Java Code Examples for java.util.concurrent.LinkedBlockingDeque#poll()

@Override
public void run() {
    LinkedBlockingDeque<MessageVo> messageQueue = MESSAGE_QUEUE_MAP.get(userId);
    BaseResponse<List<MessageVo>> response = new BaseResponse<>();
    List<MessageVo> list = Lists.newArrayList();

    MessageVo vo;
    try {
        if ((vo = messageQueue.poll(timeout, TimeUnit.MILLISECONDS)) != null) {
            list.add(vo);
            //一次最多取10条信息
            for (int i = 0; i < 9; i++) {
                vo = messageQueue.poll();
                if (vo == null) {
                    break;
                }
                list.add(vo);
            }
        }
    } catch (InterruptedException e) {
        e.printStackTrace();
    }

    response.setData(list);
    deferredResult.setResult(response);
}
 

/**
 * drainTo(c, n) empties first min(n, size) elements of queue into c
 */
public void testDrainToN() {
    LinkedBlockingDeque q = new LinkedBlockingDeque();
    for (int i = 0; i < SIZE + 2; ++i) {
        for (int j = 0; j < SIZE; j++)
            assertTrue(q.offer(new Integer(j)));
        ArrayList l = new ArrayList();
        q.drainTo(l, i);
        int k = (i < SIZE) ? i : SIZE;
        assertEquals(k, l.size());
        assertEquals(SIZE - k, q.size());
        for (int j = 0; j < k; ++j)
            assertEquals(l.get(j), new Integer(j));
        do {} while (q.poll() != null);
    }
}
 

/**
 * drainTo(c, n) empties first min(n, size) elements of queue into c
 */
public void testDrainToN() {
    LinkedBlockingDeque q = new LinkedBlockingDeque();
    for (int i = 0; i < SIZE + 2; ++i) {
        for (int j = 0; j < SIZE; j++)
            assertTrue(q.offer(new Integer(j)));
        ArrayList l = new ArrayList();
        q.drainTo(l, i);
        int k = (i < SIZE) ? i : SIZE;
        assertEquals(k, l.size());
        assertEquals(SIZE - k, q.size());
        for (int j = 0; j < k; ++j)
            assertEquals(l.get(j), new Integer(j));
        do {} while (q.poll() != null);
    }
}
 

@Override
protected boolean evictItem(LinkedBlockingDeque<Job> deque) {
    final Job job = deque.poll();

    if (job != null) {
        if (job.getState().isDone()) {
            return true;
        } else {
            boolean addResult = add(job);
            boolean secondEviction = evictItem(deque);

            return addResult && secondEviction;
        }
    } else {
        return false;
    }
}
 

/**
 * element returns next element, or throws NSEE if empty
 */
public void testElement() {
    LinkedBlockingDeque q = populatedDeque(SIZE);
    for (int i = 0; i < SIZE; ++i) {
        assertEquals(i, q.element());
        q.poll();
    }
    try {
        q.element();
        shouldThrow();
    } catch (NoSuchElementException success) {}
}
 

/**
 * contains(x) reports true when elements added but not yet removed
 */
public void testContains() {
    LinkedBlockingDeque q = populatedDeque(SIZE);
    for (int i = 0; i < SIZE; ++i) {
        assertTrue(q.contains(new Integer(i)));
        q.poll();
        assertFalse(q.contains(new Integer(i)));
    }
}
 

/**
 * element returns next element, or throws NSEE if empty
 */
public void testElement() {
    LinkedBlockingDeque q = populatedDeque(SIZE);
    for (int i = 0; i < SIZE; ++i) {
        assertEquals(i, q.element());
        q.poll();
    }
    try {
        q.element();
        shouldThrow();
    } catch (NoSuchElementException success) {}
}
 

