Madan Jampani | c9ed9be | 2014-10-02 16:13:11 -0700 | [diff] [blame^] | 1 | package org.onlab.netty; |
Madan Jampani | 890bc35 | 2014-10-01 22:35:29 -0700 | [diff] [blame] | 2 | |
| 3 | import java.util.concurrent.TimeUnit; |
| 4 | import java.util.concurrent.TimeoutException; |
| 5 | |
Madan Jampani | 890bc35 | 2014-10-01 22:35:29 -0700 | [diff] [blame] | 6 | /** |
| 7 | * An asynchronous response. |
| 8 | * This class provides a base implementation of Response, with methods to retrieve the |
| 9 | * result and query to see if the result is ready. The result can only be retrieved when |
| 10 | * it is ready and the get methods will block if the result is not ready yet. |
| 11 | * @param <T> type of response. |
| 12 | */ |
| 13 | public class AsyncResponse<T> implements Response<T> { |
| 14 | |
| 15 | private T value; |
| 16 | private boolean done = false; |
| 17 | private final long start = System.nanoTime(); |
| 18 | |
| 19 | @Override |
| 20 | public T get(long timeout, TimeUnit tu) throws TimeoutException { |
| 21 | timeout = tu.toNanos(timeout); |
| 22 | boolean interrupted = false; |
| 23 | try { |
| 24 | synchronized (this) { |
| 25 | while (!done) { |
| 26 | try { |
| 27 | long timeRemaining = timeout - (System.nanoTime() - start); |
| 28 | if (timeRemaining <= 0) { |
| 29 | throw new TimeoutException("Operation timed out."); |
| 30 | } |
| 31 | TimeUnit.NANOSECONDS.timedWait(this, timeRemaining); |
| 32 | } catch (InterruptedException e) { |
| 33 | interrupted = true; |
| 34 | } |
| 35 | } |
| 36 | } |
| 37 | } finally { |
| 38 | if (interrupted) { |
| 39 | Thread.currentThread().interrupt(); |
| 40 | } |
| 41 | } |
| 42 | return value; |
| 43 | } |
| 44 | |
| 45 | @Override |
| 46 | public T get() throws InterruptedException { |
| 47 | throw new UnsupportedOperationException(); |
| 48 | } |
| 49 | |
| 50 | @Override |
| 51 | public boolean isReady() { |
| 52 | return done; |
| 53 | } |
| 54 | |
| 55 | /** |
| 56 | * Sets response value and unblocks any thread blocking on the response to become |
| 57 | * available. |
| 58 | * @param data response data. |
| 59 | */ |
| 60 | @SuppressWarnings("unchecked") |
| 61 | public synchronized void setResponse(Object data) { |
| 62 | if (!done) { |
| 63 | done = true; |
| 64 | value = (T) data; |
| 65 | this.notifyAll(); |
| 66 | } |
| 67 | } |
| 68 | } |