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Diffstat (limited to 'common/plugins/org.eclipse.jpt.common.utility/src/org/eclipse/jpt/common/utility/internal/SynchronizedQueue.java')
-rw-r--r--common/plugins/org.eclipse.jpt.common.utility/src/org/eclipse/jpt/common/utility/internal/SynchronizedQueue.java348
1 files changed, 0 insertions, 348 deletions
diff --git a/common/plugins/org.eclipse.jpt.common.utility/src/org/eclipse/jpt/common/utility/internal/SynchronizedQueue.java b/common/plugins/org.eclipse.jpt.common.utility/src/org/eclipse/jpt/common/utility/internal/SynchronizedQueue.java
deleted file mode 100644
index 5abb326021..0000000000
--- a/common/plugins/org.eclipse.jpt.common.utility/src/org/eclipse/jpt/common/utility/internal/SynchronizedQueue.java
+++ /dev/null
@@ -1,348 +0,0 @@
-/*******************************************************************************
- * Copyright (c) 2009 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.common.utility.internal;
-
-import java.io.Serializable;
-import java.util.NoSuchElementException;
-
-import org.eclipse.jpt.common.utility.Command;
-
-/**
- * Thread-safe implementation of the {@link Queue} interface.
- * This also provides protocol for suspending a thread until the
- * queue is empty or not empty, with optional time-outs.
- */
-public class SynchronizedQueue<E>
- implements Queue<E>, Serializable
-{
- /** Backing queue. */
- private final Queue<E> queue;
-
- /** Object to synchronize on. */
- private final Object mutex;
-
- private static final long serialVersionUID = 1L;
-
-
- // ********** constructors **********
-
- /**
- * Construct a synchronized queue that wraps the
- * specified queue and locks on the specified mutex.
- */
- public SynchronizedQueue(Queue<E> queue, Object mutex) {
- super();
- if (queue == null) {
- throw new NullPointerException();
- }
- this.queue = queue;
- this.mutex = mutex;
- }
-
- /**
- * Construct a synchronized queue that wraps the
- * specified queue and locks on itself.
- */
- public SynchronizedQueue(Queue<E> queue) {
- super();
- if (queue == null) {
- throw new NullPointerException();
- }
- this.queue = queue;
- this.mutex = this;
- }
-
- /**
- * Construct an empty synchronized queue that locks on the specified mutex.
- */
- public SynchronizedQueue(Object mutex) {
- this(new SimpleQueue<E>(), mutex);
- }
-
- /**
- * Construct an empty synchronized queue that locks on itself.
- */
- public SynchronizedQueue() {
- this(new SimpleQueue<E>());
- }
-
-
- // ********** Queue implementation **********
-
- public void enqueue(E element) {
- synchronized (this.mutex) {
- this.enqueue_(element);
- }
- }
-
- /**
- * Pre-condition: synchronized
- */
- private void enqueue_(E element) {
- this.queue.enqueue(element);
- this.mutex.notifyAll();
- }
-
- public E dequeue() {
- synchronized (this.mutex) {
- return this.dequeue_();
- }
- }
-
- /**
- * Pre-condition: synchronized
- */
- private E dequeue_() {
- E element = this.queue.dequeue();
- this.mutex.notifyAll();
- return element;
- }
-
- public E peek() {
- synchronized (this.mutex) {
- return this.queue.peek();
- }
- }
-
- public boolean isEmpty() {
- synchronized (this.mutex) {
- return this.queue.isEmpty();
- }
- }
-
-
- // ********** indefinite waits **********
-
- /**
- * Suspend the current thread until the queue's empty status changes
- * to the specified value.
- */
- public void waitUntilEmptyIs(boolean empty) throws InterruptedException {
- synchronized (this.mutex) {
- this.waitUntilEmptyIs_(empty);
- }
- }
-
- /**
- * Pre-condition: synchronized
- */
- private void waitUntilEmptyIs_(boolean empty) throws InterruptedException {
- while (this.queue.isEmpty() != empty) {
- this.mutex.wait();
- }
- }
-
- /**
- * Suspend the current thread until the queue is empty.
- */
- public void waitUntilEmpty() throws InterruptedException {
- this.waitUntilEmptyIs(true);
- }
-
- /**
- * Suspend the current thread until the queue has something on it.
- */
- public void waitUntilNotEmpty() throws InterruptedException {
- this.waitUntilEmptyIs(false);
- }
-
- /**
- * Suspend the current thread until the queue is empty,
- * then "enqueue" the specified item to the tail of the queue
- * and continue executing.
- */
- public void waitToEnqueue(E element) throws InterruptedException {
- synchronized (this.mutex) {
- this.waitUntilEmptyIs_(true);
- this.enqueue_(element);
- }
- }
-
- /**
- * Suspend the current thread until the queue has something on it,
- * then "dequeue" an item from the head of the queue and return it.
- */
- public Object waitToDequeue() throws InterruptedException {
- synchronized (this.mutex) {
- this.waitUntilEmptyIs_(false);
- return this.dequeue_();
- }
- }
-
-
- // ********** timed waits **********
-
- /**
- * Suspend the current thread until the queue's empty status changes
- * to the specified value or the specified time-out occurs.
