java.lang.management

Class MonitorInfo

java.lang.Object

java.lang.management.LockInfo

java.lang.management.MonitorInfo

public class MonitorInfo
extends LockInfo

Provides information on a monitor lock held by a thread. A monitor lock is obtained when a thread enters a synchronized block or method.

Since:

1.6

Constructor Summary

Constructors

Constructor and Description
MonitorInfo(String className, int identityHashCode, int stackDepth, StackTraceElement stackFrame) Constructs a new MonitorInfo using the specified lock class name and identity hash code, and the given stack depth and frame.

Method Summary

Methods

Modifier and Type	Method and Description
static MonitorInfo	from(CompositeData data) Returns a MonitorInfo instance using the values given in the supplied CompositeData object.
int	getLockedStackDepth() Returns the depth of the stack at which the lock was obtained.
StackTraceElement	getLockedStackFrame() Returns the stack frame at which the lock was obtained.

Methods inherited from class java.lang.management.LockInfo

getClassName, getIdentityHashCode, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

MonitorInfo

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

Constructs a new MonitorInfo using the specified lock class name and identity hash code, and the given stack depth and frame.

Parameters:

className - the class name of the lock object.

identityHashCode - the identity hash code of the lock object.

stackDepth - the depth of the stack at which the lock was obtained.

stackFrame - the frame of the stack at which the lock was obtained.

Throws:

IllegalArgumentException - if the stack depth and frame are inconsistent i.e. the frame is null but the depth is ≥ 0, or the frame is not null but the depth is < 0.

Method Detail

from

public static MonitorInfo from(CompositeData data)

Returns a MonitorInfo instance using the values given in the supplied CompositeData object. The composite data instance should contain the following attributes with the specified types:

	Name	Type
className	java.lang.String
identityHashCode	java.lang.Integer
lockedStackDepth	java.lang.Integer
lockedStackFrame	javax.management.openmbean.CompositeData

The stack trace is further described as:

	Name	Type
className	java.lang.String
methodName	java.lang.String
fileName	java.lang.String
lineNumber	java.lang.Integer
nativeMethod	java.lang.Boolean

Parameters:

data - the composite data structure to take values from.

Returns:

a new instance containing the values from the composite data structure, or null if the data structure was also null.

Throws:

IllegalArgumentException - if the composite data structure does not match the structure outlined above.

getLockedStackDepth

public int getLockedStackDepth()

Returns the depth of the stack at which the lock was obtained. This works as an index into the array returned by ThreadInfo.getStackTrace().

Returns:

the depth of the stack at which the lock was obtained, or a negative number if this information is unavailable.

getLockedStackFrame

public StackTraceElement getLockedStackFrame()

Returns the stack frame at which the lock was obtained.

Returns:

the stack frame at which the lock was obtained, or null if this informati0on is unavailable.