JAVA多线程-基础Lock Condition 并发集合

代码的逻辑:

1)SProducer不停的产生number到queue中.
2)3个carrier不停的取出queue中的number.
3)如果queue中存在10个剩余number时,SProducer会停下来等Carrier消费一些后再生产.
4)如果Carrier发现queue中没有number时,会等待.
5)如果Carrier取出的数字末尾为4, 则会挑起罢工事件.
6)Carrier罢工会引发一个Negotiation线程进行谈判.
7)罢工阶段SProducer和所有Carrier均停工.
8)Negotiation如果发现取出的number首位为3或者7,将引发谈判失败.
9)如果谈判成功,则恢复工作,如果谈判失败,则破产,所有线程均退出.

注意:使用lock的时候一定要注意, lock()和unlock()方法一定要成对出现. 最好放到try{}finally{}中,这样,unlock()方法必会调到.倘若没有使用unlock()就return了,会导致线程死锁.

view source print ?

001	package concurrency;

002

003	import java.util.ArrayList;

004	import java.util.concurrent.ArrayBlockingQueue;

005	import java.util.concurrent.locks.Condition;

006	import java.util.concurrent.locks.ReentrantLock;

007

008	public class Producer extends Thread {

009	private final static ArrayBlockingQueue<String> numbers = new ArrayBlockingQueue<String>(10);

010	private final static ArrayList<Thread> threads = new ArrayList<Thread>();

011	private volatile boolean negotiating  = false;

012	private ReentrantLock negotiationLock = new ReentrantLock();

013	private Condition negotiationCondition = negotiationLock.newCondition();

014

015	private class Negotiation implements Runnable {

016	private String number;

017	private Negotiation(String number) {

018	this.number = number;

019

}

020	public void run() {

021

try {

022	System.out.println("Start negotiation...");

023	sleep(5000);

024	if (number.startsWith("7") || number.startsWith("3")) {

025	System.out.println("Negotiation broken.");

026	for (Thread t : threads) {

027	t.interrupt();

028

}

029	System.out.println("Negotiation broken post handle.");

030

return;

031

}

032	System.out.println("Negotiation succeeds.");

033	} catch (InterruptedException e) {

034	System.out.println("Middle man is killed.");

035

}

036	negotiationLock.lock();

037	negotiating = false;

038	negotiationCondition.signalAll();

039	negotiationLock.unlock();

040

}

041

}

042

043	private class Carrier implements Runnable {

044	private String name;

045	private Carrier(String name) {

046	this.name = name;

047

}

048	public void run() {

049	while(true) {

050

try{

051	negotiationLock.lock();

052	while(negotiating) {

053

try {

054	System.out.println("Carrier ["+name+"] join stricks.");

055	negotiationCondition.await();

056	} catch (InterruptedException e) {

057	System.out.println("Negotiation fails. Carrier [" + name + "] retires.");

058

return;

059

}

060

}

061	} finally {

062	negotiationLock.unlock();

063

}

064	String number;

065

try {

066	number = numbers.take();

067	System.out.println("Carrier [" + name + "] carries "+ number +" out of List;");

068	} catch (InterruptedException e1) {

069	System.out.println("Negotiation fails. Carrier [" + name + "] retires.");

070

return;

071

}

072

073	if (number.endsWith("4")) {

074

try {

075	negotiationLock.lock();

076	while (negotiating) {

077

try {

078	negotiationCondition.await();

079	} catch (InterruptedException e) {

080	System.out.println("Negotiation fails. Carrier [" + name + "] retires.");

081

return;

082

}

083

}

084	negotiating = true;

085	System.out.println("Stricks happen on number:"+number);

086	new Thread(new Negotiation(number)).start();

087	} finally {

088	negotiationLock.unlock();

089

}

090

}

091

}

092

}

093

}

094

095	public void run() {

096	Thread a = new Thread(new Carrier("a"));

097	Thread b = new Thread(new Carrier("b"));

098	Thread c = new Thread(new Carrier("c"));

099	threads.add(this);

100	threads.add(a);

101	threads.add(b);

102	threads.add(c);

103

104	a.start();

105	b.start();

106	c.start();

107

108	this.produceNumbers();

109

110

}

111

112	private void produceNumbers() {

113	while (true) {

114	while(negotiating) {

115	negotiationLock.lock();

116

try {

117	System.out.println("Stricking... Producer waiting for negotiation result.");

118	negotiationCondition.await();

119	System.out.println("Negotiation succeeds. Producer happy.");

120	} catch (InterruptedException e) {

121	System.out.println("Negotiation fails. Producer breaks up.");

122

return;

123	} finally {

124	negotiationLock.unlock();

125

}

126

}

127

128	String number = ""+new java.util.Random().nextInt(47);

129

130

try {

131	numbers.put(number);

132	System.out.println("Produce number " + number + " into List;");

133	} catch (InterruptedException e) {

134	System.out.println("Negotiation fails. Producer breaks up.");

135

return;

136

}

137

}

138

}

139

140

141	public static void main(String[] args) {

142	new Producer().start();

143

}

144

}