| /******************************************************************************* |
| * Copyright (c) 2008, 2010 VMware Inc. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * VMware Inc. - initial contribution |
| *******************************************************************************/ |
| |
| package org.eclipse.virgo.kernel.deployer.core.internal; |
| |
| import java.util.concurrent.CountDownLatch; |
| import java.util.concurrent.TimeUnit; |
| |
| import org.eclipse.virgo.kernel.core.Signal; |
| import org.eclipse.virgo.kernel.deployer.core.DeploymentException; |
| |
| |
| /** |
| * {@link BlockingSignal} is a {@link Signal} that blocks until complete. |
| * <p /> |
| * |
| * <strong>Concurrent Semantics</strong><br /> |
| * |
| * This class is thread safe. |
| * |
| */ |
| public final class BlockingSignal implements Signal { |
| |
| private Object monitor = new Object(); |
| |
| private final CountDownLatch latch = new CountDownLatch(1); |
| |
| private boolean complete = false; |
| |
| private Throwable cause = null; |
| |
| private final boolean block; |
| |
| public BlockingSignal(boolean block) { |
| this.block = block; |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public void signalFailure(Throwable cause) { |
| synchronized (this.monitor) { |
| this.complete = true; |
| this.cause = cause; |
| latch.countDown(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public void signalSuccessfulCompletion() { |
| synchronized (this.monitor) { |
| this.complete = true; |
| latch.countDown(); |
| } |
| } |
| |
| public boolean awaitCompletion(long timeInSeconds) throws DeploymentException { |
| if (this.block) { |
| try { |
| this.latch.await(timeInSeconds, TimeUnit.SECONDS); |
| } catch (InterruptedException i) { |
| throw new DeploymentException("latch await interrupted", i); |
| } |
| } |
| synchronized (this.monitor) { |
| if (!complete) { |
| return false; |
| } else { |
| if (this.cause == null) { |
| return true; |
| } else { |
| try { |
| throw this.cause; |
| } catch (DeploymentException de) { |
| throw de; |
| } catch (Throwable t) { |
| throw new DeploymentException(t.getMessage(), t.getCause()); |
| } |
| } |
| } |
| } |
| } |
| |
| public boolean checkComplete() throws DeploymentException { |
| if (this.block) { |
| try { |
| this.latch.await(); |
| } catch (InterruptedException i) { |
| throw new DeploymentException("latch await interrupted", i); |
| } |
| } |
| synchronized (this.monitor) { |
| if (!complete) { |
| return false; |
| } else { |
| if (this.cause == null) { |
| return true; |
| } else { |
| try { |
| throw this.cause; |
| } catch (DeploymentException de) { |
| throw de; |
| } catch (Throwable t) { |
| throw new DeploymentException(t.getMessage(), t.getCause()); |
| } |
| } |
| } |
| } |
| } |
| |
| } |