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| import java.util.Random;
class WorkerThread extends Thread {
private final Channel channel;
WorkerThread(String name, Channel channel) {
super(name);
this.channel = channel;
}
@Override
public void run() {
while(true) {
Request request = channel.takeRequest();
request.execute();
}
}
}
class Channel {
private static final int MAX_REQUEST = 100;
private final Request[] requestQueue;
private int tail;
private int head;
private int count;
private final WorkerThread[] threadPool;
Channel(int threads) {
this.requestQueue = new Request[MAX_REQUEST];
this.head = 0;
this.tail = 0;
this.count = 0;
threadPool = new WorkerThread[threads];
for(int i = 0; i < threadPool.length; i++) {
threadPool[i] = new WorkerThread("Worker-" + i, this);
}
}
void startWorkers() {
for(int i = 0; i < threadPool.length; i++) {
threadPool[i].start();
}
}
synchronized void putRequest(Request request) {
while(count >= requestQueue.length) {
try {
wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
requestQueue[tail] = request;
tail = (tail + 1) % requestQueue.length;
count++;
notifyAll();
}
synchronized Request takeRequest() {
while(count <= 0) {
try {
wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
Request request = requestQueue[head];
head = (head + 1) % requestQueue.length;
count--;
notifyAll();
return request;
}
}
class Request {
private final String name;
private final int number;
private static final Random random = new Random();
Request(String name, int number) {
this.name = name;
this.number = number;
}
void execute() {
System.out.println(Thread.currentThread().getName() + " executes " + this);
try {
Thread.sleep(random.nextInt(1000));
} catch (InterruptedException e) {
e.printStackTrace();
}
}
public String toString() {
return "{ Request from " + name + " No." + number + " }";
}
}
class ClientThread extends Thread {
private final Channel channel;
private static final Random random = new Random();
ClientThread(String name, Channel channel) {
super(name);
this.channel = channel;
}
@Override
public void run() {
try {
for(int i = 0; true; i++) {
Request request = new Request(getName(), i);
channel.putRequest(request);
Thread.sleep(random.nextInt(1000));
}
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
public class Test {
public static void main(String[] args) {
Channel channel = new Channel(5);
channel.startWorkers();
new ClientThread("Alice", channel).start();
new ClientThread("Bobby", channel).start();
new ClientThread("Chris", channel).start();
}
}
|