public abstract class

AbstractMonitoredVm

extends Object
implements BufferedMonitoredVm
java.lang.Object
   ↳ sun.jvmstat.perfdata.monitor.AbstractMonitoredVm
Known Direct Subclasses

Class Overview

Base class for all MonitoredVm implementations that utilize the HotSpot PerfData instrumentation buffer as the communications mechanism to the target Java Virtual Machine.

Summary

Fields
protected int interval The sampling interval, if the instrumentation buffer is acquired by sampling instead of shared memory mechanisms.
protected AbstractPerfDataBuffer pdb The shared memory instrumentation buffer for the target.
protected VmIdentifier vmid The VmIdentifier for the target.
Public Constructors
AbstractMonitoredVm(VmIdentifier vmid, int interval)
Create an AbstractMonitoredVm instance.
Public Methods
abstract void addVmListener(VmListener l)
Add a VmListener.
void clearLastException()
Clear the last exception.
void detach()
Detach from target Java Virtual Machine.
Monitor findByName(String name)
Find a named Instrumentation object.
List<Monitor> findByPattern(String patternString)
Find all Instrumentation objects with names matching the given pattern.
byte[] getBytes()
Interface to get the bytes associated with the instrumentation for the target Java Virtual Machine.
int getCapacity()
Interface to get the the size of the instrumentation buffer for the target Java Virtual Machine.
int getInterval()
Get the polling interval.
Exception getLastException()
Get the last exception encountered while polling this MonitoredVm.
MonitorStatus getMonitorStatus()
Get a list of the inserted and removed monitors since last called.
VmIdentifier getVmIdentifier()
Get the VmIdentifier associated with this MonitoredVm
boolean isErrored()
Test if this MonitoredVm is in the errored state.
abstract void removeVmListener(VmListener l)
Remove a VmListener.
void setInterval(int interval)
Set the polling interval to interval milliseconds.
void setLastException(Exception e)
Set the last exception encountered while polling this MonitoredVm.
[Expand]
Inherited Methods
From class java.lang.Object
From interface sun.jvmstat.monitor.MonitoredVm
From interface sun.jvmstat.monitor.remote.BufferedMonitoredVm

Fields

protected int interval

The sampling interval, if the instrumentation buffer is acquired by sampling instead of shared memory mechanisms.

protected AbstractPerfDataBuffer pdb

The shared memory instrumentation buffer for the target.

protected VmIdentifier vmid

The VmIdentifier for the target.

Public Constructors

public AbstractMonitoredVm (VmIdentifier vmid, int interval)

Create an AbstractMonitoredVm instance.

Parameters
vmid the VmIdentifier for the target
interval the initial sampling interval
Throws
MonitorException

Public Methods

public abstract void addVmListener (VmListener l)

Add a VmListener. The given listener is added to the list of VmListener objects to be notified of MonitoredVm related events.

Parameters
l the VmListener to add.

public void clearLastException ()

Clear the last exception. Calling this method will clear the errored state of this MonitoredVm. However, there is no guarantee that clearing the the errored state return the asynchronous polling task to an operational state.

public void detach ()

Detach from target Java Virtual Machine. After calling this method, updates of the instrumentation data values may be halted. All event notifications are halted. Further interactions with this object should be avoided.

public Monitor findByName (String name)

Find a named Instrumentation object. This method will look for the named instrumentation object in the instrumentation exported by this Java Virtual Machine. If an instrumentation object with the given name exists, a Monitor interface to that object will be return. Otherwise, the method returns null.

Parameters
name the name of the Instrumentation object to find.
Returns
  • Monitor - the Monitor object that can be used to monitor the the named instrumentation object, or null if the named object doesn't exist.
Throws
MonitorException

public List<Monitor> findByPattern (String patternString)

Find all Instrumentation objects with names matching the given pattern. This method returns a List of Monitor objects such that the name of each object matches the given pattern.

Parameters
patternString a string containing a pattern as described in Pattern.
Returns
  • List - a List of Monitor objects that can be used to monitor the instrumentation objects whose names match the given pattern. If no instrumentation objects have` names matching the given pattern, then an empty List is returned.
Throws
MonitorException

public byte[] getBytes ()

Interface to get the bytes associated with the instrumentation for the target Java Virtual Machine.

Returns
  • byte[] - a byte array containing the current bytes for the instrumentation exported by the target Java Virtual Machine.

public int getCapacity ()

Interface to get the the size of the instrumentation buffer for the target Java Virtual Machine.

Returns
  • int - the size of the instrumentation buffer for the target Java Virtual Machine.

public int getInterval ()

Get the polling interval.

Returns
  • int - the current polling interval in milliseconds.

public Exception getLastException ()

Get the last exception encountered while polling this MonitoredVm. Returns the last exception observed by the implementation dependent polling task or null if no such error has occurred.

Returns
  • Exception - the last exception that occurred during polling or null if no error condition exists.

public MonitorStatus getMonitorStatus ()

Get a list of the inserted and removed monitors since last called.

Returns
  • MonitorStatus - the status of available Monitors for the target Java Virtual Machine.
Throws
MonitorException Thrown if communications errors occur while communicating with the target.

public VmIdentifier getVmIdentifier ()

Get the VmIdentifier associated with this MonitoredVm

Returns
  • VmIdentifier - the fully resolved Vm identifier associated with this MonitoredVm.

public boolean isErrored ()

Test if this MonitoredVm is in the errored state. The errored state exists only if an error was reported with call to setLastException(Exception) and only if the parameter to that call was non-null and no subsequent calls are made to clearLastException().

Returns
  • boolean - true if the instance has a non-null error condition set, false otherwise.

public abstract void removeVmListener (VmListener l)

Remove a VmListener. The given listener is removed from the list of VmListener objects to be notified of MonitoredVm related events.

Parameters
l the VmListener to be removed.

public void setInterval (int interval)

Set the polling interval to interval milliseconds. Polling based monitoring implementations need to refresh the instrumentation data on a periodic basis. This interface allows the interval to override the implementation specific default interval.

Parameters
interval the polling interval in milliseconds

public void setLastException (Exception e)

Set the last exception encountered while polling this MonitoredVm. Polling implementations may choose to poll asynchronously. This method allows an asynchronous task to communicate any polling related exceptions with the application. When an a non-null exception is reported through this interface, the MonitoredVm instance is considered to be in the errored state.

Parameters
e the exception to record.