--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/share/classes/java/lang/Object.java Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,613 @@
+/*
+ * Copyright (c) 1994, 2017, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package java.lang;
+
+import jdk.internal.HotSpotIntrinsicCandidate;
+
+/**
+ * Class {@code Object} is the root of the class hierarchy.
+ * Every class has {@code Object} as a superclass. All objects,
+ * including arrays, implement the methods of this class.
+ *
+ * @author unascribed
+ * @see java.lang.Class
+ * @since 1.0
+ */
+public class Object {
+
+ private static native void registerNatives();
+ static {
+ registerNatives();
+ }
+
+ /**
+ * Constructs a new object.
+ */
+ @HotSpotIntrinsicCandidate
+ public Object() {}
+
+ /**
+ * Returns the runtime class of this {@code Object}. The returned
+ * {@code Class} object is the object that is locked by {@code
+ * static synchronized} methods of the represented class.
+ *
+ * <p><b>The actual result type is {@code Class<? extends |X|>}
+ * where {@code |X|} is the erasure of the static type of the
+ * expression on which {@code getClass} is called.</b> For
+ * example, no cast is required in this code fragment:</p>
+ *
+ * <p>
+ * {@code Number n = 0; }<br>
+ * {@code Class<? extends Number> c = n.getClass(); }
+ * </p>
+ *
+ * @return The {@code Class} object that represents the runtime
+ * class of this object.
+ * @jls 15.8.2 Class Literals
+ */
+ @HotSpotIntrinsicCandidate
+ public final native Class<?> getClass();
+
+ /**
+ * Returns a hash code value for the object. This method is
+ * supported for the benefit of hash tables such as those provided by
+ * {@link java.util.HashMap}.
+ * <p>
+ * The general contract of {@code hashCode} is:
+ * <ul>
+ * <li>Whenever it is invoked on the same object more than once during
+ * an execution of a Java application, the {@code hashCode} method
+ * must consistently return the same integer, provided no information
+ * used in {@code equals} comparisons on the object is modified.
+ * This integer need not remain consistent from one execution of an
+ * application to another execution of the same application.
+ * <li>If two objects are equal according to the {@code equals(Object)}
+ * method, then calling the {@code hashCode} method on each of
+ * the two objects must produce the same integer result.
+ * <li>It is <em>not</em> required that if two objects are unequal
+ * according to the {@link java.lang.Object#equals(java.lang.Object)}
+ * method, then calling the {@code hashCode} method on each of the
+ * two objects must produce distinct integer results. However, the
+ * programmer should be aware that producing distinct integer results
+ * for unequal objects may improve the performance of hash tables.
+ * </ul>
+ * <p>
+ * As much as is reasonably practical, the hashCode method defined
+ * by class {@code Object} does return distinct integers for
+ * distinct objects. (The hashCode may or may not be implemented
+ * as some function of an object's memory address at some point
+ * in time.)
+ *
+ * @return a hash code value for this object.
+ * @see java.lang.Object#equals(java.lang.Object)
+ * @see java.lang.System#identityHashCode
+ */
+ @HotSpotIntrinsicCandidate
+ public native int hashCode();
+
+ /**
+ * Indicates whether some other object is "equal to" this one.
+ * <p>
+ * The {@code equals} method implements an equivalence relation
+ * on non-null object references:
+ * <ul>
+ * <li>It is <i>reflexive</i>: for any non-null reference value
+ * {@code x}, {@code x.equals(x)} should return
+ * {@code true}.
+ * <li>It is <i>symmetric</i>: for any non-null reference values
+ * {@code x} and {@code y}, {@code x.equals(y)}
+ * should return {@code true} if and only if
+ * {@code y.equals(x)} returns {@code true}.
+ * <li>It is <i>transitive</i>: for any non-null reference values
+ * {@code x}, {@code y}, and {@code z}, if
+ * {@code x.equals(y)} returns {@code true} and
+ * {@code y.equals(z)} returns {@code true}, then
+ * {@code x.equals(z)} should return {@code true}.
