JAVAマルチスレッド(5)生産者消費者モデルをlock,synchronized,ブロックキューの3つの方法で実現
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このブログは前のJAVAマルチスレッド(三)生産者の消費者モデルと実現方法の補充と言える.生産者消費者モードは、3つの方法(lock、synchronized、ブロックキュー)で実現される.具体的には、生産者が乱数を生成し(結果を読みやすくするために、乱数を10以内の整数に限定します)、消費者が読み取り、印刷します.
ブロックキューは最も簡単な実装方法です
JAVAが提供してくれた既存のブロックキューを使わない以上、私たちは自分でキューを作成したほうがいいです.コードは以下の通りです.
synchronizedは自分で手動でロックを解除する必要はありません.ここでは前述したwait()¬ify()メソッドを使用します.
1ブロックキューによる生産者消費者モデルの実現
ブロックキューは最も簡単な実装方法です
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.util.Random;
public class BlockingQueuePattern {
public static void main(String args[]){
//
BlockingQueue sharedQueue = new LinkedBlockingQueue();
//
Thread prodThread = new Thread(new Producer(sharedQueue));
Thread consThread = new Thread(new Consumer(sharedQueue));
//
prodThread.start();
consThread.start();
}
}
//
class Producer implements Runnable {
private final BlockingQueue sharedQueue;
public Producer(BlockingQueue sharedQueue) {
this.sharedQueue = sharedQueue;
}
@Override
public void run() {
for(int i=0; i<10; i++){
try {
// 10
Random random = new Random();
int ProdRandom=random.nextInt(10);
System.out.println("Produced: " + ProdRandom);
sharedQueue.put(ProdRandom);
} catch (InterruptedException ex) {
Logger.getLogger(Producer.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
}
//
class Consumer implements Runnable{
private final BlockingQueue sharedQueue;
public Consumer (BlockingQueue sharedQueue) {
this.sharedQueue = sharedQueue;
}
@Override
public void run() {
while(true){
try {
System.out.println("Consumed: "+ sharedQueue.take());
} catch (InterruptedException ex) {
Logger.getLogger(Consumer.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
}
Output：
Produced: 4
Produced: 7
Produced: 8
Consumed: 4
Consumed: 7
Produced: 6
Consumed: 8
Consumed: 6
Produced: 1
Produced: 7
Consumed: 1
Consumed: 7
Produced: 3
Produced: 5
Consumed: 3
Consumed: 5
Produced: 9
Produced: 7
Consumed: 9
Consumed: 7
2 lock生産者消費者モデルの実現
JAVAが提供してくれた既存のブロックキューを使わない以上、私たちは自分でキューを作成したほうがいいです.コードは以下の通りです.
import java.util.LinkedList;
import java.util.Random;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
public class OptimisticLockPattern {
public static void main(String[] args){
SelfQueue selfqueue = new SelfQueue();
//
Thread prodThread = new Thread(new Producer(selfqueue));
Thread consThread = new Thread(new Consumer(selfqueue));
//
prodThread.start();
consThread.start();
}
}
class SelfQueue{
int max = 5;
LinkedList ProdLine = new LinkedList();
Lock lock = new ReentrantLock();
Condition full = lock.newCondition();
Condition empty = lock.newCondition();
public void produce(int ProdRandom){
try {
lock.lock();
while(max == ProdLine.size()){
System.out.println(" ， ");
full.await();
}
ProdLine.add(ProdRandom);
empty.signal();
} catch (InterruptedException e) {
e.printStackTrace();
}finally{
lock.unlock();
}
}
public int consume(){
int m = 0;
try {
lock.lock();
while(ProdLine.size() == 0){
System.out.println(" ， ");
empty.await();
}
m = ProdLine.removeFirst();
full.signal();
} catch (InterruptedException e) {
e.printStackTrace();
}finally{
lock.unlock();
return m;
}
}
}
//
class Producer implements Runnable{
private final SelfQueue selfqueue;
public Producer(SelfQueue selfqueue) {
this.selfqueue = selfqueue;
}
public void run() {
for (int i = 0; i < 10; i++) {
Random random = new Random();
int ProdRandom=random.nextInt(10);
System.out.println("Produced: " + ProdRandom);
selfqueue.produce(ProdRandom);
}
}
}
//
class Consumer implements Runnable{
private final SelfQueue selfqueue;
public Consumer(SelfQueue selfqueue) {
this.selfqueue = selfqueue;
}
public void run() {
while(true) {
System.out.println("Consumed: "+ selfqueue.consume());
}
}
}
Output:
Produced: 1
Produced: 9
Consumed: 1
Consumed: 9
，
Produced: 9
Produced: 1
Consumed: 9
Produced: 8
Consumed: 1
Consumed: 8
，
Produced: 6
Produced: 8
Consumed: 6
Produced: 4
Consumed: 8
Produced: 4
Consumed: 4
Produced: 0
Consumed: 4
Consumed: 0
， 3 synchronized生産者消費者モデルの実現
synchronizedは自分で手動でロックを解除する必要はありません.ここでは前述したwait()¬ify()メソッドを使用します.
import java.util.Random;
public class PessimisticLockPattern {
public static void main(String[] args){
SelfQueue selfqueue = new SelfQueue();
//
Thread prodThread = new Thread(new Producer(selfqueue));
Thread consThread = new Thread(new Consumer(selfqueue));
//
prodThread.start();
consThread.start();
}
}
class SelfQueue{
int index = 0;
int[] ProdLine = new int[6];
public synchronized void produce(int ProdRandom){
while(index == ProdLine.length){
try {
this.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
this.notify();
ProdLine[index] = ProdRandom;
index++;
}
public synchronized int consume(){
while(index == 0){
try {
this.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
this.notify();
index--;
return ProdLine[index];
}
}
//
class Producer implements Runnable{
private final SelfQueue selfqueue;
public Producer(SelfQueue selfqueue) {
this.selfqueue = selfqueue;
}
public void run() {
for (int i = 0; i < 10; i++) {
Random random = new Random();
int ProdRandom = random.nextInt(10);
System.out.println("Produced: " + ProdRandom);
selfqueue.produce(ProdRandom);
}
}
}
//
class Consumer implements Runnable{
private final SelfQueue selfqueue;
public Consumer(SelfQueue selfqueue) {
this.selfqueue = selfqueue;
}
public void run() {
while(true) {
System.out.println("Consumed: "+ selfqueue.consume());
}
}
}
Output:
Produced: 3
Produced: 3
Consumed: 3
Produced: 8
Produced: 3
Consumed: 3
Produced: 2
Produced: 6
Consumed: 3
Produced: 7
Produced: 8
Produced: 1
Produced: 9
Consumed: 6
Consumed: 9
Consumed: 1
Consumed: 8
Consumed: 7
Consumed: 2
Consumed: 8