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Diffstat (limited to 'jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/SynchronizedObject.java')
-rw-r--r--jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/SynchronizedObject.java472
1 files changed, 0 insertions, 472 deletions
diff --git a/jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/SynchronizedObject.java b/jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/SynchronizedObject.java
deleted file mode 100644
index 0c82a09896..0000000000
--- a/jpa/plugins/org.eclipse.jpt.utility/src/org/eclipse/jpt/utility/internal/SynchronizedObject.java
+++ /dev/null
@@ -1,472 +0,0 @@
-/*******************************************************************************
- * Copyright (c) 2007, 2010 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.utility.internal;
-
-import java.io.Serializable;
-import org.eclipse.jpt.utility.Command;
-import org.eclipse.jpt.utility.ObjectReference;
-
-/**
- * This class provides synchronized access to an object of type <code>V</code>.
- * It also provides protocol for suspending a thread until the
- * value is set to <code>null</code> or a non-<code>null</code> value,
- * with optional time-outs.
- *
- * @parm V the type of the synchronized object's value
- * @see SimpleObjectReference
- */
-public class SynchronizedObject<V>
- implements ObjectReference<V>, Cloneable, Serializable
-{
- /** Backing value. */
- private V value;
-
- /** Object to synchronize on. */
- private final Object mutex;
-
- private static final long serialVersionUID = 1L;
-
-
- // ********** constructors **********
-
- /**
- * Create a synchronized object with the specified initial value
- * and mutex.
- */
- public SynchronizedObject(V value, Object mutex) {
- super();
- this.value = value;
- this.mutex = mutex;
- }
-
- /**
- * Create a synchronized object with the specified initial value.
- * The synchronized object itself will be the mutex.
- */
- public SynchronizedObject(V value) {
- super();
- this.value = value;
- this.mutex = this;
- }
-
- /**
- * Create a synchronized object with an initial value of <code>null</code>.
- * The synchronized object itself will be the mutex.
- */
- public SynchronizedObject() {
- this(null);
- }
-
-
- // ********** accessors **********
-
- public V getValue() {
- synchronized (this.mutex) {
- return this.value;
- }
- }
-
- public boolean valueEquals(Object object) {
- return Tools.valuesAreEqual(this.getValue(), object);
- }
-
- public boolean valueNotEqual(Object object) {
- return Tools.valuesAreDifferent(this.getValue(), object);
- }
-
- public boolean isNull() {
- synchronized (this.mutex) {
- return this.value == null;
- }
- }
-
- public boolean isNotNull() {
- synchronized (this.mutex) {
- return this.value != null;
- }
- }
-
- /**
- * Set the value. If the value changes, all waiting
- * threads are notified. Return the previous value.
- */
- public V setValue(V value) {
- synchronized (this.mutex) {
- return this.setValue_(value);
- }
- }
-
- /**
- * Pre-condition: synchronized
- */
- private V setValue_(V v) {
- V old = this.value;
- return Tools.valuesAreEqual(old, v) ? old : this.setValue_(v, old);
- }
-
- /**
- * Pre-condition: synchronized and new value is different
- */
- private V setChangedValue_(V v) {
- return this.setValue_(v, this.value);
- }
-
- /**
- * Pre-condition: synchronized and new value is different
- */
- private V setValue_(V v, V old) {
- this.value = v;
- this.mutex.notifyAll();
- return old;
- }
-
- /**
- * Set the value to <code>null</code>. If the value changes, all waiting
- * threads are notified. Return the previous value.
- */
- public V setNull() {
- return this.setValue(null);
- }
-
- /**
- * If the current value is the specified expected value, set it to the
- * specified new value. Return the previous value.
- */
- public V compareAndSwap(V expectedValue, V newValue) {
- synchronized (this.mutex) {
- return this.compareAndSwap_(expectedValue, newValue);
- }
- }
-
- /**
- * Pre-condition: synchronized
- */
- private V compareAndSwap_(V expectedValue, V newValue) {
- return Tools.valuesAreEqual(this.value, expectedValue) ? this.setValue_(newValue) : this.value;
- }
-
- /**
- * Return the object the synchronized object locks on while performing
- * its operations.
- */
- public Object getMutex() {
- return this.mutex;
- }
-
-
- // ********** indefinite waits **********
-
- /**
- * Suspend the current thread until the value changes
- * to the specified value. If the value is already the
- * specified value, return immediately.