+ * <li>It is <i>consistent</i>: for any non-null reference values
+ * {@code x} and {@code y}, multiple invocations of
+ * {@code x.equals(y)} consistently return {@code true}
+ * or consistently return {@code false}, provided no
+ * information used in {@code equals} comparisons on the
+ * objects is modified.
+ * <li>For any non-null reference value {@code x},
+ * {@code x.equals(null)} should return {@code false}.
+ * </ul>
+ * <p>
+ * The {@code equals} method for class {@code Object} implements
+ * the most discriminating possible equivalence relation on objects;
+ * that is, for any non-null reference values {@code x} and
+ * {@code y}, this method returns {@code true} if and only
+ * if {@code x} and {@code y} refer to the same object
+ * ({@code x == y} has the value {@code true}).
+ * <p>
+ * Note that it is generally necessary to override the {@code hashCode}
+ * method whenever this method is overridden, so as to maintain the
+ * general contract for the {@code hashCode} method, which states
+ * that equal objects must have equal hash codes.
+ *
+ * @param obj the reference object with which to compare.
+ * @return {@code true} if this object is the same as the obj
+ * argument; {@code false} otherwise.
+ * @see #hashCode()
+ * @see java.util.HashMap
+ */
+ public boolean equals(Object obj) {
+ return (this == obj);
+ }
+
+ /**
+ * Creates and returns a copy of this object. The precise meaning
+ * of "copy" may depend on the class of the object. The general
+ * intent is that, for any object {@code x}, the expression:
+ * <blockquote>
+ * <pre>
+ * x.clone() != x</pre></blockquote>
+ * will be true, and that the expression:
+ * <blockquote>
+ * <pre>
+ * x.clone().getClass() == x.getClass()</pre></blockquote>
+ * will be {@code true}, but these are not absolute requirements.
+ * While it is typically the case that:
+ * <blockquote>
+ * <pre>
+ * x.clone().equals(x)</pre></blockquote>
+ * will be {@code true}, this is not an absolute requirement.
+ * <p>
+ * By convention, the returned object should be obtained by calling
+ * {@code super.clone}. If a class and all of its superclasses (except
+ * {@code Object}) obey this convention, it will be the case that
+ * {@code x.clone().getClass() == x.getClass()}.
+ * <p>
+ * By convention, the object returned by this method should be independent
+ * of this object (which is being cloned). To achieve this independence,
+ * it may be necessary to modify one or more fields of the object returned
+ * by {@code super.clone} before returning it. Typically, this means
+ * copying any mutable objects that comprise the internal "deep structure"
+ * of the object being cloned and replacing the references to these
+ * objects with references to the copies. If a class contains only
+ * primitive fields or references to immutable objects, then it is usually
+ * the case that no fields in the object returned by {@code super.clone}
+ * need to be modified.
+ * <p>
+ * The method {@code clone} for class {@code Object} performs a
+ * specific cloning operation. First, if the class of this object does
+ * not implement the interface {@code Cloneable}, then a
+ * {@code CloneNotSupportedException} is thrown. Note that all arrays
+ * are considered to implement the interface {@code Cloneable} and that
+ * the return type of the {@code clone} method of an array type {@code T[]}
+ * is {@code T[]} where T is any reference or primitive type.
+ * Otherwise, this method creates a new instance of the class of this
+ * object and initializes all its fields with exactly the contents of
+ * the corresponding fields of this object, as if by assignment; the
+ * contents of the fields are not themselves cloned. Thus, this method
+ * performs a "shallow copy" of this object, not a "deep copy" operation.
+ * <p>
+ * The class {@code Object} does not itself implement the interface
+ * {@code Cloneable}, so calling the {@code clone} method on an object
+ * whose class is {@code Object} will result in throwing an
+ * exception at run time.
+ *
+ * @return a clone of this instance.
+ * @throws CloneNotSupportedException if the object's class does not
+ * support the {@code Cloneable} interface. Subclasses
+ * that override the {@code clone} method can also
+ * throw this exception to indicate that an instance cannot
+ * be cloned.
