root / prex-0.9.0 / usr / sample / sem / sem.c @ 03e9c04a
History | View | Annotate | Download (2.86 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 |
* sem.c - sample program for semaphore.
|
32 |
*/
|
33 |
|
34 |
#include <sys/prex.h> |
35 |
#include <stdio.h> |
36 |
|
37 |
static sem_t sem;
|
38 |
|
39 |
void
|
40 |
thread_run(void (*start)(void), void *stack) |
41 |
{ |
42 |
thread_t t; |
43 |
|
44 |
if (thread_create(task_self(), &t) != 0) |
45 |
panic("thread_create is failed");
|
46 |
|
47 |
if (thread_load(t, start, stack) != 0) |
48 |
panic("thread_load is failed");
|
49 |
|
50 |
if (thread_resume(t) != 0) |
51 |
panic("thread_resume failed");
|
52 |
|
53 |
return;
|
54 |
} |
55 |
|
56 |
/*
|
57 |
* The main routine create 10 copy of this thread. But, since the
|
58 |
* initial semaphore value is 3, only 3 threads can run at same time.
|
59 |
*/
|
60 |
static void |
61 |
new_thread(void)
|
62 |
{ |
63 |
thread_t t; |
64 |
|
65 |
t = thread_self(); |
66 |
printf("Start thread=%x\n", (u_int)t);
|
67 |
thread_yield(); |
68 |
|
69 |
/*
|
70 |
* Acquire semaphore
|
71 |
*/
|
72 |
sem_wait(&sem, 0);
|
73 |
|
74 |
/*
|
75 |
* Sleep 2000 ms
|
76 |
*/
|
77 |
printf("Running thread=%x\n", (u_int)t);
|
78 |
timer_sleep(2000, 0); |
79 |
|
80 |
/*
|
81 |
* Release semaphore
|
82 |
*/
|
83 |
sem_post(&sem); |
84 |
|
85 |
printf("End thread=%x\n", (u_int)t);
|
86 |
thread_terminate(t); |
87 |
} |
88 |
|
89 |
int
|
90 |
main(int argc, char *argv[]) |
91 |
{ |
92 |
static char stack[10][1024]; |
93 |
int i;
|
94 |
|
95 |
printf("Semaphore sample program\n");
|
96 |
|
97 |
/*
|
98 |
* Initialize semaphore with initial count 3
|
99 |
*/
|
100 |
sem_init(&sem, 3);
|
101 |
|
102 |
/*
|
103 |
* Boost the priority of this thread
|
104 |
*/
|
105 |
thread_setpri(thread_self(), 100);
|
106 |
|
107 |
/*
|
108 |
* Create 10 threads
|
109 |
*/
|
110 |
for (i = 0; i < 10; i++) |
111 |
thread_run(new_thread, stack[i]+1024);
|
112 |
|
113 |
/*
|
114 |
* Wait...
|
115 |
*/
|
116 |
thread_suspend(thread_self()); |
117 |
|
118 |
return 0; |
119 |
} |