/**
 * contains(x) reports true when elements added but not yet removed
 */
public void testContains() {
    LinkedBlockingDeque q = populatedDeque(SIZE);
    for (int i = 0; i < SIZE; ++i) {
        assertTrue(q.contains(new Integer(i)));
        q.poll();
        assertFalse(q.contains(new Integer(i)));
    }
}
 

public List<Integer> getFeatureIndices(){
    List<Integer> featureIndices = new ArrayList<Integer>();
    LinkedBlockingDeque<Node> queue = new LinkedBlockingDeque<Node>();
    queue.offer(this.root);
    while(queue.size()!=0){
        Node node = queue.poll();
        if (! node.isLeaf()){
            //don't add the feature for leaf node, as it is useless
            featureIndices.add(node.getFeatureIndex());
            queue.offer(node.getLeftChild());
            queue.offer(node.getRightChild());
        }
    }
    return featureIndices;
}
 

public K poll() {
    synchronized (_lock) {
        Iterator<LinkedBlockingDeque<K>> itr = _buckets.descendingIterator();
        while (itr.hasNext()) {
            LinkedBlockingDeque<K> bucket = itr.next();
            K entry = bucket.poll();
            if (entry != null) {
                return entry;
            }
        }

        return null;
    }
}
 

@Override
  public void run() {

    Txn<ByteBuffer> writeTxn = null;
    Map<Integer, Cursor<ByteBuffer>> openCoursors = new HashMap<>();
    List<Integer> opIDs = new ArrayList<>();
    int opID = 0;
    Cursor<ByteBuffer> c = null;
    int count = 0;
    while (currentDbiCount == 0) {
      if (dbMapRef.size() > 0 && dataQueueMapRef.size() > 0) {
        writeTxn = this.envRef.txnWrite();
        for (Map.Entry<Integer, Dbi<ByteBuffer>> dbiEntry : dbMapRef.entrySet()) {
          opID = dbiEntry.getKey();
          c = dbiEntry.getValue().openCursor(writeTxn);
          currentDbiCount++;
        }
      }
    }

    Pair<byte[], byte[]> tempPair = null;
    LinkedBlockingDeque<Pair<byte[], byte[]>> dataQueue = dataQueueMapRef.get(opID);

    while (true) {

//      if (dbMapRef.size() > currentDbiCount) {
//        for (Map.Entry<Integer, Dbi<ByteBuffer>> dbiEntry : dbMapRef.entrySet()) {
//          if (!openCoursors.containsKey(dbiEntry.getKey())) {
//            openCoursors.put(dbiEntry.getKey(), dbiEntry.getValue().openCursor(writeTxn));
//            opIDs.add(dbiEntry.getKey());
//            currentDbiCount++;
//          }
//        }
//      }
//
//      if(currentDbiCount == 0){
//        Thread.yield();
//      }
      tempPair = dataQueue.poll();
      if (tempPair != null) {
        setupThreadLocalBuffers(tempPair.getKey().length, tempPair.getValue().length);
        keyBuffer.put(tempPair.getKey());
        keyBuffer.flip();

        dataBuffer.putInt(tempPair.getValue().length);
        dataBuffer.put(tempPair.getValue());
        dataBuffer.flip();

        c.put(keyBuffer, dataBuffer);
        LMDBMemoryManager.needsCommitWriter = true;
        count++;
        if (count % 2000000 == 0 && count > 0) {
          writeTxn.commit();
          writeTxn.close();
          writeTxn = this.envRef.txnWrite();
          c = dbMapRef.get(opID).openCursor(writeTxn);
          LMDBMemoryManager.needsCommitWriter = false;
          LMDBMemoryManager.needsCommitReader = false;
          System.out.println("added 2  mil to mm");
        }
      }

      if (LMDBMemoryManager.needsCommitReader) {
        writeTxn.commit();
        writeTxn.close();
        writeTxn = this.envRef.txnWrite();
        c = dbMapRef.get(opID).openCursor(writeTxn);
        LMDBMemoryManager.needsCommitWriter = false;
        LMDBMemoryManager.needsCommitReader = false;
      }

    }


  }