diff options
Diffstat (limited to 'jpa/plugins/org.eclipse.jpt.core/src/org/eclipse/jpt/core/internal/SynchronousJpaProjectUpdater.java')
-rw-r--r-- | jpa/plugins/org.eclipse.jpt.core/src/org/eclipse/jpt/core/internal/SynchronousJpaProjectUpdater.java | 142 |
1 files changed, 0 insertions, 142 deletions
diff --git a/jpa/plugins/org.eclipse.jpt.core/src/org/eclipse/jpt/core/internal/SynchronousJpaProjectUpdater.java b/jpa/plugins/org.eclipse.jpt.core/src/org/eclipse/jpt/core/internal/SynchronousJpaProjectUpdater.java deleted file mode 100644 index b6ec3cdd26..0000000000 --- a/jpa/plugins/org.eclipse.jpt.core/src/org/eclipse/jpt/core/internal/SynchronousJpaProjectUpdater.java +++ /dev/null @@ -1,142 +0,0 @@ -/******************************************************************************* - * Copyright (c) 2008 Oracle. 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: - * Oracle - initial API and implementation - ******************************************************************************/ -package org.eclipse.jpt.core.internal; - -import org.eclipse.core.runtime.IProgressMonitor; -import org.eclipse.core.runtime.NullProgressMonitor; -import org.eclipse.jpt.core.JpaProject; -import org.eclipse.jpt.utility.internal.StringTools; -import org.eclipse.jpt.utility.internal.SynchronizedBoolean; - -/** - * This updater will "update" the JPA project immediately and not return until - * the "update" and all resulting "updates" are complete. This implementation - * should be used sparingly and for as short a time as possible, as it increases - * the probability of deadlocks. A deadlock can occur when a JPA project is - * updated from multiple threads and various resources are locked in varying - * orders. - */ -public class SynchronousJpaProjectUpdater implements JpaProject.Updater { - protected final JpaProject jpaProject; - protected final SynchronizedFlags flags; - - protected static final IProgressMonitor NULL_PROGRESS_MONITOR = new NullProgressMonitor(); - - public SynchronousJpaProjectUpdater(JpaProject jpaProject) { - super(); - this.jpaProject = jpaProject; - this.flags = new SynchronizedFlags(); - } - - /** - * Initialize the flags and execute an "update". - */ - public void start() { - this.flags.start(); - this.update(); - } - - // recursion: we come back here when IJpaProject#update() is called during the "update" - public void update() { - if (this.flags.updateCanStart()) { - do { - this.jpaProject.update(NULL_PROGRESS_MONITOR); - } while (this.flags.updateMustExecuteAgain()); - } - } - - public void stop() { - this.flags.stop(); - } - - @Override - public String toString() { - return StringTools.buildToStringFor(this, this.jpaProject); - } - - - /** - * synchronize access to the pair of 'updating' and 'again' flags - */ - protected static class SynchronizedFlags { - protected SynchronizedBoolean updating = new SynchronizedBoolean(false, this); - protected boolean again = false; - protected boolean stop = true; - - /** - * Simply clear the 'stop' flag. - */ - protected synchronized void start() { - if ( ! this.stop) { - throw new IllegalStateException("The Updater was not stopped."); //$NON-NLS-1$ - } - this.stop = false; - } - - /** - * A client has requested an "update"; - * return whether the updater can start an "update". - * Side-effects: - * - If we are supposed to stop, both the 'updating' and 'again' flags are cleared in #stop(). - * - If we are currently "updating", set the 'again' flag. - * - If we are not currently "updating", set the 'updating' flag and clear the 'again' flag. - */ - protected synchronized boolean updateCanStart() { - if (this.stop) { - return false; - } - if (this.updating.isTrue()) { - this.again = true; - return false; - } - this.updating.setTrue(); - this.again = false; - return true; - } - - /** - * The "update" has finished; - * return whether the updater must execute another "update". - * Side-effects: - * - If we are supposed to stop, - * the 'again' flag was cleared in #stop(); - * clear the 'updating' flag so #stop() can complete. - * - If we have to "update" again, clear the 'again' flag and leave the 'updating' flag set. - * - If we are finished (i.e. no recursive "update" requests occurred), clear the 'updating' flag. - */ - protected synchronized boolean updateMustExecuteAgain() { - if (this.stop) { - this.updating.setFalse(); - return false; - } - if (this.again) { - this.again = false; - return true; - } - this.updating.setFalse(); - return false; - } - - /** - * Restore our start-up state and wait for any current update to complete. - */ - protected synchronized void stop() { - this.stop = true; - this.again = false; - try { - this.updating.waitUntilFalse(); - } catch (InterruptedException ex) { - // the "update" thread was interrupted while waiting - ignore - } - } - - } - -} |