线程池的实现

Java代码

1. package threadpool;  
2.   
3. import ojadb.core.thread.OjadbThreadPool;  
4. import ojadb.core.thread.task.OjadbTask;  
5. import ojadb.exception.OjadbException;  
6.   
7. public class BasicTest {  
8.     public static void main(String[] ojadbs) throws OjadbException {  
9.         OjadbThreadPool pool = new OjadbThreadPool(5, 10);  
10.         OjadbTask thread = new OjadbTask("test thread");  
11.         pool.excute(thread);  
12.         System.exit(0);  
13.     }  
14. }  

package threadpool; import ojadb.core.thread.OjadbThreadPool; import ojadb.core.thread.task.OjadbTask; import ojadb.exception.OjadbException; public class BasicTest { public static void main(String[] ojadbs) throws OjadbException { OjadbThreadPool pool = new OjadbThreadPool(5, 10); OjadbTask thread = new OjadbTask("test thread"); pool.excute(thread); System.exit(0); } }

 

线程池：

Java代码

1. package ojadb.core.thread;  
2.   
3. import java.util.concurrent.BlockingQueue;  
4. import java.util.concurrent.LinkedBlockingQueue;  
5. import ojadb.core.thread.task.OjadbTask;  
6. import ojadb.core.thread.thread.OjadbThread;  
7. import ojadb.exception.OjadbException;  
8.   
9. public class OjadbThreadPool {  
10.     private int minimum;  
11.     private int maximum;  
12.     private LinkedBlockingQueue<OjadbThread> ojadbThreads;  
13.     private BlockingQueue<OjadbTask> ojadbTasks;  
14.   
15.     public OjadbThreadPool(int min, int max) throws OjadbException {  
16.         if (0 < min && min < max) {  
17.             minimum = min;  
18.             maximum = max;  
19.             ojadbThreads = new LinkedBlockingQueue<OjadbThread>();  
20.             ojadbTasks = new LinkedBlockingQueue<OjadbTask>();  
21.             for (int i = 0; i < minimum; i++) {  
22.                 OjadbThread worker = new OjadbThread(this, "worker" + i);  
23.                 worker.start();  
24.             }  
25.         } else {  
26.             throw new OjadbException("无法建立线程池: 最小值必须大于零,小于最大值");  
27.         }  
28.     }  
29.   
30.     public void addWorker(OjadbThread ojadbThreadWorker) {  
31.         ojadbThreads.offer(ojadbThreadWorker);  
32.     }  
33.   
34.     public void excute(OjadbTask thread) {  
35.         // 生产任务  
36.         ojadbTasks.offer(thread);  
37.   
38.         OjadbThread worker = ojadbThreads.remove();  
39.         if (worker != null) {  
40.             worker.work();  
41.         } else if (ojadbThreads.size() < maximum) {  
42.             OjadbThread newWorker = new OjadbThread(this, "worker" + ojadbThreads.size());  
43.             newWorker.start();  
44.         } else {  
45.   
46.         }  
47.         releaseThreads();  
48.     }  
49.   
50.     private void releaseThreads() {  
51.         while (ojadbThreads.size() > minimum) {  
52.             OjadbThread worker = ojadbThreads.remove();  
53.             System.out.println(worker + "is killed");  
54.             worker.kill();  
55.         }  
56.     }  
57.   
58.     public OjadbTask getTask() {  
59.         if (ojadbTasks.size() == 0)  
60.             return null;  
61.         // 消费任务  
62.         return ojadbTasks.remove();  
63.     }  
64. }  

package ojadb.core.thread; import java.util.concurrent.BlockingQueue; import java.util.concurrent.LinkedBlockingQueue; import ojadb.core.thread.task.OjadbTask; import ojadb.core.thread.thread.OjadbThread; import ojadb.exception.OjadbException; public class OjadbThreadPool { private int minimum; private int maximum; private LinkedBlockingQueue<OjadbThread> ojadbThreads; private BlockingQueue<OjadbTask> ojadbTasks; public OjadbThreadPool(int min, int max) throws OjadbException { if (0 < min && min < max) { minimum = min; maximum = max; ojadbThreads = new LinkedBlockingQueue<OjadbThread>(); ojadbTasks = new LinkedBlockingQueue<OjadbTask>(); for (int i = 0; i < minimum; i++) { OjadbThread worker = new OjadbThread(this, "worker" + i); worker.start(); } } else { throw new OjadbException("无法建立线程池: 最小值必须大于零,小于最大值"); } } public void addWorker(OjadbThread ojadbThreadWorker) { ojadbThreads.offer(ojadbThreadWorker); } public void excute(OjadbTask thread) { // 生产任务 ojadbTasks.offer(thread); OjadbThread worker = ojadbThreads.remove(); if (worker != null) { worker.work(); } else if (ojadbThreads.size() < maximum) { OjadbThread newWorker = new OjadbThread(this, "worker" + ojadbThreads.size()); newWorker.start(); } else { } releaseThreads(); } private void releaseThreads() { while (ojadbThreads.size() > minimum) { OjadbThread worker = ojadbThreads.remove(); System.out.println(worker + "is killed"); worker.kill(); } } public OjadbTask getTask() { if (ojadbTasks.size() == 0) return null; // 消费任务 return ojadbTasks.remove(); } }