+ * @see java.lang.Cloneable
+ */
+ @HotSpotIntrinsicCandidate
+ protected native Object clone() throws CloneNotSupportedException;
+
+ /**
+ * Returns a string representation of the object. In general, the
+ * {@code toString} method returns a string that
+ * "textually represents" this object. The result should
+ * be a concise but informative representation that is easy for a
+ * person to read.
+ * It is recommended that all subclasses override this method.
+ * <p>
+ * The {@code toString} method for class {@code Object}
+ * returns a string consisting of the name of the class of which the
+ * object is an instance, the at-sign character `{@code @}', and
+ * the unsigned hexadecimal representation of the hash code of the
+ * object. In other words, this method returns a string equal to the
+ * value of:
+ * <blockquote>
+ * <pre>
+ * getClass().getName() + '@' + Integer.toHexString(hashCode())
+ * </pre></blockquote>
+ *
+ * @return a string representation of the object.
+ */
+ public String toString() {
+ return getClass().getName() + "@" + Integer.toHexString(hashCode());
+ }
+
+ /**
+ * Wakes up a single thread that is waiting on this object's
+ * monitor. If any threads are waiting on this object, one of them
+ * is chosen to be awakened. The choice is arbitrary and occurs at
+ * the discretion of the implementation. A thread waits on an object's
+ * monitor by calling one of the {@code wait} methods.
+ * <p>
+ * The awakened thread will not be able to proceed until the current
+ * thread relinquishes the lock on this object. The awakened thread will
+ * compete in the usual manner with any other threads that might be
+ * actively competing to synchronize on this object; for example, the
+ * awakened thread enjoys no reliable privilege or disadvantage in being
+ * the next thread to lock this object.
+ * <p>
+ * This method should only be called by a thread that is the owner
+ * of this object's monitor. A thread becomes the owner of the
+ * object's monitor in one of three ways:
+ * <ul>
+ * <li>By executing a synchronized instance method of that object.
+ * <li>By executing the body of a {@code synchronized} statement
+ * that synchronizes on the object.
+ * <li>For objects of type {@code Class,} by executing a
+ * synchronized static method of that class.
+ * </ul>
+ * <p>
+ * Only one thread at a time can own an object's monitor.
+ *
+ * @throws IllegalMonitorStateException if the current thread is not
+ * the owner of this object's monitor.
+ * @see java.lang.Object#notifyAll()
+ * @see java.lang.Object#wait()
+ */
+ @HotSpotIntrinsicCandidate
+ public final native void notify();
+
+ /**
+ * Wakes up all threads that are waiting on this object's monitor. A
+ * thread waits on an object's monitor by calling one of the
+ * {@code wait} methods.
+ * <p>
+ * The awakened threads will not be able to proceed until the current
+ * thread relinquishes the lock on this object. The awakened threads
+ * will compete in the usual manner with any other threads that might
+ * be actively competing to synchronize on this object; for example,
+ * the awakened threads enjoy no reliable privilege or disadvantage in
+ * being the next thread to lock this object.
+ * <p>
+ * This method should only be called by a thread that is the owner
+ * of this object's monitor. See the {@code notify} method for a
+ * description of the ways in which a thread can become the owner of
+ * a monitor.
+ *
+ * @throws IllegalMonitorStateException if the current thread is not
+ * the owner of this object's monitor.
+ * @see java.lang.Object#notify()
+ * @see java.lang.Object#wait()
+ */
+ @HotSpotIntrinsicCandidate
+ public final native void notifyAll();
+
+ /**
+ * Causes the current thread to wait until either another thread invokes the
+ * {@link java.lang.Object#notify()} method or the
+ * {@link java.lang.Object#notifyAll()} method for this object, or a
+ * specified amount of time has elapsed.
+ * <p>
+ * The current thread must own this object's monitor.
+ * <p>
+ * This method causes the current thread (call it <var>T</var>) to
+ * place itself in the wait set for this object and then to relinquish
+ * any and all synchronization claims on this object. Thread <var>T</var>
+ * becomes disabled for thread scheduling purposes and lies dormant
+ * until one of four things happens:
+ * <ul>
+ * <li>Some other thread invokes the {@code notify} method for this
+ * object and thread <var>T</var> happens to be arbitrarily chosen as
+ * the thread to be awakened.
