ワークキューの例
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/**
*
*/
public class WorkQueue {
private final PoolWorker[] threads;
private final LinkedList<Runnable> queue;
private static WorkQueue instance = null;
/**
*
* @param nThreads
* @return
*/
public static WorkQueue newInstance(int nThreads) {
if(instance == null) {
synchronized(WorkQueue.class) {
if(instance == null) {
instance = new WorkQueue(nThreads);
}
}
}
return instance;
}
/**
* 5
* @return
*/
public static WorkQueue getInstance() {
if(instance == null) {
synchronized(WorkQueue.class) {
if(instance == null) {
// default set work queue size to 5
instance = new WorkQueue(5);
}
}
}
return instance;
}
/**
*
* @param nThreads
*/
private WorkQueue(int nThreads) {
queue = new LinkedList<Runnable>();
threads = new PoolWorker[nThreads];
for (int i = 0; i < nThreads; i++) {
threads[i] = new PoolWorker();
threads[i].start();
}
}
/**
*
* @param r
*/
public void execute(Runnable r) {
synchronized (queue) {
queue.addLast(r);
queue.notify();
}
}
/**
*
*/
private class PoolWorker extends Thread {
public void run() {
Runnable r;
while (true) {
synchronized (queue) {
while (queue.isEmpty()) {
try {
queue.wait();
}
catch (InterruptedException ignored) {
}
}
r = (Runnable) queue.removeFirst();
}
// If we don't catch RuntimeException,
// the pool could leak threads
try {
r.run();
}
catch (RuntimeException e) {
// You might want to log something here
}
}
}
}
}