 

内部线程：

Java代码

1. package ojadb.core.thread.thread;  
2.   
3. import java.util.concurrent.locks.Condition;  
4. import java.util.concurrent.locks.ReentrantLock;  
5.   
6. import ojadb.core.thread.OjadbThreadPool;  
7. import ojadb.core.thread.task.OjadbTask;  
8.   
9. public class OjadbThread extends Thread {  
10.     private boolean isActived;  
11.     private ReentrantLock lock = new ReentrantLock();  
12.     private Condition condition = lock.newCondition();  
13.     private OjadbThreadPool pool;  
14.   
15.     public OjadbThread(OjadbThreadPool pool, String threadName) {  
16.         super(threadName);  
17.         this.pool = pool;  
18.         isActived = true;  
19.     }  
20.   
21.     @Override  
22.     public synchronized void start() {  
23.         super.start();  
24.     }  
25.   
26.     @Override  
27.     public void run() {  
28.         try {  
29.             lock.lock();  
30.   
31.             while (isActived) {  
32.                 OjadbTask task = pool.getTask();  
33.                 if (task != null) {  
34.                     String result = (String) task.excute();  
35.   
36.                     if (result.length() > 0) {  
37.                         pool.addWorker(this);  
38.                         // 懒工人策略 -- 没人招呼工作，绝不睡醒  
39.                         condition.await();  
40.                     }  
41.                 } else {  
42.                     pool.addWorker(this);  
43.                     condition.await();  
44.                 }  
45.             }  
46.         } catch (InterruptedException e) {  
47.             e.printStackTrace();  
48.         } finally {  
49.             lock.unlock();  
50.         }  
51.     }  
52.   
53.     public void work() {  
54.         try {  
55.             lock.lock();  
56.             condition.signal();  
57.         } finally {  
58.             lock.unlock();  
59.         }  
60.     }  
61.   
62.     public void kill() {  
63.         isActived = false;  
64.         work();  
65.     }  
66.   
67.     @Override  
68.     public String toString() {  
69.         return getName();  
70.     }  
71. }  

package ojadb.core.thread.thread; import java.util.concurrent.locks.Condition; import java.util.concurrent.locks.ReentrantLock; import ojadb.core.thread.OjadbThreadPool; import ojadb.core.thread.task.OjadbTask; public class OjadbThread extends Thread { private boolean isActived; private ReentrantLock lock = new ReentrantLock(); private Condition condition = lock.newCondition(); private OjadbThreadPool pool; public OjadbThread(OjadbThreadPool pool, String threadName) { super(threadName); this.pool = pool; isActived = true; } @Override public synchronized void start() { super.start(); } @Override public void run() { try { lock.lock(); while (isActived) { OjadbTask task = pool.getTask(); if (task != null) { String result = (String) task.excute(); if (result.length() > 0) { pool.addWorker(this); // 懒工人策略 -- 没人招呼工作，绝不睡醒 condition.await(); } } else { pool.addWorker(this); condition.await(); } } } catch (InterruptedException e) { e.printStackTrace(); } finally { lock.unlock(); } } public void work() { try { lock.lock(); condition.signal(); } finally { lock.unlock(); } } public void kill() { isActived = false; work(); } @Override public String toString() { return getName(); } }

 

用户线程：

Java代码

1. package ojadb.core.thread.task;  
2.   
3. public class OjadbTask {  
4.     private String threadName;  
5.   
6.     public OjadbTask(String threadName) {  
7.         this.threadName = threadName;  
8.     }  
9.   
10.     public Object excute() {  
11.         System.out.println("excuting " + threadName);  
12.         return "success";  
13.     }  
14.   
15.     public String getName() {  
16.         return threadName;  
17.     }  
18.   
19.     public String toString() {  
20.         return threadName;  
21.     }  
22. }