+ * <li>Some other thread invokes the {@code notifyAll} method for this
+ * object.
+ * <li>Some other thread {@linkplain Thread#interrupt() interrupts}
+ * thread <var>T</var>.
+ * <li>The specified amount of real time has elapsed, more or less. If
+ * {@code timeout} is zero, however, then real time is not taken into
+ * consideration and the thread simply waits until notified.
+ * </ul>
+ * The thread <var>T</var> is then removed from the wait set for this
+ * object and re-enabled for thread scheduling. It then competes in the
+ * usual manner with other threads for the right to synchronize on the
+ * object; once it has gained control of the object, all its
+ * synchronization claims on the object are restored to the status quo
+ * ante - that is, to the situation as of the time that the {@code wait}
+ * method was invoked. Thread <var>T</var> then returns from the
+ * invocation of the {@code wait} method. Thus, on return from the
+ * {@code wait} method, the synchronization state of the object and of
+ * thread {@code T} is exactly as it was when the {@code wait} method
+ * was invoked.
+ * <p>
+ * A thread can also wake up without being notified, interrupted, or
+ * timing out, a so-called <i>spurious wakeup</i>. While this will rarely
+ * occur in practice, applications must guard against it by testing for
+ * the condition that should have caused the thread to be awakened, and
+ * continuing to wait if the condition is not satisfied. In other words,
+ * waits should always occur in loops, like this one:
+ * <pre>
+ * synchronized (obj) {
+ * while (<condition does not hold>)
+ * obj.wait(timeout);
+ * ... // Perform action appropriate to condition
+ * }
+ * </pre>
+ *
+ * (For more information on this topic, see section 14.2,
+ * Condition Queues, in Brian Goetz and others' "Java Concurrency
+ * in Practice" (Addison-Wesley, 2006) or Item 69 in Joshua
+ * Bloch's "Effective Java (Second Edition)" (Addison-Wesley,
+ * 2008).
+ *
+ * <p>If the current thread is {@linkplain java.lang.Thread#interrupt()
+ * interrupted} by any thread before or while it is waiting, then an
+ * {@code InterruptedException} is thrown. This exception is not
+ * thrown until the lock status of this object has been restored as
+ * described above.
+ *
+ * <p>
+ * Note that the {@code wait} method, as it places the current thread
+ * into the wait set for this object, unlocks only this object; any
+ * other objects on which the current thread may be synchronized remain
+ * locked while the thread waits.
+ * <p>
+ * This method should only be called by a thread that is the owner
+ * of this object's monitor. See the {@code notify} method for a
+ * description of the ways in which a thread can become the owner of
+ * a monitor.
+ *
+ * @param timeout the maximum time to wait in milliseconds.
+ * @throws IllegalArgumentException if the value of timeout is
+ * negative.
+ * @throws IllegalMonitorStateException if the current thread is not
+ * the owner of the object's monitor.
+ * @throws InterruptedException if any thread interrupted the
+ * current thread before or while the current thread
+ * was waiting for a notification. The <i>interrupted
+ * status</i> of the current thread is cleared when
+ * this exception is thrown.
+ * @see java.lang.Object#notify()
+ * @see java.lang.Object#notifyAll()
+ */
+ public final native void wait(long timeout) throws InterruptedException;
+
+ /**
+ * Causes the current thread to wait until another thread invokes the
+ * {@link java.lang.Object#notify()} method or the
+ * {@link java.lang.Object#notifyAll()} method for this object, or
+ * some other thread interrupts the current thread, or a certain
+ * amount of real time has elapsed.
+ * <p>
+ * This method is similar to the {@code wait} method of one
+ * argument, but it allows finer control over the amount of time to
+ * wait for a notification before giving up. The amount of real time,
+ * measured in nanoseconds, is given by:
+ * <blockquote>
+ * <pre>
+ * 1000000*timeout+nanos</pre></blockquote>
+ * <p>
+ * In all other respects, this method does the same thing as the
+ * method {@link #wait(long)} of one argument. In particular,
+ * {@code wait(0, 0)} means the same thing as {@code wait(0)}.
