\n");
|
139 |
thread_terminate(th_2); |
140 |
} |
141 |
|
142 |
int
|
143 |
main(int argc, char *argv[]) |
144 |
{ |
145 |
printf("Deadlock test program\n");
|
146 |
|
147 |
/*
|
148 |
* Boost priority of this thread
|
149 |
*/
|
150 |
thread_setpri(thread_self(), 90);
|
151 |
|
152 |
/*
|
153 |
* Initialize mutexes.
|
154 |
*/
|
155 |
mutex_init(&mtx_A); |
156 |
mutex_init(&mtx_B); |
157 |
|
158 |
/*
|
159 |
* Create new threads
|
160 |
*/
|
161 |
th_1 = thread_run(thread_1, stack[0]+1024); |
162 |
thread_setpri(th_1, 100);
|
163 |
|
164 |
th_2 = thread_run(thread_2, stack[1]+1024); |
165 |
thread_setpri(th_2, 101);
|
166 |
|
167 |
/*
|
168 |
* Start thread 2
|
169 |
*/
|
170 |
thread_resume(th_2); |
171 |
|
172 |
/*
|
173 |
* Wait...
|
174 |
*/
|
175 |
thread_suspend(thread_self()); |
176 |
|
177 |
return 0; |
178 |
} |