blockingqueue

问题 Consider a BlockingQueue and a few threads waiting on poll(long, TimeUnit) (possibly also on on take() ). Now the queue is empty and it is desired to notify the waiting threads that they can stop waiting. The expected behaviour is to have either null returned or the declared InterruptedException thrown. Object.notify() won't work for LinkedBlockingQueue as the threads are waiting on an internal lock. Any straightforward way? 回答1: Javadoc for the BlockingQueue suggests a good way: A

问题 Consider a BlockingQueue and a few threads waiting on poll(long, TimeUnit) (possibly also on on take() ). Now the queue is empty and it is desired to notify the waiting threads that they can stop waiting. The expected behaviour is to have either null returned or the declared InterruptedException thrown. Object.notify() won't work for LinkedBlockingQueue as the threads are waiting on an internal lock. Any straightforward way? 回答1: Javadoc for the BlockingQueue suggests a good way: A

问题 When populating the queue from the contents of the file, depth does not seem to ever increase, as elements are not added in this implementation. BlockingQueue<String> q = new SynchronousQueue<String>(); ... fstream = new FileInputStream("/path/to/file.txt"); ... while ((line = br.readLine()) != null) { if (q.offer(line)) System.out.println("Depth: " + q.size()); //0 } When replacing offer with add , exception if thrown Exception in thread "main" java.lang.IllegalStateException: Queue full ...

问题 I’m using java.util.concurrent.BlockingQueue in a very simple producer-consumer scenario. E.g. this pseudo code depicts the consumer part: class QueueConsumer implements Runnable { @Override public void run() { while(true) { try { ComplexObject complexObject = myBlockingQueue.take(); //do something with the complex object } catch (InterruptedException e) { Thread.currentThread().interrupt(); } } } } So far so good. In the javadoc of the blocking queue I read: A BlockingQueue does not

问题 I have this piece of code. A LinkedBlockingQueue should only throw an Exception if interrupted while waiting to add to the queue. But this queue is unbounded so it should add asap. Why does my shutdown methode throw an InterruptedException ? private final LinkedBlockingQueue<Message> messages= new LinkedBlockingQueue<Message>(); public void run(){ LinkedList<Message> messages = new LinkedList<Message>(); while (true){ try{ messages.clear(); messages.add(this.messages.take()); this.messages

问题 I want to know Advantages to use BlockingQueue instead of ( PipedOutputStream and PipedInputStream ) import java.io.*; import java.util.concurrent.*; public class PipedStreamVsBlocking { public static void main(String... args) { BlockingQueue<Integer> blockingQueue = new LinkedBlockingDeque<>(2); ExecutorService executor = Executors.newFixedThreadPool(4); Runnable producerTask = () -> { try { while (true) { int value = ThreadLocalRandom.current().nextInt(0, 1000); blockingQueue.put(value);

问题 I have two separated blocking queues. The clients usually use either the first of the second blocking queue to retrieve elements to be processed. In some case, the clients are interested in elements from the two blocking queues, whichever queue provides the data first. How can a client wait for the two queues, in parallel? 回答1: You could try using the poll method in some sort of loop to only wait a specified amount of time for one queue before polling the other one. Other than that, I'd say

问题 I have two separated blocking queues. The clients usually use either the first of the second blocking queue to retrieve elements to be processed. In some case, the clients are interested in elements from the two blocking queues, whichever queue provides the data first. How can a client wait for the two queues, in parallel? 回答1: You could try using the poll method in some sort of loop to only wait a specified amount of time for one queue before polling the other one. Other than that, I'd say

问题 I am using Java collections BlockingQueue for data processing. The current code looks like while(true){ if(queue.size() > 0) handle(queue.take()) } Is there a way (in Java or other frameworks) where I can process it asynchronously, like, queue.setHandler(new Handler<E>()); somewhere down the class.. class Handler implements IHandler<E>{ void handle(E e){ handle(e) } } 来源： https://stackoverflow.com/questions/32793159/asynchronous-execution-in-blockingqueue

问题 I have a blocking queue class based on Marc Gravell's Blocking Queue Now I have situations where I want to dequeue only a certain object, I know this is not really the use case of a queue, but in some cases I think this is a good extension, for example waiting for a certain network answer. This would be something like a TryDequeueWhere(Func<T, bool> expression, out T value, int? waitTimeInMs = null) The problem is I don't know how to wait and block for a certain object. 回答1: After posting my