阅读《线程池》后我感到非常困惑。我了解了这个概念,以及它们实际上是如何工作的。 但我对如何编码这部分感到困惑。
网上查了很多资料。最后我得到了一个博客,其中有代码,如下所示,
条件是不要使用内置类
代码 1
public class ThreadPool {
private BlockingQueue taskQueue = null;
private List<PoolThread> threads = new ArrayList<PoolThread>();
private boolean isStopped = false;
public ThreadPool(int noOfThreads, int maxNoOfTasks){
taskQueue = new BlockingQueue(maxNoOfTasks);
for(int i=0; i<noOfThreads; i++){
threads.add(new PoolThread(taskQueue));
}
for(PoolThread thread : threads){
thread.start();
}
}
public void synchronized execute(Runnable task){
if(this.isStopped) throw
new IllegalStateException("ThreadPool is stopped");
this.taskQueue.enqueue(task);
}
public synchronized void stop(){
this.isStopped = true;
for(PoolThread thread : threads){
thread.stop();
}
}
}
代码2
public class PoolThread extends Thread {
private BlockingQueue taskQueue = null;
private boolean isStopped = false;
public PoolThread(BlockingQueue queue){
taskQueue = queue;
}
public void run(){
while(!isStopped()){
try{
Runnable runnable = (Runnable) taskQueue.dequeue();
runnable.run();
} catch(Exception e){
//log or otherwise report exception,
//but keep pool thread alive.
}
}
}
public synchronized void stop(){
isStopped = true;
this.interrupt(); //break pool thread out of dequeue() call.
}
public synchronized void isStopped(){
return isStopped;
}
}
代码 3:-
public class BlockingQueue {
private List queue = new LinkedList();
private int limit = 10;
public BlockingQueue(int limit){
this.limit = limit;
}
public synchronized void enqueue(Object item)
throws InterruptedException {
while(this.queue.size() == this.limit) {
wait();
}
if(this.queue.size() == 0) {
notifyAll();
}
this.queue.add(item);
}
public synchronized Object dequeue()
throws InterruptedException{
while(this.queue.size() == 0){
wait();
}
if(this.queue.size() == this.limit){
notifyAll();
}
return this.queue.remove(0);
}
}
我试图理解这段代码的作用。 但我不明白这段代码的流程。你能帮我理解这段代码吗?
Mainly I have problems in **Code 2 :- run method**
Why execute method's argument are of Runnable type?
How input array given to this code??
帮助我。
提前致谢。
最佳答案
public void run(){
while(!isStopped()){
循环直到线程池停止。
try{
Runnable runnable = (Runnable) taskQueue.dequeue();
将头任务从任务队列中拉出。
runnable.run();
运行任务。
} catch(Exception e){
//log or otherwise report exception,
//but keep pool thread alive.
如果任务抛出异常,则不执行任何特殊操作,只是不要传递异常。
}
}
}
关于java - 如何在线程池中编写run方法,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/14459454/