algorithms/src/test/java/GuardedObject.java at master · verifyCode/algorithms · GitHub

Repository navigation

History

import java.util.Map;

import java.util.concurrent.ConcurrentHashMap;

import java.util.concurrent.TimeUnit;

import java.util.concurrent.locks.Condition;

import java.util.concurrent.locks.Lock;

import java.util.concurrent.locks.ReentrantLock;

import java.util.function.Predicate;

public class GuardedObject<T> {

//受保护的对象

T obj;

final Lock lock = new ReentrantLock();

final Condition done = lock.newCondition();

final int timeout = 2;

//保存所有GuardedObject

final static Map<Object, GuardedObject> gos = new ConcurrentHashMap<>();

//静态方法创建GuardedObject

static <K> GuardedObject create(K key) {

GuardedObject go = new GuardedObject();

gos.put(key, go);

return go;

}

static <K, T> void fireEvent(K key, T obj) {

GuardedObject go = gos.remove(key);

if (go != null) {

go.onChanged(obj);

}

//获取受保护对象

T get(Predicate<T> p) {

lock.lock();

try {

//MESA管程推荐写法

while (!p.test(obj)) {

done.await(timeout,

TimeUnit.SECONDS);

}

} catch (InterruptedException e) {

throw new RuntimeException(e);

} finally {

lock.unlock();

}

//返回非空的受保护对象

return obj;

}

//事件通知方法

void onChanged(T obj) {

lock.lock();

try {

this.obj = obj;

done.signalAll();

} finally {

lock.unlock();

}

algorithms/src/test/java/GuardedObject.java at master · verifyCode/algorithms · GitHub

Repository navigation

Expand file tree

Breadcrumbs

GuardedObject.java

Latest commit

History

Breadcrumbs

GuardedObject.java

File metadata and controls