forked from DreamCats/java-notes
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathT11.java
More file actions
187 lines (153 loc) · 4.63 KB
/
T11.java
File metadata and controls
187 lines (153 loc) · 4.63 KB
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
package com.basic; /**
* @program JavaBooks
* @description: 通信
* @author: mf
* @create: 2019/12/30 15:54
*/
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
/**
* 实现一个容器，提供两个方法add size
* 写两个线程，线程1添加10个元素到容器中，线程2实现监控元素的个数，当个数到5个时，线程2给出提示并结束
*/
public class T11 {
// List lists = new ArrayList();
// 解决方法1， 添加volatile，使t2能够得到通知
volatile List lists = new ArrayList();
public void add(Object o) {
lists.add(o);
}
public int size() {
return lists.size();
}
public static void main(String[] args) {
T11 t11 = new T11();
new Thread(() -> {
for (int i = 0; i < 10; i++) {
t11.add(new Object());
System.out.println("add " + i);
try {
TimeUnit.SECONDS.sleep(1);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}, "t1").start();
new Thread(() -> {
while (true) {
if (t11.size() == 5) {
break;
}
}
System.out.println("t2结束");
}, "t2").start();
}
}
/**
* 使用wait和notify优化
* wait释放锁，但是notify不释放
*/
class T11_1 {
List lists = new ArrayList();
public void add(Object o) {
lists.add(o);
}
public int size() {
return lists.size();
}
public static void main(String[] args) {
T11_1 t11_1 = new T11_1();
final Object lock = new Object();
new Thread(() -> {
synchronized (lock) {
System.out.println("t2 启动");
if (t11_1.size() != 5) {
try {
lock.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
System.out.println("t2 结束");
lock.notify();
}
}, "t2").start();
try {
TimeUnit.SECONDS.sleep(1);
} catch (InterruptedException e) {
e.printStackTrace();
}
new Thread(() -> {
System.out.println("t1 启动");
synchronized (lock) {
for (int i = 0; i < 10; i++) {
t11_1.add(new Object());
System.out.println("add " + i);
if (t11_1.size() == 5) {
lock.notify();
try {
lock.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
try {
TimeUnit.SECONDS.sleep(1);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}, "t1").start();
}
}
/**
* 使用CountDownLatch CyclicBarrier semaphore
*/
class T11_2 {
List lists = new ArrayList();
public void add (Object o) {
lists.add(o);
}
public int size() {
return lists.size();
}
public static void main(String[] args) {
T11_2 t11_2 = new T11_2();
CountDownLatch countDownLatch = new CountDownLatch(1);
new Thread(() -> {
System.out.println("t2启动");
if (t11_2.size() != 5) {
try {
countDownLatch.await(); // 上个门闩
} catch (InterruptedException e) {
e.printStackTrace();
}
}
System.out.println("t2结束");
}, "t2").start();
try {
TimeUnit.SECONDS.sleep(1);
} catch (InterruptedException e) {
e.printStackTrace();
}
new Thread(() -> {
System.out.println("t1启动");
for (int i = 0; i < 10; i++) {
t11_2.add(new Object());
System.out.println("add " + i);
if (t11_2.size() == 5) {
// 打开门闩，让t2得以执行
countDownLatch.countDown();
}
try {
TimeUnit.SECONDS.sleep(1);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}, "t1").start();
}
}