+ * <p>
+ * The current thread must own this object's monitor. The thread
+ * releases ownership of this monitor and waits until either of the
+ * following two conditions has occurred:
+ * <ul>
+ * <li>Another thread notifies threads waiting on this object's monitor
+ * to wake up either through a call to the {@code notify} method
+ * or the {@code notifyAll} method.
+ * <li>The timeout period, specified by {@code timeout}
+ * milliseconds plus {@code nanos} nanoseconds arguments, has
+ * elapsed.
+ * </ul>
+ * <p>
+ * The thread then waits until it can re-obtain ownership of the
+ * monitor and resumes execution.
+ * <p>
+ * As in the one argument version, interrupts and spurious wakeups are
+ * possible, and this method should always be used in a loop:
+ * <pre>
+ * synchronized (obj) {
+ * while (<condition does not hold>)
+ * obj.wait(timeout, nanos);
+ * ... // Perform action appropriate to condition
+ * }
+ * </pre>
+ * This method should only be called by a thread that is the owner
+ * of this object's monitor. See the {@code notify} method for a
+ * description of the ways in which a thread can become the owner of
+ * a monitor.
+ *
+ * @param timeout the maximum time to wait in milliseconds.
+ * @param nanos additional time, in nanoseconds range
+ * 0-999999.
+ * @throws IllegalArgumentException if the value of timeout is
+ * negative or the value of nanos is
+ * not in the range 0-999999.
+ * @throws IllegalMonitorStateException if the current thread is not
+ * the owner of this object's monitor.
+ * @throws InterruptedException if any thread interrupted the
+ * current thread before or while the current thread
+ * was waiting for a notification. The <i>interrupted
+ * status</i> of the current thread is cleared when
+ * this exception is thrown.
+ */
+ public final void wait(long timeout, int nanos) throws InterruptedException {
+ if (timeout < 0) {
+ throw new IllegalArgumentException("timeout value is negative");
+ }
+
+ if (nanos < 0 || nanos > 999999) {
+ throw new IllegalArgumentException(
+ "nanosecond timeout value out of range");
+ }
+
+ if (nanos > 0) {
+ timeout++;
+ }
+
+ wait(timeout);
+ }
+
+ /**
+ * Causes the current thread to wait until another thread invokes the
+ * {@link java.lang.Object#notify()} method or the
+ * {@link java.lang.Object#notifyAll()} method for this object.
+ * In other words, this method behaves exactly as if it simply
+ * performs the call {@code wait(0)}.
+ * <p>
+ * The current thread must own this object's monitor. The thread
+ * releases ownership of this monitor and waits until another thread
+ * notifies threads waiting on this object's monitor to wake up
+ * either through a call to the {@code notify} method or the
+ * {@code notifyAll} method. The thread then waits until it can
+ * re-obtain ownership of the monitor and resumes execution.
+ * <p>
+ * As in the one argument version, interrupts and spurious wakeups are
+ * possible, and this method should always be used in a loop:
+ * <pre>
+ * synchronized (obj) {
+ * while (<condition does not hold>)
+ * obj.wait();
+ * ... // Perform action appropriate to condition
+ * }
+ * </pre>
+ * This method should only be called by a thread that is the owner
+ * of this object's monitor. See the {@code notify} method for a
+ * description of the ways in which a thread can become the owner of
+ * a monitor.
+ *
+ * @throws IllegalMonitorStateException if the current thread is not
+ * the owner of the object's monitor.
+ * @throws InterruptedException if any thread interrupted the
+ * current thread before or while the current thread
+ * was waiting for a notification. The <i>interrupted
+ * status</i> of the current thread is cleared when
+ * this exception is thrown.
+ * @see java.lang.Object#notify()
+ * @see java.lang.Object#notifyAll()
+ */
+ public final void wait() throws InterruptedException {
+ wait(0);
+ }
+
+ /**
+ * Called by the garbage collector on an object when garbage collection
+ * determines that there are no more references to the object.
+ * A subclass overrides the {@code finalize} method to dispose of
+ * system resources or to perform other cleanup.
