Class MonitorInfo

java.lang.Object

java.lang.management.LockInfo

java.lang.management.MonitorInfo

public class MonitorInfo
extends LockInfo

This class represents information about objects locked via a synchronized method or block.

Since:

1.6

Constructor Summary

Constructors

Constructor	Description
MonitorInfo(String className, int identityHashCode, int stackDepth, StackTraceElement stackFrame)	Creates a new MonitorInfo instance.

Method Summary

Modifier and Type	Method	Description
static MonitorInfo	from(CompositeData cd)	Receives a CompositeData representing a MonitorInfo object and attempts to return the root MonitorInfo instance.
int	getLockedStackDepth()	Returns an integer which is the number of frames deep into the stack where the monitor locking took place.
StackTraceElement	getLockedStackFrame()	The complete StackTraceElement in which the monitor was locked.

Methods declared in class LockInfo

getClassName, getIdentityHashCode, toString

Modifier and Type	Method	Description
String	getClassName()	Returns the name of the lock object's class in fully qualified form (i.e. including the package prefix).
int	getIdentityHashCode()	Returns the value of the associated lock object's identity hash code
String	toString()	Provides callers with a string value that represents the associated lock.

Methods declared in class Object

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

Modifier and Type	Method	Description
protected Object	clone()	Answers a new instance of the same class as the receiver, whose slots have been filled in with the values in the slots of the receiver.
boolean	equals(Object o)	Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison.
protected void	finalize()	Deprecated, for removal: This API element is subject to removal in a future version. May cause performance issues, deadlocks and hangs.
final Class<? extends Object>	getClass()	Answers the unique instance of java.lang.Class which represents the class of the receiver.
int	hashCode()	Answers an integer hash code for the receiver.
final void	notify()	Causes one thread which is waiting on the receiver to be made ready to run.
final void	notifyAll()	Causes all threads which are waiting on the receiver to be made ready to run.
final void	wait()	Causes the thread which sent this message to be made not ready to run pending some change in the receiver (as indicated by notify or notifyAll).
final void	wait(long time)	Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.
final void	wait(long time, int frac)	Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.

Constructor Details

MonitorInfo

public MonitorInfo(String className,
 int identityHashCode,
 int stackDepth,
 StackTraceElement stackFrame)

Creates a new MonitorInfo instance.

Parameters:

className - the name (including the package prefix) of the associated monitor lock object's class

identityHashCode - the value of the associated monitor lock object's identity hash code. This amounts to the result of calling System.identityHashCode(Object) with the monitor lock object as the sole argument.

stackDepth - the number of frames deep in the stack where the locking of the monitor took place

stackFrame - the complete stack frame at which the locking of the monitor occurred

Throws:

IllegalArgumentException - if either of the following two conditions apply:

• the supplied stackFrame is non-null yet the value of stackDepth is less than zero
• the supplied stackFrame is null yet the value of stackDepth is zero or greater

Method Details

getLockedStackDepth

public int getLockedStackDepth()

Returns an integer which is the number of frames deep into the stack where the monitor locking took place.

Returns:

the number of frames into the stack trace at which point the monitor object locking too place

getLockedStackFrame

public StackTraceElement getLockedStackFrame()

The complete StackTraceElement in which the monitor was locked.

Returns:

the StackTraceElement in which the associated monitor was locked

from

public static MonitorInfo from(CompositeData cd)

Receives a CompositeData representing a MonitorInfo object and attempts to return the root MonitorInfo instance.

Parameters:

cd - a CompositeData that represents a MonitorInfo.

Returns:

if cd is non- null, returns a new instance of MonitorInfo. If cd is null, returns null.

Throws:

IllegalArgumentException - if argument cd does not correspond to a MonitorInfo with the expected attributes of a LockInfo - className(java.lang.String) and identityHashCode(java.lang.Integer) - plus the following:

• lockedStackFrame(javax.management.openmbean.CompositeData)
• lockedStackDepth( java.lang.Integer)

The lockedStackFrame attribute must correspond to a java.lang.StackTraceElement which has the following attributes:

• moduleName(java.lang.String)
• moduleVersion(java.lang.String)
• className (java.lang.String)
• methodName (java.lang.String)
• fileName (java.lang.String)
• lineNumber (java.lang.Integer)
• nativeMethod (java.lang.Boolean)