Class LockInfo

java.lang.Object

java.lang.management.LockInfo

Direct Known Subclasses:: MonitorInfo

public class LockInfo extends Object

Information about a lock. A lock can be a built-in object monitor, an ownable synchronizer, or the Condition object associated with synchronizers.

An ownable synchronizer is a synchronizer that may be exclusively owned by a thread and uses AbstractOwnableSynchronizer (or its subclass) to implement its synchronization property. ReentrantLock and the write-lock (but not the read-lock) of ReentrantReadWriteLock are two examples of ownable synchronizers provided by the platform.

MXBean Mapping

LockInfo is mapped to a CompositeData as specified in the from method.

Since:

1.6

See Also:

Constructor Summary

Constructor	Description
`LockInfo(String className, int identityHashCode)`	Constructs a `LockInfo` object.

Method Summary

Modifier and Type	Method	Description
`static LockInfo`	`from(CompositeData cd)`	Returns a `LockInfo` object represented by the given `CompositeData`.
`String`	`getClassName()`	Returns the fully qualified name of the class of the lock object.
`int`	`getIdentityHashCode()`	Returns the identity hash code of the lock object returned from the `System.identityHashCode(Object)` method.
`String`	`toString()`	Returns a string representation of a lock.

Methods declared in class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Modifier and Type	Method	Description
`protected Object`	`clone()`	Creates and returns a copy of this object.
`boolean`	`equals(Object obj)`	Indicates whether some other object is "equal to" this one.
`protected void`	`finalize()`	Deprecated, for removal: This API element is subject to removal in a future version. Finalization is deprecated and subject to removal in a future release.
`final Class<?>`	`getClass()`	Returns the runtime class of this `Object`.
`int`	`hashCode()`	Returns a hash code value for this object.
`final void`	`notify()`	Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()`	Wakes up all threads that are waiting on this object's monitor.
`final void`	`wait()`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
`final void`	`wait(long timeoutMillis)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis, int nanos)`	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

Constructor Details

LockInfo

public LockInfo(String className, int identityHashCode)

Constructs a LockInfo object.

Parameters:: className - the fully qualified name of the class of the lock object.; identityHashCode - the identity hash code of the lock object.

Method Details

getClassName

public String getClassName()

Returns the fully qualified name of the class of the lock object.

Returns:: the fully qualified name of the class of the lock object.

getIdentityHashCode

public int getIdentityHashCode()

Returns the identity hash code of the lock object returned from the System.identityHashCode(Object) method.

Returns:: the identity hash code of the lock object.

from

public static LockInfo from(CompositeData cd)

Returns a LockInfo object represented by the given CompositeData. The given CompositeData must contain the following attributes:

The attributes and the types the given CompositeData contains
Attribute Name	Type
className	`java.lang.String`
identityHashCode	`java.lang.Integer`

Parameters:: cd - CompositeData representing a LockInfo
Returns:: a LockInfo object represented by cd if cd is not null; null otherwise.
Throws:: IllegalArgumentException - if cd does not represent a LockInfo with the attributes described above.
Since:: 1.8

toString

public String toString()

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 identity hash code of the object. This method returns a string equals to the value of:

lock.getClass().getName() + '@' + Integer.toHexString(System.identityHashCode(lock))

where lock is the lock object.

Overrides:: toString in class Object
Returns:: the string representation of a lock.

© 1993, 2025, Oracle and/or its affiliates. All rights reserved.
Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.