/*
* Copyright (c) 2005, 2006, 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.management;
import javax.management.openmbean.CompositeData;
import java.util.concurrent.locks.*;
import java.beans.ConstructorProperties;
/**
* Information about a <em>lock</em>. A lock can be a built-in object monitor,
* an <em>ownable synchronizer</em>, or the {@link Condition Condition}
* object associated with synchronizers.
* <p>
* <a name="OwnableSynchronizer">An ownable synchronizer</a> is
* a synchronizer that may be exclusively owned by a thread and uses
* {@link AbstractOwnableSynchronizer AbstractOwnableSynchronizer}
* (or its subclass) to implement its synchronization property.
* {@link ReentrantLock ReentrantLock} and
* {@link ReentrantReadWriteLock ReentrantReadWriteLock} are
* two examples of ownable synchronizers provided by the platform.
*
* <h4><a name="MappedType">MXBean Mapping</a></h4>
* <tt>LockInfo</tt> is mapped to a {@link CompositeData CompositeData}
* as specified in the <a href="../../../javax/management/MXBean.html#mapping-rules">
* type mapping rules</a> of {@linkplain javax.management.MXBean MXBeans}.
*
* @see java.util.concurrent.locks.AbstractOwnableSynchronizer
* @see java.util.concurrent.locks.Condition
*
* @author Mandy Chung
* @since 1.6
*/
public class LockInfo {
private String className;
private int identityHashCode;
/**
* Constructs a <tt>LockInfo</tt> object.
*
* @param className the fully qualified name of the class of the lock object.
* @param identityHashCode the {@link System#identityHashCode
* identity hash code} of the lock object.
*/
@ConstructorProperties({"className", "identityHashCode"})
public LockInfo(String className, int identityHashCode) {
if (className == null) {
throw new NullPointerException("Parameter className cannot be null");
}
this.className = className;
this.identityHashCode = identityHashCode;
}
/**
* package-private constructors
*/
LockInfo(Object lock) {
this.className = lock.getClass().getName();
this.identityHashCode = System.identityHashCode(lock);
}
/**
* Returns the fully qualified name of the class of the lock object.
*
* @return the fully qualified name of the class of the lock object.
*/
public String getClassName() {
return className;
}
/**
* Returns the identity hash code of the lock object
* returned from the {@link System#identityHashCode} method.
*
* @return the identity hash code of the lock object.
*/
public int getIdentityHashCode() {
return identityHashCode;
}
/**
* Returns a string representation of a lock. The returned
* string representation consists of the name of the class of the
* lock object, the at-sign character `@', and the unsigned
* hexadecimal representation of the <em>identity</em> hash code
* of the object. This method returns a string equals to the value of:
* <blockquote>
* <pre>
* lock.getClass().getName() + '@' + Integer.toHexString(System.identityHashCode(lock))
* </pre></blockquote>
* where <tt>lock</tt> is the lock object.
*
* @return the string representation of a lock.
*/
public String toString() {
return className + '@' + Integer.toHexString(identityHashCode);
}
}