- * The time-out is specified in milliseconds. Return <code>true</code> if the specified
- * empty status was achieved; return <code>false</code> if a time-out occurred.
- * If the queue's empty status is already the specified value,
- * return <code>true</code> immediately.
- * If the time-out is zero, wait indefinitely.
- */
- public boolean waitUntilEmptyIs(boolean empty, long timeout) throws InterruptedException {
- synchronized (this.mutex) {
- return this.waitUntilEmptyIs_(empty, timeout);
- }
- }
-
- /**
- * Pre-condition: synchronized
- */
- private boolean waitUntilEmptyIs_(boolean empty, long timeout) throws InterruptedException {
- if (timeout == 0L) {
- this.waitUntilEmptyIs_(empty); // wait indefinitely until notified
- return true; // if it ever comes back, the condition was met
- }
-
- long stop = System.currentTimeMillis() + timeout;
- long remaining = timeout;
- while ((this.queue.isEmpty() != empty) && (remaining > 0L)) {
- this.mutex.wait(remaining);
- remaining = stop - System.currentTimeMillis();
- }
- return (this.queue.isEmpty() == empty);
- }
-
- /**
- * Suspend the current thread until the queue is empty
- * or the specified time-out occurs.
- * The time-out is specified in milliseconds. Return <code>true</code> if
- * the queue is empty; return <code>false</code> if a time-out occurred.
- * If the queue is already empty, return <code>true</code> immediately.
- * If the time-out is zero, wait indefinitely.
- */
- public boolean waitUntilEmpty(long timeout) throws InterruptedException {
- return this.waitUntilEmptyIs(true, timeout);
- }
-
- /**
- * Suspend the current thread until the queue has something on it.
- * or the specified time-out occurs.
- * The time-out is specified in milliseconds. Return <code>true</code> if
- * the queue is not empty; return <code>false</code> if a time-out occurred.
- * If the queue already has something on it, return <code>true</code> immediately.
- * If the time-out is zero, wait indefinitely.
- */
- public boolean waitUntilNotEmpty(long timeout) throws InterruptedException {
- return this.waitUntilEmptyIs(false, timeout);
- }
-
- /**
- * Suspend the current thread until the queue is empty,
- * then "enqueue" the specified item to the tail of the queue
- * and continue executing. If the queue is not emptied out
- * before the time-out, simply continue executing without
- * "enqueueing" the item.
- * The time-out is specified in milliseconds. Return <code>true</code> if the
- * item was enqueued; return <code>false</code> if a time-out occurred.
- * If the queue is already empty, "enqueue" the specified item and
- * return <code>true</code> immediately.
- * If the time-out is zero, wait indefinitely.
- */
- public boolean waitToEnqueue(E element, long timeout) throws InterruptedException {
- synchronized (this.mutex) {
- boolean success = this.waitUntilEmptyIs_(true, timeout);
- if (success) {
- this.enqueue_(element);
- }
- return success;
- }
- }
-
- /**
- * Suspend the current thread until the queue has something on it,
- * then "dequeue" an item from the head of the queue and return it.
- * If the queue is empty and nothing is "enqueued" on to it before the
- * time-out, throw a no such element exception.
- * The time-out is specified in milliseconds.
- * If the queue is not empty, "dequeue" an item and
- * return it immediately.
- * If the time-out is zero, wait indefinitely.
- */
- public Object waitToDequeue(long timeout) throws InterruptedException {
- synchronized (this.mutex) {
- boolean success = this.waitUntilEmptyIs_(false, timeout);
- if (success) {
- return this.dequeue_();
- }
- throw new NoSuchElementException();
- }
- }
-
-
- // ********** synchronized behavior **********
-
- /**
- * If the current thread is not interrupted, execute the specified command
- * with the mutex locked. This is useful for initializing the queue in another
- * thread.
- */
- public void execute(Command command) throws InterruptedException {
- if (Thread.interrupted()) {
- throw new InterruptedException();
- }
- synchronized (this.mutex) {
- command.execute();
- }
- }
-
-
- // ********** additional public protocol **********
-
- /**
- * "Drain" all the current items from the queue into specified queue.
- */
- public void drainTo(Queue<E> q) {
- synchronized (this.mutex) {
- this.drainTo_(q);
- }
- }
-
- /**
- * Pre-condition: synchronized
- */
- private void drainTo_(Queue<E> q) {
- boolean changed = false;
- while ( ! this.queue.isEmpty()) {
- q.enqueue(this.queue.dequeue());
- changed = true;
- }
- if (changed) {
- this.mutex.notifyAll();
- }
- }
-
- /**
- * Return the object the queue locks on while performing
- * its operations.
- */
- public Object getMutex() {
- return this.mutex;
- }
-
-
- // ********** standard methods **********
-
- @Override
- public String toString() {
- synchronized (this.mutex) {
- return '[' + this.queue.toString() + ']';
- }
- }
-
- private void writeObject(java.io.ObjectOutputStream s) throws java.io.IOException {
- synchronized (this.mutex) {
- s.defaultWriteObject();
- }
- }
-
-}

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