java.lang.management

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

Method Summary
static MonitorInfo	from(CompositeData data) Returns a {@link MonitorInfo} instance using the values given in the supplied {@link javax.management.openmbean.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.

Constructor Detail

MonitorInfo

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

Constructs a new {@link 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 {@link MonitorInfo} instance using the values given in the supplied {@link javax.management.openmbean.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 {@link 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.