+ * <p>
+ * The general contract of {@code finalize} is that it is invoked
+ * if and when the Java™ virtual
+ * machine has determined that there is no longer any
+ * means by which this object can be accessed by any thread that has
+ * not yet died, except as a result of an action taken by the
+ * finalization of some other object or class which is ready to be
+ * finalized. The {@code finalize} method may take any action, including
+ * making this object available again to other threads; the usual purpose
+ * of {@code finalize}, however, is to perform cleanup actions before
+ * the object is irrevocably discarded. For example, the finalize method
+ * for an object that represents an input/output connection might perform
+ * explicit I/O transactions to break the connection before the object is
+ * permanently discarded.
+ * <p>
+ * The {@code finalize} method of class {@code Object} performs no
+ * special action; it simply returns normally. Subclasses of
+ * {@code Object} may override this definition.
+ * <p>
+ * The Java programming language does not guarantee which thread will
+ * invoke the {@code finalize} method for any given object. It is
+ * guaranteed, however, that the thread that invokes finalize will not
+ * be holding any user-visible synchronization locks when finalize is
+ * invoked. If an uncaught exception is thrown by the finalize method,
+ * the exception is ignored and finalization of that object terminates.
+ * <p>
+ * After the {@code finalize} method has been invoked for an object, no
+ * further action is taken until the Java virtual machine has again
+ * determined that there is no longer any means by which this object can
+ * be accessed by any thread that has not yet died, including possible
+ * actions by other objects or classes which are ready to be finalized,
+ * at which point the object may be discarded.
+ * <p>
+ * The {@code finalize} method is never invoked more than once by a Java
+ * virtual machine for any given object.
+ * <p>
+ * Any exception thrown by the {@code finalize} method causes
+ * the finalization of this object to be halted, but is otherwise
+ * ignored.
+ *
+ * @apiNote
+ * Classes that embed non-heap resources have many options
+ * for cleanup of those resources. The class must ensure that the
+ * lifetime of each instance is longer than that of any resource it embeds.
+ * {@link java.lang.ref.Reference#reachabilityFence} can be used to ensure that
+ * objects remain reachable while resources embedded in the object are in use.
+ * <p>
+ * A subclass should avoid overriding the {@code finalize} method
+ * unless the subclass embeds non-heap resources that must be cleaned up
+ * before the instance is collected.
+ * Finalizer invocations are not automatically chained, unlike constructors.
+ * If a subclass overrides {@code finalize} it must invoke the superclass
+ * finalizer explicitly.
+ * To guard against exceptions prematurely terminating the finalize chain,
+ * the subclass should use a {@code try-finally} block to ensure
+ * {@code super.finalize()} is always invoked. For example,
+ * <pre>{@code @Override
+ * protected void finalize() throws Throwable {
+ * try {
+ * ... // cleanup subclass state
+ * } finally {
+ * super.finalize();
+ * }
+ * }
+ * }</pre>
+ *
+ * @deprecated The finalization mechanism is inherently problematic.
+ * Finalization can lead to performance issues, deadlocks, and hangs.
+ * Errors in finalizers can lead to resource leaks; there is no way to cancel
+ * finalization if it is no longer necessary; and no ordering is specified
+ * among calls to {@code finalize} methods of different objects.
+ * Furthermore, there are no guarantees regarding the timing of finalization.
+ * The {@code finalize} method might be called on a finalizable object
+ * only after an indefinite delay, if at all.
+ *
+ * Classes whose instances hold non-heap resources should provide a method
+ * to enable explicit release of those resources, and they should also
+ * implement {@link AutoCloseable} if appropriate.
+ * The {@link java.lang.ref.Cleaner} and {@link java.lang.ref.PhantomReference}
+ * provide more flexible and efficient ways to release resources when an object
+ * becomes unreachable.
+ *
+ * @throws Throwable the {@code Exception} raised by this method
+ * @see java.lang.ref.WeakReference
+ * @see java.lang.ref.PhantomReference
+ * @jls 12.6 Finalization of Class Instances
+ */
+ @Deprecated(since="9")
+ protected void finalize() throws Throwable { }
+}