- */
- public void waitUntilValueIs(V v) throws InterruptedException {
- synchronized (this.mutex) {
- this.waitUntilValueIs_(v);
- }
- }
-
- /**
- * Pre-condition: synchronized
- */
- private void waitUntilValueIs_(V v) throws InterruptedException {
- while (Tools.valuesAreDifferent(this.value, v)) {
- this.mutex.wait();
- }
- }
-
- /**
- * Suspend the current thread until the value changes
- * to something other than the specified value. If the
- * value is already <em>not</em> the specified value,
- * return immediately.
- */
- public void waitUntilValueIsNot(V v) throws InterruptedException {
- synchronized (this.mutex) {
- this.waitUntilValueIsNot_(v);
- }
- }
-
- /**
- * Pre-condition: synchronized
- */
- private void waitUntilValueIsNot_(V v) throws InterruptedException {
- while (Tools.valuesAreEqual(this.value, v)) {
- this.mutex.wait();
- }
- }
-
- /**
- * Suspend the current thread until the value changes to <code>null</code>.
- * If the value is already <code>null</code>, return immediately.
- */
- public void waitUntilNull() throws InterruptedException {
- this.waitUntilValueIs(null);
- }
-
- /**
- * Suspend the current thread until the value changes
- * to something other than <code>null</code>.
- * If the value is already <em>not</em> <code>null</code>,
- * return immediately.
- */
- public void waitUntilNotNull() throws InterruptedException {
- this.waitUntilValueIsNot(null);
- }
-
- /**
- * Suspend the current thread until the value changes to
- * something other than the specified value, then change
- * it back to the specified value and continue executing.
- * If the value is already <em>not</em> the specified value, set
- * the value immediately.
- * Return the previous value.
- */
- public V waitToSetValue(V v) throws InterruptedException {
- synchronized (this.mutex) {
- this.waitUntilValueIsNot_(v);
- return this.setChangedValue_(v);
- }
- }
-
- /**
- * Suspend the current thread until the value changes to
- * something other than <code>null</code>, then change it
- * back to <code>null</code> and continue executing.
- * If the value is already <em>not</em> <code>null</code>,
- * set the value to <code>null</code> immediately.
- * Return the previous value.
- */
- public V waitToSetNull() throws InterruptedException {
- return this.waitToSetValue(null);
- }
-
- /**
- * Suspend the current thread until the value changes to
- * the specified expected value, then change it
- * to the specified new value and continue executing.
- * If the value is already the specified expected value,
- * set the value to the specified new value immediately.
- * Return the previous value.
- */
- public V waitToSwap(V expectedValue, V newValue) throws InterruptedException {
- synchronized (this.mutex) {
- this.waitUntilValueIs_(expectedValue);
- return this.setValue_(newValue);
- }
- }
-
-
- // ********** timed waits **********
-
- /**
- * Suspend the current thread until the value 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 value was achieved; return <code>false</code>
- * if a time-out occurred.
- * If the value is already the specified value, return true immediately.
- * If the time-out is zero, wait indefinitely.
- */
- public boolean waitUntilValueIs(V v, long timeout) throws InterruptedException {
- synchronized (this.mutex) {
- return this.waitUntilValueIs_(v, timeout);
- }
- }
-
- /**
- * Pre-condition: synchronized
- */
- private boolean waitUntilValueIs_(V v, long timeout) throws InterruptedException {
- if (timeout == 0L) {
- this.waitUntilValueIs_(v); // wait indefinitely until notified
- return true; // if it ever comes back, the condition was met
- }
-
- long stop = System.currentTimeMillis() + timeout;
- long remaining = timeout;
- while (Tools.valuesAreDifferent(this.value, v) && (remaining > 0L)) {
- this.mutex.wait(remaining);
- remaining = stop - System.currentTimeMillis();
- }
- return Tools.valuesAreEqual(this.value, v);
- }
-
- /**
- * Suspend the current thread until the value changes to something
- * other than the specified value or the specified time-out occurs.
- * The time-out is specified in milliseconds. Return <code>true</code>
- * if the specified value was removed; return <code>false</code> if a
- * time-out occurred. If the value is already <em>not</em> the specified
- * value, return <code>true</code> immediately.
- * If the time-out is zero, wait indefinitely.
- */
- public boolean waitUntilValueIsNot(V v, long timeout) throws InterruptedException {
- synchronized (this.mutex) {
- return this.waitUntilValueIsNot_(v, timeout);
- }
- }
-
- /**
- * Pre-condition: synchronized
- */
- private boolean waitUntilValueIsNot_(V v, long timeout) throws InterruptedException {
- if (timeout == 0L) {
- this.waitUntilValueIsNot_(v); // wait indefinitely until notified
- return true; // if it ever comes back, the condition was met
- }
-
- long stop = System.currentTimeMillis() + timeout;
- long remaining = timeout;
- while (Tools.valuesAreEqual(this.value, v) && (remaining > 0L)) {
- this.mutex.wait(remaining);
- remaining = stop - System.currentTimeMillis();
- }
- return Tools.valuesAreDifferent(this.value, v);
- }
-
- /**
- * Suspend the current thread until the value changes
- * to <code>null</code> or the specified time-out occurs.
- * The time-out is specified in milliseconds. Return <code>true</code>
- * if the specified value was achieved; return <code>false</code>
- * if a time-out occurred. If the value is already <code>null</code>,
- * return <code>true</code> immediately.
- * If the time-out is zero, wait indefinitely.
- */
- public boolean waitUntilNull(long timeout) throws InterruptedException {
- return this.waitUntilValueIs(null, timeout);
- }
-
- /**
- * Suspend the current thread until the value changes
- * to something other than <code>null</code> or the specified time-out occurs.
- * The time-out is specified in milliseconds. Return <code>true</code>
- * if the specified value was achieved; return <code>false</code>
- * if a time-out occurred. If the value is already <em>not</em>
- * <code>null</code>, return <code>true</code> immediately.
- * If the time-out is zero, wait indefinitely.
- */
- public boolean waitUntilNotNull(long timeout) throws InterruptedException {
- return this.waitUntilValueIsNot(null, timeout);
- }
-
- /**
- * Suspend the current thread until the value changes to
- * something other than the specified value, then change
- * it back to the specified value and continue executing.
- * If the value does not change to something other than the
- * specified value before the time-out, simply continue executing
- * without changing the value.
- * The time-out is specified in milliseconds. Return <code>true</code>
- * if the value was set to the specified value; return <code>false</code>
- * if a time-out occurred.
- * If the value is already something other than the specified value, set
- * the value immediately and return <code>true</code>.
- * If the time-out is zero, wait indefinitely.
- */
- public boolean waitToSetValue(V v, long timeout) throws InterruptedException {
- synchronized (this.mutex) {
- boolean success = this.waitUntilValueIsNot_(v, timeout);
- if (success) {
- this.setChangedValue_(v);
- }
- return success;
- }
- }
-
- /**
- * Suspend the current thread until the value changes to something
- * other than <code>null</code>, then change it back to <code>null</code>
- * and continue executing. If the value does not change to something
- * other than <code>null</code> before the time-out, simply continue
- * executing without changing the value.
- * The time-out is specified in milliseconds. Return <code>true</code>
- * if the value was set to <code>null</code>; return <code>false</code>
- * if a time-out occurred.
- * If the value is already something other than <code>null</code>, set
- * the value to <code>null</code> immediately and return <code>true</code>.
- * If the time-out is zero, wait indefinitely.
- */
- public boolean waitToSetNull(long timeout) throws InterruptedException {
- return this.waitToSetValue(null, timeout);
- }
-
- /**
- * Suspend the current thread until the value changes to
- * the specified expected value, then change it
- * to the specified new value and continue executing.
- * If the value does not change to the specified expected value
- * before the time-out, simply continue executing without changing
- * the value.
- * The time-out is specified in milliseconds. Return <code>true</code>
- * if the value was set to the specified new value; return
- * <code>false</code> if a time-out occurred.
- * If the value is already the specified expected value,
- * set the value to the specified new value immediately.
- * Return the previous value.
- * If the time-out is zero, wait indefinitely.
- */
- public boolean waitToSwap(V expectedValue, V newValue, long timeout) throws InterruptedException {
- synchronized (this.mutex) {
- boolean success = this.waitUntilValueIs_(expectedValue, timeout);
- if (success) {
- this.setValue_(newValue);
- }
- return success;
- }
- }
-
-
- // ********** synchronized behavior **********
-
- /**
- * If current thread is not interrupted, execute the specified command
- * with the mutex locked. This is useful for initializing the value from another
- * thread.
- */
- public void execute(Command command) throws InterruptedException {
- if (Thread.interrupted()) {
- throw new InterruptedException();
- }
- synchronized (this.mutex) {
- command.execute();
- }
- }
-
-
- // ********** standard methods **********
-
- @Override
- public SynchronizedObject<V> clone() {
- try {
- synchronized (this.mutex) {
- @SuppressWarnings("unchecked")
- SynchronizedObject<V> clone = (SynchronizedObject<V>) super.clone();
- return clone;
- }
- } catch (CloneNotSupportedException ex) {
- throw new InternalError();
- }
- }
-
- @Override
- public String toString() {
- return '[' + String.valueOf(this.getValue()) + ']';
- }
-
- private void writeObject(java.io.ObjectOutputStream s) throws java.io.IOException {
- synchronized (this.mutex) {
- s.defaultWriteObject();
- }
- }
-
-}

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